commit b39a5966a9e64d343b65d7678e4759aed6860bec
Author: mjw <mjw@a5019735-40e9-0310-863c-91ae7b9d1cf9>
Date:   Wed Feb 24 11:12:01 2016 +0000

    Bug 359733 amd64 implement ld.so strchr/index override like x86
    
    The suppression and redirection for ld.so strchr/index isn't needed for
    x86. When testing a newer glibc or calling the ld.so through an alternative
    path neither the suppression (doesn't match path/name) nor the redirection
    (triggers too late) works. Since there is already an hardwire override for
    strlen in amd64 ld.so anyway it makes sense to also hardware index (it is
    always called when ld.so loads the preload images).
    
    This was also explained in the easy hacks Fosdem session.
    See https://bugs.kde.org/show_bug.cgi?id=359733 for a pointer.
    
    git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15812 a5019735-40e9-0310-863c-91ae7b9d1cf9

diff --git a/coregrind/m_redir.c b/coregrind/m_redir.c
index dcf1fb4..dae47f1 100644
--- a/coregrind/m_redir.c
+++ b/coregrind/m_redir.c
@@ -1353,6 +1353,9 @@ void VG_(redir_initialise) ( void )
    if (0==VG_(strcmp)("Memcheck", VG_(details).name)) {
 
       add_hardwired_spec(
+         "ld-linux-x86-64.so.2", "index",
+         (Addr)&VG_(amd64_linux_REDIR_FOR_index), NULL);
+      add_hardwired_spec(
          "ld-linux-x86-64.so.2", "strlen",
          (Addr)&VG_(amd64_linux_REDIR_FOR_strlen),
 #        ifndef GLIBC_MANDATORY_STRLEN_REDIRECT
diff --git a/coregrind/m_trampoline.S b/coregrind/m_trampoline.S
index cac2288..176ea66 100644
--- a/coregrind/m_trampoline.S
+++ b/coregrind/m_trampoline.S
@@ -220,6 +220,30 @@ VG_(amd64_linux_REDIR_FOR_strlen):
 .LfnE5:
 .size VG_(amd64_linux_REDIR_FOR_strlen), .-VG_(amd64_linux_REDIR_FOR_strlen)
 
+.global VG_(amd64_linux_REDIR_FOR_index)
+.type   VG_(amd64_linux_REDIR_FOR_index), @function
+VG_(amd64_linux_REDIR_FOR_index):
+        movzbl  (%rdi), %eax
+        movl    %esi, %edx
+        cmpb    %sil, %al
+        jne     .L4
+        jmp     .L5
+.L10:
+        addq    $1, %rdi
+        movzbl  (%rdi), %eax
+        cmpb    %dl, %al
+        je      .L5
+.L4:
+        testb   %al, %al
+        jne     .L10
+        xorl    %eax, %eax
+        ret
+.L5:
+        movq    %rdi, %rax
+        ret
+.size VG_(amd64_linux_REDIR_FOR_index), .-VG_(amd64_linux_REDIR_FOR_index)
+
+
 
 /* A CIE for the above four functions, followed by their FDEs */
 	.section .eh_frame,"a",@progbits
diff --git a/coregrind/pub_core_trampoline.h b/coregrind/pub_core_trampoline.h
index eda5ec6..1396519 100644
--- a/coregrind/pub_core_trampoline.h
+++ b/coregrind/pub_core_trampoline.h
@@ -71,6 +71,7 @@ extern Addr VG_(amd64_linux_REDIR_FOR_vgettimeofday);
 extern Addr VG_(amd64_linux_REDIR_FOR_vtime);
 extern Addr VG_(amd64_linux_REDIR_FOR_vgetcpu);
 extern UInt VG_(amd64_linux_REDIR_FOR_strlen)( void* );
+extern Char* VG_(amd64_linux_REDIR_FOR_index) ( const Char*, Int );
 #endif
 
 #if defined(VGP_ppc32_linux)
diff --git a/shared/vg_replace_strmem.c b/shared/vg_replace_strmem.c
index 005b679..8de085a 100644
--- a/shared/vg_replace_strmem.c
+++ b/shared/vg_replace_strmem.c
@@ -247,7 +247,7 @@ static inline void my_exit ( int x )
  STRCHR(VG_Z_LIBC_SONAME,          __strchr_sse2)
  STRCHR(VG_Z_LIBC_SONAME,          __strchr_sse2_no_bsf)
  STRCHR(VG_Z_LIBC_SONAME,          index)
-# if !defined(VGP_x86_linux)
+# if !defined(VGP_x86_linux) && !defined(VGP_amd64_linux)
   STRCHR(VG_Z_LD_LINUX_SO_2,        strchr)
   STRCHR(VG_Z_LD_LINUX_SO_2,        index)
   STRCHR(VG_Z_LD_LINUX_X86_64_SO_2, strchr)