commit 947388eb043ea1c44b37df94046e1eee790ad776

Author: Mike Crowe <mac@mcrowe.com>

Date:   Mon Sep 9 14:16:16 2019 +0100

    Intercept strncmp for glibc ld.so v2.28+

    In glibc 5aad5f617892e75d91d4c8fb7594ff35b610c042 (first released in

    v2.28) a call to strncmp was added to dl-load.c:is_dst. This causes

    valgrind to complain about glibc's highly-optimised strncmp performing

    sixteen-byte reads on short strings in ld.so. Let's intercept strncmp in

    ld.so too so we use valgrind's simple version to avoid this problem.

diff --git a/shared/vg_replace_strmem.c b/shared/vg_replace_strmem.c

index 3b42b3a87..5396e83be 100644

--- a/shared/vg_replace_strmem.c

+++ b/shared/vg_replace_strmem.c

@@ -710,6 +710,8 @@ static inline void my_exit ( int x )

  STRNCMP(VG_Z_LIBC_SONAME, __GI_strncmp)

  STRNCMP(VG_Z_LIBC_SONAME, __strncmp_sse2)

  STRNCMP(VG_Z_LIBC_SONAME, __strncmp_sse42)

+ STRNCMP(VG_Z_LD_LINUX_SO_2, strncmp)

+ STRNCMP(VG_Z_LD_LINUX_X86_64_SO_2, strncmp)

 #elif defined(VGO_freebsd)

  STRNCMP(VG_Z_LIBC_SONAME, strncmp)