From aa2bf9bc6414b6972b9e51903c1ce7b1f057aee2 Mon Sep 17 00:00:00 2001 From: Sasikantha babu Date: Wed, 21 Mar 2012 20:10:54 +0530 Subject: itimer: Schedule silent NULL pointer fixup in setitimer() for removal setitimer() should return -EFAULT if called with an invalid pointer for value. The current code excludes a NULL pointer from this rule and silently uses it to stop the timer. This violates the spec. Warn about user space apps which rely on that feature and schedule it for removal. [ tglx: Massaged changelog, warn message and Doc entry ] Signed-off-by: Sasikantha babu Link: http://lkml.kernel.org/r/1332340854-26053-1-git-send-email-sasikanth.v19@gmail.com Signed-off-by: Thomas Gleixner --- kernel/itimer.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel/itimer.c') diff --git a/kernel/itimer.c b/kernel/itimer.c index 22000c3db0dd..c70369a74b5a 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -284,8 +284,11 @@ SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value, if (value) { if(copy_from_user(&set_buffer, value, sizeof(set_buffer))) return -EFAULT; - } else + } else { memset((char *) &set_buffer, 0, sizeof(set_buffer)); + WARN_ONCE(1, "setitimer: new_value pointer is NULL." + " Misfeature support will be removed\n"); + } error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL); if (error || !ovalue) -- cgit v1.2.3 From 9886f444129171569461d8c39983e16f4871e3b4 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 10 Apr 2012 10:50:55 +0200 Subject: itimer: Use printk_once instead of WARN_ONCE David pointed out, that WARN_ONCE() to report usage of an deprecated misfeature make folks unhappy. Use printk_once() instead. Andrew told me to stop grumbling and to remove the silly typecast while touching the file. Reported-by: David Rientjes Cc: Andrew Morton Signed-off-by: Thomas Gleixner --- kernel/itimer.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'kernel/itimer.c') diff --git a/kernel/itimer.c b/kernel/itimer.c index c70369a74b5a..8d262b467573 100644 --- a/kernel/itimer.c +++ b/kernel/itimer.c @@ -285,9 +285,10 @@ SYSCALL_DEFINE3(setitimer, int, which, struct itimerval __user *, value, if(copy_from_user(&set_buffer, value, sizeof(set_buffer))) return -EFAULT; } else { - memset((char *) &set_buffer, 0, sizeof(set_buffer)); - WARN_ONCE(1, "setitimer: new_value pointer is NULL." - " Misfeature support will be removed\n"); + memset(&set_buffer, 0, sizeof(set_buffer)); + printk_once(KERN_WARNING "%s calls setitimer() with new_value NULL pointer." + " Misfeature support will be removed\n", + current->comm); } error = do_setitimer(which, &set_buffer, ovalue ? &get_buffer : NULL); -- cgit v1.2.3