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Add support for CFI based stack walking on Arm64.

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This CL adds CFI based stack walking support for Arm64 to BreakPad along with
unit tests.  The Arm64 CFI stack walker is based on the Arm CFI stack walker

BUG=367367,335641,354405
R=blundell@chromium.org, mark@chromium.org

Review URL: https://breakpad.appspot.com/1664002

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1325 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
rmcilroy@chromium.org 2014-05-06 09:18:30 +00:00
parent 44ba0b2050
commit a789d1d26b
3 changed files with 420 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

73
src/processor/stackwalker_arm64.cc
View file

@ -78,8 +78,77 @@ StackFrame* StackwalkerARM64::GetContextFrame() {
StackFrameARM64* StackwalkerARM64::GetCallerByCFIFrameInfo(
const vector<StackFrame*> &frames,
CFIFrameInfo* cfi_frame_info) {
// Obtaining the stack frame from CFI info is not yet supported for ARM64.
return NULL;
StackFrameARM64* last_frame = static_cast<StackFrameARM64*>(frames.back());
static const char* register_names[] = {
"x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
"x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
"x16", "x17", "x18", "x19", "x20", "x21", "x22", "x23",
"x24", "x25", "x26", "x27", "x28", "x29", "x30", "sp",
"pc", NULL
};
// Populate a dictionary with the valid register values in last_frame.
CFIFrameInfo::RegisterValueMap<uint64_t> callee_registers;
for (int i = 0; register_names[i]; i++) {
if (last_frame->context_validity & StackFrameARM64::RegisterValidFlag(i))
callee_registers[register_names[i]] = last_frame->context.iregs[i];
}
// Use the STACK CFI data to recover the caller's register values.
CFIFrameInfo::RegisterValueMap<uint64_t> caller_registers;
if (!cfi_frame_info->FindCallerRegs(callee_registers, *memory_,
&caller_registers)) {
return NULL;
}
// Construct a new stack frame given the values the CFI recovered.
scoped_ptr<StackFrameARM64> frame(new StackFrameARM64());
for (int i = 0; register_names[i]; i++) {
CFIFrameInfo::RegisterValueMap<uint64_t>::iterator entry =
caller_registers.find(register_names[i]);
if (entry != caller_registers.end()) {
// We recovered the value of this register; fill the context with the
// value from caller_registers.
frame->context_validity |= StackFrameARM64::RegisterValidFlag(i);
frame->context.iregs[i] = entry->second;
} else if (19 <= i && i <= 29 && (last_frame->context_validity &
StackFrameARM64::RegisterValidFlag(i))) {
// If the STACK CFI data doesn't mention some callee-saves register, and
// it is valid in the callee, assume the callee has not yet changed it.
// Registers r19 through r29 are callee-saves, according to the Procedure
// Call Standard for the ARM AARCH64 Architecture, which the Linux ABI
// follows.
frame->context_validity |= StackFrameARM64::RegisterValidFlag(i);
frame->context.iregs[i] = last_frame->context.iregs[i];
}
}
// If the CFI doesn't recover the PC explicitly, then use .ra.
if (!(frame->context_validity & StackFrameARM64::CONTEXT_VALID_PC)) {
CFIFrameInfo::RegisterValueMap<uint64_t>::iterator entry =
caller_registers.find(".ra");
if (entry != caller_registers.end()) {
frame->context_validity |= StackFrameARM64::CONTEXT_VALID_PC;
frame->context.iregs[MD_CONTEXT_ARM64_REG_PC] = entry->second;
}
}
// If the CFI doesn't recover the SP explicitly, then use .cfa.
if (!(frame->context_validity & StackFrameARM64::CONTEXT_VALID_SP)) {
CFIFrameInfo::RegisterValueMap<uint64_t>::iterator entry =
caller_registers.find(".cfa");
if (entry != caller_registers.end()) {
frame->context_validity |= StackFrameARM64::CONTEXT_VALID_SP;
frame->context.iregs[MD_CONTEXT_ARM64_REG_SP] = entry->second;
}
}
// If we didn't recover the PC and the SP, then the frame isn't very useful.
static const uint64_t essentials = (StackFrameARM64::CONTEXT_VALID_SP
| StackFrameARM64::CONTEXT_VALID_PC);
if ((frame->context_validity & essentials) != essentials)
return NULL;
frame->trust = StackFrame::FRAME_TRUST_CFI;
return frame.release();
}
StackFrameARM64* StackwalkerARM64::GetCallerByStackScan(