From a2354569bf5883206577a8299c38449391cce3e6 Mon Sep 17 00:00:00 2001
From: Vitaly Buka <vitalybuka@google.com>
Date: Wed, 13 Sep 2017 06:24:59 +0000
Subject: [compiler-rt] Move dump_instruction_bytes and dump_registers into
 sanitizer_common

Summary: Part of https://github.com/google/sanitizers/issues/637

Reviewers: eugenis, alekseyshl

Subscribers: kubamracek, llvm-commits, dberris

Differential Revision: https://reviews.llvm.org/D37766

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@313117 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/sanitizer_common/sanitizer_common_libcdep.cc | 41 ++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

(limited to 'lib/sanitizer_common/sanitizer_common_libcdep.cc')

diff --git a/lib/sanitizer_common/sanitizer_common_libcdep.cc b/lib/sanitizer_common/sanitizer_common_libcdep.cc
index b54503a6d..cccb3be3e 100644
--- a/lib/sanitizer_common/sanitizer_common_libcdep.cc
+++ b/lib/sanitizer_common/sanitizer_common_libcdep.cc
@@ -16,6 +16,8 @@
 #include "sanitizer_allocator_interface.h"
 #include "sanitizer_file.h"
 #include "sanitizer_flags.h"
+#include "sanitizer_procmaps.h"
+#include "sanitizer_report_decorator.h"
 #include "sanitizer_stackdepot.h"
 #include "sanitizer_stacktrace.h"
 #include "sanitizer_symbolizer.h"
@@ -145,6 +147,45 @@ void BackgroundThread(void *arg) {
 }
 #endif
 
+void MaybeReportNonExecRegion(uptr pc) {
+#if SANITIZER_FREEBSD || SANITIZER_LINUX || SANITIZER_NETBSD
+  MemoryMappingLayout proc_maps(/*cache_enabled*/ true);
+  MemoryMappedSegment segment;
+  while (proc_maps.Next(&segment)) {
+    if (pc >= segment.start && pc < segment.end && !segment.IsExecutable())
+      Report("Hint: PC is at a non-executable region. Maybe a wild jump?\n");
+  }
+#endif
+}
+
+static void PrintMemoryByte(InternalScopedString *str, const char *before,
+                            u8 byte) {
+  SanitizerCommonDecorator d;
+  str->append("%s%s%x%x%s ", before, d.MemoryByte(), byte >> 4, byte & 15,
+              d.Default());
+}
+
+void MaybeDumpInstructionBytes(uptr pc) {
+  if (!common_flags()->dump_instruction_bytes || (pc < GetPageSizeCached()))
+    return;
+  InternalScopedString str(1024);
+  str.append("First 16 instruction bytes at pc: ");
+  if (IsAccessibleMemoryRange(pc, 16)) {
+    for (int i = 0; i < 16; ++i) {
+      PrintMemoryByte(&str, "", ((u8 *)pc)[i]);
+    }
+    str.append("\n");
+  } else {
+    str.append("unaccessible\n");
+  }
+  Report("%s", str.data());
+}
+
+void MaybeDumpRegisters(void *context) {
+  if (!common_flags()->dump_registers) return;
+  SignalContext::DumpAllRegisters(context);
+}
+
 void WriteToSyslog(const char *msg) {
   InternalScopedString msg_copy(kErrorMessageBufferSize);
   msg_copy.append("%s", msg);
-- 
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