-/* src/vm/jit/x86_64/md.c - machine dependent x86_64 Linux functions
+/* src/vm/jit/x86_64/md.c - machine dependent x86_64 functions
- Copyright (C) 1996-2005, 2006 R. Grafl, A. Krall, C. Kruegel,
- C. Oates, R. Obermaisser, M. Platter, M. Probst, S. Ring,
- E. Steiner, C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich,
- J. Wenninger, Institut f. Computersprachen - TU Wien
+ Copyright (C) 1996-2005, 2006, 2007, 2008
+ CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
+ Copyright (C) 2009 Theobroma Systems Ltd.
This file is part of CACAO.
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301, USA.
- Contact: cacao@cacaojvm.org
-
- Authors: Christian Thalinger
-
- Changes: Edwin Steiner
-
- $Id: md.c 4623 2006-03-16 00:05:18Z edwin $
-
*/
-#define _GNU_SOURCE
-
#include "config.h"
+#include <assert.h>
+#include <stdint.h>
#include <stdlib.h>
-#include <ucontext.h>
+#include "vm/jit/x86_64/codegen.h"
#include "vm/jit/x86_64/md-abi.h"
-#include "vm/exceptions.h"
-#include "vm/signallocal.h"
-#include "vm/jit/asmpart.h"
-#include "vm/jit/stacktrace.h"
-#include "vm/options.h" /* XXX debug */
-#include "vm/jit/disass.h" /* XXX debug */
+#include "vm/vm.hpp"
+
+#include "vm/jit/codegen-common.hpp"
+#include "vm/jit/executionstate.h"
+#include "vm/jit/jit.hpp"
+#include "vm/jit/trap.hpp"
/* md_init *********************************************************************
}
-/* md_signal_handler_sigsegv ***************************************************
-
- NullPointerException signal handler for hardware null pointer
- check.
-
-*******************************************************************************/
-
-void md_signal_handler_sigsegv(int sig, siginfo_t *siginfo, void *_p)
-{
- ucontext_t *_uc;
- mcontext_t *_mc;
- u1 *sp;
- u1 *ra;
- u1 *xpc;
-
- _uc = (ucontext_t *) _p;
- _mc = &_uc->uc_mcontext;
+/* md_jit_method_patch_address *************************************************
- /* ATTENTION: don't use CACAO internal REG_* defines as they are */
- /* different to the ones in <ucontext.h> */
+ Gets the patch address of the currently compiled method. The offset
+ is extracted from the load instruction(s) before the jump and added
+ to the right base address (PV or REG_METHODPTR).
- sp = (u1 *) _mc->gregs[REG_RSP];
- xpc = (u1 *) _mc->gregs[REG_RIP];
- ra = xpc; /* return address is equal to xpc */
+ INVOKESTATIC/SPECIAL:
- _mc->gregs[REG_RAX] =
- (ptrint) stacktrace_hardware_nullpointerexception(NULL, sp, ra, xpc);
+ 4d 8b 15 e2 fe ff ff mov -286(%rip),%r10
+ 49 ff d2 rex64Z callq *%r10
- _mc->gregs[REG_R10] = (ptrint) xpc; /* REG_ITMP2_XPC */
- _mc->gregs[REG_RIP] = (ptrint) asm_handle_exception;
-}
+ INVOKEVIRTUAL:
+ 4c 8b 17 mov (%rdi),%r10
+ 49 8b 82 00 00 00 00 mov 0x0(%r10),%rax
+ 48 ff d3 rex64 callq *%rax
-/* md_signal_handler_sigfpe ****************************************************
+ INVOKEINTERFACE:
- ArithmeticException signal handler for hardware divide by zero
- check.
+ 4c 8b 17 mov (%rdi),%r10
+ 4d 8b 92 00 00 00 00 mov 0x0(%r10),%r10
+ 49 8b 82 00 00 00 00 mov 0x0(%r10),%rax
+ 48 ff d3 rex64 callq *%r11
*******************************************************************************/
-void md_signal_handler_sigfpe(int sig, siginfo_t *siginfo, void *_p)
+void *md_jit_method_patch_address(void *pv, void *ra, void *mptr)
{
- ucontext_t *_uc;
- mcontext_t *_mc;
- u1 *sp;
- u1 *ra;
- u1 *xpc;
+ uint8_t *pc;
+ uint8_t mcode;
+ int32_t offset;
+ void *pa; /* patch address */
- _uc = (ucontext_t *) _p;
- _mc = &_uc->uc_mcontext;
+ /* go back to the actual call instruction (3-bytes) */
- /* ATTENTION: don't use CACAO internal REG_* defines as they are */
- /* different to the ones in <ucontext.h> */
+ pc = ((uint8_t *) ra) - 3;
- sp = (u1 *) _mc->gregs[REG_RSP];
- xpc = (u1 *) _mc->gregs[REG_RIP];
- ra = xpc; /* return address is equal to xpc */
+ /* get the last byte of the call */
- _mc->gregs[REG_RAX] =
- (ptrint) stacktrace_hardware_arithmeticexception(NULL, sp, ra, xpc);
+ mcode = pc[2];
- _mc->gregs[REG_R10] = (ptrint) xpc; /* REG_ITMP2_XPC */
- _mc->gregs[REG_RIP] = (ptrint) asm_handle_exception;
-}
+ /* check for the different calls */
+ if (mcode == 0xd2) {
+ /* INVOKESTATIC/SPECIAL */
-#if defined(USE_THREADS) && defined(NATIVE_THREADS)
-void thread_restartcriticalsection(ucontext_t *uc)
-{
- void *critical;
+ /* Get the offset from the instruction (the offset address is
+ 4-bytes before the call instruction). */
- critical = thread_checkcritical((void *) uc->uc_mcontext.gregs[REG_RIP]);
+ offset = *((int32_t *) (pc - 4));
- if (critical)
- uc->uc_mcontext.gregs[REG_RIP] = (ptrint) critical;
-}
-#endif
+ /* add the offset to the return address (IP-relative addressing) */
+ pa = pc + offset;
+ }
+ else if (mcode == 0xd3) {
+ /* INVOKEVIRTUAL/INTERFACE */
-/* md_stacktrace_get_returnaddress *********************************************
+ /* return NULL if no mptr was specified (used for replacement) */
- Returns the return address of the current stackframe, specified by
- the passed stack pointer and the stack frame size.
