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-rw-r--r--lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cpp180
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diff --git a/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cpp b/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cpp
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index 000000000000..b2628dcc4dc1
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+++ b/lib/sanitizer_common/sanitizer_unwind_linux_libcdep.cpp
@@ -0,0 +1,180 @@
+//===-- sanitizer_unwind_linux_libcdep.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 Linux, Android, NetBSD, FreeBSD, and Solaris.
+//===----------------------------------------------------------------------===//
+
+#include "sanitizer_platform.h"
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD || \
+ SANITIZER_SOLARIS
+#include "sanitizer_common.h"
+#include "sanitizer_stacktrace.h"
+
+#if SANITIZER_ANDROID
+#include <dlfcn.h> // for dlopen()
+#endif
+
+#if SANITIZER_FREEBSD
+#define _GNU_SOURCE // to declare _Unwind_Backtrace() from <unwind.h>
+#endif
+#include <unwind.h>
+
+namespace __sanitizer {
+
+namespace {
+
+//---------------------------- UnwindSlow --------------------------------------
+
+typedef struct {
+ uptr absolute_pc;
+ uptr stack_top;
+ uptr stack_size;
+} backtrace_frame_t;
+
+extern "C" {
+typedef void *(*acquire_my_map_info_list_func)();
+typedef void (*release_my_map_info_list_func)(void *map);
+typedef sptr (*unwind_backtrace_signal_arch_func)(
+ void *siginfo, void *sigcontext, void *map_info_list,
+ backtrace_frame_t *backtrace, uptr ignore_depth, uptr max_depth);
+acquire_my_map_info_list_func acquire_my_map_info_list;
+release_my_map_info_list_func release_my_map_info_list;
+unwind_backtrace_signal_arch_func unwind_backtrace_signal_arch;
+} // extern "C"
+
+#if defined(__arm__) && !SANITIZER_NETBSD
+// NetBSD uses dwarf EH
+#define UNWIND_STOP _URC_END_OF_STACK
+#define UNWIND_CONTINUE _URC_NO_REASON
+#else
+#define UNWIND_STOP _URC_NORMAL_STOP
+#define UNWIND_CONTINUE _URC_NO_REASON
+#endif
+
+uptr Unwind_GetIP(struct _Unwind_Context *ctx) {
+#if defined(__arm__) && !SANITIZER_MAC
+ uptr val;
+ _Unwind_VRS_Result res = _Unwind_VRS_Get(ctx, _UVRSC_CORE,
+ 15 /* r15 = PC */, _UVRSD_UINT32, &val);
+ CHECK(res == _UVRSR_OK && "_Unwind_VRS_Get failed");
+ // Clear the Thumb bit.
+ return val & ~(uptr)1;
+#else
+ return (uptr)_Unwind_GetIP(ctx);
+#endif
+}
+
+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);
+ const uptr kPageSize = GetPageSizeCached();
+ // Let's assume that any pointer in the 0th page (i.e. <0x1000 on i386 and
+ // x86_64) is invalid and stop unwinding here. If we're adding support for
+ // a platform where this isn't true, we need to reconsider this check.
+ if (pc < kPageSize) return UNWIND_STOP;
+ arg->stack->trace_buffer[arg->stack->size++] = pc;
+ if (arg->stack->size == arg->max_depth) return UNWIND_STOP;
+ return UNWIND_CONTINUE;
+}
+
+} // namespace
+
+#if SANITIZER_ANDROID
+void SanitizerInitializeUnwinder() {
+ if (AndroidGetApiLevel() >= ANDROID_LOLLIPOP_MR1) return;
+
+ // Pre-lollipop Android can not unwind through signal handler frames with
+ // libgcc unwinder, but it has a libcorkscrew.so library with the necessary
+ // workarounds.
+ void *p = dlopen("libcorkscrew.so", RTLD_LAZY);
+ if (!p) {
+ VReport(1,
+ "Failed to open libcorkscrew.so. You may see broken stack traces "
+ "in SEGV reports.");
+ return;
+ }
+ acquire_my_map_info_list =
+ (acquire_my_map_info_list_func)(uptr)dlsym(p, "acquire_my_map_info_list");
+ release_my_map_info_list =
+ (release_my_map_info_list_func)(uptr)dlsym(p, "release_my_map_info_list");
+ unwind_backtrace_signal_arch = (unwind_backtrace_signal_arch_func)(uptr)dlsym(
+ p, "unwind_backtrace_signal_arch");
+ if (!acquire_my_map_info_list || !release_my_map_info_list ||
+ !unwind_backtrace_signal_arch) {
+ VReport(1,
+ "Failed to find one of the required symbols in libcorkscrew.so. "
+ "You may see broken stack traces in SEGV reports.");
+ acquire_my_map_info_list = 0;
+ unwind_backtrace_signal_arch = 0;
+ release_my_map_info_list = 0;
+ }
+}
+#endif
+
+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);
+#if defined(__GNUC__) && defined(__sparc__)
+ // __builtin_return_address returns the address of the call instruction
+ // on the SPARC and not the return address, so we need to compensate.
+ trace_buffer[0] = GetNextInstructionPc(pc);
+#else
+ trace_buffer[0] = pc;
+#endif
+}
+
+void BufferedStackTrace::UnwindSlow(uptr pc, void *context, u32 max_depth) {
+ CHECK(context);
+ CHECK_GE(max_depth, 2);
+ if (!unwind_backtrace_signal_arch) {
+ UnwindSlow(pc, max_depth);
+ return;
+ }
+
+ void *map = acquire_my_map_info_list();
+ CHECK(map);
+ InternalMmapVector<backtrace_frame_t> frames(kStackTraceMax);
+ // siginfo argument appears to be unused.
+ sptr res = unwind_backtrace_signal_arch(/* siginfo */ 0, context, map,
+ frames.data(),
+ /* ignore_depth */ 0, max_depth);
+ release_my_map_info_list(map);
+ if (res < 0) return;
+ CHECK_LE((uptr)res, kStackTraceMax);
+
+ size = 0;
+ // +2 compensate for libcorkscrew unwinder returning addresses of call
+ // instructions instead of raw return addresses.
+ for (sptr i = 0; i < res; ++i)
+ trace_buffer[size++] = frames[i].absolute_pc + 2;
+}
+
+} // namespace __sanitizer
+
+#endif // SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD ||
+ // SANITIZER_SOLARIS