--- /dev/null
+/*
+ * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
+ * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved.
+ * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved.
+ * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved.
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program
+ * for any purpose, provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is granted,
+ * provided the above notices are retained, and a notice that the code was
+ * modified is included with the above copyright notice.
+ */
+
+#include "private/gc_priv.h"
+
+#if defined(LINUX) && !defined(POWERPC)
+# include <linux/version.h>
+# if (LINUX_VERSION_CODE <= 0x10400)
+ /* Ugly hack to get struct sigcontext_struct definition. Required */
+ /* for some early 1.3.X releases. Will hopefully go away soon. */
+ /* in some later Linux releases, asm/sigcontext.h may have to */
+ /* be included instead. */
+# define __KERNEL__
+# include <asm/signal.h>
+# undef __KERNEL__
+# else
+ /* Kernels prior to 2.1.1 defined struct sigcontext_struct instead of */
+ /* struct sigcontext. libc6 (glibc2) uses "struct sigcontext" in */
+ /* prototypes, so we have to include the top-level sigcontext.h to */
+ /* make sure the former gets defined to be the latter if appropriate. */
+# include <features.h>
+# if 2 <= __GLIBC__
+# if 2 == __GLIBC__ && 0 == __GLIBC_MINOR__
+ /* glibc 2.1 no longer has sigcontext.h. But signal.h */
+ /* has the right declaration for glibc 2.1. */
+# include <sigcontext.h>
+# endif /* 0 == __GLIBC_MINOR__ */
+# else /* not 2 <= __GLIBC__ */
+ /* libc5 doesn't have <sigcontext.h>: go directly with the kernel */
+ /* one. Check LINUX_VERSION_CODE to see which we should reference. */
+# include <asm/sigcontext.h>
+# endif /* 2 <= __GLIBC__ */
+# endif
+#endif
+
+#if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \
+ && !defined(MSWINCE) && !defined(__CC_ARM)
+# include <sys/types.h>
+# if !defined(MSWIN32)
+# include <unistd.h>
+# endif
+#endif
+
+#include <stdio.h>
+#if defined(MSWINCE) || defined(SN_TARGET_PS3)
+# define SIGSEGV 0 /* value is irrelevant */
+#else
+# include <signal.h>
+#endif
+
+#if defined(UNIX_LIKE) || defined(CYGWIN32) || defined(NACL)
+# include <fcntl.h>
+#endif
+
+#if defined(LINUX) || defined(LINUX_STACKBOTTOM)
+# include <ctype.h>
+#endif
+
+/* Blatantly OS dependent routines, except for those that are related */
+/* to dynamic loading. */
+
+#ifdef AMIGA
+# define GC_AMIGA_DEF
+# include "extra/AmigaOS.c"
+# undef GC_AMIGA_DEF
+#endif
+
+#if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)
+# ifndef WIN32_LEAN_AND_MEAN
+# define WIN32_LEAN_AND_MEAN 1
+# endif
+# define NOSERVICE
+# include <windows.h>
+ /* It's not clear this is completely kosher under Cygwin. But it */
+ /* allows us to get a working GC_get_stack_base. */
+#endif
+
+#ifdef MACOS
+# include <Processes.h>
+#endif
+
+#ifdef IRIX5
+# include <sys/uio.h>
+# include <malloc.h> /* for locking */
+#endif
+
+#if defined(LINUX) || defined(FREEBSD) || defined(SOLARIS) || defined(IRIX5) \
+ || ((defined(USE_MMAP) || defined(USE_MUNMAP)) \
+ && !defined(MSWIN32) && !defined(MSWINCE))
+# define MMAP_SUPPORTED
+#endif
+
+#if defined(MMAP_SUPPORTED) || defined(ADD_HEAP_GUARD_PAGES)
+# if defined(USE_MUNMAP) && !defined(USE_MMAP)
+# error "invalid config - USE_MUNMAP requires USE_MMAP"
+# endif
+# include <sys/types.h>
+# include <sys/mman.h>
+# include <sys/stat.h>
+# include <errno.h>
+#endif
+
+#ifdef DARWIN
+ /* for get_etext and friends */
+# include <mach-o/getsect.h>
+#endif
+
+#ifdef DJGPP
+ /* Apparently necessary for djgpp 2.01. May cause problems with */
+ /* other versions. */
+ typedef long unsigned int caddr_t;
+#endif
+
+#ifdef PCR
+# include "il/PCR_IL.h"
+# include "th/PCR_ThCtl.h"
+# include "mm/PCR_MM.h"
+#endif
+
+#if !defined(NO_EXECUTE_PERMISSION)
+ STATIC GC_bool GC_pages_executable = TRUE;
+#else
+ STATIC GC_bool GC_pages_executable = FALSE;
+#endif
+#define IGNORE_PAGES_EXECUTABLE 1
+ /* Undefined on GC_pages_executable real use. */
+
+#ifdef NEED_PROC_MAPS
+/* We need to parse /proc/self/maps, either to find dynamic libraries, */
+/* and/or to find the register backing store base (IA64). Do it once */
+/* here. */
+
+#define READ read
+
+/* Repeatedly perform a read call until the buffer is filled or */
+/* we encounter EOF. */
+STATIC ssize_t GC_repeat_read(int fd, char *buf, size_t count)
+{
+ size_t num_read = 0;
+ ssize_t result;
+
+ ASSERT_CANCEL_DISABLED();
+ while (num_read < count) {
+ result = READ(fd, buf + num_read, count - num_read);
+ if (result < 0) return result;
+ if (result == 0) break;
+ num_read += result;
+ }
+ return num_read;
+}
+
+#ifdef THREADS
+ /* Determine the length of a file by incrementally reading it into a */
+ /* This would be silly to use on a file supporting lseek, but Linux */
+ /* /proc files usually do not. */
+ STATIC size_t GC_get_file_len(int f)
+ {
+ size_t total = 0;
+ ssize_t result;
+# define GET_FILE_LEN_BUF_SZ 500
+ char buf[GET_FILE_LEN_BUF_SZ];
+
+ do {
+ result = read(f, buf, GET_FILE_LEN_BUF_SZ);
+ if (result == -1) return 0;
+ total += result;
+ } while (result > 0);
+ return total;
+ }
+
+ STATIC size_t GC_get_maps_len(void)
+ {
+ int f = open("/proc/self/maps", O_RDONLY);
+ size_t result;
+ if (f < 0) return 0; /* treat missing file as empty */
+ result = GC_get_file_len(f);
+ close(f);
+ return result;
+ }
+#endif /* THREADS */
+
+/* Copy the contents of /proc/self/maps to a buffer in our address */
+/* space. Return the address of the buffer, or zero on failure. */
+/* This code could be simplified if we could determine its size ahead */
+/* of time. */
+GC_INNER char * GC_get_maps(void)
+{
+ int f;
+ ssize_t result;
+ static char *maps_buf = NULL;
+ static size_t maps_buf_sz = 1;
+ size_t maps_size, old_maps_size = 0;
+
+ /* The buffer is essentially static, so there must be a single client. */
+ GC_ASSERT(I_HOLD_LOCK());
+
+ /* Note that in the presence of threads, the maps file can */
+ /* essentially shrink asynchronously and unexpectedly as */
+ /* threads that we already think of as dead release their */
+ /* stacks. And there is no easy way to read the entire */
+ /* file atomically. This is arguably a misfeature of the */
+ /* /proc/.../maps interface. */
+
+ /* Since we don't believe the file can grow */
+ /* asynchronously, it should suffice to first determine */
+ /* the size (using lseek or read), and then to reread the */
+ /* file. If the size is inconsistent we have to retry. */
+ /* This only matters with threads enabled, and if we use */
+ /* this to locate roots (not the default). */
+
+# ifdef THREADS
+ /* Determine the initial size of /proc/self/maps. */
+ /* Note that lseek doesn't work, at least as of 2.6.15. */
+ maps_size = GC_get_maps_len();
+ if (0 == maps_size) return 0;
+# else
+ maps_size = 4000; /* Guess */
+# endif
+
+ /* Read /proc/self/maps, growing maps_buf as necessary. */
+ /* Note that we may not allocate conventionally, and */
+ /* thus can't use stdio. */
+ do {
+ while (maps_size >= maps_buf_sz) {
+ /* Grow only by powers of 2, since we leak "too small" buffers.*/
+ while (maps_size >= maps_buf_sz) maps_buf_sz *= 2;
+ maps_buf = GC_scratch_alloc(maps_buf_sz);
+# ifdef THREADS
+ /* Recompute initial length, since we allocated. */
+ /* This can only happen a few times per program */
+ /* execution. */
+ maps_size = GC_get_maps_len();
+ if (0 == maps_size) return 0;
+# endif
+ if (maps_buf == 0) return 0;
+ }
+ GC_ASSERT(maps_buf_sz >= maps_size + 1);
+ f = open("/proc/self/maps", O_RDONLY);
+ if (-1 == f) return 0;
+# ifdef THREADS
+ old_maps_size = maps_size;
+# endif
+ maps_size = 0;
+ do {
+ result = GC_repeat_read(f, maps_buf, maps_buf_sz-1);
+ if (result <= 0)
+ break;
+ maps_size += result;
+ } while ((size_t)result == maps_buf_sz-1);
+ close(f);
+ if (result <= 0)
+ return 0;
+# ifdef THREADS
+ if (maps_size > old_maps_size) {
+ if (GC_print_stats)
+ GC_log_printf(
+ "Unexpected maps size growth from %lu to %lu\n",
+ (unsigned long)old_maps_size,
+ (unsigned long)maps_size);
+ ABORT("Unexpected asynchronous /proc/self/maps growth: "
+ "unregistered thread?");
+ }
+# endif
+ } while (maps_size >= maps_buf_sz || maps_size < old_maps_size);
+ /* In the single-threaded case, the second clause is false. */
+ maps_buf[maps_size] = '\0';
+
+ /* Apply fn to result. */
+ return maps_buf;
+}
+
+/*
+ * GC_parse_map_entry parses an entry from /proc/self/maps so we can
+ * locate all writable data segments that belong to shared libraries.
+ * The format of one of these entries and the fields we care about
+ * is as follows:
+ * XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n
+ * ^^^^^^^^ ^^^^^^^^ ^^^^ ^^
+ * start end prot maj_dev
+ *
+ * Note that since about august 2003 kernels, the columns no longer have
+ * fixed offsets on 64-bit kernels. Hence we no longer rely on fixed offsets
+ * anywhere, which is safer anyway.
+ */
+
+/* Assign various fields of the first line in buf_ptr to (*start), */
+/* (*end), (*prot), (*maj_dev) and (*mapping_name). mapping_name may */
+/* be NULL. (*prot) and (*mapping_name) are assigned pointers into the */
+/* original buffer. */
+GC_INNER char *GC_parse_map_entry(char *buf_ptr, ptr_t *start, ptr_t *end,
+ char **prot, unsigned int *maj_dev,
+ char **mapping_name)
+{
+ char *start_start, *end_start, *maj_dev_start;
+ char *p;
+ char *endp;
+
+ if (buf_ptr == NULL || *buf_ptr == '\0') {
+ return NULL;
+ }
+
+ p = buf_ptr;
+ while (isspace(*p)) ++p;
+ start_start = p;
+ GC_ASSERT(isxdigit(*start_start));
+ *start = (ptr_t)strtoul(start_start, &endp, 16); p = endp;
+ GC_ASSERT(*p=='-');
+
+ ++p;
+ end_start = p;
+ GC_ASSERT(isxdigit(*end_start));
+ *end = (ptr_t)strtoul(end_start, &endp, 16); p = endp;
+ GC_ASSERT(isspace(*p));
+
+ while (isspace(*p)) ++p;
+ GC_ASSERT(*p == 'r' || *p == '-');
+ *prot = p;
+ /* Skip past protection field to offset field */
+ while (!isspace(*p)) ++p; while (isspace(*p)) ++p;
+ GC_ASSERT(isxdigit(*p));
+ /* Skip past offset field, which we ignore */
+ while (!isspace(*p)) ++p; while (isspace(*p)) ++p;
+ maj_dev_start = p;
+ GC_ASSERT(isxdigit(*maj_dev_start));
+ *maj_dev = strtoul(maj_dev_start, NULL, 16);
+
+ if (mapping_name == 0) {
+ while (*p && *p++ != '\n');
+ } else {
+ while (*p && *p != '\n' && *p != '/' && *p != '[') p++;
+ *mapping_name = p;
+ while (*p && *p++ != '\n');
+ }
+
+ return p;
+}
+
+#if defined(IA64) || defined(INCLUDE_LINUX_THREAD_DESCR)
+ /* Try to read the backing store base from /proc/self/maps. */
+ /* Return the bounds of the writable mapping with a 0 major device, */
+ /* which includes the address passed as data. */
+ /* Return FALSE if there is no such mapping. */
+ GC_INNER GC_bool GC_enclosing_mapping(ptr_t addr, ptr_t *startp,
+ ptr_t *endp)
+ {
+ char *prot;
+ ptr_t my_start, my_end;
+ unsigned int maj_dev;
+ char *maps = GC_get_maps();
+ char *buf_ptr = maps;
+
+ if (0 == maps) return(FALSE);
+ for (;;) {
+ buf_ptr = GC_parse_map_entry(buf_ptr, &my_start, &my_end,
+ &prot, &maj_dev, 0);
+
+ if (buf_ptr == NULL) return FALSE;
+ if (prot[1] == 'w' && maj_dev == 0) {
+ if (my_end > addr && my_start <= addr) {
+ *startp = my_start;
+ *endp = my_end;
+ return TRUE;
+ }
+ }
+ }
+ return FALSE;
+ }
+#endif /* IA64 || INCLUDE_LINUX_THREAD_DESCR */
+
+#if defined(REDIRECT_MALLOC)
+ /* Find the text(code) mapping for the library whose name, after */
+ /* stripping the directory part, starts with nm. */
+ GC_INNER GC_bool GC_text_mapping(char *nm, ptr_t *startp, ptr_t *endp)
+ {
+ size_t nm_len = strlen(nm);
+ char *prot;
+ char *map_path;
+ ptr_t my_start, my_end;
+ unsigned int maj_dev;
+ char *maps = GC_get_maps();
+ char *buf_ptr = maps;
+
+ if (0 == maps) return(FALSE);
+ for (;;) {
+ buf_ptr = GC_parse_map_entry(buf_ptr, &my_start, &my_end,
+ &prot, &maj_dev, &map_path);
+
+ if (buf_ptr == NULL) return FALSE;
+ if (prot[0] == 'r' && prot[1] == '-' && prot[2] == 'x') {
+ char *p = map_path;
+ /* Set p to point just past last slash, if any. */
+ while (*p != '\0' && *p != '\n' && *p != ' ' && *p != '\t') ++p;
+ while (*p != '/' && p >= map_path) --p;
+ ++p;
+ if (strncmp(nm, p, nm_len) == 0) {
+ *startp = my_start;
+ *endp = my_end;
+ return TRUE;
+ }
+ }
+ }
+ return FALSE;
+ }
+#endif /* REDIRECT_MALLOC */
+
+#ifdef IA64
+ static ptr_t backing_store_base_from_proc(void)
+ {
+ ptr_t my_start, my_end;
+ if (!GC_enclosing_mapping(GC_save_regs_in_stack(), &my_start, &my_end)) {
+ if (GC_print_stats) {
+ GC_log_printf("Failed to find backing store base from /proc\n");
+ }
+ return 0;
+ }
+ return my_start;
+ }
+#endif
+
+#endif /* NEED_PROC_MAPS */
+
+#if defined(SEARCH_FOR_DATA_START)
+ /* The I386 case can be handled without a search. The Alpha case */
+ /* used to be handled differently as well, but the rules changed */
+ /* for recent Linux versions. This seems to be the easiest way to */
+ /* cover all versions. */
+
+# if defined(LINUX) || defined(HURD)
+ /* Some Linux distributions arrange to define __data_start. Some */
+ /* define data_start as a weak symbol. The latter is technically */
+ /* broken, since the user program may define data_start, in which */
+ /* case we lose. Nonetheless, we try both, preferring __data_start.*/
+ /* We assume gcc-compatible pragmas. */
+# pragma weak __data_start
+ extern int __data_start[];
+# pragma weak data_start
+ extern int data_start[];
+# endif /* LINUX */
+ extern int _end[];
+
+ ptr_t GC_data_start = NULL;
+
+ ptr_t GC_find_limit(ptr_t, GC_bool);
+
+ GC_INNER void GC_init_linux_data_start(void)
+ {
+
+# if defined(LINUX) || defined(HURD)
+ /* Try the easy approaches first: */
+ if ((ptr_t)__data_start != 0) {
+ GC_data_start = (ptr_t)(__data_start);
+ return;
+ }
+ if ((ptr_t)data_start != 0) {
+ GC_data_start = (ptr_t)(data_start);
+ return;
+ }
+# endif /* LINUX */
+ GC_data_start = GC_find_limit((ptr_t)(_end), FALSE);
+ }
+#endif /* SEARCH_FOR_DATA_START */
+
+#ifdef ECOS
+
+# ifndef ECOS_GC_MEMORY_SIZE
+# define ECOS_GC_MEMORY_SIZE (448 * 1024)
+# endif /* ECOS_GC_MEMORY_SIZE */
+
+ /* FIXME: This is a simple way of allocating memory which is */
+ /* compatible with ECOS early releases. Later releases use a more */
+ /* sophisticated means of allocating memory than this simple static */
+ /* allocator, but this method is at least bound to work. */
+ static char ecos_gc_memory[ECOS_GC_MEMORY_SIZE];
+ static char *ecos_gc_brk = ecos_gc_memory;
+
+ static void *tiny_sbrk(ptrdiff_t increment)
+ {
+ void *p = ecos_gc_brk;
+ ecos_gc_brk += increment;
+ if (ecos_gc_brk > ecos_gc_memory + sizeof(ecos_gc_memory)) {
+ ecos_gc_brk -= increment;
+ return NULL;
+ }
+ return p;
+ }
+# define sbrk tiny_sbrk
+#endif /* ECOS */
+
+#if defined(NETBSD) && defined(__ELF__)
+ ptr_t GC_data_start = NULL;
+ ptr_t GC_find_limit(ptr_t, GC_bool);
+
+ extern char **environ;
+
+ GC_INNER void GC_init_netbsd_elf(void)
+ {
+ /* This may need to be environ, without the underscore, for */
+ /* some versions. */
+ GC_data_start = GC_find_limit((ptr_t)&environ, FALSE);
+ }
+#endif /* NETBSD */
+
+#ifdef OPENBSD
+ static struct sigaction old_segv_act;
+ STATIC sigjmp_buf GC_jmp_buf_openbsd;
+
+# ifdef THREADS
+# include <sys/syscall.h>
+ extern sigset_t __syscall(quad_t, ...);
+# endif
+
