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authorVitaly Mayatskikh <v.mayatskih@gmail.com>2009-09-24 00:56:52 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-24 16:21:00 +0200
commitb6fe2d117e98805ee76352e6468f87d494a97292 (patch)
tree3de99eb7652647000b53bca1f6ea740c926ccfca
parentdo_wait: fix sys_waitid()-specific behaviour (diff)
downloadlinux-b6fe2d117e98805ee76352e6468f87d494a97292.tar.xz
linux-b6fe2d117e98805ee76352e6468f87d494a97292.zip
wait_noreap_copyout(): check for ->wo_info != NULL
Current behaviour of sys_waitid() looks odd. If user passes infop == NULL, sys_waitid() returns success. When user additionally specifies flag WNOWAIT, sys_waitid() returns -EFAULT on the same conditions. When user combines WNOWAIT with WCONTINUED, sys_waitid() again returns success. This patch adds check for ->wo_info in wait_noreap_copyout(). User-visible change: starting from this commit, sys_waitid() always checks infop != NULL and does not fail if it is NULL. Signed-off-by: Vitaly Mayatskikh <v.mayatskih@gmail.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/exit.c26
1 files changed, 14 insertions, 12 deletions
diff --git a/kernel/exit.c b/kernel/exit.c
index 2cc69eb8db2a..6c75ff83a8fe 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1140,18 +1140,20 @@ static int wait_noreap_copyout(struct wait_opts *wo, struct task_struct *p,
put_task_struct(p);
infop = wo->wo_info;
- if (!retval)
- retval = put_user(SIGCHLD, &infop->si_signo);
- if (!retval)
- retval = put_user(0, &infop->si_errno);
- if (!retval)
- retval = put_user((short)why, &infop->si_code);
- if (!retval)
- retval = put_user(pid, &infop->si_pid);
- if (!retval)
- retval = put_user(uid, &infop->si_uid);
- if (!retval)
- retval = put_user(status, &infop->si_status);
+ if (infop) {
+ if (!retval)
+ retval = put_user(SIGCHLD, &infop->si_signo);
+ if (!retval)
+ retval = put_user(0, &infop->si_errno);
+ if (!retval)
+ retval = put_user((short)why, &infop->si_code);
+ if (!retval)
+ retval = put_user(pid, &infop->si_pid);
+ if (!retval)
+ retval = put_user(uid, &infop->si_uid);
+ if (!retval)
+ retval = put_user(status, &infop->si_status);
+ }
if (!retval)
retval = pid;
return retval;