+ if (mptr == NULL)
+ return NULL;
-*******************************************************************************/
+ /* Get the offset from the instruction (the offset address is
+ 4-bytes before the call instruction). */
-u1 *md_stacktrace_get_returnaddress(u1 *sp, u4 framesize)
-{
- u1 *ra;
+ offset = *((int32_t *) (pc - 4));
- /* on x86_64 the return address is above the current stack frame */
+ /* add the offset to the method pointer */
- ra = *((u1 **) (sp + framesize));
+ pa = ((uint8_t *) mptr) + offset;
+ }
+ else {
+ /* catch any problems */
- return ra;
-}
+ vm_abort("md_jit_method_patch_address: unknown instruction %x", mcode);
+ /* keep compiler happy */
-/* md_codegen_findmethod *******************************************************
+ pa = NULL;
+ }
- On this architecture just a wrapper function to codegen_findmethod.
+ return pa;
+}
-*******************************************************************************/
-u1 *md_codegen_findmethod(u1 *ra)
+/**
+ * Decode the trap instruction at the given PC.
+ *
+ * @param trp information about trap to be filled
+ * @param sig signal number
+ * @param xpc exception PC
+ * @param es execution state of the machine
+ * @return true if trap was decoded successfully, false otherwise.
+ */
+bool md_trap_decode(trapinfo_t* trp, int sig, void* _xpc, executionstate_t* es)
{
- u1 *pv;
-
- /* the the start address of the function which contains this
- address from the method table */
+ uint8_t* xpc = (uint8_t*) _xpc;
- pv = codegen_findmethod(ra);
+#if 0
+ // Check for StackOverflowException.
+ threads_check_stackoverflow(sp);
+#endif
- return pv;
+ switch (sig) {
+ case TRAP_SIGFPE:
+ // Check for ArithmeticException.
+ trp->type = TRAP_ArithmeticException;
+ trp->value = 0;
+ return true;
+
+ case TRAP_SIGILL:
+ // Check for valid trap instruction.
+ if (patcher_is_valid_trap_instruction_at(xpc)) {
+ trp->type = TRAP_PATCHER;
+ trp->value = 0;
+ return true;
+ }
+ return false;
+
+ case TRAP_SIGSEGV:
+ {
+ // Get exception-throwing instruction.
+ uint8_t opc = M_ALD_MEM_GET_OPC(xpc);
+ uint8_t mod = M_ALD_MEM_GET_MOD(xpc);
+ uint8_t rm = M_ALD_MEM_GET_RM(xpc);
+
+ // Check for hardware exception, for values
+ // see emit_mov_mem_reg and emit_mem.
+ if ((opc == 0x8b) && (mod == 0) && (rm == 4)) {
+ int32_t d = M_ALD_MEM_GET_REG(xpc);
+ int32_t disp = M_ALD_MEM_GET_DISP(xpc);
+
+ // We use the exception type as load displacement.
+ trp->type = disp;
+ trp->value = es->intregs[d];
+ return true;
+ }
+
+ // Default case is a normal NullPointerException.
+ else {
+ trp->type = TRAP_NullPointerException;
+ trp->value = 0;
+ return true;
+ }
+ }
+
+ default:
+ return false;
+ }
}
*******************************************************************************/
-void md_patch_replacement_point(rplpoint *rp)
+#if defined(ENABLE_REPLACEMENT)
+void md_patch_replacement_point(u1 *pc, u1 *savedmcode, bool revert)
{
- u8 mcode;
-
- /* XXX this is probably unsafe! */
-
- /* save the current machine code */
- mcode = *(u8*)rp->pc;
-
- /* write spinning instruction */
- *(u2*)(rp->pc) = 0xebfe;
+ u2 mcode;
- /* write 5th byte */
- rp->pc[4] = (rp->mcode >> 32);
+ if (revert) {
+ /* write saved machine code */
+ *(u2*)(pc) = *(u2*)(savedmcode);
+ }
+ else {
+ /* save the current machine code */
+ *(u2*)(savedmcode) = *(u2*)(pc);
- /* write first word */
- *(u4*)(rp->pc) = (u4) rp->mcode;
+ /* build the machine code for the patch */
+ mcode = 0x0b0f;
- /* store saved mcode */
- rp->mcode = mcode;
-
- {
- u1* u1ptr = rp->pc;
- DISASSINSTR(u1ptr);
- fflush(stdout);
+ /* write new machine code */
+ *(u2*)(pc) = (u2) mcode;
}
-
- /* XXX if required asm_cacheflush(rp->pc,8); */
+
+ /* XXX if required asm_cacheflush(pc,8); */
}
+#endif /* defined(ENABLE_REPLACEMENT) */
+
/*
* These are local overrides for various environment variables in Emacs.