+ /* Don't use GC_find_limit() because siglongjmp() outside of the */
+ /* signal handler by-passes our userland pthreads lib, leaving */
+ /* SIGSEGV and SIGPROF masked. Instead, use this custom one that */
+ /* works-around the issues. */
+
+ /*ARGSUSED*/
+ STATIC void GC_fault_handler_openbsd(int sig)
+ {
+ siglongjmp(GC_jmp_buf_openbsd, 1);
+ }
+
+ /* Return the first non-addressible location > p or bound. */
+ /* Requires the allocation lock. */
+ STATIC ptr_t GC_find_limit_openbsd(ptr_t p, ptr_t bound)
+ {
+ static volatile ptr_t result;
+ /* Safer if static, since otherwise it may not be */
+ /* preserved across the longjmp. Can safely be */
+ /* static since it's only called with the */
+ /* allocation lock held. */
+
+ struct sigaction act;
+ size_t pgsz = (size_t)sysconf(_SC_PAGESIZE);
+ GC_ASSERT(I_HOLD_LOCK());
+
+ act.sa_handler = GC_fault_handler_openbsd;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = SA_NODEFER | SA_RESTART;
+ sigaction(SIGSEGV, &act, &old_segv_act);
+
+ if (sigsetjmp(GC_jmp_buf_openbsd, 1) == 0) {
+ result = (ptr_t)((word)p & ~(pgsz-1));
+ for (;;) {
+ result += pgsz;
+ if (result >= bound) {
+ result = bound;
+ break;
+ }
+ GC_noop1((word)(*result));
+ }
+ }
+
+# ifdef THREADS
+ /* Due to the siglongjump we need to manually unmask SIGPROF. */
+ __syscall(SYS_sigprocmask, SIG_UNBLOCK, sigmask(SIGPROF));
+# endif
+
+ sigaction(SIGSEGV, &old_segv_act, 0);
+ return(result);
+ }
+
+ /* Return first addressable location > p or bound. */
+ /* Requires the allocation lock. */
+ STATIC ptr_t GC_skip_hole_openbsd(ptr_t p, ptr_t bound)
+ {
+ static volatile ptr_t result;
+ static volatile int firstpass;
+
+ struct sigaction act;
+ size_t pgsz = (size_t)sysconf(_SC_PAGESIZE);
+ GC_ASSERT(I_HOLD_LOCK());
+
+ act.sa_handler = GC_fault_handler_openbsd;
+ sigemptyset(&act.sa_mask);
+ act.sa_flags = SA_NODEFER | SA_RESTART;
+ sigaction(SIGSEGV, &act, &old_segv_act);
+
+ firstpass = 1;
+ result = (ptr_t)((word)p & ~(pgsz-1));
+ if (sigsetjmp(GC_jmp_buf_openbsd, 1) != 0 || firstpass) {
+ firstpass = 0;
+ result += pgsz;
+ if (result >= bound) {
+ result = bound;
+ } else {
+ GC_noop1((word)(*result));
+ }
+ }
+
+ sigaction(SIGSEGV, &old_segv_act, 0);
+ return(result);
+ }
+#endif /* OPENBSD */
+
+# ifdef OS2
+
+# include <stddef.h>
+
+# if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */
+
+struct exe_hdr {
+ unsigned short magic_number;
+ unsigned short padding[29];
+ long new_exe_offset;
+};
+
+#define E_MAGIC(x) (x).magic_number
+#define EMAGIC 0x5A4D
+#define E_LFANEW(x) (x).new_exe_offset
+
+struct e32_exe {
+ unsigned char magic_number[2];
+ unsigned char byte_order;
+ unsigned char word_order;
+ unsigned long exe_format_level;
+ unsigned short cpu;
+ unsigned short os;
+ unsigned long padding1[13];
+ unsigned long object_table_offset;
+ unsigned long object_count;
+ unsigned long padding2[31];
+};
+
+#define E32_MAGIC1(x) (x).magic_number[0]
+#define E32MAGIC1 'L'
+#define E32_MAGIC2(x) (x).magic_number[1]
+#define E32MAGIC2 'X'
+#define E32_BORDER(x) (x).byte_order
+#define E32LEBO 0
+#define E32_WORDER(x) (x).word_order
+#define E32LEWO 0
+#define E32_CPU(x) (x).cpu
+#define E32CPU286 1
+#define E32_OBJTAB(x) (x).object_table_offset
+#define E32_OBJCNT(x) (x).object_count
+
+struct o32_obj {
+ unsigned long size;
+ unsigned long base;
+ unsigned long flags;
+ unsigned long pagemap;
+ unsigned long mapsize;
+ unsigned long reserved;
+};
+
+#define O32_FLAGS(x) (x).flags
+#define OBJREAD 0x0001L
+#define OBJWRITE 0x0002L
+#define OBJINVALID 0x0080L
+#define O32_SIZE(x) (x).size
+#define O32_BASE(x) (x).base
+
+# else /* IBM's compiler */
+
+/* A kludge to get around what appears to be a header file bug */
+# ifndef WORD
+# define WORD unsigned short
+# endif
+# ifndef DWORD
+# define DWORD unsigned long
+# endif
+
+# define EXE386 1
+# include <newexe.h>
+# include <exe386.h>
+
+# endif /* __IBMC__ */
+
+# define INCL_DOSEXCEPTIONS
+# define INCL_DOSPROCESS
+# define INCL_DOSERRORS
+# define INCL_DOSMODULEMGR
+# define INCL_DOSMEMMGR
+# include <os2.h>
+
+# endif /* OS/2 */
+
+/* Find the page size */
+GC_INNER word GC_page_size = 0;
+
+#if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)
+# ifndef VER_PLATFORM_WIN32_CE
+# define VER_PLATFORM_WIN32_CE 3
+# endif
+
+# if defined(MSWINCE) && defined(THREADS)
+ GC_INNER GC_bool GC_dont_query_stack_min = FALSE;
+# endif
+
+ GC_INNER void GC_setpagesize(void)
+ {
+ GetSystemInfo(&GC_sysinfo);
+ GC_page_size = GC_sysinfo.dwPageSize;
+# if defined(MSWINCE) && !defined(_WIN32_WCE_EMULATION)
+ {
+ OSVERSIONINFO verInfo;
+ /* Check the current WinCE version. */
+ verInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
+ if (!GetVersionEx(&verInfo))
+ ABORT("GetVersionEx failed");
+ if (verInfo.dwPlatformId == VER_PLATFORM_WIN32_CE &&
+ verInfo.dwMajorVersion < 6) {
+ /* Only the first 32 MB of address space belongs to the */
+ /* current process (unless WinCE 6.0+ or emulation). */
+ GC_sysinfo.lpMaximumApplicationAddress = (LPVOID)((word)32 << 20);
+# ifdef THREADS
+ /* On some old WinCE versions, it's observed that */
+ /* VirtualQuery calls don't work properly when used to */
+ /* get thread current stack committed minimum. */
+ if (verInfo.dwMajorVersion < 5)
+ GC_dont_query_stack_min = TRUE;
+# endif
+ }
+ }
+# endif
+ }
+
+# ifndef CYGWIN32
+# define is_writable(prot) ((prot) == PAGE_READWRITE \
+ || (prot) == PAGE_WRITECOPY \
+ || (prot) == PAGE_EXECUTE_READWRITE \
+ || (prot) == PAGE_EXECUTE_WRITECOPY)
+ /* Return the number of bytes that are writable starting at p. */
+ /* The pointer p is assumed to be page aligned. */
+ /* If base is not 0, *base becomes the beginning of the */
+ /* allocation region containing p. */
+ STATIC word GC_get_writable_length(ptr_t p, ptr_t *base)
+ {
+ MEMORY_BASIC_INFORMATION buf;
+ word result;
+ word protect;
+
+ result = VirtualQuery(p, &buf, sizeof(buf));
+ if (result != sizeof(buf)) ABORT("Weird VirtualQuery result");
+ if (base != 0) *base = (ptr_t)(buf.AllocationBase);
+ protect = (buf.Protect & ~(PAGE_GUARD | PAGE_NOCACHE));
+ if (!is_writable(protect)) {
+ return(0);
+ }
+ if (buf.State != MEM_COMMIT) return(0);
+ return(buf.RegionSize);
+ }
+
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ ptr_t trunc_sp = (ptr_t)((word)GC_approx_sp() & ~(GC_page_size - 1));
+ /* FIXME: This won't work if called from a deeply recursive */
+ /* client code (and the committed stack space has grown). */
+ word size = GC_get_writable_length(trunc_sp, 0);
+ GC_ASSERT(size != 0);
+ sb -> mem_base = trunc_sp + size;
+ return GC_SUCCESS;
+ }
+# else /* CYGWIN32 */
+ /* An alternate version for Cygwin (adapted from Dave Korn's */
+ /* gcc version of boehm-gc). */
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ extern void * _tlsbase __asm__ ("%fs:4");
+ sb -> mem_base = _tlsbase;
+ return GC_SUCCESS;
+ }
+# endif /* CYGWIN32 */
+# define HAVE_GET_STACK_BASE
+
+#else /* !MSWIN32 */
+ GC_INNER void GC_setpagesize(void)
+ {
+# if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP)
+ GC_page_size = GETPAGESIZE();
+ if (!GC_page_size) ABORT("getpagesize() failed");
+# else
+ /* It's acceptable to fake it. */
+ GC_page_size = HBLKSIZE;
+# endif
+ }
+#endif /* !MSWIN32 */
+
+#ifdef BEOS
+# include <kernel/OS.h>
+
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ thread_info th;
+ get_thread_info(find_thread(NULL),&th);
+ sb->mem_base = th.stack_end;
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* BEOS */
+
+#ifdef OS2
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ PTIB ptib; /* thread information block */
+ PPIB ppib;
+ if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
+ ABORT("DosGetInfoBlocks failed");
+ }
+ sb->mem_base = ptib->tib_pstacklimit;
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* OS2 */
+
+# ifdef AMIGA
+# define GC_AMIGA_SB
+# include "extra/AmigaOS.c"
+# undef GC_AMIGA_SB
+# endif /* AMIGA */
+
+# if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE)
+
+ typedef void (*GC_fault_handler_t)(int);
+
+# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \
+ || defined(HURD) || defined(NETBSD)
+ static struct sigaction old_segv_act;
+# if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) \
+ || defined(HURD) || defined(NETBSD) || defined(FREEBSD)
+ static struct sigaction old_bus_act;
+# endif
+# else
+ static GC_fault_handler_t old_segv_handler, old_bus_handler;
+# endif
+
+ GC_INNER void GC_set_and_save_fault_handler(GC_fault_handler_t h)
+ {
+# if defined(SUNOS5SIGS) || defined(IRIX5) \
+ || defined(OSF1) || defined(HURD) || defined(NETBSD)
+ struct sigaction act;
+
+ act.sa_handler = h;
+# ifdef SIGACTION_FLAGS_NODEFER_HACK
+ /* Was necessary for Solaris 2.3 and very temporary */
+ /* NetBSD bugs. */
+ act.sa_flags = SA_RESTART | SA_NODEFER;
+# else
+ act.sa_flags = SA_RESTART;
+# endif
+
+ (void) sigemptyset(&act.sa_mask);
+# ifdef GC_IRIX_THREADS
+ /* Older versions have a bug related to retrieving and */
+ /* and setting a handler at the same time. */
+ (void) sigaction(SIGSEGV, 0, &old_segv_act);
+ (void) sigaction(SIGSEGV, &act, 0);
+# else
+ (void) sigaction(SIGSEGV, &act, &old_segv_act);
+# if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
+ || defined(HPUX) || defined(HURD) || defined(NETBSD) \
+ || defined(FREEBSD)
+ /* Under Irix 5.x or HP/UX, we may get SIGBUS. */
+ /* Pthreads doesn't exist under Irix 5.x, so we */
+ /* don't have to worry in the threads case. */
+ (void) sigaction(SIGBUS, &act, &old_bus_act);
+# endif
+# endif /* GC_IRIX_THREADS */
+# else
+ old_segv_handler = signal(SIGSEGV, h);
+# ifdef SIGBUS
+ old_bus_handler = signal(SIGBUS, h);
+# endif
+# endif
+ }
+# endif /* NEED_FIND_LIMIT || UNIX_LIKE */
+
+# if defined(NEED_FIND_LIMIT) \
+ || (defined(USE_PROC_FOR_LIBRARIES) && defined(THREADS))
+ /* Some tools to implement HEURISTIC2 */
+# define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */
+
+ /*ARGSUSED*/
+ STATIC void GC_fault_handler(int sig)
+ {
+ LONGJMP(GC_jmp_buf, 1);
+ }
+
+ GC_INNER void GC_setup_temporary_fault_handler(void)
+ {
+ /* Handler is process-wide, so this should only happen in */
+ /* one thread at a time. */
+ GC_ASSERT(I_HOLD_LOCK());
+ GC_set_and_save_fault_handler(GC_fault_handler);
+ }
+
+ GC_INNER void GC_reset_fault_handler(void)
+ {
+# if defined(SUNOS5SIGS) || defined(IRIX5) \
+ || defined(OSF1) || defined(HURD) || defined(NETBSD)
+ (void) sigaction(SIGSEGV, &old_segv_act, 0);
+# if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
+ || defined(HPUX) || defined(HURD) || defined(NETBSD) \
+ || defined(FREEBSD)
+ (void) sigaction(SIGBUS, &old_bus_act, 0);
+# endif
+# else
+ (void) signal(SIGSEGV, old_segv_handler);
+# ifdef SIGBUS
+ (void) signal(SIGBUS, old_bus_handler);
+# endif
+# endif
+ }
+
+ /* Return the first non-addressable location > p (up) or */
+ /* the smallest location q s.t. [q,p) is addressable (!up). */
+ /* We assume that p (up) or p-1 (!up) is addressable. */
+ /* Requires allocation lock. */
+ STATIC ptr_t GC_find_limit_with_bound(ptr_t p, GC_bool up, ptr_t bound)
+ {
+ static volatile ptr_t result;
+ /* Safer if static, since otherwise it may not be */
+ /* preserved across the longjmp. Can safely be */
+ /* static since it's only called with the */
+ /* allocation lock held. */
+
+ GC_ASSERT(I_HOLD_LOCK());
+ GC_setup_temporary_fault_handler();
+ if (SETJMP(GC_jmp_buf) == 0) {
+ result = (ptr_t)(((word)(p))
+ & ~(MIN_PAGE_SIZE-1));
+ for (;;) {
+ if (up) {
+ result += MIN_PAGE_SIZE;
+ if (result >= bound) {
+ result = bound;
+ break;
+ }
+ } else {
+ result -= MIN_PAGE_SIZE;
+ if (result <= bound) {
+ result = bound - MIN_PAGE_SIZE;
+ /* This is to compensate */
+ /* further result increment (we */
+ /* do not modify "up" variable */
+ /* since it might be clobbered */
+ /* by setjmp otherwise). */
+ break;
+ }
+ }
+ GC_noop1((word)(*result));
+ }
+ }
+ GC_reset_fault_handler();
+ if (!up) {
+ result += MIN_PAGE_SIZE;
+ }
+ return(result);
+ }
+
+ ptr_t GC_find_limit(ptr_t p, GC_bool up)
+ {
+ return GC_find_limit_with_bound(p, up, up ? (ptr_t)(word)(-1) : 0);
+ }
+# endif /* NEED_FIND_LIMIT || USE_PROC_FOR_LIBRARIES */
+
+#ifdef HPUX_STACKBOTTOM
+
+#include <sys/param.h>
+#include <sys/pstat.h>
+
+ GC_INNER ptr_t GC_get_register_stack_base(void)
+ {
+ struct pst_vm_status vm_status;
+
+ int i = 0;
+ while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) {
+ if (vm_status.pst_type == PS_RSESTACK) {
+ return (ptr_t) vm_status.pst_vaddr;
+ }
+ }
+
+ /* old way to get the register stackbottom */
+ return (ptr_t)(((word)GC_stackbottom - BACKING_STORE_DISPLACEMENT - 1)
+ & ~(BACKING_STORE_ALIGNMENT - 1));
+ }
+
+#endif /* HPUX_STACK_BOTTOM */
+
+#ifdef LINUX_STACKBOTTOM
+
+# include <sys/types.h>
+# include <sys/stat.h>
+
+# define STAT_SKIP 27 /* Number of fields preceding startstack */
+ /* field in /proc/self/stat */
+
+# ifdef USE_LIBC_PRIVATES
+# pragma weak __libc_stack_end
+ extern ptr_t __libc_stack_end;
+# endif
+
+# ifdef IA64
+# ifdef USE_LIBC_PRIVATES
+# pragma weak __libc_ia64_register_backing_store_base
+ extern ptr_t __libc_ia64_register_backing_store_base;
+# endif
+
+ GC_INNER ptr_t GC_get_register_stack_base(void)
+ {
+ ptr_t result;
+
+# ifdef USE_LIBC_PRIVATES
+ if (0 != &__libc_ia64_register_backing_store_base
+ && 0 != __libc_ia64_register_backing_store_base) {
+ /* Glibc 2.2.4 has a bug such that for dynamically linked */
+ /* executables __libc_ia64_register_backing_store_base is */
+ /* defined but uninitialized during constructor calls. */
+ /* Hence we check for both nonzero address and value. */
+ return __libc_ia64_register_backing_store_base;
+ }
+# endif
+ result = backing_store_base_from_proc();
+ if (0 == result) {
+ result = GC_find_limit(GC_save_regs_in_stack(), FALSE);
+ /* Now seems to work better than constant displacement */
+ /* heuristic used in 6.X versions. The latter seems to */
+ /* fail for 2.6 kernels. */
+ }
+ return result;
+ }
+# endif /* IA64 */
+
+ STATIC ptr_t GC_linux_main_stack_base(void)
+ {
+ /* We read the stack base value from /proc/self/stat. We do this */
+ /* using direct I/O system calls in order to avoid calling malloc */
+ /* in case REDIRECT_MALLOC is defined. */
+# ifndef STAT_READ
+ /* Also defined in pthread_support.c. */
+# define STAT_BUF_SIZE 4096
+# define STAT_READ read
+# endif
+ /* Should probably call the real read, if read is wrapped. */
+ char stat_buf[STAT_BUF_SIZE];
+ int f;
+ word result;
+ int i, buf_offset = 0, len;
+
+ /* First try the easy way. This should work for glibc 2.2 */
+ /* This fails in a prelinked ("prelink" command) executable */
+ /* since the correct value of __libc_stack_end never */
+ /* becomes visible to us. The second test works around */
+ /* this. */
+# ifdef USE_LIBC_PRIVATES
+ if (0 != &__libc_stack_end && 0 != __libc_stack_end ) {
+# if defined(IA64)
+ /* Some versions of glibc set the address 16 bytes too */
+ /* low while the initialization code is running. */
+ if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) {
+ return __libc_stack_end + 0x10;
+ } /* Otherwise it's not safe to add 16 bytes and we fall */
+ /* back to using /proc. */
+# elif defined(SPARC)
+ /* Older versions of glibc for 64-bit Sparc do not set
+ * this variable correctly, it gets set to either zero
+ * or one.
