diff options
authorRichard Cochran <richardcochran@gmail.com>2015-12-22 22:19:58 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-03-03 15:06:23 -0800
commit794c33bd215bbd1f7a3513f9c70a8e0afcbfcd7a (patch)
parenteeb7b0e01658684a743ccfd66a668e8a56d5ebb9 (diff)
posix-clock: Fix return code on the poll method's error path
commit 1b9f23727abb92c5e58f139e7d180befcaa06fe0 upstream. The posix_clock_poll function is supposed to return a bit mask of POLLxxx values. However, in case the hardware has disappeared (due to hot plugging for example) this code returns -ENODEV in a futile attempt to throw an error at the file descriptor level. The kernel's file_operations interface does not accept such error codes from the poll method. Instead, this function aught to return POLLERR. The value -ENODEV does, in fact, contain the POLLERR bit (and almost all the other POLLxxx bits as well), but only by chance. This patch fixes code to return a proper bit mask. Credit goes to Markus Elfring for pointing out the suspicious signed/unsigned mismatch. Reported-by: Markus Elfring <elfring@users.sourceforge.net> igned-off-by: Richard Cochran <richardcochran@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Julia Lawall <julia.lawall@lip6.fr> Link: http://lkml.kernel.org/r/1450819198-17420-1-git-send-email-richardcochran@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c
index ce033c7aa2e8..9cff0ab82b63 100644
--- a/kernel/time/posix-clock.c
+++ b/kernel/time/posix-clock.c
@@ -69,10 +69,10 @@ static ssize_t posix_clock_read(struct file *fp, char __user *buf,
static unsigned int posix_clock_poll(struct file *fp, poll_table *wait)
struct posix_clock *clk = get_posix_clock(fp);
- int result = 0;
+ unsigned int result = 0;
if (!clk)
- return -ENODEV;
+ return POLLERR;
if (clk->ops.poll)
result = clk->ops.poll(clk, fp, wait);