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[sanitizer_common] Implement address sanitizer on AIX: stack unwinding #138188
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@llvm/pr-subscribers-compiler-rt-sanitizer Author: Jake Egan (jakeegan) ChangesImplement unwind.h-based stack unwinding routines on AIX. Full diff: https://github.com/llvm/llvm-project/pull/138188.diff 2 Files Affected:
diff --git a/compiler-rt/lib/sanitizer_common/CMakeLists.txt b/compiler-rt/lib/sanitizer_common/CMakeLists.txt
index 6e6dfd2f33ebf..96c23c6d8ab82 100644
--- a/compiler-rt/lib/sanitizer_common/CMakeLists.txt
+++ b/compiler-rt/lib/sanitizer_common/CMakeLists.txt
@@ -97,6 +97,7 @@ set(SANITIZER_SYMBOLIZER_SOURCES
sanitizer_symbolizer_report_fuchsia.cpp
sanitizer_symbolizer_win.cpp
sanitizer_thread_history.cpp
+ sanitizer_unwind_aix.cpp
sanitizer_unwind_linux_libcdep.cpp
sanitizer_unwind_fuchsia.cpp
sanitizer_unwind_win.cpp
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_unwind_aix.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_unwind_aix.cpp
new file mode 100644
index 0000000000000..45b4b1f3d5c9d
--- /dev/null
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_unwind_aix.cpp
@@ -0,0 +1,66 @@
+//===-- sanitizer_unwind_aix.cpp ------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the unwind.h-based (aka "slow") stack unwinding routines
+// available to the tools on AIX.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+
+#if SANITIZER_AIX
+# include <unwind.h>
+
+# include "sanitizer_common.h"
+# include "sanitizer_stacktrace.h"
+
+namespace __sanitizer {
+
+struct UnwindTraceArg {
+ BufferedStackTrace *stack;
+ u32 max_depth;
+};
+
+_Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) {
+ UnwindTraceArg *arg = (UnwindTraceArg *)param;
+ CHECK_LT(arg->stack->size, arg->max_depth);
+ uptr pc = _Unwind_GetIP(ctx);
+ // On AIX 32-bit and 64-bit, address smaller than 0x0fffffff is for kernel.
+ if (pc <= 0x0fffffff)
+ return _URC_NORMAL_STOP;
+ arg->stack->trace_buffer[arg->stack->size++] = pc;
+ if (arg->stack->size == arg->max_depth)
+ return _URC_NORMAL_STOP;
+ return _URC_NO_REASON;
+}
+
+void BufferedStackTrace::UnwindSlow(uptr pc, u32 max_depth) {
+ CHECK_GE(max_depth, 2);
+ size = 0;
+ UnwindTraceArg arg = {this, Min(max_depth + 1, kStackTraceMax)};
+ _Unwind_Backtrace(Unwind_Trace, &arg);
+ // We need to pop a few frames so that pc is on top.
+ uptr to_pop = LocatePcInTrace(pc);
+ // trace_buffer[0] belongs to the current function so we always pop it,
+ // unless there is only 1 frame in the stack trace (1 frame is always better
+ // than 0!).
+ // 1-frame stacks don't normally happen, but this depends on the actual
+ // unwinder implementation (libgcc, libunwind, etc) which is outside of our
+ // control.
+ if (to_pop == 0 && size > 1)
+ to_pop = 1;
+
+ PopStackFrames(to_pop);
+ trace_buffer[0] = pc;
+}
+
+void BufferedStackTrace::UnwindSlow(uptr pc, void *context, u32 max_depth) {
+ UnwindSlow(pc, max_depth);
+}
+} // namespace __sanitizer
+
+#endif // SANITIZER_AIX
|
u32 max_depth; | ||
}; | ||
|
||
_Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) { |
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I think this function can be static?
UnwindTraceArg *arg = (UnwindTraceArg *)param; | ||
CHECK_LT(arg->stack->size, arg->max_depth); | ||
uptr pc = _Unwind_GetIP(ctx); | ||
// On AIX 32-bit and 64-bit, address smaller than 0x0fffffff is for kernel. |
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Comment wording should match use of <=
in the code.
// On AIX 32-bit and 64-bit, address smaller than 0x0fffffff is for kernel. | |
// On AIX 32-bit and 64-bit, addresses up through 0x0fffffff are for kernel. |
} | ||
|
||
void BufferedStackTrace::UnwindSlow(uptr pc, void *context, u32 max_depth) { | ||
UnwindSlow(pc, max_depth); |
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Let's enforce the interface preconditions even if they are currently harmless to ignore. This conveniently removes any possible warnings that context
is unused.
UnwindSlow(pc, max_depth); | |
CHECK(context); | |
UnwindSlow(pc, max_depth); |
Implement unwind.h-based stack unwinding routines on AIX.
Issue: #138916