+ */
+ if (__libc_stack_end != (ptr_t) (unsigned long)0x1)
+ return __libc_stack_end;
+# else
+ return __libc_stack_end;
+# endif
+ }
+# endif
+ f = open("/proc/self/stat", O_RDONLY);
+ if (f < 0)
+ ABORT("Couldn't read /proc/self/stat");
+ len = STAT_READ(f, stat_buf, STAT_BUF_SIZE);
+ close(f);
+
+ /* Skip the required number of fields. This number is hopefully */
+ /* constant across all Linux implementations. */
+ for (i = 0; i < STAT_SKIP; ++i) {
+ while (buf_offset < len && isspace(stat_buf[buf_offset++])) {
+ /* empty */
+ }
+ while (buf_offset < len && !isspace(stat_buf[buf_offset++])) {
+ /* empty */
+ }
+ }
+ /* Skip spaces. */
+ while (buf_offset < len && isspace(stat_buf[buf_offset])) {
+ buf_offset++;
+ }
+ /* Find the end of the number and cut the buffer there. */
+ for (i = 0; buf_offset + i < len; i++) {
+ if (!isdigit(stat_buf[buf_offset + i])) break;
+ }
+ if (buf_offset + i >= len) ABORT("Could not parse /proc/self/stat");
+ stat_buf[buf_offset + i] = '\0';
+
+ result = (word)STRTOULL(&stat_buf[buf_offset], NULL, 10);
+ if (result < 0x100000 || (result & (sizeof(word) - 1)) != 0)
+ ABORT("Absurd stack bottom value");
+ return (ptr_t)result;
+ }
+#endif /* LINUX_STACKBOTTOM */
+
+#ifdef FREEBSD_STACKBOTTOM
+ /* This uses an undocumented sysctl call, but at least one expert */
+ /* believes it will stay. */
+
+# include <unistd.h>
+# include <sys/types.h>
+# include <sys/sysctl.h>
+
+ STATIC ptr_t GC_freebsd_main_stack_base(void)
+ {
+ int nm[2] = {CTL_KERN, KERN_USRSTACK};
+ ptr_t base;
+ size_t len = sizeof(ptr_t);
+ int r = sysctl(nm, 2, &base, &len, NULL, 0);
+ if (r) ABORT("Error getting main stack base");
+ return base;
+ }
+#endif /* FREEBSD_STACKBOTTOM */
+
+#if defined(ECOS) || defined(NOSYS)
+ ptr_t GC_get_main_stack_base(void)
+ {
+ return STACKBOTTOM;
+ }
+# define GET_MAIN_STACKBASE_SPECIAL
+#elif !defined(BEOS) && !defined(AMIGA) && !defined(OS2) \
+ && !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32) \
+ && !defined(GC_OPENBSD_THREADS) \
+ && (!defined(GC_SOLARIS_THREADS) || defined(_STRICT_STDC))
+
+# if defined(LINUX) && defined(USE_GET_STACKBASE_FOR_MAIN)
+# include <pthread.h>
+# elif defined(DARWIN) && !defined(NO_PTHREAD_GET_STACKADDR_NP)
+ /* We could use pthread_get_stackaddr_np even in case of a */
+ /* single-threaded gclib (there is no -lpthread on Darwin). */
+# include <pthread.h>
+# undef STACKBOTTOM
+# define STACKBOTTOM (ptr_t)pthread_get_stackaddr_np(pthread_self())
+# endif
+
+ ptr_t GC_get_main_stack_base(void)
+ {
+ ptr_t result;
+# if defined(LINUX) && !defined(NACL) \
+ && (defined(USE_GET_STACKBASE_FOR_MAIN) \
+ || (defined(THREADS) && !defined(REDIRECT_MALLOC)))
+ pthread_attr_t attr;
+ void *stackaddr;
+ size_t size;
+
+ if (pthread_getattr_np(pthread_self(), &attr) == 0) {
+ if (pthread_attr_getstack(&attr, &stackaddr, &size) == 0
+ && stackaddr != NULL) {
+ pthread_attr_destroy(&attr);
+# ifdef STACK_GROWS_DOWN
+ stackaddr = (char *)stackaddr + size;
+# endif
+ return (ptr_t)stackaddr;
+ }
+ pthread_attr_destroy(&attr);
+ }
+ WARN("pthread_getattr_np or pthread_attr_getstack failed"
+ " for main thread\n", 0);
+# endif
+# ifdef STACKBOTTOM
+ result = STACKBOTTOM;
+# else
+# define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1)
+# ifdef HEURISTIC1
+# ifdef STACK_GROWS_DOWN
+ result = (ptr_t)(((word)GC_approx_sp() + STACKBOTTOM_ALIGNMENT_M1)
+ & ~STACKBOTTOM_ALIGNMENT_M1);
+# else
+ result = (ptr_t)((word)GC_approx_sp() & ~STACKBOTTOM_ALIGNMENT_M1);
+# endif
+# endif /* HEURISTIC1 */
+# ifdef LINUX_STACKBOTTOM
+ result = GC_linux_main_stack_base();
+# endif
+# ifdef FREEBSD_STACKBOTTOM
+ result = GC_freebsd_main_stack_base();
+# endif
+# ifdef HEURISTIC2
+ {
+ ptr_t sp = GC_approx_sp();
+# ifdef STACK_GROWS_DOWN
+ result = GC_find_limit(sp, TRUE);
+# ifdef HEURISTIC2_LIMIT
+ if (result > HEURISTIC2_LIMIT
+ && sp < HEURISTIC2_LIMIT) {
+ result = HEURISTIC2_LIMIT;
+ }
+# endif
+# else
+ result = GC_find_limit(sp, FALSE);
+# ifdef HEURISTIC2_LIMIT
+ if (result < HEURISTIC2_LIMIT
+ && sp > HEURISTIC2_LIMIT) {
+ result = HEURISTIC2_LIMIT;
+ }
+# endif
+# endif
+ }
+# endif /* HEURISTIC2 */
+# ifdef STACK_GROWS_DOWN
+ if (result == 0)
+ result = (ptr_t)(signed_word)(-sizeof(ptr_t));
+# endif
+# endif
+ GC_ASSERT(GC_approx_sp() HOTTER_THAN result);
+ return(result);
+ }
+# define GET_MAIN_STACKBASE_SPECIAL
+#endif /* !AMIGA, !BEOS, !OPENBSD, !OS2, !Windows */
+
+#if (defined(GC_LINUX_THREADS) || defined(PLATFORM_ANDROID)) && !defined(NACL)
+
+# include <pthread.h>
+ /* extern int pthread_getattr_np(pthread_t, pthread_attr_t *); */
+
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
+ {
+ pthread_attr_t attr;
+ size_t size;
+# ifdef IA64
+ DCL_LOCK_STATE;
+# endif
+
+ if (pthread_getattr_np(pthread_self(), &attr) != 0) {
+ WARN("pthread_getattr_np failed\n", 0);
+ return GC_UNIMPLEMENTED;
+ }
+ if (pthread_attr_getstack(&attr, &(b -> mem_base), &size) != 0) {
+ ABORT("pthread_attr_getstack failed");
+ }
+ pthread_attr_destroy(&attr);
+# ifdef STACK_GROWS_DOWN
+ b -> mem_base = (char *)(b -> mem_base) + size;
+# endif
+# ifdef IA64
+ /* We could try backing_store_base_from_proc, but that's safe */
+ /* only if no mappings are being asynchronously created. */
+ /* Subtracting the size from the stack base doesn't work for at */
+ /* least the main thread. */
+ LOCK();
+ {
+ IF_CANCEL(int cancel_state;)
+ ptr_t bsp;
+ ptr_t next_stack;
+
+ DISABLE_CANCEL(cancel_state);
+ bsp = GC_save_regs_in_stack();
+ next_stack = GC_greatest_stack_base_below(bsp);
+ if (0 == next_stack) {
+ b -> reg_base = GC_find_limit(bsp, FALSE);
+ } else {
+ /* Avoid walking backwards into preceding memory stack and */
+ /* growing it. */
+ b -> reg_base = GC_find_limit_with_bound(bsp, FALSE, next_stack);
+ }
+ RESTORE_CANCEL(cancel_state);
+ }
+ UNLOCK();
+# endif
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* GC_LINUX_THREADS */
+
+#if defined(GC_DARWIN_THREADS) && !defined(NO_PTHREAD_GET_STACKADDR_NP)
+# include <pthread.h>
+
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
+ {
+ /* pthread_get_stackaddr_np() should return stack bottom (highest */
+ /* stack address plus 1). */
+ b->mem_base = pthread_get_stackaddr_np(pthread_self());
+ GC_ASSERT((void *)GC_approx_sp() HOTTER_THAN b->mem_base);
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* GC_DARWIN_THREADS */
+
+#ifdef GC_OPENBSD_THREADS
+# include <sys/signal.h>
+# include <pthread.h>
+# include <pthread_np.h>
+
+ /* Find the stack using pthread_stackseg_np(). */
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ stack_t stack;
+ if (pthread_stackseg_np(pthread_self(), &stack))
+ ABORT("pthread_stackseg_np(self) failed");
+ sb->mem_base = stack.ss_sp;
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* GC_OPENBSD_THREADS */
+
+#if defined(GC_SOLARIS_THREADS) && !defined(_STRICT_STDC)
+
+# include <thread.h>
+# include <signal.h>
+# include <pthread.h>
+
+ /* These variables are used to cache ss_sp value for the primordial */
+ /* thread (it's better not to call thr_stksegment() twice for this */
+ /* thread - see JDK bug #4352906). */
+ static pthread_t stackbase_main_self = 0;
+ /* 0 means stackbase_main_ss_sp value is unset. */
+ static void *stackbase_main_ss_sp = NULL;
+
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
+ {
+ stack_t s;
+ pthread_t self = pthread_self();
+
+ if (self == stackbase_main_self)
+ {
+ /* If the client calls GC_get_stack_base() from the main thread */
+ /* then just return the cached value. */
+ b -> mem_base = stackbase_main_ss_sp;
+ GC_ASSERT(b -> mem_base != NULL);
+ return GC_SUCCESS;
+ }
+
+ if (thr_stksegment(&s)) {
+ /* According to the manual, the only failure error code returned */
+ /* is EAGAIN meaning "the information is not available due to the */
+ /* thread is not yet completely initialized or it is an internal */
+ /* thread" - this shouldn't happen here. */
+ ABORT("thr_stksegment failed");
+ }
+ /* s.ss_sp holds the pointer to the stack bottom. */
+ GC_ASSERT((void *)GC_approx_sp() HOTTER_THAN s.ss_sp);
+
+ if (!stackbase_main_self && thr_main() != 0)
+ {
+ /* Cache the stack base value for the primordial thread (this */
+ /* is done during GC_init, so there is no race). */
+ stackbase_main_ss_sp = s.ss_sp;
+ stackbase_main_self = self;
+ }
+
+ b -> mem_base = s.ss_sp;
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* GC_SOLARIS_THREADS */
+
+#ifdef GC_RTEMS_PTHREADS
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb)
+ {
+ sb->mem_base = rtems_get_stack_bottom();
+ return GC_SUCCESS;
+ }
+# define HAVE_GET_STACK_BASE
+#endif /* GC_RTEMS_PTHREADS */
+
+#ifndef HAVE_GET_STACK_BASE
+ /* Retrieve stack base. */
+ /* Using the GC_find_limit version is risky. */
+ /* On IA64, for example, there is no guard page between the */
+ /* stack of one thread and the register backing store of the */
+ /* next. Thus this is likely to identify way too large a */
+ /* "stack" and thus at least result in disastrous performance. */
+ /* FIXME - Implement better strategies here. */
+ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b)
+ {
+# ifdef NEED_FIND_LIMIT
+ IF_CANCEL(int cancel_state;)
+ DCL_LOCK_STATE;
+
+ LOCK();
+ DISABLE_CANCEL(cancel_state); /* May be unnecessary? */
+# ifdef STACK_GROWS_DOWN
+ b -> mem_base = GC_find_limit(GC_approx_sp(), TRUE);
+# ifdef IA64
+ b -> reg_base = GC_find_limit(GC_save_regs_in_stack(), FALSE);
+# endif
+# else
+ b -> mem_base = GC_find_limit(GC_approx_sp(), FALSE);
+# endif
+ RESTORE_CANCEL(cancel_state);
+ UNLOCK();
+ return GC_SUCCESS;
+# else
+ return GC_UNIMPLEMENTED;
+# endif
+ }
+#endif /* !HAVE_GET_STACK_BASE */
+
+#ifndef GET_MAIN_STACKBASE_SPECIAL
+ /* This is always called from the main thread. Default implementation. */
+ ptr_t GC_get_main_stack_base(void)
+ {
+ struct GC_stack_base sb;
+
+ if (GC_get_stack_base(&sb) != GC_SUCCESS)
+ ABORT("GC_get_stack_base failed");
+ GC_ASSERT((void *)GC_approx_sp() HOTTER_THAN sb.mem_base);
+ return (ptr_t)sb.mem_base;
+ }
+#endif /* !GET_MAIN_STACKBASE_SPECIAL */
+
+/* Register static data segment(s) as roots. If more data segments are */
+/* added later then they need to be registered at that point (as we do */
+/* with SunOS dynamic loading), or GC_mark_roots needs to check for */
+/* them (as we do with PCR). Called with allocator lock held. */
+# ifdef OS2
+
+void GC_register_data_segments(void)
+{
+ PTIB ptib;
+ PPIB ppib;
+ HMODULE module_handle;
+# define PBUFSIZ 512
+ UCHAR path[PBUFSIZ];
+ FILE * myexefile;
+ struct exe_hdr hdrdos; /* MSDOS header. */
+ struct e32_exe hdr386; /* Real header for my executable */
+ struct o32_obj seg; /* Currrent segment */
+ int nsegs;
+
+
+ if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) {
+ ABORT("DosGetInfoBlocks failed");
+ }
+ module_handle = ppib -> pib_hmte;
+ if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) {
+ GC_err_printf("DosQueryModuleName failed\n");
+ ABORT("DosGetInfoBlocks failed");
+ }
+ myexefile = fopen(path, "rb");
+ if (myexefile == 0) {
+ if (GC_print_stats) {
+ GC_err_puts("Couldn't open executable ");
+ GC_err_puts(path);
+ GC_err_puts("\n");
+ }
+ ABORT("Failed to open executable");
+ }
+ if (fread((char *)(&hdrdos), 1, sizeof(hdrdos), myexefile)
+ < sizeof(hdrdos)) {
+ if (GC_print_stats) {
+ GC_err_puts("Couldn't read MSDOS header from ");
+ GC_err_puts(path);
+ GC_err_puts("\n");
+ }
+ ABORT("Couldn't read MSDOS header");
+ }
+ if (E_MAGIC(hdrdos) != EMAGIC) {
+ if (GC_print_stats) {
+ GC_err_puts("Executable has wrong DOS magic number: ");
+ GC_err_puts(path);
+ GC_err_puts("\n");
+ }
+ ABORT("Bad DOS magic number");
+ }
+ if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) {
+ if (GC_print_stats) {
+ GC_err_puts("Seek to new header failed in ");
+ GC_err_puts(path);
+ GC_err_puts("\n");
+ }
+ ABORT("Bad DOS magic number");
+ }
+ if (fread((char *)(&hdr386), 1, sizeof(hdr386), myexefile)
+ < sizeof(hdr386)) {
+ if (GC_print_stats) {
+ GC_err_puts("Couldn't read MSDOS header from ");
+ GC_err_puts(path);
+ GC_err_puts("\n");
+ }
+ ABORT("Couldn't read OS/2 header");
+ }
+ if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) {
+ if (GC_print_stats) {
+ GC_err_puts("Executable has wrong OS/2 magic number: ");
+ GC_err_puts(path);
+ GC_err_puts("\n");
+ }
+ ABORT("Bad OS/2 magic number");
+ }
+ if (E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) {
+ if (GC_print_stats) {
+ GC_err_puts("Executable has wrong byte order: ");
+ GC_err_puts(path);
+ GC_err_puts("\n");
+ }
+ ABORT("Bad byte order");
+ }
+ if (E32_CPU(hdr386) == E32CPU286) {
+ if (GC_print_stats) {
+ GC_err_puts("GC can't handle 80286 executables: ");
+ GC_err_puts(path);
+ GC_err_puts("\n");
+ }
+ ABORT("Intel 80286 executables are unsupported");
+ }
+ if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386),
+ SEEK_SET) != 0) {
+ if (GC_print_stats) {
+ GC_err_puts("Seek to object table failed: ");
+ GC_err_puts(path);
+ GC_err_puts("\n");
+ }
+ ABORT("Seek to object table failed");
+ }
+ for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) {
+ int flags;
+ if (fread((char *)(&seg), 1, sizeof(seg), myexefile) < sizeof(seg)) {
+ if (GC_print_stats) {
+ GC_err_puts("Couldn't read obj table entry from ");
+ GC_err_puts(path);
+ GC_err_puts("\n");
+ }
+ ABORT("Couldn't read obj table entry");
+ }
+ flags = O32_FLAGS(seg);
+ if (!(flags & OBJWRITE)) continue;
+ if (!(flags & OBJREAD)) continue;
+ if (flags & OBJINVALID) {
+ GC_err_printf("Object with invalid pages?\n");
+ continue;
+ }
+ GC_add_roots_inner((ptr_t)O32_BASE(seg),
+ (ptr_t)(O32_BASE(seg)+O32_SIZE(seg)), FALSE);
+ }
+}
+
+# else /* !OS2 */
+
+# if defined(GWW_VDB)
+# ifndef MEM_WRITE_WATCH
+# define MEM_WRITE_WATCH 0x200000
+# endif
+# ifndef WRITE_WATCH_FLAG_RESET
+# define WRITE_WATCH_FLAG_RESET 1
+# endif
+
+ /* Since we can't easily check whether ULONG_PTR and SIZE_T are */
+ /* defined in Win32 basetsd.h, we define own ULONG_PTR. */
+# define GC_ULONG_PTR word
+
+ typedef UINT (WINAPI * GetWriteWatch_type)(
+ DWORD, PVOID, GC_ULONG_PTR /* SIZE_T */,
+ PVOID *, GC_ULONG_PTR *, PULONG);
+ static GetWriteWatch_type GetWriteWatch_func;
+ static DWORD GetWriteWatch_alloc_flag;
+
+# define GC_GWW_AVAILABLE() (GetWriteWatch_func != NULL)
+
+ static void detect_GetWriteWatch(void)
+ {
+ static GC_bool done;
+ HMODULE hK32;
+ if (done)
+ return;
+
+# if defined(MPROTECT_VDB)
+ {
+ char * str = GETENV("GC_USE_GETWRITEWATCH");
+# if defined(GC_PREFER_MPROTECT_VDB)
+ if (str == NULL || (*str == '0' && *(str + 1) == '\0')) {
+ /* GC_USE_GETWRITEWATCH is unset or set to "0". */
+ done = TRUE; /* falling back to MPROTECT_VDB strategy. */
+ /* This should work as if GWW_VDB is undefined. */
+ return;
+ }
+# else
+ if (str != NULL && *str == '0' && *(str + 1) == '\0') {
+ /* GC_USE_GETWRITEWATCH is set "0". */
+ done = TRUE; /* falling back to MPROTECT_VDB strategy. */
+ return;
+ }
+# endif
+ }
+# endif
+
+ hK32 = GetModuleHandle(TEXT("kernel32.dll"));
+ if (hK32 != (HMODULE)0 &&
+ (GetWriteWatch_func = (GetWriteWatch_type)GetProcAddress(hK32,
+ "GetWriteWatch")) != NULL) {
+ /* Also check whether VirtualAlloc accepts MEM_WRITE_WATCH, */
+ /* as some versions of kernel32.dll have one but not the */
+ /* other, making the feature completely broken. */
+ void * page = VirtualAlloc(NULL, GC_page_size,
+ MEM_WRITE_WATCH | MEM_RESERVE,
+ PAGE_READWRITE);
+ if (page != NULL) {
+ PVOID pages[16];
+ GC_ULONG_PTR count = 16;
+ DWORD page_size;
+ /* Check that it actually works. In spite of some */
+ /* documentation it actually seems to exist on W2K. */
+ /* This test may be unnecessary, but ... */
+ if (GetWriteWatch_func(WRITE_WATCH_FLAG_RESET,
+ page, GC_page_size,
+ pages,
+ &count,
+ &page_size) != 0) {
+ /* GetWriteWatch always fails. */
+ GetWriteWatch_func = NULL;
+ } else {
+ GetWriteWatch_alloc_flag = MEM_WRITE_WATCH;
+ }
+ VirtualFree(page, GC_page_size, MEM_RELEASE);
+ } else {
+ /* GetWriteWatch will be useless. */
+ GetWriteWatch_func = NULL;
+ }
+ }
+ if (GC_print_stats) {
+ if (GetWriteWatch_func == NULL) {
+ GC_log_printf("Did not find a usable GetWriteWatch()\n");
+ } else {
+ GC_log_printf("Using GetWriteWatch()\n");
+ }
+ }
+ done = TRUE;
+ }
+
+# else
+# define GetWriteWatch_alloc_flag 0
+# endif /* !GWW_VDB */
+
+# if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)
+
+# ifdef MSWIN32
+ /* Unfortunately, we have to handle win32s very differently from NT, */
+ /* Since VirtualQuery has very different semantics. In particular, */
+ /* under win32s a VirtualQuery call on an unmapped page returns an */
+ /* invalid result. Under NT, GC_register_data_segments is a no-op */
+ /* and all real work is done by GC_register_dynamic_libraries. Under */
+ /* win32s, we cannot find the data segments associated with dll's. */
+ /* We register the main data segment here. */
+ GC_INNER GC_bool GC_no_win32_dlls = FALSE;
+ /* This used to be set for gcc, to avoid dealing with */
+ /* the structured exception handling issues. But we now have */
+ /* assembly code to do that right. */
+
+ GC_INNER GC_bool GC_wnt = FALSE;
+ /* This is a Windows NT derivative, i.e. NT, W2K, XP or later. */
+
+ GC_INNER void GC_init_win32(void)
+ {
+ /* Set GC_wnt. If we're running under win32s, assume that no DLLs */
+ /* will be loaded. I doubt anyone still runs win32s, but... */
+ DWORD v = GetVersion();
+ GC_wnt = !(v & 0x80000000);
+ GC_no_win32_dlls |= ((!GC_wnt) && (v & 0xff) <= 3);
+# ifdef USE_MUNMAP
+ if (GC_no_win32_dlls) {
+ /* Turn off unmapping for safety (since may not work well with */
+ /* GlobalAlloc). */
+ GC_unmap_threshold = 0;
+ }
+# endif
+ }
+
+ /* Return the smallest address a such that VirtualQuery */
+ /* returns correct results for all addresses between a and start. */
+ /* Assumes VirtualQuery returns correct information for start. */
+ STATIC ptr_t GC_least_described_address(ptr_t start)
+ {
+ MEMORY_BASIC_INFORMATION buf;
+ size_t result;
+ LPVOID limit;
+ ptr_t p;
+ LPVOID q;
+
+ limit = GC_sysinfo.lpMinimumApplicationAddress;
+ p = (ptr_t)((word)start & ~(GC_page_size - 1));
+ for (;;) {
+ q = (LPVOID)(p - GC_page_size);
+ if ((ptr_t)q > (ptr_t)p /* underflow */ || q < limit) break;
+ result = VirtualQuery(q, &buf, sizeof(buf));
+ if (result != sizeof(buf) || buf.AllocationBase == 0) break;
+ p = (ptr_t)(buf.AllocationBase);
+ }
+ return p;
+ }
+# endif /* MSWIN32 */
+
+# ifndef REDIRECT_MALLOC
+ /* We maintain a linked list of AllocationBase values that we know */
+ /* correspond to malloc heap sections. Currently this is only called */
+ /* during a GC. But there is some hope that for long running */
+ /* programs we will eventually see most heap sections. */
+
+ /* In the long run, it would be more reliable to occasionally walk */
+ /* the malloc heap with HeapWalk on the default heap. But that */
+ /* apparently works only for NT-based Windows. */
+
+ STATIC size_t GC_max_root_size = 100000; /* Appr. largest root size. */
+
+# ifndef CYGWIN32
+ /* In the long run, a better data structure would also be nice ... */
+ STATIC struct GC_malloc_heap_list {
+ void * allocation_base;
+ struct GC_malloc_heap_list *next;
+ } *GC_malloc_heap_l = 0;
+
+ /* Is p the base of one of the malloc heap sections we already know */
+ /* about? */
+ STATIC GC_bool GC_is_malloc_heap_base(ptr_t p)
+ {
+ struct GC_malloc_heap_list *q = GC_malloc_heap_l;
+
+ while (0 != q) {
+ if (q -> allocation_base == p) return TRUE;
+ q = q -> next;
+ }
+ return FALSE;
+ }
+
+ STATIC void *GC_get_allocation_base(void *p)
+ {
+ MEMORY_BASIC_INFORMATION buf;
+ size_t result = VirtualQuery(p, &buf, sizeof(buf));
+ if (result != sizeof(buf)) {
+ ABORT("Weird VirtualQuery result");
+ }
+ return buf.AllocationBase;
+ }
+
+ GC_INNER void GC_add_current_malloc_heap(void)
+ {
+ struct GC_malloc_heap_list *new_l =
+ malloc(sizeof(struct GC_malloc_heap_list));
+ void * candidate = GC_get_allocation_base(new_l);
+
+ if (new_l == 0) return;
+ if (GC_is_malloc_heap_base(candidate)) {
+ /* Try a little harder to find malloc heap. */
+ size_t req_size = 10000;
+ do {
+ void *p = malloc(req_size);
+ if (0 == p) {
+ free(new_l);
+ return;
+ }
+ candidate = GC_get_allocation_base(p);
+ free(p);
+ req_size *= 2;
+ } while (GC_is_malloc_heap_base(candidate)
+ && req_size < GC_max_root_size/10 && req_size < 500000);
+ if (GC_is_malloc_heap_base(candidate)) {
+ free(new_l);
+ return;
+ }
+ }
+ if (GC_print_stats)
+ GC_log_printf("Found new system malloc AllocationBase at %p\n",
+ candidate);
+ new_l -> allocation_base = candidate;
+ new_l -> next = GC_malloc_heap_l;
+ GC_malloc_heap_l = new_l;
+ }
+# endif /* !CYGWIN32 */
+
+# endif /* !REDIRECT_MALLOC */
+
+ STATIC word GC_n_heap_bases = 0; /* See GC_heap_bases. */
+
+ /* Is p the start of either the malloc heap, or of one of our */
+ /* heap sections? */
+ GC_INNER GC_bool GC_is_heap_base(ptr_t p)
+ {
+ unsigned i;
+# ifndef REDIRECT_MALLOC
+ if (GC_root_size > GC_max_root_size) GC_max_root_size = GC_root_size;
+# ifndef CYGWIN32
+ if (GC_is_malloc_heap_base(p)) return TRUE;
+# endif
+# endif
+ for (i = 0; i < GC_n_heap_bases; i++) {
+ if (GC_heap_bases[i] == p) return TRUE;
+ }
+ return FALSE;
+ }
+
+#ifdef MSWIN32
+ STATIC void GC_register_root_section(ptr_t static_root)
+ {
+ MEMORY_BASIC_INFORMATION buf;
+ size_t result;
+ DWORD protect;
+ LPVOID p;
+ char * base;
+ char * limit, * new_limit;
+
+ if (!GC_no_win32_dlls) return;
+ p = base = limit = GC_least_described_address(static_root);
+ while (p < GC_sysinfo.lpMaximumApplicationAddress) {
+ result = VirtualQuery(p, &buf, sizeof(buf));
+ if (result != sizeof(buf) || buf.AllocationBase == 0
+ || GC_is_heap_base(buf.AllocationBase)) break;
+ new_limit = (char *)p + buf.RegionSize;
+ protect = buf.Protect;
+ if (buf.State == MEM_COMMIT
+ && is_writable(protect)) {
+ if ((char *)p == limit) {
+ limit = new_limit;
+ } else {
+ if (base != limit) GC_add_roots_inner(base, limit, FALSE);
+ base = p;
+ limit = new_limit;
+ }
+ }
+ if (p > (LPVOID)new_limit /* overflow */) break;
+ p = (LPVOID)new_limit;
+ }
+ if (base != limit) GC_add_roots_inner(base, limit, FALSE);
+ }
+#endif /* MSWIN32 */
+
+ void GC_register_data_segments(void)
+ {
+# ifdef MSWIN32
+ GC_register_root_section((ptr_t)&GC_pages_executable);
+ /* any other GC global variable would fit too. */
+# endif
+ }
+
+# else /* !OS2 && !Windows */
+
+# if (defined(SVR4) || defined(AUX) || defined(DGUX) \
+ || (defined(LINUX) && defined(SPARC))) && !defined(PCR)
+ ptr_t GC_SysVGetDataStart(size_t max_page_size, ptr_t etext_addr)
+ {
+ word text_end = ((word)(etext_addr) + sizeof(word) - 1)
+ & ~(sizeof(word) - 1);
+ /* etext rounded to word boundary */
+ word next_page = ((text_end + (word)max_page_size - 1)
+ & ~((word)max_page_size - 1));
+ word page_offset = (text_end & ((word)max_page_size - 1));
+ char * volatile result = (char *)(next_page + page_offset);
+ /* Note that this isn't equivalent to just adding */
+ /* max_page_size to &etext if &etext is at a page boundary */
+
+ GC_setup_temporary_fault_handler();
+ if (SETJMP(GC_jmp_buf) == 0) {
+ /* Try writing to the address. */
+ *result = *result;
+ GC_reset_fault_handler();
+ } else {
+ GC_reset_fault_handler();
+ /* We got here via a longjmp. The address is not readable. */
+ /* This is known to happen under Solaris 2.4 + gcc, which place */
+ /* string constants in the text segment, but after etext. */
+ /* Use plan B. Note that we now know there is a gap between */
+ /* text and data segments, so plan A bought us something. */
+ result = (char *)GC_find_limit((ptr_t)(DATAEND), FALSE);
+ }
+ return((ptr_t)result);
+ }
+# endif
+
+# if defined(FREEBSD) && !defined(PCR) && (defined(I386) || defined(X86_64) \
+ || defined(powerpc) || defined(__powerpc__))
+
+/* Its unclear whether this should be identical to the above, or */
+/* whether it should apply to non-X86 architectures. */
+/* For now we don't assume that there is always an empty page after */
+/* etext. But in some cases there actually seems to be slightly more. */
+/* This also deals with holes between read-only data and writable data. */
+ptr_t GC_FreeBSDGetDataStart(size_t max_page_size, ptr_t etext_addr)
+{
+ word text_end = ((word)(etext_addr) + sizeof(word) - 1)
+ & ~(sizeof(word) - 1);
+ /* etext rounded to word boundary */
+ volatile word next_page = (text_end + (word)max_page_size - 1)
+ & ~((word)max_page_size - 1);
+ volatile ptr_t result = (ptr_t)text_end;
+ GC_setup_temporary_fault_handler();
+ if (SETJMP(GC_jmp_buf) == 0) {
+ /* Try reading at the address. */
+ /* This should happen before there is another thread. */
+ for (; next_page < (word)(DATAEND); next_page += (word)max_page_size)
+ *(volatile char *)next_page;
+ GC_reset_fault_handler();
+ } else {
+ GC_reset_fault_handler();
+ /* As above, we go to plan B */
+ result = GC_find_limit((ptr_t)(DATAEND), FALSE);
+ }
+ return(result);
+}
+
+# endif /* FREEBSD */
+
+
+#ifdef AMIGA
+
+# define GC_AMIGA_DS
+# include "extra/AmigaOS.c"
+# undef GC_AMIGA_DS
+
+#elif defined(OPENBSD)
+
+/* Depending on arch alignment, there can be multiple holes */
+/* between DATASTART and DATAEND. Scan in DATASTART .. DATAEND */
+/* and register each region. */
+void GC_register_data_segments(void)
+{
+ ptr_t region_start = DATASTART;
+ ptr_t region_end;
+
+ for (;;) {
+ region_end = GC_find_limit_openbsd(region_start, DATAEND);
+ GC_add_roots_inner(region_start, region_end, FALSE);
+ if (region_end >= DATAEND)
+ break;
+ region_start = GC_skip_hole_openbsd(region_end, DATAEND);
+ }
+}
+
+# else /* !OS2 && !Windows && !AMIGA && !OPENBSD */
+
+void GC_register_data_segments(void)
+{
+# if !defined(PCR) && !defined(MACOS)
+# if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS)
+ /* As of Solaris 2.3, the Solaris threads implementation */
+ /* allocates the data structure for the initial thread with */
+ /* sbrk at process startup. It needs to be scanned, so that */
+ /* we don't lose some malloc allocated data structures */
+ /* hanging from it. We're on thin ice here ... */
+ extern caddr_t sbrk(int);
+
+ GC_add_roots_inner(DATASTART, (ptr_t)sbrk(0), FALSE);
+# else
+ GC_add_roots_inner(DATASTART, (ptr_t)(DATAEND), FALSE);
+# if defined(DATASTART2)
+ GC_add_roots_inner(DATASTART2, (ptr_t)(DATAEND2), FALSE);
+# endif
+# endif
+# endif
+# if defined(MACOS)
+ {
+# if defined(THINK_C)
+ extern void* GC_MacGetDataStart(void);
+ /* globals begin above stack and end at a5. */
+ GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
+ (ptr_t)LMGetCurrentA5(), FALSE);
+# else
+# if defined(__MWERKS__)
+# if !__POWERPC__
+ extern void* GC_MacGetDataStart(void);
+ /* MATTHEW: Function to handle Far Globals (CW Pro 3) */
+# if __option(far_data)
+ extern void* GC_MacGetDataEnd(void);
+# endif
+ /* globals begin above stack and end at a5. */
+ GC_add_roots_inner((ptr_t)GC_MacGetDataStart(),
+ (ptr_t)LMGetCurrentA5(), FALSE);
+ /* MATTHEW: Handle Far Globals */
+# if __option(far_data)
+ /* Far globals follow he QD globals: */
+ GC_add_roots_inner((ptr_t)LMGetCurrentA5(),
+ (ptr_t)GC_MacGetDataEnd(), FALSE);
+# endif
+# else
+ extern char __data_start__[], __data_end__[];
+ GC_add_roots_inner((ptr_t)&__data_start__,
+ (ptr_t)&__data_end__, FALSE);
+# endif /* __POWERPC__ */
+# endif /* __MWERKS__ */
+# endif /* !THINK_C */
+ }
+# endif /* MACOS */
+
+ /* Dynamic libraries are added at every collection, since they may */
+ /* change. */
+}
+
+# endif /* ! AMIGA */
+# endif /* ! MSWIN32 && ! MSWINCE*/
+# endif /* ! OS2 */
+
+/*
+ * Auxiliary routines for obtaining memory from OS.
