Created attachment 62839 [details]
source of test program showing fault

Version:           unspecified
OS:                Linux

source code v3.6.1 from Valgrind site.

program fails with gpf under valgrind - in signal handler.
failing instruction is moveaps which requires 16 byte alignment - stack in signal handler is 8 byte aligned.

run without valgrind , stack is 16 byte aligned and program runs o.k.

Reproducible: Always

Steps to Reproduce:
 g++ -m64 -lrt  -ggdb  <source>

run - no arguments

Actual Results:  
gpf

Expected Results:  
program runs - no output.

problem is fixed by the following change :

 diff valgrind/valgrind-3.6.1/coregrind/m_sigframe/sigframe-amd64-linux.c valgrind/valgrind-3.6.1/coregrind/m_sigframe/sigframe-amd64-linux.c.orig
454c454
<    rsp = VG_ROUNDDN(rsp, 16) - 8;
---
>    rsp = VG_ROUNDDN(rsp, 16);