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| author | Vitaly Mayatskikh <v.mayatskih@gmail.com> | 2009-09-23 15:56:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-24 07:21:00 -0700 |
| commit | b6fe2d117e98805ee76352e6468f87d494a97292 (patch) | |
| tree | 3de99eb7652647000b53bca1f6ea740c926ccfca /kernel/exit.c | |
| parent | dfe16dfa4ac178d9a10b489a73d535c6976e48d2 (diff) | |
| download | lwn-b6fe2d117e98805ee76352e6468f87d494a97292.tar.gz lwn-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>
Diffstat (limited to 'kernel/exit.c')
| -rw-r--r-- | kernel/exit.c | 26 |
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; |