Revert 502f0cc0e38 "[GWP-ASan] Split the unwinder into segv/non-segv."
It was causing tests to fail in -DCOMPILER_RT_BUILD_BUILTINS=OFF builds:
GwpAsan-Unittest :: ./GwpAsan-x86_64-Test/BacktraceGuardedPoolAllocator.DoubleFree
GwpAsan-Unittest :: ./GwpAsan-x86_64-Test/BacktraceGuardedPoolAllocator.UseAfterFree
see comment on the code review.
> Summary:
> Splits the unwinder into a non-segv (for allocation/deallocation traces) and a
> segv unwinder. This ensures that implementations can select an accurate, slower
> unwinder in the segv handler (if they choose to use the GWP-ASan provided one).
> This is important as fast frame-pointer unwinders (like the sanitizer unwinder)
> don't like unwinding through signal handlers.
>
> Reviewers: morehouse, cryptoad
>
> Reviewed By: morehouse, cryptoad
>
> Subscribers: cryptoad, mgorny, eugenis, pcc, #sanitizers
>
> Tags: #sanitizers
>
> Differential Revision: https://reviews.llvm.org/D83994
This reverts commit 502f0cc0e3889229e923e187f38dda91324ae139.
GitOrigin-RevId: ab6263c9258ccd0e3c9cb4f675979f22cfba6131
diff --git a/optional/backtrace_linux_libc.cpp b/optional/backtrace_linux_libc.cpp
index 92eb293..bb0aad2 100644
--- a/optional/backtrace_linux_libc.cpp
+++ b/optional/backtrace_linux_libc.cpp
@@ -23,14 +23,6 @@
return backtrace(reinterpret_cast<void **>(TraceBuffer), Size);
}
-// We don't need any custom handling for the Segv backtrace - the libc unwinder
-// has no problems with unwinding through a signal handler. Force inlining here
-// to avoid the additional frame.
-GWP_ASAN_ALWAYS_INLINE size_t SegvBacktrace(uintptr_t *TraceBuffer, size_t Size,
- void * /*Context*/) {
- return Backtrace(TraceBuffer, Size);
-}
-
static void PrintBacktrace(uintptr_t *Trace, size_t TraceLength,
gwp_asan::crash_handler::Printf_t Printf) {
if (TraceLength == 0) {
@@ -61,8 +53,4 @@
return PrintBacktrace;
}
} // namespace options
-
-namespace crash_handler {
-SegvBacktrace_t getSegvBacktraceFunction() { return SegvBacktrace; }
-} // namespace crash_handler
} // namespace gwp_asan
diff --git a/optional/backtrace_sanitizer_common.cpp b/optional/backtrace_sanitizer_common.cpp
index a8083e4..3ac4b52 100644
--- a/optional/backtrace_sanitizer_common.cpp
+++ b/optional/backtrace_sanitizer_common.cpp
@@ -22,45 +22,28 @@
void *context,
bool request_fast,
u32 max_depth) {
- if (!StackTrace::WillUseFastUnwind(request_fast))
- return Unwind(max_depth, pc, 0, context, 0, 0, false);
-
- uptr top = 0;
- uptr bottom = 0;
- GetThreadStackTopAndBottom(/*at_initialization*/ false, &top, &bottom);
-
- return Unwind(max_depth, pc, bp, context, top, bottom, request_fast);
+ if (!StackTrace::WillUseFastUnwind(request_fast)) {
+ return Unwind(max_depth, pc, bp, context, 0, 0, request_fast);
+ }
+ Unwind(max_depth, pc, 0, context, 0, 0, false);
}
namespace {
-size_t BacktraceCommon(uintptr_t *TraceBuffer, size_t Size, void *Context) {
- // Use the slow sanitizer unwinder in the segv handler. Fast frame pointer
- // unwinders can end up dropping frames because the kernel sigreturn() frame's
- // return address is the return address at time of fault. This has the result
- // of never actually capturing the PC where the signal was raised.
- bool UseFastUnwind = (Context == nullptr);
-
+size_t Backtrace(uintptr_t *TraceBuffer, size_t Size) {
__sanitizer::BufferedStackTrace Trace;
Trace.Reset();
if (Size > __sanitizer::kStackTraceMax)
Size = __sanitizer::kStackTraceMax;
Trace.Unwind((__sanitizer::uptr)__builtin_return_address(0),
- (__sanitizer::uptr)__builtin_frame_address(0), Context,
- UseFastUnwind, Size - 1);
+ (__sanitizer::uptr)__builtin_frame_address(0),
+ /* ucontext */ nullptr,
+ /* fast unwind */ true, Size - 1);
memcpy(TraceBuffer, Trace.trace, Trace.size * sizeof(uintptr_t));
return Trace.size;
}
-size_t Backtrace(uintptr_t *TraceBuffer, size_t Size) {
- return BacktraceCommon(TraceBuffer, Size, nullptr);
-}
-
-size_t SegvBacktrace(uintptr_t *TraceBuffer, size_t Size, void *Context) {
- return BacktraceCommon(TraceBuffer, Size, Context);
-}
-
static void PrintBacktrace(uintptr_t *Trace, size_t TraceLength,
gwp_asan::crash_handler::Printf_t Printf) {
__sanitizer::StackTrace StackTrace;
@@ -94,8 +77,4 @@
return PrintBacktrace;
}
} // namespace options
-
-namespace crash_handler {
-SegvBacktrace_t getSegvBacktraceFunction() { return SegvBacktrace; }
-} // namespace crash_handler
} // namespace gwp_asan
diff --git a/optional/segv_handler.h b/optional/segv_handler.h
index 0fed4f2..10af150 100644
--- a/optional/segv_handler.h
+++ b/optional/segv_handler.h
@@ -59,15 +59,6 @@
// without any symbolization.
