From c15bcbbcea383d1a1ac3c16cdea5ada4f26c5611 Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Mon, 27 Jul 2015 18:45:02 +0100 Subject: [PATCH] libxl: properly clean up array in libxl_list_cpupool failure path Document how cpupool_info works. Distinguish success (ERROR_FAIL + ENOENT) vs failure in libxl_list_cpupool and properly clean up the array in failure path. Also switch to libxl__realloc and call libxl_cpupool_{init,dispose} where appropriate. There is change of behaviour. Previously if memory allocation fails the said function returns NULL. Now memory allocation failure is fatal. This is in line with how we deal with memory allocation failure in other places in libxl though. Signed-off-by: Wei Liu Reviewed-by: Dario Faggioli Acked-by: Ian Campbell --- tools/libxl/libxl.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c index 614ca33c3a..083f099459 100644 --- a/tools/libxl/libxl.c +++ b/tools/libxl/libxl.c @@ -682,6 +682,11 @@ int libxl_domain_info(libxl_ctx *ctx, libxl_dominfo *info_r, return 0; } +/* Returns: + * 0 - success + * ERROR_FAIL + errno == ENOENT - no entry found + * ERROR_$FOO + errno != ENOENT - other failure + */ static int cpupool_info(libxl__gc *gc, libxl_cpupoolinfo *info, uint32_t poolid, @@ -737,7 +742,8 @@ int libxl_cpupool_info(libxl_ctx *ctx, libxl_cpupoolinfo * libxl_list_cpupool(libxl_ctx *ctx, int *nb_pool_out) { GC_INIT(ctx); - libxl_cpupoolinfo info, *ptr, *tmp; + libxl_cpupoolinfo info, *ptr; + int i; uint32_t poolid; @@ -745,24 +751,29 @@ libxl_cpupoolinfo * libxl_list_cpupool(libxl_ctx *ctx, int *nb_pool_out) poolid = 0; for (i = 0;; i++) { - if (cpupool_info(gc, &info, poolid, false)) + libxl_cpupoolinfo_init(&info); + if (cpupool_info(gc, &info, poolid, false)) { + libxl_cpupoolinfo_dispose(&info); + if (errno != ENOENT) goto out; break; - tmp = realloc(ptr, (i + 1) * sizeof(libxl_cpupoolinfo)); - if (!tmp) { - LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "allocating cpupool info"); - libxl_cpupoolinfo_list_free(ptr, i); - ptr = NULL; - goto out; } - ptr = tmp; + + ptr = libxl__realloc(NOGC, ptr, (i+1) * sizeof(libxl_cpupoolinfo)); ptr[i] = info; poolid = info.poolid + 1; + /* Don't dispose of info because it will be returned to caller */ } *nb_pool_out = i; -out: + GC_FREE; return ptr; + +out: + libxl_cpupoolinfo_list_free(ptr, i); + *nb_pool_out = 0; + GC_FREE; + return NULL; } /* this API call only list VM running on this host. A VM can -- 2.39.5