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[compiler-rt] Move IsStackOverflow into sanitizer_posix_libcdep.cc to the rest 

of instrumentation code.

llvm-svn: 313100
This commit is contained in:
Vitaly Buka 2017-09-13 00:24:44 +00:00
parent d8ab8c2528
commit 97ec1451a8
2 changed files with 45 additions and 47 deletions
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47
compiler-rt/lib/sanitizer_common/sanitizer_posix.cc
View File

@ -321,53 +321,6 @@ const char *DescribeSignalOrException(int signo) {
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

45
compiler-rt/lib/sanitizer_common/sanitizer_posix_libcdep.cc
View File

@ -215,6 +215,51 @@ void InstallDeadlySignalHandlers(SignalHandlerType handler) {
MaybeInstallSigaction(SIGFPE, handler);
MaybeInstallSigaction(SIGILL, handler);
}
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
bool IsAccessibleMemoryRange(uptr beg, uptr size) {