+ */
+
+# if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \
+ && !defined(MSWINCE) && !defined(MACOS) && !defined(DOS4GW) \
+ && !defined(NONSTOP) && !defined(SN_TARGET_PS3) && !defined(RTEMS) \
+ && !defined(__CC_ARM)
+
+# define SBRK_ARG_T ptrdiff_t
+
+#if defined(MMAP_SUPPORTED)
+
+#ifdef USE_MMAP_FIXED
+# define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE
+ /* Seems to yield better performance on Solaris 2, but can */
+ /* be unreliable if something is already mapped at the address. */
+#else
+# define GC_MMAP_FLAGS MAP_PRIVATE
+#endif
+
+#ifdef USE_MMAP_ANON
+# define zero_fd -1
+# if defined(MAP_ANONYMOUS)
+# define OPT_MAP_ANON MAP_ANONYMOUS
+# else
+# define OPT_MAP_ANON MAP_ANON
+# endif
+#else
+ static int zero_fd;
+# define OPT_MAP_ANON 0
+#endif
+
+#ifndef HEAP_START
+# define HEAP_START ((ptr_t)0)
+#endif
+
+STATIC ptr_t GC_unix_mmap_get_mem(word bytes)
+{
+ void *result;
+ static ptr_t last_addr = HEAP_START;
+
+# ifndef USE_MMAP_ANON
+ static GC_bool initialized = FALSE;
+
+ if (!initialized) {
+ zero_fd = open("/dev/zero", O_RDONLY);
+ fcntl(zero_fd, F_SETFD, FD_CLOEXEC);
+ initialized = TRUE;
+ }
+# endif
+
+ if (bytes & (GC_page_size - 1)) ABORT("Bad GET_MEM arg");
+ result = mmap(last_addr, bytes, (PROT_READ | PROT_WRITE)
+ | (GC_pages_executable ? PROT_EXEC : 0),
+ GC_MMAP_FLAGS | OPT_MAP_ANON, zero_fd, 0/* offset */);
+# undef IGNORE_PAGES_EXECUTABLE
+
+ if (result == MAP_FAILED) return(0);
+ last_addr = (ptr_t)result + bytes + GC_page_size - 1;
+ last_addr = (ptr_t)((word)last_addr & ~(GC_page_size - 1));
+# if !defined(LINUX)
+ if (last_addr == 0) {
+ /* Oops. We got the end of the address space. This isn't */
+ /* usable by arbitrary C code, since one-past-end pointers */
+ /* don't work, so we discard it and try again. */
+ munmap(result, (size_t)(-GC_page_size) - (size_t)result);
+ /* Leave last page mapped, so we can't repeat. */
+ return GC_unix_mmap_get_mem(bytes);
+ }
+# else
+ GC_ASSERT(last_addr != 0);
+# endif
+ return((ptr_t)result);
+}
+
+# endif /* MMAP_SUPPORTED */
+
+#if defined(USE_MMAP)
+ ptr_t GC_unix_get_mem(word bytes)
+ {
+ return GC_unix_mmap_get_mem(bytes);
+ }
+#else /* !USE_MMAP */
+
+STATIC ptr_t GC_unix_sbrk_get_mem(word bytes)
+{
+ ptr_t result;
+# ifdef IRIX5
+ /* Bare sbrk isn't thread safe. Play by malloc rules. */
+ /* The equivalent may be needed on other systems as well. */
+ __LOCK_MALLOC();
+# endif
+ {
+ ptr_t cur_brk = (ptr_t)sbrk(0);
+ SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1);
+
+ if ((SBRK_ARG_T)bytes < 0) {
+ result = 0; /* too big */
+ goto out;
+ }
+ if (lsbs != 0) {
+ if((ptr_t)sbrk(GC_page_size - lsbs) == (ptr_t)(-1)) {
+ result = 0;
+ goto out;
+ }
+ }
+# ifdef ADD_HEAP_GUARD_PAGES
+ /* This is useful for catching severe memory overwrite problems that */
+ /* span heap sections. It shouldn't otherwise be turned on. */
+ {
+ ptr_t guard = (ptr_t)sbrk((SBRK_ARG_T)GC_page_size);
+ if (mprotect(guard, GC_page_size, PROT_NONE) != 0)
+ ABORT("ADD_HEAP_GUARD_PAGES: mprotect failed");
+ }
+# endif /* ADD_HEAP_GUARD_PAGES */
+ result = (ptr_t)sbrk((SBRK_ARG_T)bytes);
+ if (result == (ptr_t)(-1)) result = 0;
+ }
+ out:
+# ifdef IRIX5
+ __UNLOCK_MALLOC();
+# endif
+ return(result);
+}
+
+ptr_t GC_unix_get_mem(word bytes)
+{
+# if defined(MMAP_SUPPORTED)
+ /* By default, we try both sbrk and mmap, in that order. */
+ static GC_bool sbrk_failed = FALSE;
+ ptr_t result = 0;
+
+ if (!sbrk_failed) result = GC_unix_sbrk_get_mem(bytes);
+ if (0 == result) {
+ sbrk_failed = TRUE;
+ result = GC_unix_mmap_get_mem(bytes);
+ }
+ if (0 == result) {
+ /* Try sbrk again, in case sbrk memory became available. */
+ result = GC_unix_sbrk_get_mem(bytes);
+ }
+ return result;
+# else /* !MMAP_SUPPORTED */
+ return GC_unix_sbrk_get_mem(bytes);
+# endif
+}
+
+#endif /* !USE_MMAP */
+
+# endif /* UN*X */
+
+# ifdef OS2
+
+void * os2_alloc(size_t bytes)
+{
+ void * result;
+
+ if (DosAllocMem(&result, bytes, (PAG_READ | PAG_WRITE | PAG_COMMIT)
+ | (GC_pages_executable ? PAG_EXECUTE : 0))
+ != NO_ERROR) {
+ return(0);
+ }
+ /* FIXME: What's the purpose of this recursion? (Probably, if */
+ /* DosAllocMem returns memory at 0 address then just retry once.) */
+ if (result == 0) return(os2_alloc(bytes));
+ return(result);
+}
+
+# endif /* OS2 */
+
+# if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32)
+ GC_INNER SYSTEM_INFO GC_sysinfo;
+# endif
+
+#ifdef MSWIN32
+
+# ifdef USE_GLOBAL_ALLOC
+# define GLOBAL_ALLOC_TEST 1
+# else
+# define GLOBAL_ALLOC_TEST GC_no_win32_dlls
+# endif
+
+# ifdef GC_USE_MEM_TOP_DOWN
+ STATIC DWORD GC_mem_top_down = MEM_TOP_DOWN;
+ /* Use GC_USE_MEM_TOP_DOWN for better 64-bit */
+ /* testing. Otherwise all addresses tend to */
+ /* end up in first 4GB, hiding bugs. */
+# else
+ STATIC DWORD GC_mem_top_down = 0;
+# endif
+
+#endif /* MSWIN32 */
+
+#if defined(MSWIN32) || defined(CYGWIN32)
+ ptr_t GC_win32_get_mem(word bytes)
+ {
+ ptr_t result;
+
+# ifdef CYGWIN32
+ result = GC_unix_get_mem(bytes);
+# else
+ if (GLOBAL_ALLOC_TEST) {
+ /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */
+ /* There are also unconfirmed rumors of other */
+ /* problems, so we dodge the issue. */
+ result = (ptr_t) GlobalAlloc(0, bytes + HBLKSIZE);
+ result = (ptr_t)(((word)result + HBLKSIZE - 1) & ~(HBLKSIZE-1));
+ } else {
+ /* VirtualProtect only works on regions returned by a */
+ /* single VirtualAlloc call. Thus we allocate one */
+ /* extra page, which will prevent merging of blocks */
+ /* in separate regions, and eliminate any temptation */
+ /* to call VirtualProtect on a range spanning regions. */
+ /* This wastes a small amount of memory, and risks */
+ /* increased fragmentation. But better alternatives */
+ /* would require effort. */
+# ifdef MPROTECT_VDB
+ /* We can't check for GC_incremental here (because */
+ /* GC_enable_incremental() might be called some time */
+ /* later after the GC initialization). */
+# ifdef GWW_VDB
+# define VIRTUAL_ALLOC_PAD (GC_GWW_AVAILABLE() ? 0 : 1)
+# else
+# define VIRTUAL_ALLOC_PAD 1
+# endif
+# else
+# define VIRTUAL_ALLOC_PAD 0
+# endif
+ /* Pass the MEM_WRITE_WATCH only if GetWriteWatch-based */
+ /* VDBs are enabled and the GetWriteWatch function is */
+ /* available. Otherwise we waste resources or possibly */
+ /* cause VirtualAlloc to fail (observed in Windows 2000 */
+ /* SP2). */
+ result = (ptr_t) VirtualAlloc(NULL, bytes + VIRTUAL_ALLOC_PAD,
+ GetWriteWatch_alloc_flag
+ | (MEM_COMMIT | MEM_RESERVE)
+ | GC_mem_top_down,
+ GC_pages_executable ? PAGE_EXECUTE_READWRITE :
+ PAGE_READWRITE);
+# undef IGNORE_PAGES_EXECUTABLE
+ }
+# endif /* !CYGWIN32 */
+ if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
+ /* If I read the documentation correctly, this can */
+ /* only happen if HBLKSIZE > 64k or not a power of 2. */
+ if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
+ if (0 != result) GC_heap_bases[GC_n_heap_bases++] = result;
+ return(result);
+ }
+
+ GC_API void GC_CALL GC_win32_free_heap(void)
+ {
+# ifndef CYGWIN32
+ if (GC_no_win32_dlls)
+# endif
+ {
+ while (GC_n_heap_bases-- > 0) {
+# ifdef CYGWIN32
+ /* FIXME: Is it ok to use non-GC free() here? */
+# else
+ GlobalFree(GC_heap_bases[GC_n_heap_bases]);
+# endif
+ GC_heap_bases[GC_n_heap_bases] = 0;
+ }
+ }
+ }
+#endif /* MSWIN32 || CYGWIN32 */
+
+#ifdef AMIGA
+# define GC_AMIGA_AM
+# include "extra/AmigaOS.c"
+# undef GC_AMIGA_AM
+#endif
+
+
+#ifdef MSWINCE
+ ptr_t GC_wince_get_mem(word bytes)
+ {
+ ptr_t result = 0; /* initialized to prevent warning. */
+ word i;
+
+ /* Round up allocation size to multiple of page size */
+ bytes = (bytes + GC_page_size-1) & ~(GC_page_size-1);
+
+ /* Try to find reserved, uncommitted pages */
+ for (i = 0; i < GC_n_heap_bases; i++) {
+ if (((word)(-(signed_word)GC_heap_lengths[i])
+ & (GC_sysinfo.dwAllocationGranularity-1))
+ >= bytes) {
+ result = GC_heap_bases[i] + GC_heap_lengths[i];
+ break;
+ }
+ }
+
+ if (i == GC_n_heap_bases) {
+ /* Reserve more pages */
+ word res_bytes = (bytes + GC_sysinfo.dwAllocationGranularity-1)
+ & ~(GC_sysinfo.dwAllocationGranularity-1);
+ /* If we ever support MPROTECT_VDB here, we will probably need to */
+ /* ensure that res_bytes is strictly > bytes, so that VirtualProtect */
+ /* never spans regions. It seems to be OK for a VirtualFree */
+ /* argument to span regions, so we should be OK for now. */
+ result = (ptr_t) VirtualAlloc(NULL, res_bytes,
+ MEM_RESERVE | MEM_TOP_DOWN,
+ GC_pages_executable ? PAGE_EXECUTE_READWRITE :
+ PAGE_READWRITE);
+ if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
+ /* If I read the documentation correctly, this can */
+ /* only happen if HBLKSIZE > 64k or not a power of 2. */
+ if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections");
+ if (result == NULL) return NULL;
+ GC_heap_bases[GC_n_heap_bases] = result;
+ GC_heap_lengths[GC_n_heap_bases] = 0;
+ GC_n_heap_bases++;
+ }
+
+ /* Commit pages */
+ result = (ptr_t) VirtualAlloc(result, bytes, MEM_COMMIT,
+ GC_pages_executable ? PAGE_EXECUTE_READWRITE :
+ PAGE_READWRITE);
+# undef IGNORE_PAGES_EXECUTABLE
+
+ if (result != NULL) {
+ if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result");
+ GC_heap_lengths[i] += bytes;
+ }
+
+ return(result);
+ }
+#endif
+
+#ifdef USE_MUNMAP
+
+/* For now, this only works on Win32/WinCE and some Unix-like */
+/* systems. If you have something else, don't define */
+/* USE_MUNMAP. */
+
+#if !defined(MSWIN32) && !defined(MSWINCE)
+
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#endif
+
+/* Compute a page aligned starting address for the unmap */
+/* operation on a block of size bytes starting at start. */
+/* Return 0 if the block is too small to make this feasible. */
+STATIC ptr_t GC_unmap_start(ptr_t start, size_t bytes)
+{
+ ptr_t result;
+ /* Round start to next page boundary. */
+ result = (ptr_t)((word)(start + GC_page_size - 1) & ~(GC_page_size - 1));
+ if (result + GC_page_size > start + bytes) return 0;
+ return result;
+}
+
+/* Compute end address for an unmap operation on the indicated */
+/* block. */
+STATIC ptr_t GC_unmap_end(ptr_t start, size_t bytes)
+{
+ return (ptr_t)((word)(start + bytes) & ~(GC_page_size - 1));
+}
+
+/* Under Win32/WinCE we commit (map) and decommit (unmap) */
+/* memory using VirtualAlloc and VirtualFree. These functions */
+/* work on individual allocations of virtual memory, made */
+/* previously using VirtualAlloc with the MEM_RESERVE flag. */
+/* The ranges we need to (de)commit may span several of these */
+/* allocations; therefore we use VirtualQuery to check */
+/* allocation lengths, and split up the range as necessary. */
+
+/* We assume that GC_remap is called on exactly the same range */
+/* as a previous call to GC_unmap. It is safe to consistently */
+/* round the endpoints in both places. */
+GC_INNER void GC_unmap(ptr_t start, size_t bytes)
+{
+ ptr_t start_addr = GC_unmap_start(start, bytes);
+ ptr_t end_addr = GC_unmap_end(start, bytes);
+ word len = end_addr - start_addr;
+ if (0 == start_addr) return;
+# if defined(MSWIN32) || defined(MSWINCE)
+ while (len != 0) {
+ MEMORY_BASIC_INFORMATION mem_info;
+ GC_word free_len;
+ if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
+ != sizeof(mem_info))
+ ABORT("Weird VirtualQuery result");
+ free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
+ if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
+ ABORT("VirtualFree failed");
+ GC_unmapped_bytes += free_len;
+ start_addr += free_len;
+ len -= free_len;
+ }
+# else
+ /* We immediately remap it to prevent an intervening mmap from */
+ /* accidentally grabbing the same address space. */
+ {
+ void * result;
+ result = mmap(start_addr, len, PROT_NONE,
+ MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON,
+ zero_fd, 0/* offset */);
+ if (result != (void *)start_addr)
+ ABORT("mmap(PROT_NONE) failed");
+ }
+ GC_unmapped_bytes += len;
+# endif
+}
+
+GC_INNER void GC_remap(ptr_t start, size_t bytes)
+{
+ ptr_t start_addr = GC_unmap_start(start, bytes);
+ ptr_t end_addr = GC_unmap_end(start, bytes);
+ word len = end_addr - start_addr;
+
+ /* FIXME: Handle out-of-memory correctly (at least for Win32) */
+# if defined(MSWIN32) || defined(MSWINCE)
+ ptr_t result;
+
+ if (0 == start_addr) return;
+ while (len != 0) {
+ MEMORY_BASIC_INFORMATION mem_info;
+ GC_word alloc_len;
+ if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
+ != sizeof(mem_info))
+ ABORT("Weird VirtualQuery result");
+ alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
+ result = VirtualAlloc(start_addr, alloc_len, MEM_COMMIT,
+ GC_pages_executable ? PAGE_EXECUTE_READWRITE :
+ PAGE_READWRITE);
+ if (result != start_addr) {
+ if (GetLastError() == ERROR_NOT_ENOUGH_MEMORY ||
+ GetLastError() == ERROR_OUTOFMEMORY) {
+ ABORT("Not enough memory to process remapping");
+ } else {
+ ABORT("VirtualAlloc remapping failed");
+ }
+ }
+ GC_unmapped_bytes -= alloc_len;
+ start_addr += alloc_len;
+ len -= alloc_len;
+ }
+# else
+ /* It was already remapped with PROT_NONE. */
+ int result;
+ if (0 == start_addr) return;
+
+# ifndef NACL
+ result = mprotect(start_addr, len, (PROT_READ | PROT_WRITE)
+ | (GC_pages_executable ? PROT_EXEC : 0));
+# else
+ {
+ /* NaCl does not expose mprotect, but mmap should work fine. */
+ void *mmap_result = mmap(start_addr, len, (PROT_READ | PROT_WRITE)
+ | (GC_pages_executable ? PROT_EXEC : 0),
+ MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON,
+ zero_fd, 0 /* offset */);
+ if (mmap_result != (void *)start_addr)
+ ABORT("mmap as mprotect failed");
+ /* Fake the return value as if mprotect succeeded. */
+ result = 0;
+ }
+# endif /* NACL */
+# undef IGNORE_PAGES_EXECUTABLE
+
+ if (result != 0) {
+ if (GC_print_stats)
+ GC_log_printf("Mprotect failed at %p (length %lu) with errno %d\n",
+ start_addr, (unsigned long)len, errno);
+ ABORT("mprotect remapping failed");
+ }
+ GC_unmapped_bytes -= len;
+# endif
+}
+
+/* Two adjacent blocks have already been unmapped and are about to */
+/* be merged. Unmap the whole block. This typically requires */
+/* that we unmap a small section in the middle that was not previously */
+/* unmapped due to alignment constraints. */
+GC_INNER void GC_unmap_gap(ptr_t start1, size_t bytes1, ptr_t start2,
+ size_t bytes2)
+{
+ ptr_t start1_addr = GC_unmap_start(start1, bytes1);
+ ptr_t end1_addr = GC_unmap_end(start1, bytes1);
+ ptr_t start2_addr = GC_unmap_start(start2, bytes2);
+ ptr_t start_addr = end1_addr;
+ ptr_t end_addr = start2_addr;
+ size_t len;
+ GC_ASSERT(start1 + bytes1 == start2);
+ if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2);
+ if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2);
+ if (0 == start_addr) return;
+ len = end_addr - start_addr;
+# if defined(MSWIN32) || defined(MSWINCE)
+ while (len != 0) {
+ MEMORY_BASIC_INFORMATION mem_info;
+ GC_word free_len;
+ if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info))
+ != sizeof(mem_info))
+ ABORT("Weird VirtualQuery result");
+ free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize;
+ if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT))
+ ABORT("VirtualFree failed");
+ GC_unmapped_bytes += free_len;
+ start_addr += free_len;
+ len -= free_len;
+ }
+# else
+ if (len != 0) {
+ /* Immediately remap as above. */
+ void * result;
+ result = mmap(start_addr, len, PROT_NONE,
+ MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON,
+ zero_fd, 0/* offset */);
+ if (result != (void *)start_addr)
+ ABORT("mmap(PROT_NONE) failed");
+ }
+ GC_unmapped_bytes += len;
+# endif
+}
+
+#endif /* USE_MUNMAP */
+
+/* Routine for pushing any additional roots. In THREADS */
+/* environment, this is also responsible for marking from */
+/* thread stacks. */
+#ifndef THREADS
+ void (*GC_push_other_roots)(void) = 0;
+#else /* THREADS */
+
+# ifdef PCR
+PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy)
+{
+ struct PCR_ThCtl_TInfoRep info;
+ PCR_ERes result;
+
+ info.ti_stkLow = info.ti_stkHi = 0;
+ result = PCR_ThCtl_GetInfo(t, &info);
+ GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi));
+ return(result);
+}
+
+/* Push the contents of an old object. We treat this as stack */
+/* data only because that makes it robust against mark stack */
+/* overflow. */
+PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data)
+{
+ GC_push_all_stack((ptr_t)p, (ptr_t)p + size);
+ return(PCR_ERes_okay);
+}
+
+extern struct PCR_MM_ProcsRep * GC_old_allocator;
+ /* defined in pcr_interface.c. */
+
+STATIC void GC_default_push_other_roots(void)
+{
+ /* Traverse data allocated by previous memory managers. */
+ if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false,
+ GC_push_old_obj, 0)
+ != PCR_ERes_okay) {
+ ABORT("Old object enumeration failed");
+ }
+ /* Traverse all thread stacks. */
+ if (PCR_ERes_IsErr(
+ PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0))
+ || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) {
+ ABORT("Thread stack marking failed");
+ }
+}
+
+# endif /* PCR */
+
+# if defined(GC_PTHREADS) || defined(GC_WIN32_THREADS)
+ STATIC void GC_default_push_other_roots(void)
+ {
+ GC_push_all_stacks();
+ }
+# endif /* GC_WIN32_THREADS || GC_PTHREADS */
+
+# ifdef SN_TARGET_PS3
+ STATIC void GC_default_push_other_roots(void)
+ {
+ ABORT("GC_default_push_other_roots is not implemented");
+ }
+
+ void GC_push_thread_structures(void)
+ {
+ ABORT("GC_push_thread_structures is not implemented");
+ }
+# endif /* SN_TARGET_PS3 */
+
+ void (*GC_push_other_roots)(void) = GC_default_push_other_roots;
+#endif /* THREADS */
+
+/*
+ * Routines for accessing dirty bits on virtual pages.
