[compiler-rt] 3de5322 - [sanitizer] Refactor GetNextInstructionPc/GetPreviousInstructionPc

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2022-02-22T16:20:40-08:00
New Revision: 3de5322b5f719d9414423d4237a6533fe43cd7f8

URL: https://github.com/llvm/llvm-project/commit/3de5322b5f719d9414423d4237a6533fe43cd7f8
DIFF: https://github.com/llvm/llvm-project/commit/3de5322b5f719d9414423d4237a6533fe43cd7f8.diff

LOG: [sanitizer] Refactor GetNextInstructionPc/GetPreviousInstructionPc

x86 uses offset 1 while most RISC architectures use offset 4.
Check x86 first to prevent changes for new RISC architectures.

Reviewed By: #sanitizers, vitalybuka

Differential Revision: https://reviews.llvm.org/D120362

Added: 
    

Modified: 
    compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp
    compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp
index 37e9e6dd08d7b..5a6329eec484d 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.cpp
@@ -20,11 +20,10 @@
 namespace __sanitizer {
 
 uptr StackTrace::GetNextInstructionPc(uptr pc) {
-#if defined(__sparc__) || defined(__mips__)
-  return pc + 8;
-#elif defined(__powerpc__) || defined(__arm__) || defined(__aarch64__) || \
-    defined(__hexagon__)
+#if defined(__aarch64__)
   return STRIP_PAC_PC((void *)pc) + 4;
+#elif defined(__sparc__) || defined(__mips__)
+  return pc + 8;
 #elif SANITIZER_RISCV64
   // Current check order is 4 -> 2 -> 6 -> 8
   u8 InsnByte = *(u8 *)(pc);
@@ -47,8 +46,10 @@ uptr StackTrace::GetNextInstructionPc(uptr pc) {
   }
   // bail-out if could not figure out the instruction size
   return 0;
-#else
+#elif SANITIZER_I386 || SANITIZER_X32 || SANITIZER_X64
   return pc + 1;
+#else
+  return pc + 4;
 #endif
 }
 

diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h
index aebd504669d2d..82c2fda351277 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_stacktrace.h
@@ -88,9 +88,6 @@ uptr StackTrace::GetPreviousInstructionPc(uptr pc) {
   // so we return (pc-2) in that case in order to be safe.
   // For A32 mode we return (pc-4) because all instructions are 32 bit long.
   return (pc - 3) & (~1);
-#elif defined(__powerpc__) || defined(__powerpc64__) || defined(__aarch64__)
-  // PCs are always 4 byte aligned.
-  return pc - 4;
 #elif defined(__sparc__) || defined(__mips__)
   return pc - 8;
 #elif SANITIZER_RISCV64
@@ -101,8 +98,10 @@ uptr StackTrace::GetPreviousInstructionPc(uptr pc) {
   // It seems 
diff icult to figure out the exact instruction length -
   // pc - 2 seems like a safe option for the purposes of stack tracing
   return pc - 2;
-#else
+#elif SANITIZER_I386 || SANITIZER_X32 || SANITIZER_X64
   return pc - 1;
+#else
+  return pc - 4;
 #endif
 }