[PATCH] D155013: [compiler-rt][xray] Fix alignment of XRayFileHeader

[Leandro Lupori via Phabricator via llvm-commits]

luporl created this revision.
Herald added subscribers: Enna1, kristof.beyls, dberris.
Herald added a project: All.
luporl added reviewers: MaskRay, DavidSpickett.
luporl added a subscriber: llvm-commits.
luporl published this revision for review.
Herald added a project: Sanitizers.
Herald added a subscriber: Sanitizers.

XRayFileHeader storage was obtained from std::aligned_storage
using its default alignment and not the struct's alignment
requirement. This was causing a bus error on AArch32, on armv8
machines, where vld1.64/vst1.64 instructions with 128-bit
alignment requirement were being used to copy XRayFileHeader.

There is still another issue with fdr-single-thread.cpp test on
armv7. Now it runs until completion and produces a valid log file,
but for some reason the function name appears as _end in it,
instead of the expected mangled fn name.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D155013

Files:
  compiler-rt/lib/xray/xray_fdr_logging.cpp


Index: compiler-rt/lib/xray/xray_fdr_logging.cpp
===================================================================
--- compiler-rt/lib/xray/xray_fdr_logging.cpp
+++ compiler-rt/lib/xray/xray_fdr_logging.cpp
@@ -140,7 +140,8 @@
 }
 
 static XRayFileHeader &fdrCommonHeaderInfo() {
-  static std::aligned_storage<sizeof(XRayFileHeader)>::type HStorage;
+  static std::aligned_storage<sizeof(XRayFileHeader),
+                              alignof(XRayFileHeader)>::type HStorage;
   static pthread_once_t OnceInit = PTHREAD_ONCE_INIT;
   static bool TSCSupported = true;
   static uint64_t CycleFrequency = NanosecondsPerSecond;
@@ -204,7 +205,8 @@
   // initialized the first time this function is called. We'll update one part
   // of this information with some relevant data (in particular the number of
   // buffers to expect).
-  static std::aligned_storage<sizeof(XRayFileHeader)>::type HeaderStorage;
+  static std::aligned_storage<sizeof(XRayFileHeader),
+                              alignof(XRayFileHeader)>::type HeaderStorage;
   static pthread_once_t HeaderOnce = PTHREAD_ONCE_INIT;
   pthread_once(
       &HeaderOnce, +[] {


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D155013.539269.patch
Type: text/x-patch
Size: 1142 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20230711/7be2d924/attachment.bin>