+ * There are six ways to maintain this information:
+ * DEFAULT_VDB: A simple dummy implementation that treats every page
+ * as possibly dirty. This makes incremental collection
+ * useless, but the implementation is still correct.
+ * MANUAL_VDB: Stacks and static data are always considered dirty.
+ * Heap pages are considered dirty if GC_dirty(p) has been
+ * called on some pointer p pointing to somewhere inside
+ * an object on that page. A GC_dirty() call on a large
+ * object directly dirties only a single page, but for
+ * MANUAL_VDB we are careful to treat an object with a dirty
+ * page as completely dirty.
+ * In order to avoid races, an object must be marked dirty
+ * after it is written, and a reference to the object
+ * must be kept on a stack or in a register in the interim.
+ * With threads enabled, an object directly reachable from the
+ * stack at the time of a collection is treated as dirty.
+ * In single-threaded mode, it suffices to ensure that no
+ * collection can take place between the pointer assignment
+ * and the GC_dirty() call.
+ * PCR_VDB: Use PPCRs virtual dirty bit facility.
+ * PROC_VDB: Use the /proc facility for reading dirty bits. Only
+ * works under some SVR4 variants. Even then, it may be
+ * too slow to be entirely satisfactory. Requires reading
+ * dirty bits for entire address space. Implementations tend
+ * to assume that the client is a (slow) debugger.
+ * MPROTECT_VDB:Protect pages and then catch the faults to keep track of
+ * dirtied pages. The implementation (and implementability)
+ * is highly system dependent. This usually fails when system
+ * calls write to a protected page. We prevent the read system
+ * call from doing so. It is the clients responsibility to
+ * make sure that other system calls are similarly protected
+ * or write only to the stack.
+ * GWW_VDB: Use the Win32 GetWriteWatch functions, if available, to
+ * read dirty bits. In case it is not available (because we
+ * are running on Windows 95, Windows 2000 or earlier),
+ * MPROTECT_VDB may be defined as a fallback strategy.
+ */
+#ifndef GC_DISABLE_INCREMENTAL
+ GC_INNER GC_bool GC_dirty_maintained = FALSE;
+#endif
+
+#if defined(PROC_VDB) || defined(GWW_VDB)
+ /* Add all pages in pht2 to pht1 */
+ STATIC void GC_or_pages(page_hash_table pht1, page_hash_table pht2)
+ {
+ register unsigned i;
+ for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i];
+ }
+
+# ifdef MPROTECT_VDB
+ STATIC GC_bool GC_gww_page_was_dirty(struct hblk * h)
+# else
+ GC_INNER GC_bool GC_page_was_dirty(struct hblk * h)
+# endif
+ {
+ register word index;
+ if (HDR(h) == 0)
+ return TRUE;
+ index = PHT_HASH(h);
+ return get_pht_entry_from_index(GC_grungy_pages, index);
+ }
+
+# if defined(CHECKSUMS) || defined(PROC_VDB)
+ /* Used only if GWW_VDB. */
+# ifdef MPROTECT_VDB
+ STATIC GC_bool GC_gww_page_was_ever_dirty(struct hblk * h)
+# else
+ GC_INNER GC_bool GC_page_was_ever_dirty(struct hblk * h)
+# endif
+ {
+ register word index;
+ if (HDR(h) == 0)
+ return TRUE;
+ index = PHT_HASH(h);
+ return get_pht_entry_from_index(GC_written_pages, index);
+ }
+# endif /* CHECKSUMS || PROC_VDB */
+
+# ifndef MPROTECT_VDB
+ /* Ignore write hints. They don't help us here. */
+ /*ARGSUSED*/
+ GC_INNER void GC_remove_protection(struct hblk *h, word nblocks,
+ GC_bool is_ptrfree) {}
+# endif
+
+#endif /* PROC_VDB || GWW_VDB */
+
+#ifdef GWW_VDB
+
+# define GC_GWW_BUF_LEN (MAXHINCR * HBLKSIZE / 4096 /* X86 page size */)
+ /* Still susceptible to overflow, if there are very large allocations, */
+ /* and everything is dirty. */
+ static PVOID gww_buf[GC_GWW_BUF_LEN];
+
+# ifdef MPROTECT_VDB
+ GC_INNER GC_bool GC_gww_dirty_init(void)
+ {
+ detect_GetWriteWatch();
+ return GC_GWW_AVAILABLE();
+ }
+# else
+ GC_INNER void GC_dirty_init(void)
+ {
+ detect_GetWriteWatch();
+ GC_dirty_maintained = GC_GWW_AVAILABLE();
+ }
+# endif /* !MPROTECT_VDB */
+
+# ifdef MPROTECT_VDB
+ STATIC void GC_gww_read_dirty(void)
+# else
+ GC_INNER void GC_read_dirty(void)
+# endif
+ {
+ word i;
+
+ BZERO(GC_grungy_pages, sizeof(GC_grungy_pages));
+
+ for (i = 0; i != GC_n_heap_sects; ++i) {
+ GC_ULONG_PTR count;
+
+ do {
+ PVOID * pages, * pages_end;
+ DWORD page_size;
+
+ pages = gww_buf;
+ count = GC_GWW_BUF_LEN;
+ /* GetWriteWatch is documented as returning non-zero when it */
+ /* fails, but the documentation doesn't explicitly say why it */
+ /* would fail or what its behaviour will be if it fails. */
+ /* It does appear to fail, at least on recent W2K instances, if */
+ /* the underlying memory was not allocated with the appropriate */
+ /* flag. This is common if GC_enable_incremental is called */
+ /* shortly after GC initialization. To avoid modifying the */
+ /* interface, we silently work around such a failure, it only */
+ /* affects the initial (small) heap allocation. If there are */
+ /* more dirty pages than will fit in the buffer, this is not */
+ /* treated as a failure; we must check the page count in the */
+ /* loop condition. Since each partial call will reset the */
+ /* status of some pages, this should eventually terminate even */
+ /* in the overflow case. */
+ if (GetWriteWatch_func(WRITE_WATCH_FLAG_RESET,
+ GC_heap_sects[i].hs_start,
+ GC_heap_sects[i].hs_bytes,
+ pages,
+ &count,
+ &page_size) != 0) {
+ static int warn_count = 0;
+ unsigned j;
+ struct hblk * start = (struct hblk *)GC_heap_sects[i].hs_start;
+ static struct hblk *last_warned = 0;
+ size_t nblocks = divHBLKSZ(GC_heap_sects[i].hs_bytes);
+
+ if ( i != 0 && last_warned != start && warn_count++ < 5) {
+ last_warned = start;
+ WARN(
+ "GC_gww_read_dirty unexpectedly failed at %p: "
+ "Falling back to marking all pages dirty\n", start);
+ }
+ for (j = 0; j < nblocks; ++j) {
+ word hash = PHT_HASH(start + j);
+ set_pht_entry_from_index(GC_grungy_pages, hash);
+ }
+ count = 1; /* Done with this section. */
+ } else /* succeeded */ {
+ pages_end = pages + count;
+ while (pages != pages_end) {
+ struct hblk * h = (struct hblk *) *pages++;
+ struct hblk * h_end = (struct hblk *) ((char *) h + page_size);
+ do
+ set_pht_entry_from_index(GC_grungy_pages, PHT_HASH(h));
+ while (++h < h_end);
+ }
+ }
+ } while (count == GC_GWW_BUF_LEN);
+ /* FIXME: It's unclear from Microsoft's documentation if this loop */
+ /* is useful. We suspect the call just fails if the buffer fills */
+ /* up. But that should still be handled correctly. */
+ }
+
+ GC_or_pages(GC_written_pages, GC_grungy_pages);
+ }
+#endif /* GWW_VDB */
+
+#ifdef DEFAULT_VDB
+ /* All of the following assume the allocation lock is held. */
+
+ /* The client asserts that unallocated pages in the heap are never */
+ /* written. */
+
+ /* Initialize virtual dirty bit implementation. */
+ GC_INNER void GC_dirty_init(void)
+ {
+ if (GC_print_stats == VERBOSE)
+ GC_log_printf("Initializing DEFAULT_VDB...\n");
+ GC_dirty_maintained = TRUE;
+ }
+
+ /* Retrieve system dirty bits for heap to a local buffer. */
+ /* Restore the systems notion of which pages are dirty. */
+ GC_INNER void GC_read_dirty(void) {}
+
+ /* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */
+ /* If the actual page size is different, this returns TRUE if any */
+ /* of the pages overlapping h are dirty. This routine may err on the */
+ /* side of labeling pages as dirty (and this implementation does). */
+ /*ARGSUSED*/
+ GC_INNER GC_bool GC_page_was_dirty(struct hblk *h)
+ {
+ return(TRUE);
+ }
+
+ /* The following two routines are typically less crucial. */
+ /* They matter most with large dynamic libraries, or if we can't */
+ /* accurately identify stacks, e.g. under Solaris 2.X. Otherwise the */
+ /* following default versions are adequate. */
+# ifdef CHECKSUMS
+ /* Could any valid GC heap pointer ever have been written to this page? */
+ /*ARGSUSED*/
+ GC_INNER GC_bool GC_page_was_ever_dirty(struct hblk *h)
+ {
+ return(TRUE);
+ }
+# endif /* CHECKSUMS */
+
+ /* A call that: */
+ /* I) hints that [h, h+nblocks) is about to be written. */
+ /* II) guarantees that protection is removed. */
+ /* (I) may speed up some dirty bit implementations. */
+ /* (II) may be essential if we need to ensure that */
+ /* pointer-free system call buffers in the heap are */
+ /* not protected. */
+ /*ARGSUSED*/
+ GC_INNER void GC_remove_protection(struct hblk *h, word nblocks,
+ GC_bool is_ptrfree) {}
+#endif /* DEFAULT_VDB */
+
+#ifdef MANUAL_VDB
+ /* Initialize virtual dirty bit implementation. */
+ GC_INNER void GC_dirty_init(void)
+ {
+ if (GC_print_stats == VERBOSE)
+ GC_log_printf("Initializing MANUAL_VDB...\n");
+ /* GC_dirty_pages and GC_grungy_pages are already cleared. */
+ GC_dirty_maintained = TRUE;
+ }
+
+ /* Retrieve system dirty bits for heap to a local buffer. */
+ /* Restore the systems notion of which pages are dirty. */
+ GC_INNER void GC_read_dirty(void)
+ {
+ BCOPY((word *)GC_dirty_pages, GC_grungy_pages,
+ (sizeof GC_dirty_pages));
+ BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages));
+ }
+
+ /* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */
+ /* If the actual page size is different, this returns TRUE if any */
+ /* of the pages overlapping h are dirty. This routine may err on the */
+ /* side of labeling pages as dirty (and this implementation does). */
+ GC_INNER GC_bool GC_page_was_dirty(struct hblk *h)
+ {
+ register word index = PHT_HASH(h);
+ return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index));
+ }
+
+# define async_set_pht_entry_from_index(db, index) \
+ set_pht_entry_from_index(db, index) /* for now */
+
+ /* Mark the page containing p as dirty. Logically, this dirties the */
+ /* entire object. */
+ void GC_dirty(ptr_t p)
+ {
+ word index = PHT_HASH(p);
+ async_set_pht_entry_from_index(GC_dirty_pages, index);
+ }
+
+ /*ARGSUSED*/
+ GC_INNER void GC_remove_protection(struct hblk *h, word nblocks,
+ GC_bool is_ptrfree) {}
+
+# ifdef CHECKSUMS
+ /* Could any valid GC heap pointer ever have been written to this page? */
+ /*ARGSUSED*/
+ GC_INNER GC_bool GC_page_was_ever_dirty(struct hblk *h)
+ {
+ /* FIXME - implement me. */
+ return(TRUE);
+ }
+# endif /* CHECKSUMS */
+
+#endif /* MANUAL_VDB */
+
+#ifdef MPROTECT_VDB
+ /* See DEFAULT_VDB for interface descriptions. */
+
+ /*
+ * This implementation maintains dirty bits itself by catching write
+ * faults and keeping track of them. We assume nobody else catches
+ * SIGBUS or SIGSEGV. We assume no write faults occur in system calls.
+ * This means that clients must ensure that system calls don't write
+ * to the write-protected heap. Probably the best way to do this is to
+ * ensure that system calls write at most to POINTERFREE objects in the
+ * heap, and do even that only if we are on a platform on which those
+ * are not protected. Another alternative is to wrap system calls
+ * (see example for read below), but the current implementation holds
+ * applications.
+ * We assume the page size is a multiple of HBLKSIZE.
+ * We prefer them to be the same. We avoid protecting POINTERFREE
+ * objects only if they are the same.
+ */
+# ifdef DARWIN
+ /* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to
+ decrease the likelihood of some of the problems described below. */
+# include <mach/vm_map.h>
+ STATIC mach_port_t GC_task_self = 0;
+# define PROTECT(addr,len) \
+ if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \
+ FALSE, VM_PROT_READ \
+ | (GC_pages_executable ? VM_PROT_EXECUTE : 0)) \
+ != KERN_SUCCESS) { \
+ ABORT("vm_protect(PROTECT) failed"); \
+ }
+# define UNPROTECT(addr,len) \
+ if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \
+ FALSE, (VM_PROT_READ | VM_PROT_WRITE) \
+ | (GC_pages_executable ? VM_PROT_EXECUTE : 0)) \
+ != KERN_SUCCESS) { \
+ ABORT("vm_protect(UNPROTECT) failed"); \
+ }
+
+# elif !defined(MSWIN32) && !defined(MSWINCE)
+# include <sys/mman.h>
+# include <signal.h>
+# include <sys/syscall.h>
+
+# define PROTECT(addr, len) \
+ if (mprotect((caddr_t)(addr), (size_t)(len), \
+ PROT_READ \
+ | (GC_pages_executable ? PROT_EXEC : 0)) < 0) { \
+ ABORT("mprotect failed"); \
+ }
+# define UNPROTECT(addr, len) \
+ if (mprotect((caddr_t)(addr), (size_t)(len), \
+ (PROT_READ | PROT_WRITE) \
+ | (GC_pages_executable ? PROT_EXEC : 0)) < 0) { \
+ ABORT(GC_pages_executable ? "un-mprotect executable page" \
+ " failed (probably disabled by OS)" : \
+ "un-mprotect failed"); \
+ }
+# undef IGNORE_PAGES_EXECUTABLE
+
+# else /* MSWIN32 */
+# ifndef MSWINCE
+# include <signal.h>
+# endif
+
+ static DWORD protect_junk;
+# define PROTECT(addr, len) \
+ if (!VirtualProtect((addr), (len), \
+ GC_pages_executable ? PAGE_EXECUTE_READ : \
+ PAGE_READONLY, \
+ &protect_junk)) { \
+ if (GC_print_stats) \
+ GC_log_printf("Last error code: 0x%lx\n", (long)GetLastError()); \
+ ABORT("VirtualProtect failed"); \
+ }
+# define UNPROTECT(addr, len) \
+ if (!VirtualProtect((addr), (len), \
+ GC_pages_executable ? PAGE_EXECUTE_READWRITE : \
+ PAGE_READWRITE, \
+ &protect_junk)) { \
+ ABORT("un-VirtualProtect failed"); \
+ }
+# endif /* MSWIN32 || MSWINCE || DARWIN */
+
+# if defined(MSWIN32)
+ typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_HNDLR_PTR;
+# undef SIG_DFL
+# define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER)((signed_word)-1)
+# elif defined(MSWINCE)
+ typedef LONG (WINAPI *SIG_HNDLR_PTR)(struct _EXCEPTION_POINTERS *);
+# undef SIG_DFL
+# define SIG_DFL (SIG_HNDLR_PTR) (-1)
+# elif defined(DARWIN)
+ typedef void (* SIG_HNDLR_PTR)();
+# else
+ typedef void (* SIG_HNDLR_PTR)(int, siginfo_t *, void *);
+ typedef void (* PLAIN_HNDLR_PTR)(int);
+# endif
+
+# if defined(__GLIBC__)
+# if __GLIBC__ < 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ < 2
+# error glibc too old?
