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author | Richard Cochran <richardcochran@gmail.com> | 2015-12-23 00:19:58 +0300 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2015-12-29 13:33:06 +0300 |
commit | 1b9f23727abb92c5e58f139e7d180befcaa06fe0 (patch) | |
tree | 7a5f0545c6ebad9d9eb42380e6624c37bb06aaf9 /kernel/time/posix-clock.c | |
parent | 74bf8efb5fa6e958d2d7c7917b8bb672085ec0c6 (diff) | |
download | linux-1b9f23727abb92c5e58f139e7d180befcaa06fe0.tar.xz |
posix-clock: Fix return code on the poll method's error path
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
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time/posix-clock.c')
-rw-r--r-- | kernel/time/posix-clock.c | 4 |
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); |