Index: cacao-0.99.3/src/vm/jit/arm/linux/md-os.c
===================================================================
--- cacao-0.99.3.orig/src/vm/jit/arm/linux/md-os.c 2008-07-07 13:36:19.000000000 +0200
+++ cacao-0.99.3/src/vm/jit/arm/linux/md-os.c 2008-09-24 17:15:23.191805889 +0200
@@ -2,6 +2,7 @@
Copyright (C) 1996-2005, 2006, 2007, 2008
CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
+ Copyright (C) 2008 Theobroma Systems Ltd.
This file is part of CACAO.
@@ -60,7 +61,7 @@
#include "vm/jit/executionstate.h"
#include "vm/jit/stacktrace.h"
#include "vm/jit/trap.h"
-
+#include "vm/jit/patcher-common.h"
/* md_signal_handler_sigsegv ***************************************************
@@ -126,56 +127,52 @@
void md_signal_handler_sigill(int sig, siginfo_t *siginfo, void *_p)
{
- ucontext_t *_uc;
- scontext_t *_sc;
- u1 *pv;
- u1 *sp;
- u1 *ra;
- u1 *xpc;
- u4 mcode;
- int type;
- intptr_t val;
- void *p;
-
- _uc = (ucontext_t*) _p;
- _sc = &_uc->uc_mcontext;
-
- /* ATTENTION: glibc included messed up kernel headers we needed a
- workaround for the ucontext structure. */
-
- pv = (u1 *) _sc->arm_ip;
- sp = (u1 *) _sc->arm_sp;
- ra = (u1 *) _sc->arm_lr; /* this is correct for leafs */
- xpc = (u1 *) _sc->arm_pc;
-
- /* get exception-throwing instruction */
-
- mcode = *((u4 *) xpc);
-
- /* check for undefined instruction we use */
-
- if ((mcode & 0x0ff000f0) != 0x07f000f0) {
- log_println("md_signal_handler_sigill: unknown illegal instruction: inst=%x", mcode);
-#if defined(ENABLE_DISASSEMBLER)
- DISASSINSTR(xpc);
-#endif
- vm_abort("Aborting...");
- }
-
- type = (mcode >> 8) & 0x0fff;
- val = *((s4 *) _sc + OFFSET(scontext_t, arm_r0)/4 + (mcode & 0x0f));
-
- /* Handle the trap. */
-
- p = trap_handle(type, val, pv, sp, ra, xpc, _p);
-
- /* set registers if we have an exception, continue execution
- otherwise (this is needed for patchers to work) */
-
- if (p != NULL) {
- _sc->arm_r10 = (uintptr_t) p;
- _sc->arm_fp = (uintptr_t) xpc;
- _sc->arm_pc = (uintptr_t) asm_handle_exception;
+ int type;
+ intptr_t val;
+ void *p;
+ ucontext_t* _uc = (ucontext_t*) _p;
+ scontext_t* _sc = &_uc->uc_mcontext;
+
+ /* ATTENTION: glibc included messed up kernel headers we needed a
+ workaround for the ucontext structure. */
+
+ void* pv = (void*) _sc->arm_ip;
+ void* sp = (void*) _sc->arm_sp;
+ void* ra = (void*) _sc->arm_lr; // The RA is correct for leaf methods.
+ void* xpc = (void*) _sc->arm_pc;
+
+ // Get the exception-throwing instruction.
+ uint32_t mcode = *((uint32_t*) xpc);
+
+ // Check if the trap instruction is valid.
+ // TODO Move this into patcher_handler.
+ if (patcher_is_valid_trap_instruction_at(xpc) == false) {
+ // Check if the PC has been patched during our way to this
+ // signal handler (see PR85).
+ // NOTE: ARM uses SIGILL for other traps too, but it's OK to
+ // do this check anyway because it will fail.
+ if (patcher_is_patched_at(xpc) == true)
+ return;
+
+ // We have a problem...