+# endif
+# endif
+
+#ifndef DARWIN
+ STATIC SIG_HNDLR_PTR GC_old_segv_handler = 0;
+ /* Also old MSWIN32 ACCESS_VIOLATION filter */
+# if !defined(MSWIN32) && !defined(MSWINCE)
+ STATIC SIG_HNDLR_PTR GC_old_bus_handler = 0;
+ STATIC GC_bool GC_old_bus_handler_used_si = FALSE;
+ STATIC GC_bool GC_old_segv_handler_used_si = FALSE;
+# endif
+#endif /* !DARWIN */
+
+#if defined(THREADS)
+/* We need to lock around the bitmap update in the write fault handler */
+/* in order to avoid the risk of losing a bit. We do this with a */
+/* test-and-set spin lock if we know how to do that. Otherwise we */
+/* check whether we are already in the handler and use the dumb but */
+/* safe fallback algorithm of setting all bits in the word. */
+/* Contention should be very rare, so we do the minimum to handle it */
+/* correctly. */
+#ifdef AO_HAVE_test_and_set_acquire
+ GC_INNER volatile AO_TS_t GC_fault_handler_lock = AO_TS_INITIALIZER;
+ static void async_set_pht_entry_from_index(volatile page_hash_table db,
+ size_t index)
+ {
+ while (AO_test_and_set_acquire(&GC_fault_handler_lock) == AO_TS_SET) {
+ /* empty */
+ }
+ /* Could also revert to set_pht_entry_from_index_safe if initial */
+ /* GC_test_and_set fails. */
+ set_pht_entry_from_index(db, index);
+ AO_CLEAR(&GC_fault_handler_lock);
+ }
+#else /* !AO_HAVE_test_and_set_acquire */
+# error No test_and_set operation: Introduces a race.
+ /* THIS WOULD BE INCORRECT! */
+ /* The dirty bit vector may be temporarily wrong, */
+ /* just before we notice the conflict and correct it. We may end up */
+ /* looking at it while it's wrong. But this requires contention */
+ /* exactly when a GC is triggered, which seems far less likely to */
+ /* fail than the old code, which had no reported failures. Thus we */
+ /* leave it this way while we think of something better, or support */
+ /* GC_test_and_set on the remaining platforms. */
+ static volatile word currently_updating = 0;
+ static void async_set_pht_entry_from_index(volatile page_hash_table db,
+ size_t index)
+ {
+ unsigned int update_dummy;
+ currently_updating = (word)(&update_dummy);
+ set_pht_entry_from_index(db, index);
+ /* If we get contention in the 10 or so instruction window here, */
+ /* and we get stopped by a GC between the two updates, we lose! */
+ if (currently_updating != (word)(&update_dummy)) {
+ set_pht_entry_from_index_safe(db, index);
+ /* We claim that if two threads concurrently try to update the */
+ /* dirty bit vector, the first one to execute UPDATE_START */
+ /* will see it changed when UPDATE_END is executed. (Note that */
+ /* &update_dummy must differ in two distinct threads.) It */
+ /* will then execute set_pht_entry_from_index_safe, thus */
+ /* returning us to a safe state, though not soon enough. */
+ }
+ }
+#endif /* !AO_HAVE_test_and_set_acquire */
+#else /* !THREADS */
+# define async_set_pht_entry_from_index(db, index) \
+ set_pht_entry_from_index(db, index)
+#endif /* !THREADS */
+
+#ifdef CHECKSUMS
+ void GC_record_fault(struct hblk * h); /* from checksums.c */
+#endif
+
+#ifndef DARWIN
+
+# if !defined(MSWIN32) && !defined(MSWINCE)
+# include <errno.h>
+# if defined(FREEBSD) || defined(HURD) || defined(HPUX)
+# define SIG_OK (sig == SIGBUS || sig == SIGSEGV)
+# else
+# define SIG_OK (sig == SIGSEGV)
+# endif
+# if defined(FREEBSD)
+# ifndef SEGV_ACCERR
+# define SEGV_ACCERR 2
+# endif
+# define CODE_OK (si -> si_code == BUS_PAGE_FAULT \
+ || si -> si_code == SEGV_ACCERR)
+# elif defined(OSF1)
+# define CODE_OK (si -> si_code == 2 /* experimentally determined */)
+# elif defined(IRIX5)
+# define CODE_OK (si -> si_code == EACCES)
+# elif defined(HURD)
+# define CODE_OK TRUE
+# elif defined(LINUX)
+# define CODE_OK TRUE
+ /* Empirically c.trapno == 14, on IA32, but is that useful? */
+ /* Should probably consider alignment issues on other */
+ /* architectures. */
+# elif defined(HPUX)
+# define CODE_OK (si -> si_code == SEGV_ACCERR \
+ || si -> si_code == BUS_ADRERR \
+ || si -> si_code == BUS_UNKNOWN \
+ || si -> si_code == SEGV_UNKNOWN \
+ || si -> si_code == BUS_OBJERR)
+# elif defined(SUNOS5SIGS)
+# define CODE_OK (si -> si_code == SEGV_ACCERR)
+# endif
+# ifndef NO_GETCONTEXT
+# include <ucontext.h>
+# endif
+ /*ARGSUSED*/
+ STATIC void GC_write_fault_handler(int sig, siginfo_t *si, void *raw_sc)
+# else
+# define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode \
+ == STATUS_ACCESS_VIOLATION)
+# define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] \
+ == 1) /* Write fault */
+ STATIC LONG WINAPI GC_write_fault_handler(
+ struct _EXCEPTION_POINTERS *exc_info)
+# endif /* MSWIN32 || MSWINCE */
+ {
+# if !defined(MSWIN32) && !defined(MSWINCE)
+ char *addr = si -> si_addr;
+# else
+ char * addr = (char *) (exc_info -> ExceptionRecord
+ -> ExceptionInformation[1]);
+# endif
+ unsigned i;
+
+ if (SIG_OK && CODE_OK) {
+ register struct hblk * h =
+ (struct hblk *)((word)addr & ~(GC_page_size-1));
+ GC_bool in_allocd_block;
+# ifdef CHECKSUMS
+ GC_record_fault(h);
+# endif
+
+# ifdef SUNOS5SIGS
+ /* Address is only within the correct physical page. */
+ in_allocd_block = FALSE;
+ for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
+ if (HDR(h+i) != 0) {
+ in_allocd_block = TRUE;
+ break;
+ }
+ }
+# else
+ in_allocd_block = (HDR(addr) != 0);
+# endif
+ if (!in_allocd_block) {
+ /* FIXME - We should make sure that we invoke the */
+ /* old handler with the appropriate calling */
+ /* sequence, which often depends on SA_SIGINFO. */
+
+ /* Heap blocks now begin and end on page boundaries */
+ SIG_HNDLR_PTR old_handler;
+
+# if defined(MSWIN32) || defined(MSWINCE)
+ old_handler = GC_old_segv_handler;
+# else
+ GC_bool used_si;
+
+ if (sig == SIGSEGV) {
+ old_handler = GC_old_segv_handler;
+ used_si = GC_old_segv_handler_used_si;
+ } else {
+ old_handler = GC_old_bus_handler;
+ used_si = GC_old_bus_handler_used_si;
+ }
+# endif
+
+ if (old_handler == (SIG_HNDLR_PTR)SIG_DFL) {
+# if !defined(MSWIN32) && !defined(MSWINCE)
+ if (GC_print_stats)
+ GC_log_printf("Unexpected segfault at %p\n", addr);
+ ABORT("Unexpected bus error or segmentation fault");
+# else
+ return(EXCEPTION_CONTINUE_SEARCH);
+# endif
+ } else {
+ /*
+ * FIXME: This code should probably check if the
+ * old signal handler used the traditional style and
+ * if so call it using that style.
+ */
+# if defined(MSWIN32) || defined(MSWINCE)
+ return((*old_handler)(exc_info));
+# else
+ if (used_si)
+ ((SIG_HNDLR_PTR)old_handler) (sig, si, raw_sc);
+ else
+ /* FIXME: should pass nonstandard args as well. */
+ ((PLAIN_HNDLR_PTR)old_handler) (sig);
+ return;
+# endif
+ }
+ }
+ UNPROTECT(h, GC_page_size);
+ /* We need to make sure that no collection occurs between */
+ /* the UNPROTECT and the setting of the dirty bit. Otherwise */
+ /* a write by a third thread might go unnoticed. Reversing */
+ /* the order is just as bad, since we would end up unprotecting */
+ /* a page in a GC cycle during which it's not marked. */
+ /* Currently we do this by disabling the thread stopping */
+ /* signals while this handler is running. An alternative might */
+ /* be to record the fact that we're about to unprotect, or */
+ /* have just unprotected a page in the GC's thread structure, */
+ /* and then to have the thread stopping code set the dirty */
+ /* flag, if necessary. */
+ for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
+ size_t index = PHT_HASH(h+i);
+
+ async_set_pht_entry_from_index(GC_dirty_pages, index);
+ }
+ /* The write may not take place before dirty bits are read. */
+ /* But then we'll fault again ... */
+# if defined(MSWIN32) || defined(MSWINCE)
+ return(EXCEPTION_CONTINUE_EXECUTION);
+# else
+ return;
+# endif
+ }
+# if defined(MSWIN32) || defined(MSWINCE)
+ return EXCEPTION_CONTINUE_SEARCH;
+# else
+ if (GC_print_stats)
+ GC_log_printf("Unexpected segfault at %p\n", addr);
+ ABORT("Unexpected bus error or segmentation fault");
+# endif
+ }
+
+# ifdef GC_WIN32_THREADS
+ GC_INNER void GC_set_write_fault_handler(void)
+ {
+ SetUnhandledExceptionFilter(GC_write_fault_handler);
+ }
+# endif
+#endif /* !DARWIN */
+
+/* We hold the allocation lock. We expect block h to be written */
+/* shortly. Ensure that all pages containing any part of the n hblks */
+/* starting at h are no longer protected. If is_ptrfree is false, also */
+/* ensure that they will subsequently appear to be dirty. Not allowed */
+/* to call GC_printf (and the friends) here, see Win32 GC_stop_world() */
+/* for the information. */
+GC_INNER void GC_remove_protection(struct hblk *h, word nblocks,
+ GC_bool is_ptrfree)
+{
+ struct hblk * h_trunc; /* Truncated to page boundary */
+ struct hblk * h_end; /* Page boundary following block end */
+ struct hblk * current;
+
+# if defined(GWW_VDB)
+ if (GC_GWW_AVAILABLE()) return;
+# endif
+ if (!GC_dirty_maintained) return;
+ h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1));
+ h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size-1)
+ & ~(GC_page_size-1));
+ if (h_end == h_trunc + 1 &&
+ get_pht_entry_from_index(GC_dirty_pages, PHT_HASH(h_trunc))) {
+ /* already marked dirty, and hence unprotected. */
+ return;
+ }
+ for (current = h_trunc; current < h_end; ++current) {
+ size_t index = PHT_HASH(current);
+ if (!is_ptrfree || current < h || current >= h + nblocks) {
+ async_set_pht_entry_from_index(GC_dirty_pages, index);
+ }
+ }
+ UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc);
+}
+
+#if !defined(DARWIN)
+ GC_INNER void GC_dirty_init(void)
+ {
+# if !defined(MSWIN32) && !defined(MSWINCE)
+ struct sigaction act, oldact;
+ act.sa_flags = SA_RESTART | SA_SIGINFO;
+ act.sa_sigaction = GC_write_fault_handler;
+ (void)sigemptyset(&act.sa_mask);
+# ifdef SIG_SUSPEND
+ /* Arrange to postpone SIG_SUSPEND while we're in a write fault */
+ /* handler. This effectively makes the handler atomic w.r.t. */
+ /* stopping the world for GC. */
+ (void)sigaddset(&act.sa_mask, SIG_SUSPEND);
+# endif /* SIG_SUSPEND */
+# endif
+ if (GC_print_stats == VERBOSE)
+ GC_log_printf(
+ "Initializing mprotect virtual dirty bit implementation\n");
+ GC_dirty_maintained = TRUE;
+ if (GC_page_size % HBLKSIZE != 0) {
+ ABORT("Page size not multiple of HBLKSIZE");
+ }
+# if !defined(MSWIN32) && !defined(MSWINCE)
+# if defined(GC_IRIX_THREADS)
+ sigaction(SIGSEGV, 0, &oldact);
+ sigaction(SIGSEGV, &act, 0);
+# else
+ {
+ int res = sigaction(SIGSEGV, &act, &oldact);
+ if (res != 0) ABORT("Sigaction failed");
+ }
+# endif
+ if (oldact.sa_flags & SA_SIGINFO) {
+ GC_old_segv_handler = oldact.sa_sigaction;
+ GC_old_segv_handler_used_si = TRUE;
+ } else {
+ GC_old_segv_handler = (SIG_HNDLR_PTR)oldact.sa_handler;
+ GC_old_segv_handler_used_si = FALSE;
+ }
+ if (GC_old_segv_handler == (SIG_HNDLR_PTR)SIG_IGN) {
+ if (GC_print_stats)
+ GC_err_printf("Previously ignored segmentation violation!?\n");
+ GC_old_segv_handler = (SIG_HNDLR_PTR)SIG_DFL;
+ }
+ if (GC_old_segv_handler != (SIG_HNDLR_PTR)SIG_DFL) {
+ if (GC_print_stats == VERBOSE)
+ GC_log_printf("Replaced other SIGSEGV handler\n");
+ }
+# if defined(HPUX) || defined(LINUX) || defined(HURD) \
+ || (defined(FREEBSD) && defined(SUNOS5SIGS))
+ sigaction(SIGBUS, &act, &oldact);
+ if (oldact.sa_flags & SA_SIGINFO) {
+ GC_old_bus_handler = oldact.sa_sigaction;
+ GC_old_bus_handler_used_si = TRUE;
+ } else {
+ GC_old_bus_handler = (SIG_HNDLR_PTR)oldact.sa_handler;
+ GC_old_bus_handler_used_si = FALSE;
+ }
+ if (GC_old_bus_handler == (SIG_HNDLR_PTR)SIG_IGN) {
+ if (GC_print_stats)
+ GC_err_printf("Previously ignored bus error!?\n");
+ GC_old_bus_handler = (SIG_HNDLR_PTR)SIG_DFL;
+ }
+ if (GC_old_bus_handler != (SIG_HNDLR_PTR)SIG_DFL) {
+ if (GC_print_stats == VERBOSE)
+ GC_log_printf("Replaced other SIGBUS handler\n");
+ }
+# endif /* HPUX || LINUX || HURD || (FREEBSD && SUNOS5SIGS) */
+# endif /* ! MS windows */
+# if defined(GWW_VDB)
+ if (GC_gww_dirty_init())
+ return;
+# endif
+# if defined(MSWIN32)
+ GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler);
+ if (GC_old_segv_handler != NULL) {
+ if (GC_print_stats)
+ GC_log_printf("Replaced other UnhandledExceptionFilter\n");
+ } else {
+ GC_old_segv_handler = SIG_DFL;
+ }
+# elif defined(MSWINCE)
+ /* MPROTECT_VDB is unsupported for WinCE at present. */
+ /* FIXME: implement it (if possible). */
+# endif
+ }
+#endif /* !DARWIN */
+
+GC_API int GC_CALL GC_incremental_protection_needs(void)
+{
+ if (GC_page_size == HBLKSIZE) {
+ return GC_PROTECTS_POINTER_HEAP;
+ } else {
+ return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP;
+ }
+}
+#define HAVE_INCREMENTAL_PROTECTION_NEEDS
+
+#define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0)
+#define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1))
+
+STATIC void GC_protect_heap(void)
+{
+ ptr_t start;
+ size_t len;
+ struct hblk * current;
+ struct hblk * current_start; /* Start of block to be protected. */
+ struct hblk * limit;
+ unsigned i;
+ GC_bool protect_all =
+ (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP));
+ for (i = 0; i < GC_n_heap_sects; i++) {
+ start = GC_heap_sects[i].hs_start;
+ len = GC_heap_sects[i].hs_bytes;
+ if (protect_all) {
+ PROTECT(start, len);
+ } else {
+ GC_ASSERT(PAGE_ALIGNED(len));
+ GC_ASSERT(PAGE_ALIGNED(start));
+ current_start = current = (struct hblk *)start;
+ limit = (struct hblk *)(start + len);
+ while (current < limit) {
+ hdr * hhdr;
+ word nhblks;
+ GC_bool is_ptrfree;
+
+ GC_ASSERT(PAGE_ALIGNED(current));
+ GET_HDR(current, hhdr);
+ if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) {
+ /* This can happen only if we're at the beginning of a */
+ /* heap segment, and a block spans heap segments. */
+ /* We will handle that block as part of the preceding */
+ /* segment. */
+ GC_ASSERT(current_start == current);
+ current_start = ++current;
+ continue;
+ }
+ if (HBLK_IS_FREE(hhdr)) {
+ GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz));
+ nhblks = divHBLKSZ(hhdr -> hb_sz);
+ is_ptrfree = TRUE; /* dirty on alloc */
+ } else {
+ nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz);
+ is_ptrfree = IS_PTRFREE(hhdr);
+ }
+ if (is_ptrfree) {
+ if (current_start < current) {
+ PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
+ }
+ current_start = (current += nhblks);
+ } else {
+ current += nhblks;
+ }
+ }
+ if (current_start < current) {
+ PROTECT(current_start, (ptr_t)current - (ptr_t)current_start);
+ }
+ }
+ }
+}
+
+/* We assume that either the world is stopped or its OK to lose dirty */
+/* bits while this is happenning (as in GC_enable_incremental). */
+GC_INNER void GC_read_dirty(void)
+{
+# if defined(GWW_VDB)
+ if (GC_GWW_AVAILABLE()) {
+ GC_gww_read_dirty();
+ return;
+ }
+# endif
+ BCOPY((word *)GC_dirty_pages, GC_grungy_pages,
+ (sizeof GC_dirty_pages));
+ BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages));
+ GC_protect_heap();
+}
+
+GC_INNER GC_bool GC_page_was_dirty(struct hblk *h)
+{
+ register word index;
+
+# if defined(GWW_VDB)
+ if (GC_GWW_AVAILABLE())
+ return GC_gww_page_was_dirty(h);
+# endif
+
+ index = PHT_HASH(h);
+ return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index));
+}
+
+/*
+ * Acquiring the allocation lock here is dangerous, since this
+ * can be called from within GC_call_with_alloc_lock, and the cord
+ * package does so. On systems that allow nested lock acquisition, this
+ * happens to work.
+ * On other systems, SET_LOCK_HOLDER and friends must be suitably defined.
