Re: [Xen-devel] [PATCH] tools/xenpaging: fix bug of Segmentation fault

[Patrick Colp <pjcolp@xxxxxxxxx>]

Great catch, thanks! Just a couple minor nitpicks, if this patch
hasn't been applied yet.

For the line:

 + Â Âint rc = -1, rc1;

could this instead be:

+    int rc = -1;
+    int rc1;


And for:

+ Â Âif ( argc != 3 ) {

would it be possible to move the { down onto it's own line?

These changes would make it fit in with the rest of the source better.


Thanks,
Patrick


On 10 February 2010 21:57, Yu Zhiguo <yuzg@xxxxxxxxxxxxxx> wrote:
> Segmentation fault occurs in two situations:
> 1. argc is less than 3
> 2. xenpaging_init() fault
>
> Signed-off-by: Yu Zhiguo <yuzg@xxxxxxxxxxxxxx>
>
> diff --git a/tools/xenpaging/xenpaging.c b/tools/xenpaging/xenpaging.c
> --- a/tools/xenpaging/xenpaging.c
> +++ b/tools/xenpaging/xenpaging.c
> @@ -212,6 +212,9 @@
> Â{
> Â Â int rc;
>
> + Â Âif ( paging == NULL )
> + Â Â Â Âreturn 0;
> +
> Â Â /* Tear down domain paging in Xen */
> Â Â rc = xc_mem_event_disable(paging->xc_handle, paging->mem_event.domain_id);
> Â Â if ( rc != 0 )
> @@ -447,20 +450,29 @@
>
> Âint main(int argc, char *argv[])
> Â{
> - Â Âdomid_t domain_id = atoi(argv[1]);
> - Â Âint num_pages = atoi(argv[2]);
> + Â Âdomid_t domain_id;
> + Â Âint num_pages;
> Â Â xenpaging_t *paging;
> - Â Âxenpaging_victim_t victims[num_pages];
> + Â Âxenpaging_victim_t *victims;
> Â Â mem_event_request_t req;
> Â Â mem_event_response_t rsp;
> Â Â int i;
> - Â Âint rc;
> + Â Âint rc = -1, rc1;
>
> Â Â int open_flags = O_CREAT | O_TRUNC | O_RDWR;
> Â Â mode_t open_mode = S_IRUSR | S_IRGRP | S_IROTH | S_IWUSR | S_IWGRP | 
> S_IWOTH;
> Â Â char filename[80];
> Â Â int fd;
>
> + Â Âif ( argc != 3 ) {
> + Â Â Â Âfprintf(stderr, "Usage: %s <domain_id> <num_pages>\n", argv[0]);
> + Â Â Â return -1;
> + Â Â}
> + Â Âdomain_id = atoi(argv[1]);
> + Â Ânum_pages = atoi(argv[2]);
> +
> + Â Âvictims = calloc(num_pages, sizeof(xenpaging_victim_t));
> +
> Â Â /* Open file */
> Â Â sprintf(filename, "page_cache_%d", domain_id);
> Â Â fd = open(filename, open_flags, open_mode);
> @@ -586,15 +598,17 @@
> Â Â }
>
> Âout:
> + Â Âfree(victims);
> +
> Â Â /* Tear down domain paging */
> - Â Ârc = xenpaging_teardown(paging);
> - Â Âif ( rc != 0 )
> - Â Â{
> + Â Ârc1 = xenpaging_teardown(paging);
> + Â Âif ( rc1 != 0 )
> Â Â Â Â ERROR("Error tearing down paging");
> - Â Â Â Âexit(1);
> - Â Â}
>
> - Â Âreturn 0;
> + Â Âif ( rc == 0 )
> + Â Â Â Ârc = rc1;
> +
> + Â Âreturn rc;
> Â}
>
>
>
>
> _______________________________________________
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> http://lists.xensource.com/xen-devel
>
>

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