[Valgrind-developers] [valgrind] drd: Fix 'conflicting load' error on std::mutex::lock()

[Bart V. A. <bva...@so...>]

https://sourceware.org/git/gitweb.cgi?p=valgrind.git;h=bb8c57ec64445648788efdb458bde3b7c5d8806e

commit bb8c57ec64445648788efdb458bde3b7c5d8806e
Author: Bart Van Assche <bva...@ac...>
Date:   Wed Jan 15 19:59:44 2020 -0800

    drd: Fix 'conflicting load' error on std::mutex::lock()

Diff:
---
 NEWS                         |  1 +
 drd/drd_pthread_intercepts.c | 15 +++++++++++----
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/NEWS b/NEWS
index 895c96f..a1c1b06 100644
--- a/NEWS
+++ b/NEWS
@@ -97,6 +97,7 @@ where XXXXXX is the bug number as listed below.
 413330  avx-1 test fails on AMD EPYC 7401P 24-Core Processor
 413603  callgrind_annotate/cg_annotate truncate function names at '#'
 414565  Specific use case bug found in SysRes VG_(do_sys_sigprocmask)
+416286  DRD reports "conflicting load" error on std::mutex::lock()
 
 n-i-bz  Fix minor one time leaks in dhat.
 n-i-bz  Add --run-cxx-freeres=no in outer args to avoid inner crashes.
diff --git a/drd/drd_pthread_intercepts.c b/drd/drd_pthread_intercepts.c
index 8d095c0..bb5b9da 100644
--- a/drd/drd_pthread_intercepts.c
+++ b/drd/drd_pthread_intercepts.c
@@ -364,30 +364,37 @@ static MutexT DRD_(thread_to_drd_mutex_type)(int type)
  */
 static __always_inline MutexT DRD_(mutex_type)(pthread_mutex_t* mutex)
 {
+   MutexT mutex_type = mutex_type_unknown;
+
+   ANNOTATE_IGNORE_READS_BEGIN();
 #if defined(HAVE_PTHREAD_MUTEX_T__M_KIND)
    /* glibc + LinuxThreads. */
    if (IS_ALIGNED(&mutex->__m_kind))
    {
       const int kind = mutex->__m_kind & 3;
-      return DRD_(pthread_to_drd_mutex_type)(kind);
+      mutex_type = DRD_(pthread_to_drd_mutex_type)(kind);
    }
 #elif defined(HAVE_PTHREAD_MUTEX_T__DATA__KIND)
    /* glibc + NPTL. */
    if (IS_ALIGNED(&mutex->__data.__kind))
    {
       const int kind = mutex->__data.__kind & 3;
-      return DRD_(pthread_to_drd_mutex_type)(kind);
+      mutex_type = DRD_(pthread_to_drd_mutex_type)(kind);
    }
 #elif defined(VGO_solaris)
+   {
       const int type = ((mutex_t *) mutex)->vki_mutex_type;
-      return DRD_(thread_to_drd_mutex_type)(type);
+      mutex_type = DRD_(thread_to_drd_mutex_type)(type);
+   }
 #else
    /*
     * Another POSIX threads implementation. The mutex type won't be printed
     * when enabling --trace-mutex=yes.
     */
 #endif
-   return mutex_type_unknown;
+   ANNOTATE_IGNORE_READS_END();
+
+   return mutex_type;
 }
 
 /**