diff options
Diffstat (limited to 'src/processor/stackwalker_amd64.cc')
| -rw-r--r-- | src/processor/stackwalker_amd64.cc | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/src/processor/stackwalker_amd64.cc b/src/processor/stackwalker_amd64.cc index 8ccf73c4..440724a1 100644 --- a/src/processor/stackwalker_amd64.cc +++ b/src/processor/stackwalker_amd64.cc @@ -164,6 +164,12 @@ bool StackwalkerAMD64::IsEndOfStack(uint64_t caller_rip, uint64_t caller_rsp, return false; } +// Returns true if `ptr` is not in x86-64 canonical form. +// https://en.wikipedia.org/wiki/X86-64#Virtual_address_space_details +static bool is_non_canonical(uint64_t ptr) { + return ptr > 0x7FFFFFFFFFFF && ptr < 0xFFFF800000000000; +} + StackFrameAMD64* StackwalkerAMD64::GetCallerByFramePointerRecovery( const vector<StackFrame*>& frames) { StackFrameAMD64* last_frame = static_cast<StackFrameAMD64*>(frames.back()); @@ -186,11 +192,22 @@ StackFrameAMD64* StackwalkerAMD64::GetCallerByFramePointerRecovery( // %caller_rip = *(%callee_rbp + 8) // %caller_rbp = *(%callee_rbp) + // If rbp is not 8-byte aligned it can't be a frame pointer. + if (last_rbp % 8 != 0) { + return NULL; + } + uint64_t caller_rip, caller_rbp; if (memory_->GetMemoryAtAddress(last_rbp + 8, &caller_rip) && memory_->GetMemoryAtAddress(last_rbp, &caller_rbp)) { uint64_t caller_rsp = last_rbp + 16; + // If the recovered rip is not a canonical address it can't be + // the return address, so rbp must not have been a frame pointer. + if (is_non_canonical(caller_rip)) { + return NULL; + } + // Simple sanity check that the stack is growing downwards as expected. if (IsEndOfStack(caller_rip, caller_rsp, last_rsp) || caller_rbp < last_rbp) { |