#include <stdio.h>
#include <stdlib.h>
-#include <signal.h>
-#include <asm/ucontext.h>
+#include <stddef.h>
-unsigned int getMethodEntry(void *, char *);
-void *method_map = NULL;
+/* TODO(bernhard): use {u,}int* types */
-void set_mmap(void *mmap)
-{
- printf("set_mmap: 0x%08x\n", (unsigned int) mmap);
- method_map = mmap;
-}
+#define __USE_GNU
+// Note by hs: my signal.h includes sys/uconctext which conflicts with
+// asm/ucontext - this hack kinda solves the problem for me ;-)
+// so feel free to blame me for that s**t
+#if defined __USE_XOPEN2K8
+#undef __USE_XOPEN2K8
+#define RESTORE
+#warning hs-hack: undefining __USE_XOPEN2K8 for signal.h
+#endif
+#include <signal.h>
+#ifdef RESTORE
+#define __USE_XOPEN2K8
+#endif
-void *get_mmap()
-{
- printf("get_mmap: 0x%08x\n", (unsigned int) method_map);
- return method_map;
-}
+#include <sys/ucontext.h>
-void demo_mmap()
-{
- printf("mmap: 0x%08x\n", getMethodEntry(method_map, "fib"));
-}
+ptrdiff_t mateHandler(ptrdiff_t, ptrdiff_t, ptrdiff_t, ptrdiff_t);
+#ifdef DBG_TRAP
+#define dprintf(args...) do { printf (args); } while (0);
+#else
+#define dprintf(args...)
+#endif
-unsigned int patchme = 0;
-void print_foo(unsigned int addr)
+void chandler(int nSignal, siginfo_t *info, void *ctx)
{
- // printf("\n\nprint foo: 0x%08x\n", addr);
- patchme = addr;
-}
-
-void callertrap(int nSignal, siginfo_t *info, void *ctx)
-{
- struct ucontext *uctx = (struct ucontext *) ctx;
+ mcontext_t *mctx = &((ucontext_t *) ctx)->uc_mcontext;
+ greg_t *regs = mctx->gregs;
- printf("callertrap(mctx) by 0x%08x\n", (unsigned int) uctx->uc_mcontext.eip);
- // printf("callertrap(addr) by 0x%08x\n", info->si_addr);
- // printf("callertrap(*esp) by 0x%08x\n", * (unsigned int *) uctx->uc_mcontext.esp);
+ ptrdiff_t eip = (ptrdiff_t) regs[REG_EIP];
+ ptrdiff_t eax = (ptrdiff_t) regs[REG_EAX];
+ ptrdiff_t ebx = (ptrdiff_t) regs[REG_EBX];
+ ptrdiff_t esp = (ptrdiff_t) regs[REG_ESP];
+ ptrdiff_t esi = (ptrdiff_t) regs[REG_ESI];
+ ptrdiff_t ebp = (ptrdiff_t) regs[REG_EBP];
+ dprintf("trap: type %d, eip 0x%08x, eax 0x%08x, ebx 0x%08x, \n"
+ "esp 0x%08x, *esp 0x%08x, *(ebp+8) 0x%08x\n", nSignal, eip,
+ eax, ebx, esp, *(ptrdiff_t*) esp, *(ptrdiff_t *) (ebp + 8));
- unsigned int *to_patch = (unsigned int *) (uctx->uc_mcontext.eip + 2);
- unsigned char *insn = (unsigned char *) (uctx->uc_mcontext.eip);
- *insn = 0x90; // nop
- insn++;
- *insn = 0xe8; // call
- printf(" to_patch: 0x%08x\n", (unsigned int) to_patch);
- printf("*to_patch: 0x%08x\n", *to_patch);
- if (*to_patch != 0x00000000) {
- printf("something is wrong here. abort\n");
- exit(0);
+ ptrdiff_t ret = mateHandler(eip, eax, ebx, esi);
+ if (ret == -1) {
+ dprintf("regdump @ EIP: 0x%08x\n", regs[REG_EIP]);
+ dprintf("\tEAX: 0x%08lx EBX: 0x%08lx ECX: 0x%08lx EDX: 0x%08lx\n",
+ regs[REG_EAX], regs[REG_EBX], regs[REG_ECX], regs[REG_EDX]);
+ dprintf("\tESI: 0x%08lx EDI: 0x%08lx EBP: 0x%08lx ESP: 0x%08lx\n",
+ regs[REG_ESI], regs[REG_EDI], regs[REG_EBP], regs[REG_ESP]);
+ mctx->gregs[REG_EIP] = eip + 6;
+ } else {
+ mctx->gregs[REG_EIP] = ret;
}
- *to_patch = (unsigned int) patchme - ((unsigned int) insn + 5);
- printf("*to_patch: 0x%08x\n", *to_patch);
- uctx->uc_mcontext.eip = (unsigned long) insn;
- // while (1) ;
}
void register_signal(void)
{
+ struct sigaction illaction;
+ illaction.sa_sigaction = chandler;
+ sigemptyset(&illaction.sa_mask);
+ illaction.sa_flags = SA_SIGINFO | SA_RESTART | SA_NODEFER;
+ sigaction(SIGILL, &illaction, NULL);
+
struct sigaction segvaction;
- segvaction.sa_sigaction = callertrap;
+ segvaction.sa_sigaction = chandler;
sigemptyset(&segvaction.sa_mask);
- segvaction.sa_flags = SA_SIGINFO | SA_RESTART;
+ segvaction.sa_flags = SA_SIGINFO | SA_RESTART | SA_NODEFER;
sigaction(SIGSEGV, &segvaction, NULL);
}
-
-unsigned int getaddr(void)
-{
- return (unsigned int) print_foo;
-}