* [PATCH v2] Documentation/watchdog: check return value for magic close
@ 2016-07-19 15:41 Arnd Bergmann
2016-07-20 1:52 ` Guenter Roeck
2016-07-22 21:30 ` Timur Tabi
0 siblings, 2 replies; 3+ messages in thread
From: Arnd Bergmann @ 2016-07-19 15:41 UTC (permalink / raw)
To: Wim Van Sebroeck
Cc: Arnd Bergmann, Guenter Roeck, Jonathan Corbet, Timur Tabi,
linux-watchdog, linux-doc, linux-kernel
A recent commit added a write to the watchdog test code for doing the "magic
close", but that caused a compile-time warning:
Documentation/watchdog/src/watchdog-test.c: In function ‘main’:
Documentation/watchdog/src/watchdog-test.c:94:5: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result]
This changes the code to print a runtime warning if the write fails.
Fixes: 5a2d3de19602 ("Documentation/watchdog: add support for magic close to watchdog-test")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
v2: fix typo as pointed out by both Guenter Roeck and Randy Dunlap
---
Documentation/watchdog/src/watchdog-test.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/Documentation/watchdog/src/watchdog-test.c b/Documentation/watchdog/src/watchdog-test.c
index c69153913722..6983d05097e2 100644
--- a/Documentation/watchdog/src/watchdog-test.c
+++ b/Documentation/watchdog/src/watchdog-test.c
@@ -2,6 +2,7 @@
* Watchdog Driver Test Program
*/
+#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@@ -35,9 +36,13 @@ static void keep_alive(void)
static void term(int sig)
{
- write(fd, &v, 1);
+ int ret = write(fd, &v, 1);
+
close(fd);
- printf("\nStopping watchdog ticks...\n");
+ if (ret < 0)
+ printf("\nStopping watchdog ticks failed (%d)...\n", errno);
+ else
+ printf("\nStopping watchdog ticks...\n");
exit(0);
}
@@ -45,6 +50,7 @@ int main(int argc, char *argv[])
{
int flags;
unsigned int ping_rate = 1;
+ int ret;
setbuf(stdout, NULL);
@@ -91,7 +97,9 @@ int main(int argc, char *argv[])
sleep(ping_rate);
}
end:
- write(fd, &v, 1);
+ ret = write(fd, &v, 1);
+ if (ret < 0)
+ printf("Stopping watchdog ticks failed (%d)...\n", errno);
close(fd);
return 0;
}
--
2.9.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] Documentation/watchdog: check return value for magic close
2016-07-19 15:41 [PATCH v2] Documentation/watchdog: check return value for magic close Arnd Bergmann
@ 2016-07-20 1:52 ` Guenter Roeck
2016-07-22 21:30 ` Timur Tabi
1 sibling, 0 replies; 3+ messages in thread
From: Guenter Roeck @ 2016-07-20 1:52 UTC (permalink / raw)
To: Arnd Bergmann, Wim Van Sebroeck
Cc: Jonathan Corbet, Timur Tabi, linux-watchdog, linux-doc, linux-kernel
On 07/19/2016 08:41 AM, Arnd Bergmann wrote:
> A recent commit added a write to the watchdog test code for doing the "magic
> close", but that caused a compile-time warning:
>
> Documentation/watchdog/src/watchdog-test.c: In function ‘main’:
> Documentation/watchdog/src/watchdog-test.c:94:5: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result]
>
> This changes the code to print a runtime warning if the write fails.
>
> Fixes: 5a2d3de19602 ("Documentation/watchdog: add support for magic close to watchdog-test")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> ---
> v2: fix typo as pointed out by both Guenter Roeck and Randy Dunlap
> ---
> Documentation/watchdog/src/watchdog-test.c | 14 +++++++++++---
> 1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/watchdog/src/watchdog-test.c b/Documentation/watchdog/src/watchdog-test.c
> index c69153913722..6983d05097e2 100644
> --- a/Documentation/watchdog/src/watchdog-test.c
> +++ b/Documentation/watchdog/src/watchdog-test.c
> @@ -2,6 +2,7 @@
> * Watchdog Driver Test Program
> */
>
> +#include <errno.h>
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> @@ -35,9 +36,13 @@ static void keep_alive(void)
>
> static void term(int sig)
> {
> - write(fd, &v, 1);
> + int ret = write(fd, &v, 1);
> +
> close(fd);
> - printf("\nStopping watchdog ticks...\n");
> + if (ret < 0)
> + printf("\nStopping watchdog ticks failed (%d)...\n", errno);
> + else
> + printf("\nStopping watchdog ticks...\n");
> exit(0);
> }
>
> @@ -45,6 +50,7 @@ int main(int argc, char *argv[])
> {
> int flags;
> unsigned int ping_rate = 1;
> + int ret;
>
> setbuf(stdout, NULL);
>
> @@ -91,7 +97,9 @@ int main(int argc, char *argv[])
> sleep(ping_rate);
> }
> end:
> - write(fd, &v, 1);
> + ret = write(fd, &v, 1);
> + if (ret < 0)
> + printf("Stopping watchdog ticks failed (%d)...\n", errno);
> close(fd);
> return 0;
> }
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] Documentation/watchdog: check return value for magic close
2016-07-19 15:41 [PATCH v2] Documentation/watchdog: check return value for magic close Arnd Bergmann
2016-07-20 1:52 ` Guenter Roeck
@ 2016-07-22 21:30 ` Timur Tabi
1 sibling, 0 replies; 3+ messages in thread
From: Timur Tabi @ 2016-07-22 21:30 UTC (permalink / raw)
To: Arnd Bergmann, Wim Van Sebroeck
Cc: Guenter Roeck, Jonathan Corbet, linux-watchdog, linux-doc, linux-kernel
Arnd Bergmann wrote:
> A recent commit added a write to the watchdog test code for doing the "magic
> close", but that caused a compile-time warning:
>
> Documentation/watchdog/src/watchdog-test.c: In function ‘main’:
> Documentation/watchdog/src/watchdog-test.c:94:5: warning: ignoring return value of ‘write’, declared with attribute warn_unused_result [-Wunused-result]
>
> This changes the code to print a runtime warning if the write fails.
>
> Fixes: 5a2d3de19602 ("Documentation/watchdog: add support for magic close to watchdog-test")
> Signed-off-by: Arnd Bergmann<arnd@arndb.de>
Acked-by: Timur Tabi <timur@codeaurora.org>
Thanks for this patch. I don't know why I didn't notice the warnings
before.
--
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm
Technologies, Inc. Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-07-20 1:52 ` Guenter Roeck
2016-07-22 21:30 ` Timur Tabi
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