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Double stack scanning length in stackwalker

Browse source 
R=jimb at http://breakpad.appspot.com/215001/show

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@715 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
ted.mielczarek 2010-10-19 13:12:29 +00:00
parent 08730fc9a6
commit 9c30407f7f
2 changed files with 58 additions and 1 deletions
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2
src/google_breakpad/processor/stackwalker.h
View file

@ -121,7 +121,7 @@ class Stackwalker {
bool ScanForReturnAddress(InstructionType location_start,
InstructionType *location_found,
InstructionType *ip_found) {
const int kRASearchWords = 15;
const int kRASearchWords = 30;
for (InstructionType location = location_start;
location <= location_start + kRASearchWords * sizeof(InstructionType);
location += sizeof(InstructionType)) {

57
src/processor/stackwalker_x86_unittest.cc
View file

@ -253,6 +253,63 @@ TEST_F(GetCallerFrame, TraditionalScan) {
EXPECT_EQ(NULL, frame1->windows_frame_info);
}
// Force scanning for a return address a long way down the stack
TEST_F(GetCallerFrame, TraditionalScanLongWay) {
stack_section.start() = 0x80000000;
Label frame1_ebp;
stack_section
// frame 0
.D32(0xf065dc76) // locals area:
.D32(0x46ee2167) // garbage that doesn't look like
.D32(0xbab023ec) // a return address
.Append(20 * 4, 0) // a bunch of space
.D32(frame1_ebp) // saved %ebp (%ebp fails to point here, forcing scan)
.D32(0x4000129d) // return address
// frame 1
.Append(8, 0) // space
.Mark(&frame1_ebp) // %ebp points here
.D32(0) // saved %ebp (stack end)
.D32(0); // return address (stack end)
RegionFromSection();
raw_context.eip = 0x4000f49d;
raw_context.esp = stack_section.start().Value();
// Make the frame pointer bogus, to make the stackwalker scan the stack
// for something that looks like a return address.
raw_context.ebp = 0xd43eed6e;
StackwalkerX86 walker(&system_info, &raw_context, &stack_region, &modules,
&supplier, &resolver);
ASSERT_TRUE(walker.Walk(&call_stack));
frames = call_stack.frames();
ASSERT_EQ(2U, frames->size());
StackFrameX86 *frame0 = static_cast<StackFrameX86 *>(frames->at(0));
EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust);
ASSERT_EQ(StackFrameX86::CONTEXT_VALID_ALL, frame0->context_validity);
EXPECT_EQ(0x4000f49dU, frame0->instruction);
EXPECT_EQ(0x4000f49dU, frame0->context.eip);
EXPECT_EQ(stack_section.start().Value(), frame0->context.esp);
EXPECT_EQ(0xd43eed6eU, frame0->context.ebp);
EXPECT_EQ(NULL, frame0->windows_frame_info);
StackFrameX86 *frame1 = static_cast<StackFrameX86 *>(frames->at(1));
EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust);
// I'd argue that CONTEXT_VALID_EBP shouldn't be here, since the
// walker does not actually fetch the EBP after a scan (forcing the
// next frame to be scanned as well). But let's grandfather the existing
// behavior in for now.
ASSERT_EQ((StackFrameX86::CONTEXT_VALID_EIP
| StackFrameX86::CONTEXT_VALID_ESP
| StackFrameX86::CONTEXT_VALID_EBP),
frame1->context_validity);
EXPECT_EQ(0x4000129dU, frame1->instruction + 1);
EXPECT_EQ(0x4000129dU, frame1->context.eip);
EXPECT_EQ(0x80000064U, frame1->context.esp);
EXPECT_EQ(0xd43eed6eU, frame1->context.ebp);
EXPECT_EQ(NULL, frame1->windows_frame_info);
}
// Use Windows frame data (a "STACK WIN 4" record, from a
// FrameTypeFrameData DIA record) to walk a stack frame.
TEST_F(GetCallerFrame, WindowsFrameData) {