[llvm-dev] Intermittent lsan failure on aarch64-linux

[Adhemerval Zanella via llvm-dev]

Hi all, 

I am investigating an intermittent failure on aarch64 linux bots related to
asan, where the use_registers.cpp sometimes fails.  I tried to check if it
some related issue on the test itself, but it does seems to do what the
code is trying to simulate (an thread with store the address of a leaked
allocation on the stack thread).

Instrumenting the code to dump some log (log_pointers=1:log_threads=1) the
following below (I omitted my local paths).  It seems that on some runs
'use_registers=1' is really working as intended.

Any idea? It started to show when we moved ours buildbots to newer ubuntu
20.04 (with has a recent glibc 2.31), but I am not sure it is a glibc
related issue.

---

FAIL: LeakSanitizer-Standalone-aarch64 :: TestCases/use_registers.cpp (289 of 80810)
******************** TEST 'LeakSanitizer-Standalone-aarch64 :: TestCases/use_registers.cpp' FAILED ********************
Script:
--
: 'RUN: at line 2';   LSAN_BASE="report_objects=1:use_stacks=0:log_pointers=1:log_threads=1"
: 'RUN: at line 3';      <build_path>/bin/clang  --driver-mode=g++ -O0     -gline-tables-only -fsanitize=leak -I<src_path>/compiler-rt/test/lsan/../ -pthread <src_path>/compiler-rt/test/lsan/TestCases/use_registers.cpp -o <build_path>/projects/compiler-rt/test/lsan/AARCH64LsanConfig/TestCases/Output/use_registers.cpp.tmp
: 'RUN: at line 4';   env LSAN_OPTIONS=:detect_leaks=1:$LSAN_BASE:"use_registers=0" not  <build_path>/projects/compiler-rt/test/lsan/AARCH64LsanConfig/TestCases/Output/use_registers.cpp.tmp 2>&1 | FileCheck <src_path>/compiler-rt/test/lsan/TestCases/use_registers.cpp
: 'RUN: at line 5';   env LSAN_OPTIONS=:detect_leaks=1:$LSAN_BASE:"use_registers=1"  <build_path>/projects/compiler-rt/test/lsan/AARCH64LsanConfig/TestCases/Output/use_registers.cpp.tmp 2>&1
: 'RUN: at line 6';   env LSAN_OPTIONS=:detect_leaks=1:""  <build_path>/projects/compiler-rt/test/lsan/AARCH64LsanConfig/TestCases/Output/use_registers.cpp.tmp 2>&1
--
Exit Code: 23

Command Output (stdout):
--
Test alloc: 0xffff7d503600 
==342105==Ignored: chunk 0xffff7db03e80-0xffff7db03fb0 of size 304.
==342105==Scanning GLOBAL range 0x0000004516f0-0x000000d25e80.
==342105==Scanning GLOBAL range 0x000000da6f00-0x000000da90d8.
==342105==Scanning GLOBAL range 0xffff7fe507d8-0xffff7fe606b0.
==342105==0xffff7fe5d3e8: found 0xffff7e500000 pointing into chunk 0xffff7e500000-0xffff7e511c00 of size 72704.
==342105==Scanning GLOBAL range 0xffff7fc7cd58-0xffff7fc7d078.
==342105==Scanning GLOBAL range 0xffff7fbcbbf8-0xffff7fbd03e8.
==342105==Scanning GLOBAL range 0xffff7fb9fd60-0xffff7fba0330.
==342105==Scanning GLOBAL range 0xffff7fb87d48-0xffff7fb88100.
==342105==Scanning GLOBAL range 0xffff7fb73db8-0xffff7fb74458.
==342105==Scanning GLOBAL range 0xffff7fb478b8-0xffff7fb4fc50.
==342105==Scanning GLOBAL range 0xffff7fe92590-0xffff7fe94200.
==342105==Processing thread 342082.
==342105==Scanning REGISTERS range 0xffff7f875000-0xffff7f875110.
==342105==TLS at 0xffff7f9cd030-0xffff7f9db6b0.
==342105==Scanning TLS range 0xffff7f9cd030-0xffff7f9cd760.
==342105==Scanning TLS range 0xffff7f9daf80-0xffff7f9db6b0.
==342105==Processing thread 342099.
==342105==Scanning REGISTERS range 0xffff7f875000-0xffff7f875110.
==342105==TLS at 0xffff7e4f1980-0xffff7e500000.
==342105==Scanning TLS range 0xffff7e4f1980-0xffff7e4f20b0.
==342105==Scanning TLS range 0xffff7e4ff8d0-0xffff7e500000.
==342105==Scanning HEAP range 0xffff7e500000-0xffff7e511c00.
==342105==Scanning HEAP range 0xffff7db03e80-0xffff7db03fb0.
==342105==Processing platform-specific allocations.
==342105==Scanning leaked chunks.
==342105==Scanning HEAP range 0xffff7d503600-0xffff7d503b39.
==342105==Scanning HEAP range 0xffff7db03e80-0xffff7db03fb0.

=================================================================
==342082==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 1337 byte(s) in 1 object(s) allocated from:
    #0 0x42bc20 in malloc <src_path>/compiler-rt/lib/lsan/lsan_interceptors.cpp:56:3
    #1 0x42dbf8 in registers_thread_func <src_path>/compiler-rt/test/lsan/TestCases/use_registers.cpp:17:13
    #2 0xffff7fba94f8 in start_thread /build/glibc-iW00TY/glibc-2.31/nptl/pthread_create.c:477:8
    #3 0xffff7fab1678  /build/glibc-iW00TY/glibc-2.31/misc/../sysdeps/unix/sysv/linux/aarch64/clone.S:78

Objects leaked above:
0xffff7d503600 (1337 bytes)

SUMMARY: LeakSanitizer: 1337 byte(s) leaked in 1 allocation(s).

--

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