Re: [PATCH] tools: Improve signal handling in xen-vmtrace

[Hubert Jasudowicz <hubert.jasudowicz@xxxxxxx>]

On 2021-02-26, Hubert Jasudowicz wrote:
> Make sure xen-vmtrace exits cleanly in case SIGPIPE is sent. This can
> happen when piping the output to some other program.
> 
> Additionaly, add volatile qualifier to interrupted flag to avoid
> it being optimized away by the compiler.
> 
> Signed-off-by: Hubert Jasudowicz <hubert.jasudowicz@xxxxxxx>
> ---
>  tools/misc/xen-vmtrace.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/misc/xen-vmtrace.c b/tools/misc/xen-vmtrace.c
> index 7572e880c5..e2da043058 100644
> --- a/tools/misc/xen-vmtrace.c
> +++ b/tools/misc/xen-vmtrace.c
> @@ -43,7 +43,7 @@ static uint32_t domid, vcpu;
>  static size_t size;
>  static char *buf;
>  
> -static sig_atomic_t interrupted;
> +static volatile sig_atomic_t interrupted;
>  static void int_handler(int signum)
>  {
>      interrupted = 1;
> @@ -81,6 +81,9 @@ int main(int argc, char **argv)
>      if ( signal(SIGINT, int_handler) == SIG_ERR )
>          err(1, "Failed to register signal handler\n");
>  
> +    if ( signal(SIGPIPE, int_handler) == SIG_ERR )
> +        err(1, "Failed to register signal handler\n");
> +
>      if ( argc != 3 )
>      {
>          fprintf(stderr, "Usage: %s <domid> <vcpu_id>\n", argv[0]);
> -- 
> 2.30.0
> 
> 

Oops, forgot 4.15 tag. But IMO this should be included.

Thanks
Hubert Jasudowicz
CERT Polska