PrintBacktrace_t getBasicPrintBacktraceFunction();
-// Returns a function pointer to a backtrace function that's suitable for
-// unwinding through a signal handler. This is important primarily for frame-
-// pointer based unwinders, DWARF or other unwinders can simply provide the
-// normal backtrace function as the implementation here. On POSIX, SignalContext
-// should be the `ucontext_t` from the signal handler.
-typedef size_t (*SegvBacktrace_t)(uintptr_t *TraceBuffer, size_t Size,
- void *SignalContext);
-SegvBacktrace_t getSegvBacktraceFunction();
-
// Install the SIGSEGV crash handler for printing use-after-free and heap-
// buffer-{under|over}flow exceptions if the user asked for it. This is platform
// specific as even though POSIX and Windows both support registering handlers
@@ -76,14 +67,14 @@
// before this function.
void installSignalHandlers(gwp_asan::GuardedPoolAllocator *GPA, Printf_t Printf,
PrintBacktrace_t PrintBacktrace,
- SegvBacktrace_t SegvBacktrace);
+ options::Backtrace_t Backtrace);
void uninstallSignalHandlers();
void dumpReport(uintptr_t ErrorPtr, const gwp_asan::AllocatorState *State,
const gwp_asan::AllocationMetadata *Metadata,
- SegvBacktrace_t SegvBacktrace, Printf_t Printf,
- PrintBacktrace_t PrintBacktrace, void *Context);
+ options::Backtrace_t Backtrace, Printf_t Printf,
+ PrintBacktrace_t PrintBacktrace);
} // namespace crash_handler
} // namespace gwp_asan
diff --git a/optional/segv_handler_posix.cpp b/optional/segv_handler_posix.cpp
index 1bd7a60..22589b8 100644
--- a/optional/segv_handler_posix.cpp
+++ b/optional/segv_handler_posix.cpp
@@ -23,14 +23,14 @@
using gwp_asan::GuardedPoolAllocator;
using gwp_asan::crash_handler::PrintBacktrace_t;
using gwp_asan::crash_handler::Printf_t;
-using gwp_asan::crash_handler::SegvBacktrace_t;
+using gwp_asan::options::Backtrace_t;
struct sigaction PreviousHandler;
bool SignalHandlerInstalled;
gwp_asan::GuardedPoolAllocator *GPAForSignalHandler;
Printf_t PrintfForSignalHandler;
PrintBacktrace_t PrintBacktraceForSignalHandler;
-SegvBacktrace_t BacktraceForSignalHandler;
+Backtrace_t BacktraceForSignalHandler;
static void sigSegvHandler(int sig, siginfo_t *info, void *ucontext) {
if (GPAForSignalHandler) {
@@ -40,7 +40,7 @@
reinterpret_cast<uintptr_t>(info->si_addr),
GPAForSignalHandler->getAllocatorState(),
GPAForSignalHandler->getMetadataRegion(), BacktraceForSignalHandler,
- PrintfForSignalHandler, PrintBacktraceForSignalHandler, ucontext);
+ PrintfForSignalHandler, PrintBacktraceForSignalHandler);
}
// Process any previous handlers.
@@ -138,11 +138,11 @@
void installSignalHandlers(gwp_asan::GuardedPoolAllocator *GPA, Printf_t Printf,
PrintBacktrace_t PrintBacktrace,
- SegvBacktrace_t SegvBacktrace) {
+ options::Backtrace_t Backtrace) {
GPAForSignalHandler = GPA;
PrintfForSignalHandler = Printf;
PrintBacktraceForSignalHandler = PrintBacktrace;
- BacktraceForSignalHandler = SegvBacktrace;
+ BacktraceForSignalHandler = Backtrace;
struct sigaction Action;
Action.sa_sigaction = sigSegvHandler;
@@ -160,8 +160,8 @@
void dumpReport(uintptr_t ErrorPtr, const gwp_asan::AllocatorState *State,
const gwp_asan::AllocationMetadata *Metadata,
- SegvBacktrace_t SegvBacktrace, Printf_t Printf,
- PrintBacktrace_t PrintBacktrace, void *Context) {
+ options::Backtrace_t Backtrace, Printf_t Printf,
+ PrintBacktrace_t PrintBacktrace) {
assert(State && "dumpReport missing Allocator State.");
assert(Metadata && "dumpReport missing Metadata.");
assert(Printf && "dumpReport missing Printf.");
@@ -194,8 +194,7 @@
// Print the fault backtrace.
static constexpr unsigned kMaximumStackFramesForCrashTrace = 512;
uintptr_t Trace[kMaximumStackFramesForCrashTrace];
- size_t TraceLength =
- SegvBacktrace(Trace, kMaximumStackFramesForCrashTrace, Context);
+ size_t TraceLength = Backtrace(Trace, kMaximumStackFramesForCrashTrace);
PrintBacktrace(Trace, TraceLength, Printf);
diff --git a/tests/harness.h b/tests/harness.h
index d303b2c..e47254e 100644
--- a/tests/harness.h
+++ b/tests/harness.h
@@ -86,8 +86,7 @@
gwp_asan::crash_handler::installSignalHandlers(
&GPA, gwp_asan::test::getPrintfFunction(),
- gwp_asan::options::getPrintBacktraceFunction(),
- gwp_asan::crash_handler::getSegvBacktraceFunction());
+ gwp_asan::options::getPrintBacktraceFunction(), Opts.Backtrace);
}
void TearDown() override {
