[compiler-rt] r312951 - [compiler-rt] Move IsStackOverflow from asan into sanitizer_common
Vitaly Buka via llvm-commits
llvm-commits at lists.llvm.org
Mon Sep 11 14:00:24 PDT 2017
Author: vitalybuka
Date: Mon Sep 11 14:00:24 2017
New Revision: 312951
URL: http://llvm.org/viewvc/llvm-project?rev=312951&view=rev
Log:
[compiler-rt] Move IsStackOverflow from asan into sanitizer_common
Summary: Part of https://github.com/google/sanitizers/issues/637
Reviewers: eugenis, alekseyshl
Subscribers: kubamracek, dberris, llvm-commits
Differential Revision: https://reviews.llvm.org/D37536
Modified:
compiler-rt/trunk/lib/asan/asan_posix.cc
compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h
compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc
Modified: compiler-rt/trunk/lib/asan/asan_posix.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/asan/asan_posix.cc?rev=312951&r1=312950&r2=312951&view=diff
==============================================================================
--- compiler-rt/trunk/lib/asan/asan_posix.cc (original)
+++ compiler-rt/trunk/lib/asan/asan_posix.cc Mon Sep 11 14:00:24 2017
@@ -35,56 +35,13 @@ namespace __asan {
void AsanOnDeadlySignal(int signo, void *siginfo, void *context) {
ScopedDeadlySignal signal_scope(GetCurrentThread());
- int code = (int)((siginfo_t*)siginfo)->si_code;
// Write the first message using fd=2, just in case.
// It may actually fail to write in case stderr is closed.
internal_write(2, SanitizerToolName, internal_strlen(SanitizerToolName));
static const char kDeadlySignal[] = ":DEADLYSIGNAL\n";
internal_write(2, kDeadlySignal, sizeof(kDeadlySignal) - 1);
SignalContext sig = SignalContext::Create(siginfo, context);
-
- // Access at a reasonable offset above SP, or slightly below it (to account
- // for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is
- // probably a stack overflow.
-#ifdef __s390__
- // On s390, the fault address in siginfo points to start of the page, not
- // to the precise word that was accessed. Mask off the low bits of sp to
- // take it into account.
- bool IsStackAccess = sig.addr >= (sig.sp & ~0xFFF) &&
- sig.addr < sig.sp + 0xFFFF;
-#else
- bool IsStackAccess = sig.addr + 512 > sig.sp && sig.addr < sig.sp + 0xFFFF;
-#endif
-
-#if __powerpc__
- // Large stack frames can be allocated with e.g.
- // lis r0,-10000
- // stdux r1,r1,r0 # store sp to [sp-10000] and update sp by -10000
- // If the store faults then sp will not have been updated, so test above
- // will not work, because the fault address will be more than just "slightly"
- // below sp.
- if (!IsStackAccess && IsAccessibleMemoryRange(sig.pc, 4)) {
- u32 inst = *(unsigned *)sig.pc;
- u32 ra = (inst >> 16) & 0x1F;
- u32 opcd = inst >> 26;
- u32 xo = (inst >> 1) & 0x3FF;
- // Check for store-with-update to sp. The instructions we accept are:
- // stbu rs,d(ra) stbux rs,ra,rb
- // sthu rs,d(ra) sthux rs,ra,rb
- // stwu rs,d(ra) stwux rs,ra,rb
- // stdu rs,ds(ra) stdux rs,ra,rb
- // where ra is r1 (the stack pointer).
- if (ra == 1 &&
- (opcd == 39 || opcd == 45 || opcd == 37 || opcd == 62 ||
- (opcd == 31 && (xo == 247 || xo == 439 || xo == 183 || xo == 181))))
- IsStackAccess = true;
- }
-#endif // __powerpc__
-
- // We also check si_code to filter out SEGV caused by something else other
- // then hitting the guard page or unmapped memory, like, for example,
- // unaligned memory access.
- if (IsStackAccess && (code == si_SEGV_MAPERR || code == si_SEGV_ACCERR))
+ if (IsStackOverflow(((siginfo_t *)siginfo)->si_code, sig))
ReportStackOverflow(sig);
else
ReportDeadlySignal(signo, sig);
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h?rev=312951&r1=312950&r2=312951&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_common.h Mon Sep 11 14:00:24 2017
@@ -306,6 +306,7 @@ void SetSoftRssLimitExceededCallback(voi
// Functions related to signal handling.
typedef void (*SignalHandlerType)(int, void *, void *);
HandleSignalMode GetHandleSignalMode(int signum);
+bool IsStackOverflow(int code, const struct SignalContext &sig);
void InstallDeadlySignalHandlers(SignalHandlerType handler);
const char *DescribeSignalOrException(int signo);
// Alternative signal stack (POSIX-only).
Modified: compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc
URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc?rev=312951&r1=312950&r2=312951&view=diff
==============================================================================
--- compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc (original)
+++ compiler-rt/trunk/lib/sanitizer_common/sanitizer_posix.cc Mon Sep 11 14:00:24 2017
@@ -321,6 +321,53 @@ const char *DescribeSignalOrException(in
return "UNKNOWN SIGNAL";
}
+#if !SANITIZER_GO
+bool IsStackOverflow(int code, const SignalContext &sig) {
+ // Access at a reasonable offset above SP, or slightly below it (to account
+ // for x86_64 or PowerPC redzone, ARM push of multiple registers, etc) is
+ // probably a stack overflow.
+#ifdef __s390__
+ // On s390, the fault address in siginfo points to start of the page, not
+ // to the precise word that was accessed. Mask off the low bits of sp to
+ // take it into account.
+ bool IsStackAccess =
+ sig.addr >= (sig.sp & ~0xFFF) && sig.addr < sig.sp + 0xFFFF;
+#else
+ bool IsStackAccess = sig.addr + 512 > sig.sp && sig.addr < sig.sp + 0xFFFF;
+#endif
+
+#if __powerpc__
+ // Large stack frames can be allocated with e.g.
+ // lis r0,-10000
+ // stdux r1,r1,r0 # store sp to [sp-10000] and update sp by -10000
+ // If the store faults then sp will not have been updated, so test above
+ // will not work, because the fault address will be more than just "slightly"
+ // below sp.
+ if (!IsStackAccess && IsAccessibleMemoryRange(sig.pc, 4)) {
+ u32 inst = *(unsigned *)sig.pc;
+ u32 ra = (inst >> 16) & 0x1F;
+ u32 opcd = inst >> 26;
+ u32 xo = (inst >> 1) & 0x3FF;
+ // Check for store-with-update to sp. The instructions we accept are:
+ // stbu rs,d(ra) stbux rs,ra,rb
+ // sthu rs,d(ra) sthux rs,ra,rb
+ // stwu rs,d(ra) stwux rs,ra,rb
+ // stdu rs,ds(ra) stdux rs,ra,rb
+ // where ra is r1 (the stack pointer).
+ if (ra == 1 &&
+ (opcd == 39 || opcd == 45 || opcd == 37 || opcd == 62 ||
+ (opcd == 31 && (xo == 247 || xo == 439 || xo == 183 || xo == 181))))
+ IsStackAccess = true;
+ }
+#endif // __powerpc__
+
+ // We also check si_code to filter out SEGV caused by something else other
+ // then hitting the guard page or unmapped memory, like, for example,
+ // unaligned memory access.
+ return IsStackAccess && (code == si_SEGV_MAPERR || code == si_SEGV_ACCERR);
+}
+#endif //! SANITIZER_GO
+
} // namespace __sanitizer
#endif // SANITIZER_POSIX
More information about the llvm-commits
mailing list