Re: [PATCH] xl: do not leak cpupool names

[Juergen Gross <juergen.gross@ts.fujitsu.com>]

Am 06.09.2012 13:46, schrieb Ian Campbell:
> # HG changeset patch
> # User Ian Campbell<ian.campbell@citrix.com>
> # Date 1346931944 -3600
> # Node ID d4d7031eb68bf0ce9bc83901b699cf13a2c73c95
> # Parent  1db796c3c0b97bba222f20db543c227e313ec1be
> xl: do not leak cpupool names.
>
> Valgrind reports:
> ==3076== 7 bytes in 1 blocks are definitely lost in loss record 1 of 1
> ==3076==    at 0x402458C: malloc (vg_replace_malloc.c:270)
> ==3076==    by 0x406F86D: libxl_cpupoolid_to_name (libxl_utils.c:102)
> ==3076==    by 0x8058742: parse_config_data (xl_cmdimpl.c:639)
> ==3076==    by 0x805BD56: create_domain (xl_cmdimpl.c:1838)
> ==3076==    by 0x805DAED: main_create (xl_cmdimpl.c:3903)
> ==3076==    by 0x804D39D: main (xl.c:285)
>
> And indeed there are several places where xl uses
> libxl_cpupoolid_to_name as a boolean to test if the pool name is
> valid and leaks the name if it is. Introduce an is_valid helper and
> use that instead.
>
> Signed-off-by: Ian Campbell<ian.campbell@citrix.com>

