Hi,
this testcase hangs on ia64:
$ echo 'int main () { return vfork (); }' >vfork.c; gcc -o vfork vfork.c;
strace -f ./vfork
execve("./vfork", ["./vfork"], [/* 41 vars */]) = 1
...
clone(Process 2929 attached (waiting for parent)
Fix tested on RHEL-5 kernel-2.6.18-94.el5.ia64. Older kernels (such as
kernel-2.6.18-53.el5.ia64) do not hang as they have a bug causing strace not
tracing the children (as strace is unable to force CLONE_PTRACE there).
Sorry for no ia64 vanilla kernels testing.
Regards,
Jan
2008-06-27 Jan Kratochvil <[EMAIL PROTECTED]>
* util.c (CLONE_VFORK): Define if not defined already.
(setbpt): Clear CLONE_VFORK for SYS_CLONE and SYS_CLONE2. New comment.
Originally found by Vitaly Mayatskikh.
--- util.c 20 May 2008 00:34:34 -0000 1.75
+++ util.c 30 Jun 2008 12:53:31 -0000
@@ -1281,6 +1281,9 @@ struct tcb *tcp;
#ifndef CLONE_PTRACE
# define CLONE_PTRACE 0x00002000
#endif
+#ifndef CLONE_VFORK
+# define CLONE_VFORK 0x00004000
+#endif
#ifndef CLONE_STOPPED
# define CLONE_STOPPED 0x02000000
#endif
@@ -1524,12 +1527,17 @@ struct tcb *tcp;
#ifdef SYS_clone2
case SYS_clone2:
#endif
- if ((tcp->u_arg[arg0_index] & CLONE_PTRACE) == 0
- && (arg_setup (tcp, &state) < 0
- || set_arg0 (tcp, &state,
- tcp->u_arg[arg0_index] | CLONE_PTRACE) < 0
- || arg_finish_change (tcp, &state) < 0))
- return -1;
+ /* ia64 calls directly `clone (CLONE_VFORK)' contrary to x86
+ SYS_vfork above. Even on x86 we turn the VFORK semantics
+ into plain FORK - each application must not depend on the
+ VFORK specifics according to POSIX. We would hang waiting
+ for the parent resume otherwise. */
+ if ((arg_setup (tcp, &state) < 0
+ || set_arg0 (tcp, &state,
+ (tcp->u_arg[arg0_index] | CLONE_PTRACE)
+ & ~CLONE_VFORK) < 0
+ || arg_finish_change (tcp, &state) < 0))
+ return -1;
tcp->flags |= TCB_BPTSET;
tcp->inst[0] = tcp->u_arg[arg0_index];
tcp->inst[1] = tcp->u_arg[arg1_index];
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