From: Petar Jovanovic <mips32r2@gmail.com>
Date: Mon, 23 Jul 2012 00:11:10 +0000 (+0000)
Subject: Avoid checking for bitset initialization if futex_wait_bitset is meant to fail.
X-Git-Tag: svn/VALGRIND_3_8_0~95
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=89c5f88c45ef07708eaed7c7048a97ceb2af273e;p=thirdparty%2Fvalgrind.git

Avoid checking for bitset initialization if futex_wait_bitset is meant to fail.

Glibc deliberately passes random value for the sixth parameter when calling
FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME. This is a regular case of using the
Futex API, so V should not complain that "Syscall param futex(val3) contains
uninitialised byte(s)", if the futex does not have a specified value initially.
For more info, see function pthread_initialize_minimal_internal at:
glibc/nptl/nptl-init.c.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12773
---

diff --git a/coregrind/m_syswrap/syswrap-linux.c b/coregrind/m_syswrap/syswrap-linux.c
index 5b3a34d59b..64cacbe17e 100644
--- a/coregrind/m_syswrap/syswrap-linux.c
+++ b/coregrind/m_syswrap/syswrap-linux.c
@@ -1008,9 +1008,20 @@ PRE(sys_futex)
                     struct timespec *, utime, vki_u32 *, uaddr2);
       break;
    case VKI_FUTEX_WAIT_BITSET:
-      PRE_REG_READ6(long, "futex", 
-                    vki_u32 *, futex, int, op, int, val,
-                    struct timespec *, utime, int, dummy, int, val3);
+      /* Check that the address at least begins in client-accessible area. */
+      if (!VG_(am_is_valid_for_client)( ARG1, 1, VKI_PROT_READ )) {
+            SET_STATUS_Failure( VKI_EFAULT );
+            return;
+      }
+      if (*(vki_u32 *)ARG1 != ARG3) {
+         PRE_REG_READ5(long, "futex",
+                       vki_u32 *, futex, int, op, int, val,
+                       struct timespec *, utime, int, dummy);
+      } else {
+         PRE_REG_READ6(long, "futex",
+                       vki_u32 *, futex, int, op, int, val,
+                       struct timespec *, utime, int, dummy, int, val3);
+      }
       break;
    case VKI_FUTEX_WAKE_BITSET:
       PRE_REG_READ6(long, "futex",