[PATCH v2] cpupower: monitor: Exit with error status if execvp() fail

[PATCH v2] cpupower: monitor: Exit with error status if execvp() fail

[Yiwei Lin]

In the case that we give a invalid command to idle_monitor for
monitoring, the execvp() will fail and thus go to the next line.
As a result, we'll see two differnt monitoring output. For
example, running `cpupower monitor -i 5 invalidcmd` which `invalidcmd`
is not executable.

---
V2:
- fix according to review from Shuah
---

Signed-off-by: Yiwei Lin <s921975628@gmail.com>
---
 tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c b/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
index f746099b5dac..7f8958f68eaa 100644
--- a/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
+++ b/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
@@ -6,6 +6,7 @@
  */
 
 
+#include <errno.h>
 #include <stdio.h>
 #include <unistd.h>
 #include <stdlib.h>
@@ -294,7 +295,10 @@ int fork_it(char **argv)
 
 	if (!child_pid) {
 		/* child */
-		execvp(argv[0], argv);
+		if (execvp(argv[0], argv) == -1) {
+			printf("Fail to execute %s\n", argv[0]);
+			exit(errno);
+		}
 	} else {
 		/* parent */
 		if (child_pid == -1) {
-- 
2.34.1

Re: [PATCH v2] cpupower: monitor: Exit with error status if execvp() fail

[Shuah Khan]

On 2/20/25 06:05, Yiwei Lin wrote:
> In the case that we give a invalid command to idle_monitor for
> monitoring, the execvp() will fail and thus go to the next line.
> As a result, we'll see two differnt monitoring output. For
> example, running `cpupower monitor -i 5 invalidcmd` which `invalidcmd`
> is not executable.
> 
> ---
> V2:
> - fix according to review from Shuah
> ---
> 
> Signed-off-by: Yiwei Lin <s921975628@gmail.com>
> ---
>   tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c b/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
> index f746099b5dac..7f8958f68eaa 100644
> --- a/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
> +++ b/tools/power/cpupower/utils/idle_monitor/cpupower-monitor.c
> @@ -6,6 +6,7 @@
>    */
>   
>   
> +#include <errno.h>
>   #include <stdio.h>
>   #include <unistd.h>
>   #include <stdlib.h>
> @@ -294,7 +295,10 @@ int fork_it(char **argv)
>   
>   	if (!child_pid) {
>   		/* child */
> -		execvp(argv[0], argv);
> +		if (execvp(argv[0], argv) == -1) {
> +			printf("Fail to execute %s\n", argv[0]);

Invalid monitor command will be a better message than
saying "failed to execute"

thanks,
-- Shuahg