Acked-by: Juergen Gross<juergen.gross@ts.fujitsu.com>

> ---
>
> This leak is in xl not libxl so this is 4.3 material IMHO.
>
> diff -r 1db796c3c0b9 -r d4d7031eb68b tools/libxl/libxl_utils.c
> --- a/tools/libxl/libxl_utils.c	Thu Sep 06 12:24:44 2012 +0100
> +++ b/tools/libxl/libxl_utils.c	Thu Sep 06 12:45:44 2012 +0100
> @@ -103,6 +103,17 @@ char *libxl_cpupoolid_to_name(libxl_ctx
>       return s;
>   }
>
> +/* This is a bit horrid but without xs_exists it seems like the only way. */
> +int libxl_cpupoolid_is_valid(libxl_ctx *ctx, uint32_t poolid)
> +{
> +    int ret;
> +    char *s = libxl_cpupoolid_to_name(ctx, poolid);
> +
> +    ret = (s != NULL);
> +    free(s);
> +    return ret;
> +}
> +
>   char *libxl__cpupoolid_to_name(libxl__gc *gc, uint32_t poolid)
>   {
>       char *s = libxl_cpupoolid_to_name(libxl__gc_owner(gc), poolid);
> diff -r 1db796c3c0b9 -r d4d7031eb68b tools/libxl/libxl_utils.h
> --- a/tools/libxl/libxl_utils.h	Thu Sep 06 12:24:44 2012 +0100
> +++ b/tools/libxl/libxl_utils.h	Thu Sep 06 12:45:44 2012 +0100
> @@ -24,6 +24,7 @@ int libxl_name_to_domid(libxl_ctx *ctx,
>   char *libxl_domid_to_name(libxl_ctx *ctx, uint32_t domid);
>   int libxl_name_to_cpupoolid(libxl_ctx *ctx, const char *name, uint32_t *poolid);
>   char *libxl_cpupoolid_to_name(libxl_ctx *ctx, uint32_t poolid);
> +int libxl_cpupoolid_is_valid(libxl_ctx *ctx, uint32_t poolid);
>   int libxl_get_stubdom_id(libxl_ctx *ctx, int guest_domid);
>   int libxl_is_stubdom(libxl_ctx *ctx, uint32_t domid, uint32_t *target_domid);
>   int libxl_create_logfile(libxl_ctx *ctx, const char *name, char **full_name);
> diff -r 1db796c3c0b9 -r d4d7031eb68b tools/libxl/xl_cmdimpl.c
> --- a/tools/libxl/xl_cmdimpl.c	Thu Sep 06 12:24:44 2012 +0100
> +++ b/tools/libxl/xl_cmdimpl.c	Thu Sep 06 12:45:44 2012 +0100
> @@ -636,7 +636,7 @@ static void parse_config_data(const char
>           c_info->poolid = -1;
>           cpupool_qualifier_to_cpupoolid(buf,&c_info->poolid, NULL);
>       }
> -    if (!libxl_cpupoolid_to_name(ctx, c_info->poolid)) {
> +    if (!libxl_cpupoolid_is_valid(ctx, c_info->poolid)) {
>           fprintf(stderr, "Illegal pool specified\n");
>           exit(1);
>       }
> @@ -4733,7 +4733,7 @@ static int sched_domain_output(libxl_sch
>
>       if (cpupool) {
>           if (cpupool_qualifier_to_cpupoolid(cpupool,&poolid, NULL) ||
> -            !libxl_cpupoolid_to_name(ctx, poolid)) {
> +            !libxl_cpupoolid_is_valid(ctx, poolid)) {
>               fprintf(stderr, "unknown cpupool \'%s\'\n", cpupool);
>               return -ERROR_FAIL;
>           }
> @@ -4863,7 +4863,7 @@ int main_sched_credit(int argc, char **a
>
>           if (cpupool) {
>               if (cpupool_qualifier_to_cpupoolid(cpupool,&poolid, NULL) ||
> -                !libxl_cpupoolid_to_name(ctx, poolid)) {
> +                !libxl_cpupoolid_is_valid(ctx, poolid)) {
>                   fprintf(stderr, "unknown cpupool \'%s\'\n", cpupool);
>                   return -ERROR_FAIL;
>               }
> @@ -6290,7 +6290,7 @@ int main_cpupooldestroy(int argc, char *
>       pool = argv[optind];
>
>       if (cpupool_qualifier_to_cpupoolid(pool,&poolid, NULL) ||
> -        !libxl_cpupoolid_to_name(ctx, poolid)) {
> +        !libxl_cpupoolid_is_valid(ctx, poolid)) {
>           fprintf(stderr, "unknown cpupool \'%s\'\n", pool);
>           return -ERROR_FAIL;
>       }
> @@ -6311,7 +6311,7 @@ int main_cpupoolrename(int argc, char **
>       pool = argv[optind++];
>
>       if (cpupool_qualifier_to_cpupoolid(pool,&poolid, NULL) ||
> -        !libxl_cpupoolid_to_name(ctx, poolid)) {
> +        !libxl_cpupoolid_is_valid(ctx, poolid)) {
>           fprintf(stderr, "unknown cpupool \'%s\'\n", pool);
>           return -ERROR_FAIL;
>       }
> @@ -6348,7 +6348,7 @@ int main_cpupoolcpuadd(int argc, char **
>       }
>
>       if (cpupool_qualifier_to_cpupoolid(pool,&poolid, NULL) ||
> -        !libxl_cpupoolid_to_name(ctx, poolid)) {
> +        !libxl_cpupoolid_is_valid(ctx, poolid)) {
>           fprintf(stderr, "unknown cpupool \'%s\'\n", pool);
>           return -ERROR_FAIL;
>       }
> @@ -6392,7 +6392,7 @@ int main_cpupoolcpuremove(int argc, char
>       }
>
>       if (cpupool_qualifier_to_cpupoolid(pool,&poolid, NULL) ||
> -        !libxl_cpupoolid_to_name(ctx, poolid)) {
> +        !libxl_cpupoolid_is_valid(ctx, poolid)) {
>           fprintf(stderr, "unknown cpupool \'%s\'\n", pool);
>           return -ERROR_FAIL;
>       }
> @@ -6435,7 +6435,7 @@ int main_cpupoolmigrate(int argc, char *
>       }
>
>       if (cpupool_qualifier_to_cpupoolid(pool,&poolid, NULL) ||
> -        !libxl_cpupoolid_to_name(ctx, poolid)) {
> +        !libxl_cpupoolid_is_valid(ctx, poolid)) {
>           fprintf(stderr, "unknown cpupool \'%s\'\n", pool);
>           return -ERROR_FAIL;
>       }
> diff -r 1db796c3c0b9 -r d4d7031eb68b tools/libxl/xl_sxp.c
> --- a/tools/libxl/xl_sxp.c	Thu Sep 06 12:24:44 2012 +0100
> +++ b/tools/libxl/xl_sxp.c	Thu Sep 06 12:45:44 2012 +0100
> @@ -37,6 +37,7 @@ void printf_info_sexp(int domid, libxl_d
>
>       libxl_domain_create_info *c_info =&d_config->c_info;
>       libxl_domain_build_info *b_info =&d_config->b_info;
> +    char *pool;
>
>       printf("(domain\n\t(domid %d)\n", domid);
>       printf("\t(create_info)\n");
> @@ -54,8 +55,10 @@ void printf_info_sexp(int domid, libxl_d
>       } else {
>           printf("\t(uuid<unknown>)\n");
>       }
> -
> -    printf("\t(cpupool %s)\n", libxl_cpupoolid_to_name(ctx, c_info->poolid));
> +    pool = libxl_cpupoolid_to_name(ctx, c_info->poolid);
> +    if (pool)
> +        printf("\t(cpupool %s)\n", pool);
> +    free(pool);
>       if (c_info->xsdata)
>           printf("\t(xsdata contains data)\n");
>       else
>
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>


-- 
Juergen Gross                 Principal Developer Operating Systems
PBG PDG ES&S SWE OS6                   Telephone: +49 (0) 89 3222 2967
Fujitsu Technology Solutions              e-mail: juergen.gross@ts.fujitsu.com
Domagkstr. 28                           Internet: ts.fujitsu.com
D-80807 Muenchen                 Company details: ts.fujitsu.com/imprint.html