Re: [PATCH] libkmod: fix uninitialized variable usage warnings
From: Lucas De Marchi <hidden>
Date: 2017-11-07 03:24:55
On Mon, Nov 6, 2017 at 1:57 PM, Eugene Syromiatnikov [off-list ref] wrote:
quoted hunk ↗ jump to hunk
There are two places where _cleanup_free_ variables are not initialised by the time function exits that have been caught by gcc: In file included from libkmod/libkmod.c:35:0: libkmod/libkmod.c: In function 'kmod_lookup_alias_is_builtin': ./shared/util.h:73:13: warning: 'line' may be used uninitialized in this function [-Wmaybe-uninitialized] free(*(void**) p); ^ libkmod/libkmod.c:551:23: note: 'line' was declared here _cleanup_free_ char *line; ^ In file included from libkmod/libkmod-module.c:42:0: libkmod/libkmod-module.c: In function 'kmod_module_probe_insert_module': ./shared/util.h:73:13: warning: 'cmd' may be used uninitialized in this function [-Wmaybe-uninitialized] free(*(void**) p); ^ libkmod/libkmod-module.c:996:23: note: 'cmd' was declared here _cleanup_free_ char *cmd; ^ This patch initializes them to NULL so free become no-op in these cases. --- libkmod/libkmod-module.c | 2 +- libkmod/libkmod.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c index 0a3ef11..6f23c1a 100644 --- a/libkmod/libkmod-module.c +++ b/libkmod/libkmod-module.c@@ -995,7 +995,7 @@ static int module_do_install_commands(struct kmod_module *mod, { const char *command = kmod_module_get_install_commands(mod); char *p; - _cleanup_free_ char *cmd; + _cleanup_free_ char *cmd = NULL; int err; size_t cmdlen, options_len, varlen;diff --git a/libkmod/libkmod.c b/libkmod/libkmod.c index 69fe431..964772d 100644 --- a/libkmod/libkmod.c +++ b/libkmod/libkmod.c@@ -556,7 +556,7 @@ finish: bool kmod_lookup_alias_is_builtin(struct kmod_ctx *ctx, const char *name) { - _cleanup_free_ char *line; + _cleanup_free_ char *line = NULL;
This seems to be a bogus warning. See the line just below... there's no way to exit this function without first assigning 'line'. Lucas De Marchi