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.
Signed-off-by: Richard Cochran <richardcoch...@gmail.com>
---
kernel/time/posix-clock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/time/posix-clock.c b/kernel/time/posix-clock.c
index ce033c7..9cff0ab 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);
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