+ log_println("md_signal_handler_sigill: Unknown illegal instruction 0x%x at 0x%x", mcode, xpc);
+ #if defined(ENABLE_DISASSEMBLER)
+ (void) disassinstr(xpc);
+ #endif
+ vm_abort("Aborting...");
+ }
+
+ type = (mcode >> 8) & 0x0fff;
+ val = *((int32_t*) _sc + OFFSET(scontext_t, arm_r0)/4 + (mcode & 0x0f));
+
+ // Handle the trap.
+ p = trap_handle(type, val, pv, sp, ra, xpc, _p);
+
+ // Set registers if we have an exception, continue execution
+ // otherwise.
+ if (p != NULL) {
+ _sc->arm_r10 = (uintptr_t) p;
+ _sc->arm_fp = (uintptr_t) xpc;
}
}
Index: cacao-0.99.3/src/vm/jit/arm/patcher.c
===================================================================
--- cacao-0.99.3.orig/src/vm/jit/arm/patcher.c 2008-04-27 23:44:08.000000000 +0200
+++ cacao-0.99.3/src/vm/jit/arm/patcher.c 2008-09-24 17:05:17.003795314 +0200
@@ -2,6 +2,7 @@
Copyright (C) 1996-2005, 2006, 2007, 2008
CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
+ Copyright (C) 2008 Theobroma Systems Ltd.
This file is part of CACAO.
@@ -76,6 +77,25 @@
PATCH_BACK_ORIGINAL_MCODE;
}
+
+/**
+ * Check if the trap instruction at the given PC is valid.
+ *
+ * @param pc Program counter.
+ *
+ * @return true if valid, false otherwise.
+ */
+bool patcher_is_valid_trap_instruction_at(void* pc)
+{
+ uint32_t mcode = *((uint32_t*) pc);
+
+ // Check for the undefined instruction we use.
+ if ((mcode & 0x0ff000f0) != 0x07f000f0) {
+ return false;
+ }
+
+ return true;
+}
/* patcher_get_putstatic *******************************************************
Index: cacao-0.99.3/src/vm/jit/patcher-common.c
===================================================================
--- cacao-0.99.3.orig/src/vm/jit/patcher-common.c 2008-04-28 21:52:41.000000000 +0200
+++ cacao-0.99.3/src/vm/jit/patcher-common.c 2008-09-24 17:05:17.047796037 +0200
@@ -2,6 +2,7 @@
Copyright (C) 2007, 2008
CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
+ Copyright (C) 2008 Theobroma Systems Ltd.
This file is part of CACAO.
@@ -254,6 +255,49 @@
}
+/**
+ * Check if the patcher is already patched. This is done by comparing
+ * the machine instruction.
+ *
+ * @param pr Patcher structure.
+ *
+ * @return true if patched, false otherwise.
+ */
+bool patcher_is_patched(patchref_t* pr)
+{
+ // Validate the instruction at the patching position is the same
+ // instruction as the patcher structure contains.
+ uint32_t mcode = *((uint32_t*) pr->mpc);
+
+ if (mcode != pr->mcode) {
+ // The code differs.
+ return false;
+ }
+
+ return true;
+}
+
+
+/**
+ *
+ */
+bool patcher_is_patched_at(void* pc)
+{
+ codeinfo* code = code_find_codeinfo_for_pc(pc);
+
+ // Get the patcher for the given PC.
+ patchref_t* pr = patcher_list_find(code, pc);
+
+ if (pr == NULL) {
+ // The given PC is not a patcher position.
+ return false;
+ }
+
+ // Validate the instruction.
+ return patcher_is_patched(pr);
+}
+
+
/* patcher_handler *************************************************************
Handles the request to patch JIT code at the given patching
Index: cacao-0.99.3/src/vm/jit/patcher-common.h
===================================================================
--- cacao-0.99.3.orig/src/vm/jit/patcher-common.h 2008-04-27 23:44:08.000000000 +0200
+++ cacao-0.99.3/src/vm/jit/patcher-common.h 2008-09-24 17:05:17.115800331 +0200
@@ -73,6 +73,12 @@
void patcher_resolve(jitdata* jd);
+bool patcher_is_patched(patchref_t* pr);
+bool patcher_is_patched_at(void* pc);
+
+// MD function.
+bool patcher_is_valid_trap_instruction_at(void* pc);
+
java_handle_t *patcher_handler(u1 *pc);