+ */
+
+#if 0
+static GC_bool syscall_acquired_lock = FALSE; /* Protected by GC lock. */
+
+void GC_begin_syscall(void)
+{
+ /* FIXME: Resurrecting this code would require fixing the */
+ /* test, which can spuriously return TRUE. */
+ if (!I_HOLD_LOCK()) {
+ LOCK();
+ syscall_acquired_lock = TRUE;
+ }
+}
+
+void GC_end_syscall(void)
+{
+ if (syscall_acquired_lock) {
+ syscall_acquired_lock = FALSE;
+ UNLOCK();
+ }
+}
+
+void GC_unprotect_range(ptr_t addr, word len)
+{
+ struct hblk * start_block;
+ struct hblk * end_block;
+ register struct hblk *h;
+ ptr_t obj_start;
+
+ if (!GC_dirty_maintained) return;
+ obj_start = GC_base(addr);
+ if (obj_start == 0) return;
+ if (GC_base(addr + len - 1) != obj_start) {
+ ABORT("GC_unprotect_range(range bigger than object)");
+ }
+ start_block = (struct hblk *)((word)addr & ~(GC_page_size - 1));
+ end_block = (struct hblk *)((word)(addr + len - 1) & ~(GC_page_size - 1));
+ end_block += GC_page_size/HBLKSIZE - 1;
+ for (h = start_block; h <= end_block; h++) {
+ register word index = PHT_HASH(h);
+
+ async_set_pht_entry_from_index(GC_dirty_pages, index);
+ }
+ UNPROTECT(start_block,
+ ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE);
+}
+
+
+/* We no longer wrap read by default, since that was causing too many */
+/* problems. It is preferred that the client instead avoids writing */
+/* to the write-protected heap with a system call. */
+/* This still serves as sample code if you do want to wrap system calls.*/
+
+#if !defined(MSWIN32) && !defined(MSWINCE) && !defined(GC_USE_LD_WRAP)
+/* Replacement for UNIX system call. */
+/* Other calls that write to the heap should be handled similarly. */
+/* Note that this doesn't work well for blocking reads: It will hold */
+/* the allocation lock for the entire duration of the call. Multithreaded */
+/* clients should really ensure that it won't block, either by setting */
+/* the descriptor nonblocking, or by calling select or poll first, to */
+/* make sure that input is available. */
+/* Another, preferred alternative is to ensure that system calls never */
+/* write to the protected heap (see above). */
+# include <unistd.h>
+# include <sys/uio.h>
+ssize_t read(int fd, void *buf, size_t nbyte)
+{
+ int result;
+
+ GC_begin_syscall();
+ GC_unprotect_range(buf, (word)nbyte);
+# if defined(IRIX5) || defined(GC_LINUX_THREADS)
+ /* Indirect system call may not always be easily available. */
+ /* We could call _read, but that would interfere with the */
+ /* libpthread interception of read. */
+ /* On Linux, we have to be careful with the linuxthreads */
+ /* read interception. */
+ {
+ struct iovec iov;
+
+ iov.iov_base = buf;
+ iov.iov_len = nbyte;
+ result = readv(fd, &iov, 1);
+ }
+# else
+# if defined(HURD)
+ result = __read(fd, buf, nbyte);
+# else
+ /* The two zero args at the end of this list are because one
+ IA-64 syscall() implementation actually requires six args
+ to be passed, even though they aren't always used. */
+ result = syscall(SYS_read, fd, buf, nbyte, 0, 0);
+# endif /* !HURD */
+# endif
+ GC_end_syscall();
+ return(result);
+}
+#endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */
+
+#if defined(GC_USE_LD_WRAP) && !defined(THREADS)
+ /* We use the GNU ld call wrapping facility. */
+ /* I'm not sure that this actually wraps whatever version of read */
+ /* is called by stdio. That code also mentions __read. */
+# include <unistd.h>
+ ssize_t __wrap_read(int fd, void *buf, size_t nbyte)
+ {
+ int result;
+
+ GC_begin_syscall();
+ GC_unprotect_range(buf, (word)nbyte);
+ result = __real_read(fd, buf, nbyte);
+ GC_end_syscall();
+ return(result);
+ }
+
+ /* We should probably also do this for __read, or whatever stdio */
+ /* actually calls. */
+#endif
+#endif /* 0 */
+
+# ifdef CHECKSUMS
+ /*ARGSUSED*/
+ GC_INNER GC_bool GC_page_was_ever_dirty(struct hblk *h)
+ {
+# if defined(GWW_VDB)
+ if (GC_GWW_AVAILABLE())
+ return GC_gww_page_was_ever_dirty(h);
+# endif
+ return(TRUE);
+ }
+# endif /* CHECKSUMS */
+
+#endif /* MPROTECT_VDB */
+
+#ifdef PROC_VDB
+/* See DEFAULT_VDB for interface descriptions. */
+
+/* This implementation assumes a Solaris 2.X like /proc */
+/* pseudo-file-system from which we can read page modified bits. This */
+/* facility is far from optimal (e.g. we would like to get the info for */
+/* only some of the address space), but it avoids intercepting system */
+/* calls. */
+
+# include <errno.h>
+# include <sys/types.h>
+# include <sys/signal.h>
+# include <sys/fault.h>
+# include <sys/syscall.h>
+# include <sys/procfs.h>
+# include <sys/stat.h>
+
+# define INITIAL_BUF_SZ 16384
+ STATIC word GC_proc_buf_size = INITIAL_BUF_SZ;
+ STATIC char *GC_proc_buf = NULL;
+ STATIC int GC_proc_fd = 0;
+
+GC_INNER void GC_dirty_init(void)
+{
+ int fd;
+ char buf[30];
+
+ if (GC_bytes_allocd != 0 || GC_bytes_allocd_before_gc != 0) {
+ memset(GC_written_pages, 0xff, sizeof(page_hash_table));
+ if (GC_print_stats == VERBOSE)
+ GC_log_printf("Allocated bytes:%lu:all pages may have been written\n",
+ (unsigned long)(GC_bytes_allocd
+ + GC_bytes_allocd_before_gc));
+ }
+
+ sprintf(buf, "/proc/%ld", (long)getpid());
+ fd = open(buf, O_RDONLY);
+ if (fd < 0) {
+ ABORT("/proc open failed");
+ }
+ GC_proc_fd = syscall(SYS_ioctl, fd, PIOCOPENPD, 0);
+ close(fd);
+ syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC);
+ if (GC_proc_fd < 0) {
+ WARN("/proc ioctl(PIOCOPENPD) failed", 0);
+ return;
+ }
+
+ GC_dirty_maintained = TRUE;
+ GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size);
+ if (GC_proc_buf == NULL)
+ ABORT("Insufficient space for /proc read");
+}
+
+# define READ read
+
+GC_INNER void GC_read_dirty(void)
+{
+ int nmaps;
+ unsigned long npages;
+ unsigned pagesize;
+ ptr_t vaddr, limit;
+ struct prasmap * map;
+ char * bufp;
+ int i;
+
+ BZERO(GC_grungy_pages, sizeof(GC_grungy_pages));
+ bufp = GC_proc_buf;
+ if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
+ /* Retry with larger buffer. */
+ word new_size = 2 * GC_proc_buf_size;
+ char *new_buf;
+ if (GC_print_stats)
+ GC_err_printf("/proc read failed: GC_proc_buf_size = %lu\n",
+ (unsigned long)GC_proc_buf_size);
+
+ new_buf = GC_scratch_alloc(new_size);
+ if (new_buf != 0) {
+ GC_proc_buf = bufp = new_buf;
+ GC_proc_buf_size = new_size;
+ }
+ if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) {
+ WARN("Insufficient space for /proc read\n", 0);
+ /* Punt: */
+ memset(GC_grungy_pages, 0xff, sizeof (page_hash_table));
+ memset(GC_written_pages, 0xff, sizeof(page_hash_table));
+ return;
+ }
+ }
+
+ /* Copy dirty bits into GC_grungy_pages */
+ nmaps = ((struct prpageheader *)bufp) -> pr_nmap;
+# ifdef DEBUG_DIRTY_BITS
+ GC_log_printf("Proc VDB read: pr_nmap= %u, pr_npage= %lu\n",
+ nmaps, ((struct prpageheader *)bufp)->pr_npage);
+
+# endif
+ bufp += sizeof(struct prpageheader);
+ for (i = 0; i < nmaps; i++) {
+ map = (struct prasmap *)bufp;
+ vaddr = (ptr_t)(map -> pr_vaddr);
+ npages = map -> pr_npage;
+ pagesize = map -> pr_pagesize;
+# ifdef DEBUG_DIRTY_BITS
+ GC_log_printf(
+ "pr_vaddr= %p, npage= %lu, mflags= 0x%x, pagesize= 0x%x\n",
+ vaddr, npages, map->pr_mflags, pagesize);
+# endif
+
+ bufp += sizeof(struct prasmap);
+ limit = vaddr + pagesize * npages;
+ for (; vaddr < limit; vaddr += pagesize) {
+ if ((*bufp++) & PG_MODIFIED) {
+ register struct hblk * h;
+ ptr_t next_vaddr = vaddr + pagesize;
+# ifdef DEBUG_DIRTY_BITS
+ GC_log_printf("dirty page at: %p\n", vaddr);
+# endif
+ for (h = (struct hblk *)vaddr; (ptr_t)h < next_vaddr; h++) {
+ register word index = PHT_HASH(h);
+ set_pht_entry_from_index(GC_grungy_pages, index);
+ }
+ }
+ }
+ bufp = (char *)(((word)bufp + (sizeof(long)-1)) & ~(sizeof(long)-1));
+ }
+# ifdef DEBUG_DIRTY_BITS
+ GC_log_printf("Proc VDB read done.\n");
+# endif
+
+ /* Update GC_written_pages. */
+ GC_or_pages(GC_written_pages, GC_grungy_pages);
+}
+
+# undef READ
+#endif /* PROC_VDB */
+
+#ifdef PCR_VDB
+
+# include "vd/PCR_VD.h"
+
+# define NPAGES (32*1024) /* 128 MB */
+
+PCR_VD_DB GC_grungy_bits[NPAGES];
+
+STATIC ptr_t GC_vd_base = NULL;
+ /* Address corresponding to GC_grungy_bits[0] */
+ /* HBLKSIZE aligned. */
+
+GC_INNER void GC_dirty_init(void)
+{
+ GC_dirty_maintained = TRUE;
+ /* For the time being, we assume the heap generally grows up */
+ GC_vd_base = GC_heap_sects[0].hs_start;
+ if (GC_vd_base == 0) {
+ ABORT("Bad initial heap segment");
+ }
+ if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE)
+ != PCR_ERes_okay) {
+ ABORT("Dirty bit initialization failed");
+ }
+}
+
+GC_INNER void GC_read_dirty(void)
+{
+ /* lazily enable dirty bits on newly added heap sects */
+ {
+ static int onhs = 0;
+ int nhs = GC_n_heap_sects;
+ for(; onhs < nhs; onhs++) {
+ PCR_VD_WriteProtectEnable(
+ GC_heap_sects[onhs].hs_start,
+ GC_heap_sects[onhs].hs_bytes );
+ }
+ }
+
+ if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits)
+ != PCR_ERes_okay) {
+ ABORT("Dirty bit read failed");
+ }
+}
+
+GC_INNER GC_bool GC_page_was_dirty(struct hblk *h)
+{
+ if((ptr_t)h < GC_vd_base || (ptr_t)h >= GC_vd_base + NPAGES*HBLKSIZE) {
+ return(TRUE);
+ }
+ return(GC_grungy_bits[h - (struct hblk *)GC_vd_base] & PCR_VD_DB_dirtyBit);
+}
+
+/*ARGSUSED*/
+GC_INNER void GC_remove_protection(struct hblk *h, word nblocks,
+ GC_bool is_ptrfree)
+{
+ PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE);
+ PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE);
+}
+
+#endif /* PCR_VDB */
+
+#if defined(MPROTECT_VDB) && defined(DARWIN)
+/* The following sources were used as a "reference" for this exception
+ handling code:
+ 1. Apple's mach/xnu documentation
+ 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the
+ omnigroup's macosx-dev list.
+ www.omnigroup.com/mailman/archive/macosx-dev/2000-June/014178.html
+ 3. macosx-nat.c from Apple's GDB source code.
+*/
+
+/* The bug that caused all this trouble should now be fixed. This should
+ eventually be removed if all goes well. */
+
+/* #define BROKEN_EXCEPTION_HANDLING */
+
+#include <mach/mach.h>
+#include <mach/mach_error.h>
+#include <mach/thread_status.h>
+#include <mach/exception.h>
+#include <mach/task.h>
+#include <pthread.h>
+
+/* These are not defined in any header, although they are documented */
+extern boolean_t
+exc_server(mach_msg_header_t *, mach_msg_header_t *);
+
+extern kern_return_t
+exception_raise(mach_port_t, mach_port_t, mach_port_t, exception_type_t,
+ exception_data_t, mach_msg_type_number_t);
+
+extern kern_return_t
+exception_raise_state(mach_port_t, mach_port_t, mach_port_t, exception_type_t,
+ exception_data_t, mach_msg_type_number_t,
+ thread_state_flavor_t*, thread_state_t,
+ mach_msg_type_number_t, thread_state_t,
+ mach_msg_type_number_t*);
+
+extern kern_return_t
+exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t,
+ exception_type_t, exception_data_t,
+ mach_msg_type_number_t, thread_state_flavor_t*,
+ thread_state_t, mach_msg_type_number_t,
+ thread_state_t, mach_msg_type_number_t*);
+
+GC_API_OSCALL kern_return_t
+catch_exception_raise(mach_port_t exception_port, mach_port_t thread,
+ mach_port_t task, exception_type_t exception,
+ exception_data_t code, mach_msg_type_number_t code_count);
+
+/* These should never be called, but just in case... */
+GC_API_OSCALL kern_return_t
+catch_exception_raise_state(mach_port_name_t exception_port, int exception,
+ exception_data_t code,
+ mach_msg_type_number_t codeCnt, int flavor,
+ thread_state_t old_state, int old_stateCnt,
+ thread_state_t new_state, int new_stateCnt)
+{
+ ABORT("Unexpected catch_exception_raise_state invocation");
+ return(KERN_INVALID_ARGUMENT);
+}
+
+GC_API_OSCALL kern_return_t
+catch_exception_raise_state_identity(mach_port_name_t exception_port,
+ mach_port_t thread, mach_port_t task,
+ int exception, exception_data_t code,
+ mach_msg_type_number_t codeCnt, int flavor,
+ thread_state_t old_state, int old_stateCnt,
+ thread_state_t new_state, int new_stateCnt)
+{
+ ABORT("Unexpected catch_exception_raise_state_identity invocation");
+ return(KERN_INVALID_ARGUMENT);
+}
+
+#define MAX_EXCEPTION_PORTS 16
+
+static struct {
+ mach_msg_type_number_t count;
+ exception_mask_t masks[MAX_EXCEPTION_PORTS];
+ exception_handler_t ports[MAX_EXCEPTION_PORTS];
+ exception_behavior_t behaviors[MAX_EXCEPTION_PORTS];
+ thread_state_flavor_t flavors[MAX_EXCEPTION_PORTS];
+} GC_old_exc_ports;
+
+STATIC struct {
+ void (*volatile os_callback[3])(void);
+ mach_port_t exception;
+# if defined(THREADS)
+ mach_port_t reply;
+# endif
+} GC_ports = {
+ {
+ /* This is to prevent stripping these routines as dead. */
+ (void (*)(void))catch_exception_raise,
+ (void (*)(void))catch_exception_raise_state,
+ (void (*)(void))catch_exception_raise_state_identity
+ },
+ 0
+};
+
+typedef struct {
+ mach_msg_header_t head;
+} GC_msg_t;
+
+typedef enum {
+ GC_MP_NORMAL,
+ GC_MP_DISCARDING,
+ GC_MP_STOPPED
+} GC_mprotect_state_t;
+
+#ifdef THREADS
+ /* FIXME: 1 and 2 seem to be safe to use in the msgh_id field, */
+ /* but it isn't documented. Use the source and see if they */
+ /* should be ok. */
+# define ID_STOP 1
+# define ID_RESUME 2
+
+ /* This value is only used on the reply port. */
+# define ID_ACK 3
+
+ STATIC GC_mprotect_state_t GC_mprotect_state = 0;
+
+ /* The following should ONLY be called when the world is stopped. */
+ STATIC void GC_mprotect_thread_notify(mach_msg_id_t id)
+ {
+ struct {
+ GC_msg_t msg;
+ mach_msg_trailer_t trailer;
+ } buf;
+ mach_msg_return_t r;
+
+ /* remote, local */
+ buf.msg.head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND, 0);
+ buf.msg.head.msgh_size = sizeof(buf.msg);
+ buf.msg.head.msgh_remote_port = GC_ports.exception;
+ buf.msg.head.msgh_local_port = MACH_PORT_NULL;
+ buf.msg.head.msgh_id = id;
+
+ r = mach_msg(&buf.msg.head, MACH_SEND_MSG | MACH_RCV_MSG | MACH_RCV_LARGE,
+ sizeof(buf.msg), sizeof(buf), GC_ports.reply,
+ MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+ if (r != MACH_MSG_SUCCESS)
+ ABORT("mach_msg failed in GC_mprotect_thread_notify");
+ if (buf.msg.head.msgh_id != ID_ACK)
+ ABORT("Invalid ack in GC_mprotect_thread_notify");
+ }
+
+ /* Should only be called by the mprotect thread */
+ STATIC void GC_mprotect_thread_reply(void)
+ {
+ GC_msg_t msg;
+ mach_msg_return_t r;
+ /* remote, local */
+
+ msg.head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND, 0);
+ msg.head.msgh_size = sizeof(msg);
+ msg.head.msgh_remote_port = GC_ports.reply;
+ msg.head.msgh_local_port = MACH_PORT_NULL;
+ msg.head.msgh_id = ID_ACK;
+
+ r = mach_msg(&msg.head, MACH_SEND_MSG, sizeof(msg), 0, MACH_PORT_NULL,
+ MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+ if (r != MACH_MSG_SUCCESS)
+ ABORT("mach_msg failed in GC_mprotect_thread_reply");
+ }
+
+ GC_INNER void GC_mprotect_stop(void)
+ {
+ GC_mprotect_thread_notify(ID_STOP);
+ }
+
+ GC_INNER void GC_mprotect_resume(void)
+ {
+ GC_mprotect_thread_notify(ID_RESUME);
+ }
+
+# ifndef GC_NO_THREADS_DISCOVERY
+ GC_INNER void GC_darwin_register_mach_handler_thread(mach_port_t thread);
+# endif
+
+#else
+ /* The compiler should optimize away any GC_mprotect_state computations */
+# define GC_mprotect_state GC_MP_NORMAL
+#endif /* !THREADS */
+
+STATIC void *GC_mprotect_thread(void *arg)
+{
+ mach_msg_return_t r;
+ /* These two structures contain some private kernel data. We don't */
+ /* need to access any of it so we don't bother defining a proper */
+ /* struct. The correct definitions are in the xnu source code. */
+ struct {
+ mach_msg_header_t head;
+ char data[256];
+ } reply;
+ struct {
+ mach_msg_header_t head;
+ mach_msg_body_t msgh_body;
+ char data[1024];
+ } msg;
+ mach_msg_id_t id;
+
+# if defined(THREADS) && !defined(GC_NO_THREADS_DISCOVERY)
+ GC_darwin_register_mach_handler_thread(mach_thread_self());
+# endif
+
+ for(;;) {
+ r = mach_msg(&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE |
+ (GC_mprotect_state == GC_MP_DISCARDING ? MACH_RCV_TIMEOUT : 0),
+ 0, sizeof(msg), GC_ports.exception,
+ GC_mprotect_state == GC_MP_DISCARDING ? 0
+ : MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
+ id = r == MACH_MSG_SUCCESS ? msg.head.msgh_id : -1;
+
+# if defined(THREADS)
+ if(GC_mprotect_state == GC_MP_DISCARDING) {
+ if(r == MACH_RCV_TIMED_OUT) {
+ GC_mprotect_state = GC_MP_STOPPED;
+ GC_mprotect_thread_reply();
+ continue;
+ }
+ if(r == MACH_MSG_SUCCESS && (id == ID_STOP || id == ID_RESUME))
+ ABORT("Out of order mprotect thread request");
+ }
+# endif /* THREADS */
+
+ if (r != MACH_MSG_SUCCESS) {
+ if (GC_print_stats)
+ GC_log_printf("mach_msg failed with code %d: %s\n", (int)r,
+ mach_error_string(r));
+ ABORT("mach_msg failed");
+ }
+
+ switch(id) {
+# if defined(THREADS)
+ case ID_STOP:
+ if(GC_mprotect_state != GC_MP_NORMAL)
+ ABORT("Called mprotect_stop when state wasn't normal");
+ GC_mprotect_state = GC_MP_DISCARDING;
+ break;
+ case ID_RESUME:
+ if(GC_mprotect_state != GC_MP_STOPPED)
+ ABORT("Called mprotect_resume when state wasn't stopped");
+ GC_mprotect_state = GC_MP_NORMAL;
+ GC_mprotect_thread_reply();
+ break;
+# endif /* THREADS */
+ default:
+ /* Handle the message (calls catch_exception_raise) */
+ if(!exc_server(&msg.head, &reply.head))
+ ABORT("exc_server failed");
+ /* Send the reply */
+ r = mach_msg(&reply.head, MACH_SEND_MSG, reply.head.msgh_size, 0,
+ MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE,
+ MACH_PORT_NULL);
+ if(r != MACH_MSG_SUCCESS) {
+ /* This will fail if the thread dies, but the thread */
+ /* shouldn't die... */
+# ifdef BROKEN_EXCEPTION_HANDLING
+ GC_err_printf("mach_msg failed with %d %s while sending "
+ "exc reply\n", (int)r, mach_error_string(r));
+# else
+ ABORT("mach_msg failed while sending exception reply");
+# endif
+ }
+ } /* switch */
+ } /* for(;;) */
+ /* NOT REACHED */
+ return NULL;
+}
+
+/* All this SIGBUS code shouldn't be necessary. All protection faults should
+ be going through the mach exception handler. However, it seems a SIGBUS is
+ occasionally sent for some unknown reason. Even more odd, it seems to be
+ meaningless and safe to ignore. */
+#ifdef BROKEN_EXCEPTION_HANDLING
+
+ /* Updates to this aren't atomic, but the SIGBUS'es seem pretty rare. */
+ /* Even if this doesn't get updated property, it isn't really a problem. */
+ STATIC int GC_sigbus_count = 0;
+
+ STATIC void GC_darwin_sigbus(int num, siginfo_t *sip, void *context)
+ {
+ if (num != SIGBUS)
+ ABORT("Got a non-sigbus signal in the sigbus handler");
+
+ /* Ugh... some seem safe to ignore, but too many in a row probably means
+ trouble. GC_sigbus_count is reset for each mach exception that is
+ handled */
+ if (GC_sigbus_count >= 8) {
+ ABORT("Got more than 8 SIGBUSs in a row!");
+ } else {
+ GC_sigbus_count++;
+ WARN("Ignoring SIGBUS.\n", 0);
+ }
+ }
+#endif /* BROKEN_EXCEPTION_HANDLING */
+
+GC_INNER void GC_dirty_init(void)
+{
+ kern_return_t r;
+ mach_port_t me;
+ pthread_t thread;
+ pthread_attr_t attr;
+ exception_mask_t mask;
+
+# ifdef CAN_HANDLE_FORK
+ if (GC_handle_fork) {
+ /* To both support GC incremental mode and GC functions usage in */
+ /* the forked child, pthread_atfork should be used to install */
+ /* handlers that switch off GC_dirty_maintained in the child */
+ /* gracefully (unprotecting all pages and clearing */
+ /* GC_mach_handler_thread). For now, we just disable incremental */
