From: Tom Hughes <tom@compton.nu>
Date: Thu, 29 Jul 2004 22:40:07 +0000 (+0000)
Subject: Modify the ipc system call so that only those calls which may block
X-Git-Tag: svn/VALGRIND_2_2_0~100
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f10c38f7e5c01721ae8b0945e5e6927321b94528;p=thirdparty%2Fvalgrind.git

Modify the ipc system call so that only those calls which may block
are treated as blocking.

This fixes bug #86000 because shmat is no longer treated as blocking
and it is therefore no longer possible for two threads to try and use
the same address for the shared memory segment.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@2536
---

diff --git a/coregrind/vg_syscalls.c b/coregrind/vg_syscalls.c
index d6f03cffa5..e1532260f6 100644
--- a/coregrind/vg_syscalls.c
+++ b/coregrind/vg_syscalls.c
@@ -2553,6 +2553,7 @@ PRE(ipc)
    case 1: /* IPCOP_semop */
       SYSCALL_TRACK( pre_mem_read, tid, "semop(sops)", arg5, 
 		     arg3 * sizeof(struct sembuf) );
+      tst->sys_flags |= MayBlock;
       break;
    case 2: /* IPCOP_semget */
    case 3: /* IPCOP_semctl */
@@ -2563,6 +2564,7 @@ PRE(ipc)
       if (arg6 != (UInt)NULL)
          SYSCALL_TRACK( pre_mem_read, tid, "semtimedop(timeout)", arg5, 
                         sizeof(struct timespec) );
+      tst->sys_flags |= MayBlock;
       break;
    case 11: /* IPCOP_msgsnd */
    {
@@ -2573,6 +2575,9 @@ PRE(ipc)
 		     (UInt)&msgp->mtype, sizeof(msgp->mtype) );
       SYSCALL_TRACK( pre_mem_read, tid, "msgsnd(msgp->mtext)", 
 		     (UInt)msgp->mtext, msgsz );
+
+      if ((arg4 & VKI_IPC_NOWAIT) == 0)
+         tst->sys_flags |= MayBlock;
       break;
    }
    case 12: /* IPCOP_msgrcv */
@@ -2588,6 +2593,9 @@ PRE(ipc)
 		     (UInt)&msgp->mtype, sizeof(msgp->mtype) );
       SYSCALL_TRACK( pre_mem_write, tid, "msgrcv(msgp->mtext)", 
 		     (UInt)msgp->mtext, msgsz );
+
+      if ((arg4 & VKI_IPC_NOWAIT) == 0)
+         tst->sys_flags |= MayBlock;
       break;
    }
    case 13: /* IPCOP_msgget */
@@ -5684,7 +5692,7 @@ static const struct sys_info sys_info[] = {
    SYSBA(gettimeofday,		0),
    SYSB_(getuid,		0),
    SYSB_(getuid32,		0),
-   SYSBA(ipc,			MayBlock),
+   SYSBA(ipc,			0),
    SYSBA(ioctl,			MayBlock),
    SYSBA(kill,			0),
    SYSB_(link,			MayBlock),
diff --git a/include/vg_kerneliface.h b/include/vg_kerneliface.h
index 79580fb588..c4b02202ee 100644
--- a/include/vg_kerneliface.h
+++ b/include/vg_kerneliface.h
@@ -769,6 +769,14 @@ struct vki_statfs64 {
 #define VKI_FUTEX_FD      2
 #define VKI_FUTEX_REQUEUE 3
 
+/*
+ * linux/ipc.h
+ */
+
+#define VKI_IPC_CREAT  00001000   /* create if key is nonexistent */
+#define VKI_IPC_EXCL   00002000   /* fail if key exists */
+#define VKI_IPC_NOWAIT 00004000   /* return error on wait */
+
 /* 
  * linux/elfcore.h
  */