+ /* mode if fork() handling is requested by the client. */
+ if (GC_print_stats)
+ GC_log_printf(
+ "GC incremental mode disabled since fork() handling requested\n");
+ return;
+ }
+# endif
+
+ if (GC_print_stats == VERBOSE)
+ GC_log_printf(
+ "Initializing mach/darwin mprotect virtual dirty bit implementation\n");
+# ifdef BROKEN_EXCEPTION_HANDLING
+ WARN("Enabling workarounds for various darwin "
+ "exception handling bugs.\n", 0);
+# endif
+ GC_dirty_maintained = TRUE;
+ if (GC_page_size % HBLKSIZE != 0) {
+ ABORT("Page size not multiple of HBLKSIZE");
+ }
+
+ GC_task_self = me = mach_task_self();
+
+ r = mach_port_allocate(me, MACH_PORT_RIGHT_RECEIVE, &GC_ports.exception);
+ if (r != KERN_SUCCESS)
+ ABORT("mach_port_allocate failed (exception port)");
+
+ r = mach_port_insert_right(me, GC_ports.exception, GC_ports.exception,
+ MACH_MSG_TYPE_MAKE_SEND);
+ if (r != KERN_SUCCESS)
+ ABORT("mach_port_insert_right failed (exception port)");
+
+# if defined(THREADS)
+ r = mach_port_allocate(me, MACH_PORT_RIGHT_RECEIVE, &GC_ports.reply);
+ if(r != KERN_SUCCESS)
+ ABORT("mach_port_allocate failed (reply port)");
+# endif
+
+ /* The exceptions we want to catch */
+ mask = EXC_MASK_BAD_ACCESS;
+
+ r = task_get_exception_ports(me, mask, GC_old_exc_ports.masks,
+ &GC_old_exc_ports.count, GC_old_exc_ports.ports,
+ GC_old_exc_ports.behaviors,
+ GC_old_exc_ports.flavors);
+ if (r != KERN_SUCCESS)
+ ABORT("task_get_exception_ports failed");
+
+ r = task_set_exception_ports(me, mask, GC_ports.exception, EXCEPTION_DEFAULT,
+ GC_MACH_THREAD_STATE);
+ if (r != KERN_SUCCESS)
+ ABORT("task_set_exception_ports failed");
+ if (pthread_attr_init(&attr) != 0)
+ ABORT("pthread_attr_init failed");
+ if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) != 0)
+ ABORT("pthread_attr_setdetachedstate failed");
+
+# undef pthread_create
+ /* This will call the real pthread function, not our wrapper */
+ if (pthread_create(&thread, &attr, GC_mprotect_thread, NULL) != 0)
+ ABORT("pthread_create failed");
+ pthread_attr_destroy(&attr);
+
+ /* Setup the sigbus handler for ignoring the meaningless SIGBUSs */
+# ifdef BROKEN_EXCEPTION_HANDLING
+ {
+ struct sigaction sa, oldsa;
+ sa.sa_handler = (SIG_HNDLR_PTR)GC_darwin_sigbus;
+ sigemptyset(&sa.sa_mask);
+ sa.sa_flags = SA_RESTART|SA_SIGINFO;
+ if (sigaction(SIGBUS, &sa, &oldsa) < 0)
+ ABORT("sigaction failed");
+ if ((SIG_HNDLR_PTR)oldsa.sa_handler != SIG_DFL) {
+ if (GC_print_stats == VERBOSE)
+ GC_err_printf("Replaced other SIGBUS handler\n");
+ }
+ }
+# endif /* BROKEN_EXCEPTION_HANDLING */
+}
+
+/* The source code for Apple's GDB was used as a reference for the */
+/* exception forwarding code. This code is similar to be GDB code only */
+/* because there is only one way to do it. */
+STATIC kern_return_t GC_forward_exception(mach_port_t thread, mach_port_t task,
+ exception_type_t exception,
+ exception_data_t data,
+ mach_msg_type_number_t data_count)
+{
+ unsigned int i;
+ kern_return_t r;
+ mach_port_t port;
+ exception_behavior_t behavior;
+ thread_state_flavor_t flavor;
+
+ thread_state_data_t thread_state;
+ mach_msg_type_number_t thread_state_count = THREAD_STATE_MAX;
+
+ for (i=0; i < GC_old_exc_ports.count; i++)
+ if (GC_old_exc_ports.masks[i] & (1 << exception))
+ break;
+ if (i == GC_old_exc_ports.count)
+ ABORT("No handler for exception!");
+
+ port = GC_old_exc_ports.ports[i];
+ behavior = GC_old_exc_ports.behaviors[i];
+ flavor = GC_old_exc_ports.flavors[i];
+
+ if (behavior == EXCEPTION_STATE || behavior == EXCEPTION_STATE_IDENTITY) {
+ r = thread_get_state(thread, flavor, thread_state, &thread_state_count);
+ if(r != KERN_SUCCESS)
+ ABORT("thread_get_state failed in forward_exception");
+ }
+
+ switch(behavior) {
+ case EXCEPTION_STATE:
+ r = exception_raise_state(port, thread, task, exception, data, data_count,
+ &flavor, thread_state, thread_state_count,
+ thread_state, &thread_state_count);
+ break;
+ case EXCEPTION_STATE_IDENTITY:
+ r = exception_raise_state_identity(port, thread, task, exception, data,
+ data_count, &flavor, thread_state,
+ thread_state_count, thread_state,
+ &thread_state_count);
+ break;
+ /* case EXCEPTION_DEFAULT: */ /* default signal handlers */
+ default: /* user-supplied signal handlers */
+ r = exception_raise(port, thread, task, exception, data, data_count);
+ }
+
+ if (behavior == EXCEPTION_STATE || behavior == EXCEPTION_STATE_IDENTITY) {
+ r = thread_set_state(thread, flavor, thread_state, thread_state_count);
+ if (r != KERN_SUCCESS)
+ ABORT("thread_set_state failed in forward_exception");
+ }
+ return r;
+}
+
+#define FWD() GC_forward_exception(thread, task, exception, code, code_count)
+
+#ifdef ARM32
+# define DARWIN_EXC_STATE ARM_EXCEPTION_STATE
+# define DARWIN_EXC_STATE_COUNT ARM_EXCEPTION_STATE_COUNT
+# define DARWIN_EXC_STATE_T arm_exception_state_t
+# define DARWIN_EXC_STATE_DAR THREAD_FLD(far)
+#elif defined(POWERPC)
+# if CPP_WORDSZ == 32
+# define DARWIN_EXC_STATE PPC_EXCEPTION_STATE
+# define DARWIN_EXC_STATE_COUNT PPC_EXCEPTION_STATE_COUNT
+# define DARWIN_EXC_STATE_T ppc_exception_state_t
+# else
+# define DARWIN_EXC_STATE PPC_EXCEPTION_STATE64
+# define DARWIN_EXC_STATE_COUNT PPC_EXCEPTION_STATE64_COUNT
+# define DARWIN_EXC_STATE_T ppc_exception_state64_t
+# endif
+# define DARWIN_EXC_STATE_DAR THREAD_FLD(dar)
+#elif defined(I386) || defined(X86_64)
+# if CPP_WORDSZ == 32
+# define DARWIN_EXC_STATE x86_EXCEPTION_STATE32
+# define DARWIN_EXC_STATE_COUNT x86_EXCEPTION_STATE32_COUNT
+# define DARWIN_EXC_STATE_T x86_exception_state32_t
+# else
+# define DARWIN_EXC_STATE x86_EXCEPTION_STATE64
+# define DARWIN_EXC_STATE_COUNT x86_EXCEPTION_STATE64_COUNT
+# define DARWIN_EXC_STATE_T x86_exception_state64_t
+# endif
+# define DARWIN_EXC_STATE_DAR THREAD_FLD(faultvaddr)
+#else
+# error FIXME for non-arm/ppc/x86 darwin
+#endif
+
+/* This violates the namespace rules but there isn't anything that can */
+/* be done about it. The exception handling stuff is hard coded to */
+/* call this. catch_exception_raise, catch_exception_raise_state and */
+/* and catch_exception_raise_state_identity are called from OS. */
+GC_API_OSCALL kern_return_t
+catch_exception_raise(mach_port_t exception_port, mach_port_t thread,
+ mach_port_t task, exception_type_t exception,
+ exception_data_t code, mach_msg_type_number_t code_count)
+{
+ kern_return_t r;
+ char *addr;
+ struct hblk *h;
+ unsigned int i;
+ thread_state_flavor_t flavor = DARWIN_EXC_STATE;
+ mach_msg_type_number_t exc_state_count = DARWIN_EXC_STATE_COUNT;
+ DARWIN_EXC_STATE_T exc_state;
+
+ if (exception != EXC_BAD_ACCESS || code[0] != KERN_PROTECTION_FAILURE) {
+# ifdef DEBUG_EXCEPTION_HANDLING
+ /* We aren't interested, pass it on to the old handler */
+ GC_log_printf("Exception: 0x%x Code: 0x%x 0x%x in catch...\n",
+ exception, code_count > 0 ? code[0] : -1,
+ code_count > 1 ? code[1] : -1);
+# endif
+ return FWD();
+ }
+
+ r = thread_get_state(thread, flavor, (natural_t*)&exc_state,
+ &exc_state_count);
+ if(r != KERN_SUCCESS) {
+ /* The thread is supposed to be suspended while the exception */
+ /* handler is called. This shouldn't fail. */
+# ifdef BROKEN_EXCEPTION_HANDLING
+ GC_err_printf("thread_get_state failed in catch_exception_raise\n");
+ return KERN_SUCCESS;
+# else
+ ABORT("thread_get_state failed in catch_exception_raise");
+# endif
+ }
+
+ /* This is the address that caused the fault */
+ addr = (char*) exc_state.DARWIN_EXC_STATE_DAR;
+ if (HDR(addr) == 0) {
+ /* Ugh... just like the SIGBUS problem above, it seems we get */
+ /* a bogus KERN_PROTECTION_FAILURE every once and a while. We wait */
+ /* till we get a bunch in a row before doing anything about it. */
+ /* If a "real" fault ever occurs it'll just keep faulting over and */
+ /* over and we'll hit the limit pretty quickly. */
+# ifdef BROKEN_EXCEPTION_HANDLING
+ static char *last_fault;
+ static int last_fault_count;
+
+ if(addr != last_fault) {
+ last_fault = addr;
+ last_fault_count = 0;
+ }
+ if(++last_fault_count < 32) {
+ if(last_fault_count == 1)
+ WARN("Ignoring KERN_PROTECTION_FAILURE at %p\n", addr);
+ return KERN_SUCCESS;
+ }
+
+ GC_err_printf(
+ "Unexpected KERN_PROTECTION_FAILURE at %p; aborting...\n", addr);
+ /* Can't pass it along to the signal handler because that is */
+ /* ignoring SIGBUS signals. We also shouldn't call ABORT here as */
+ /* signals don't always work too well from the exception handler. */
+ exit(EXIT_FAILURE);
+# else /* BROKEN_EXCEPTION_HANDLING */
+ /* Pass it along to the next exception handler
+ (which should call SIGBUS/SIGSEGV) */
+ return FWD();
+# endif /* !BROKEN_EXCEPTION_HANDLING */
+ }
+
+# ifdef BROKEN_EXCEPTION_HANDLING
+ /* Reset the number of consecutive SIGBUSs */
+ GC_sigbus_count = 0;
+# endif
+
+ if (GC_mprotect_state == GC_MP_NORMAL) { /* common case */
+ h = (struct hblk*)((word)addr & ~(GC_page_size-1));
+ UNPROTECT(h, GC_page_size);
+ for (i = 0; i < divHBLKSZ(GC_page_size); i++) {
+ register int index = PHT_HASH(h+i);
+ async_set_pht_entry_from_index(GC_dirty_pages, index);
+ }
+ } else if (GC_mprotect_state == GC_MP_DISCARDING) {
+ /* Lie to the thread for now. No sense UNPROTECT()ing the memory
+ when we're just going to PROTECT() it again later. The thread
+ will just fault again once it resumes */
+ } else {
+ /* Shouldn't happen, i don't think */
+ GC_err_printf("KERN_PROTECTION_FAILURE while world is stopped\n");
+ return FWD();
+ }
+ return KERN_SUCCESS;
+}
+#undef FWD
+
+#ifndef NO_DESC_CATCH_EXCEPTION_RAISE
+ /* These symbols should have REFERENCED_DYNAMICALLY (0x10) bit set to */
+ /* let strip know they are not to be stripped. */
+ __asm__(".desc _catch_exception_raise, 0x10");
+ __asm__(".desc _catch_exception_raise_state, 0x10");
+ __asm__(".desc _catch_exception_raise_state_identity, 0x10");
+#endif
+
+#endif /* DARWIN && MPROTECT_VDB */
+
+#ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS
+ GC_API int GC_CALL GC_incremental_protection_needs(void)
+ {
+ return GC_PROTECTS_NONE;
+ }
+#endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */
+
+#ifdef ECOS
+ /* Undo sbrk() redirection. */
+# undef sbrk
+#endif
+
+/* If value is non-zero then allocate executable memory. */
+GC_API void GC_CALL GC_set_pages_executable(int value)
+{
+ GC_ASSERT(!GC_is_initialized);
+ /* Even if IGNORE_PAGES_EXECUTABLE is defined, GC_pages_executable is */
+ /* touched here to prevent a compiler warning. */
+ GC_pages_executable = (GC_bool)(value != 0);
+}
+
+/* Returns non-zero if the GC-allocated memory is executable. */
+/* GC_get_pages_executable is defined after all the places */
+/* where GC_get_pages_executable is undefined. */
+GC_API int GC_CALL GC_get_pages_executable(void)
+{
+# ifdef IGNORE_PAGES_EXECUTABLE
+ return 1; /* Always allocate executable memory. */
+# else
+ return (int)GC_pages_executable;
+# endif
+}
+
+/* Call stack save code for debugging. Should probably be in */
+/* mach_dep.c, but that requires reorganization. */
+
+/* I suspect the following works for most X86 *nix variants, so */
+/* long as the frame pointer is explicitly stored. In the case of gcc, */
+/* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */
+#if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN)
+# include <features.h>
+
+ struct frame {
+ struct frame *fr_savfp;
+ long fr_savpc;
+ long fr_arg[NARGS]; /* All the arguments go here. */
+ };
+#endif
+
+#if defined(SPARC)
+# if defined(LINUX)
+# include <features.h>
+
+ struct frame {
+ long fr_local[8];
+ long fr_arg[6];
+ struct frame *fr_savfp;
+ long fr_savpc;
+# ifndef __arch64__
+ char *fr_stret;
+# endif
+ long fr_argd[6];
+ long fr_argx[0];
+ };
+# elif defined (DRSNX)
+# include <sys/sparc/frame.h>
+# elif defined(OPENBSD)
+# include <frame.h>
+# elif defined(FREEBSD) || defined(NETBSD)
+# include <machine/frame.h>
+# else
+# include <sys/frame.h>
+# endif
+# if NARGS > 6
+# error We only know how to get the first 6 arguments
+# endif
+#endif /* SPARC */
+
+#ifdef NEED_CALLINFO
+/* Fill in the pc and argument information for up to NFRAMES of my */
+/* callers. Ignore my frame and my callers frame. */
+
+#ifdef LINUX
+# include <unistd.h>
+#endif
+
+#endif /* NEED_CALLINFO */
+
+#if defined(GC_HAVE_BUILTIN_BACKTRACE)
+# ifdef _MSC_VER
+# include "private/msvc_dbg.h"
+# else
+# include <execinfo.h>
+# endif
+#endif
+
+#ifdef SAVE_CALL_CHAIN
+
+#if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \
+ && defined(GC_HAVE_BUILTIN_BACKTRACE)
+
+#ifdef REDIRECT_MALLOC
+ /* Deal with possible malloc calls in backtrace by omitting */
+ /* the infinitely recursing backtrace. */
+# ifdef THREADS
+ __thread /* If your compiler doesn't understand this */
+ /* you could use something like pthread_getspecific. */
+# endif
+ GC_in_save_callers = FALSE;
+#endif
+
+GC_INNER void GC_save_callers(struct callinfo info[NFRAMES])
+{
+ void * tmp_info[NFRAMES + 1];
+ int npcs, i;
+# define IGNORE_FRAMES 1
+
+ /* We retrieve NFRAMES+1 pc values, but discard the first, since it */
+ /* points to our own frame. */
+# ifdef REDIRECT_MALLOC
+ if (GC_in_save_callers) {
+ info[0].ci_pc = (word)(&GC_save_callers);
+ for (i = 1; i < NFRAMES; ++i) info[i].ci_pc = 0;
+ return;
+ }
+ GC_in_save_callers = TRUE;
+# endif
+ GC_STATIC_ASSERT(sizeof(struct callinfo) == sizeof(void *));
+ npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES);
+ BCOPY(tmp_info+IGNORE_FRAMES, info, (npcs - IGNORE_FRAMES) * sizeof(void *));
+ for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0;
+# ifdef REDIRECT_MALLOC
+ GC_in_save_callers = FALSE;
+# endif
+}
+
+#else /* No builtin backtrace; do it ourselves */
+
+#if (defined(OPENBSD) || defined(NETBSD) || defined(FREEBSD)) && defined(SPARC)
+# define FR_SAVFP fr_fp
+# define FR_SAVPC fr_pc
+#else
+# define FR_SAVFP fr_savfp
+# define FR_SAVPC fr_savpc
+#endif
+
+#if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9))
+# define BIAS 2047
+#else
+# define BIAS 0
+#endif
+
+GC_INNER void GC_save_callers(struct callinfo info[NFRAMES])
+{
+ struct frame *frame;
+ struct frame *fp;
+ int nframes = 0;
+# ifdef I386
+ /* We assume this is turned on only with gcc as the compiler. */
+ asm("movl %%ebp,%0" : "=r"(frame));
+ fp = frame;
+# else
+ frame = (struct frame *)GC_save_regs_in_stack();
+ fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS);
+#endif
+
+ for (; (!(fp HOTTER_THAN frame) && !(GC_stackbottom HOTTER_THAN (ptr_t)fp)
+ && (nframes < NFRAMES));
+ fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) {
+ register int i;
+
+ info[nframes].ci_pc = fp->FR_SAVPC;
+# if NARGS > 0
+ for (i = 0; i < NARGS; i++) {
+ info[nframes].ci_arg[i] = ~(fp->fr_arg[i]);
+ }
+# endif /* NARGS > 0 */
+ }
+ if (nframes < NFRAMES) info[nframes].ci_pc = 0;
+}
+
+#endif /* No builtin backtrace */
+
+#endif /* SAVE_CALL_CHAIN */
+
+#ifdef NEED_CALLINFO
+
+/* Print info to stderr. We do NOT hold the allocation lock */
+GC_INNER void GC_print_callers(struct callinfo info[NFRAMES])
+{
+ int i;
+ static int reentry_count = 0;
+ GC_bool stop = FALSE;
+ DCL_LOCK_STATE;
+
+ /* FIXME: This should probably use a different lock, so that we */
+ /* become callable with or without the allocation lock. */
+ LOCK();
+ ++reentry_count;
+ UNLOCK();
+
+# if NFRAMES == 1
+ GC_err_printf("\tCaller at allocation:\n");
+# else
+ GC_err_printf("\tCall chain at allocation:\n");
+# endif
+ for (i = 0; i < NFRAMES && !stop; i++) {
+ if (info[i].ci_pc == 0) break;
+# if NARGS > 0
+ {
+ int j;
+
+ GC_err_printf("\t\targs: ");
+ for (j = 0; j < NARGS; j++) {
+ if (j != 0) GC_err_printf(", ");
+ GC_err_printf("%d (0x%X)", ~(info[i].ci_arg[j]),
+ ~(info[i].ci_arg[j]));
+ }
+ GC_err_printf("\n");
+ }
+# endif
+ if (reentry_count > 1) {
+ /* We were called during an allocation during */
+ /* a previous GC_print_callers call; punt. */
+ GC_err_printf("\t\t##PC##= 0x%lx\n", info[i].ci_pc);
+ continue;
+ }
+ {
+# ifdef LINUX
+ FILE *pipe;
+# endif
+# if defined(GC_HAVE_BUILTIN_BACKTRACE) \
+ && !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
+ char **sym_name =
+ backtrace_symbols((void **)(&(info[i].ci_pc)), 1);
+ char *name = sym_name[0];
+# else
+ char buf[40];
+ char *name = buf;
+ sprintf(buf, "##PC##= 0x%lx", info[i].ci_pc);
+# endif
+# if defined(LINUX) && !defined(SMALL_CONFIG)
+ /* Try for a line number. */
+ {
+# define EXE_SZ 100
+ static char exe_name[EXE_SZ];
+# define CMD_SZ 200
+ char cmd_buf[CMD_SZ];
+# define RESULT_SZ 200
+ static char result_buf[RESULT_SZ];
+ size_t result_len;
+ char *old_preload;
+# define PRELOAD_SZ 200
+ char preload_buf[PRELOAD_SZ];
+ static GC_bool found_exe_name = FALSE;
+ static GC_bool will_fail = FALSE;
+ int ret_code;
+ /* Try to get it via a hairy and expensive scheme. */
+ /* First we get the name of the executable: */
+ if (will_fail) goto out;
+ if (!found_exe_name) {
+ ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ);
+ if (ret_code < 0 || ret_code >= EXE_SZ
+ || exe_name[0] != '/') {
+ will_fail = TRUE; /* Don't try again. */
+ goto out;
+ }
+ exe_name[ret_code] = '\0';
+ found_exe_name = TRUE;
+ }
+ /* Then we use popen to start addr2line -e <exe> <addr> */
+ /* There are faster ways to do this, but hopefully this */
+ /* isn't time critical. */
+ sprintf(cmd_buf, "/usr/bin/addr2line -f -e %s 0x%lx", exe_name,
+ (unsigned long)info[i].ci_pc);
+ old_preload = GETENV("LD_PRELOAD");
+ if (0 != old_preload) {
+ if (strlen (old_preload) >= PRELOAD_SZ) {
+ will_fail = TRUE;
+ goto out;
+ }
+ strcpy (preload_buf, old_preload);
+ unsetenv ("LD_PRELOAD");
+ }
+ pipe = popen(cmd_buf, "r");
+ if (0 != old_preload
+ && 0 != setenv ("LD_PRELOAD", preload_buf, 0)) {
+ WARN("Failed to reset LD_PRELOAD\n", 0);
+ }
+ if (pipe == NULL
+ || (result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe))
+ == 0) {
+ if (pipe != NULL) pclose(pipe);
+ will_fail = TRUE;
+ goto out;
+ }
+ if (result_buf[result_len - 1] == '\n') --result_len;
+ result_buf[result_len] = 0;
+ if (result_buf[0] == '?'
+ || (result_buf[result_len-2] == ':'
+ && result_buf[result_len-1] == '0')) {
+ pclose(pipe);
+ goto out;
+ }
+ /* Get rid of embedded newline, if any. Test for "main" */
+ {
+ char * nl = strchr(result_buf, '\n');
+ if (nl != NULL && nl < result_buf + result_len) {
+ *nl = ':';
+ }
+ if (strncmp(result_buf, "main", nl - result_buf) == 0) {
+ stop = TRUE;
+ }
+ }
+ if (result_len < RESULT_SZ - 25) {
+ /* Add in hex address */
+ sprintf(result_buf + result_len, " [0x%lx]",
+ (unsigned long)info[i].ci_pc);
+ }
+ name = result_buf;
+ pclose(pipe);
+ out:;
+ }
+# endif /* LINUX */
+ GC_err_printf("\t\t%s\n", name);
+# if defined(GC_HAVE_BUILTIN_BACKTRACE) \
+ && !defined(GC_BACKTRACE_SYMBOLS_BROKEN)
+ free(sym_name); /* May call GC_free; that's OK */
+# endif
+ }
+ }
+ LOCK();
+ --reentry_count;
+ UNLOCK();
+}
+
+#endif /* NEED_CALLINFO */
+
+#if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG)
+ /* Dump /proc/self/maps to GC_stderr, to enable looking up names for */
+ /* addresses in FIND_LEAK output. */
+ void GC_print_address_map(void)
+ {
+ char *maps;
+
+ GC_err_printf("---------- Begin address map ----------\n");
+ maps = GC_get_maps();
+ GC_err_puts(maps != NULL ? maps : "Failed to get map!\n");
+ GC_err_printf("---------- End address map ----------\n");
+ }
+#endif /* LINUX && ELF */
projects / hs-boehmgc.git / blobdiff