[pacman-dev] [PATCH 0/4] Smatch warning fixes
Hi I ran smatch[1] on the pacman source code and it reported a few minor issues. Three out of four of the following patches are checks for NULL when freeing memory which are strictly not necessary since calling free with a NULL argument is a no-op. The last patch moves a NULL check before a pointer dereference which should be the correct place to put it. Cheers, Silvan [1] http://smatch.sourceforge.net/ Silvan Jegen (4): Remove unneeded NULL check Another unneeded NULL check removed Another NULL check removed Move NULL check before dereference src/pacman/pacman.c | 16 +++++++--------- src/pacman/util.c | 10 ++++------ src/util/pacsort.c | 5 +---- 3 files changed, 12 insertions(+), 19 deletions(-) -- 1.8.5.3
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/pacman.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c index 6bf94e9..7329f0f 100644 --- a/src/pacman/pacman.c +++ b/src/pacman/pacman.c @@ -421,9 +421,7 @@ static int parsearg_global(int opt) break; case OP_CONFIG: check_optarg(); - if(config->configfile) { - free(config->configfile); - } + free(config->configfile); config->configfile = strndup(optarg, PATH_MAX); break; case OP_DEBUG: -- 1.8.5.3
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/util.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/src/pacman/util.c b/src/pacman/util.c index 58b0cec..4aaa98f 100644 --- a/src/pacman/util.c +++ b/src/pacman/util.c @@ -206,12 +206,10 @@ int rmrf(const char *path) return 1; } for(dp = readdir(dirp); dp != NULL; dp = readdir(dirp)) { - if(dp->d_name) { - if(strcmp(dp->d_name, "..") != 0 && strcmp(dp->d_name, ".") != 0) { - char name[PATH_MAX]; - snprintf(name, PATH_MAX, "%s/%s", path, dp->d_name); - errflag += rmrf(name); - } + if(strcmp(dp->d_name, "..") != 0 && strcmp(dp->d_name, ".") != 0) { + char name[PATH_MAX]; + snprintf(name, PATH_MAX, "%s/%s", path, dp->d_name); + errflag += rmrf(name); } } closedir(dirp); -- 1.8.5.3
On Tue, Jan 28, 2014 at 10:50 AM, Silvan Jegen <s.jegen@gmail.com> wrote:
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/util.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/src/pacman/util.c b/src/pacman/util.c index 58b0cec..4aaa98f 100644 --- a/src/pacman/util.c +++ b/src/pacman/util.c @@ -206,12 +206,10 @@ int rmrf(const char *path) return 1; } for(dp = readdir(dirp); dp != NULL; dp = readdir(dirp)) { - if(dp->d_name) { - if(strcmp(dp->d_name, "..") != 0 && strcmp(dp->d_name, ".") != 0) { - char name[PATH_MAX]; - snprintf(name, PATH_MAX, "%s/%s", path, dp->d_name); - errflag += rmrf(name); - } + if(strcmp(dp->d_name, "..") != 0 && strcmp(dp->d_name, ".") != 0) { + char name[PATH_MAX]; + snprintf(name, PATH_MAX, "%s/%s", path, dp->d_name); + errflag += rmrf(name);
I'm failing to see how this one is valid. Please explain? I'm not sure the original code is right (we should likely be checking that d_name[0] is != '\0;), but removing the check completely seems heavy-handed.
} } closedir(dirp); -- 1.8.5.3
On Tue, Jan 28, 2014 at 10:58:30AM -0600, Dan McGee wrote:
On Tue, Jan 28, 2014 at 10:50 AM, Silvan Jegen <s.jegen@gmail.com> wrote:
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/util.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/src/pacman/util.c b/src/pacman/util.c index 58b0cec..4aaa98f 100644 --- a/src/pacman/util.c +++ b/src/pacman/util.c @@ -206,12 +206,10 @@ int rmrf(const char *path) return 1; } for(dp = readdir(dirp); dp != NULL; dp = readdir(dirp)) { - if(dp->d_name) { - if(strcmp(dp->d_name, "..") != 0 && strcmp(dp->d_name, ".") != 0) { - char name[PATH_MAX]; - snprintf(name, PATH_MAX, "%s/%s", path, dp->d_name); - errflag += rmrf(name); - } + if(strcmp(dp->d_name, "..") != 0 && strcmp(dp->d_name, ".") != 0) { + char name[PATH_MAX]; + snprintf(name, PATH_MAX, "%s/%s", path, dp->d_name); + errflag += rmrf(name);
I'm failing to see how this one is valid. Please explain? I'm not sure the original code is right (we should likely be checking that d_name[0] is != '\0;), but removing the check completely seems heavy-handed.
My reasoning was very simple. I assume that each directory entry MUST have a filename (that only contains a terminating NULL character) so checking whether the d_name field of the dirent struct is NULL should not be necessary. If I missed a case where the filename can actually be NULL then just ignore this one.
On Tue, Jan 28, 2014 at 11:33 AM, Silvan Jegen <s.jegen@gmail.com> wrote:
On Tue, Jan 28, 2014 at 10:58:30AM -0600, Dan McGee wrote:
On Tue, Jan 28, 2014 at 10:50 AM, Silvan Jegen <s.jegen@gmail.com> wrote:
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/util.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/src/pacman/util.c b/src/pacman/util.c index 58b0cec..4aaa98f 100644 --- a/src/pacman/util.c +++ b/src/pacman/util.c @@ -206,12 +206,10 @@ int rmrf(const char *path) return 1; } for(dp = readdir(dirp); dp != NULL; dp = readdir(dirp)) { - if(dp->d_name) { - if(strcmp(dp->d_name, "..") != 0 && strcmp(dp->d_name, ".") != 0) { - char name[PATH_MAX]; - snprintf(name, PATH_MAX, "%s/%s", path, dp->d_name); - errflag += rmrf(name); - } + if(strcmp(dp->d_name, "..") != 0 && strcmp(dp->d_name, ".") != 0) { + char name[PATH_MAX]; + snprintf(name, PATH_MAX, "%s/%s", path, dp->d_name); + errflag += rmrf(name);
I'm failing to see how this one is valid. Please explain? I'm not sure the original code is right (we should likely be checking that d_name[0] is != '\0;), but removing the check completely seems heavy-handed.
My reasoning was very simple. I assume that each directory entry MUST have a filename (that only contains a terminating NULL character) so checking whether the d_name field of the dirent struct is NULL should not be necessary.
If I missed a case where the filename can actually be NULL then just ignore this one.
Looking at it more, I think you're right here, especially after I trace the history of this code. I'm OK with this change. We no longer do it in the backend either (see commit 1b50223f for some history).
-Dan
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/util/pacsort.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/src/util/pacsort.c b/src/util/pacsort.c index 443e822..df3e809 100644 --- a/src/util/pacsort.c +++ b/src/util/pacsort.c @@ -97,10 +97,7 @@ static void buffer_free(struct buffer_t *buf) return; } - if(buf->mem) { - free(buf->mem); - } - + free(buf->mem); free(buf); } -- 1.8.5.3
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/pacman.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c index 7329f0f..1d821ef 100644 --- a/src/pacman/pacman.c +++ b/src/pacman/pacman.c @@ -262,13 +262,13 @@ static void setuseragent(void) static void cleanup(int ret) { /* free alpm library resources */ - if(config->handle && alpm_release(config->handle) == -1) { - pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); - } - - /* free memory */ - FREELIST(pm_targets); if(config) { + if(config->handle && alpm_release(config->handle) == -1) { + pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); + } + + /* free memory */ + FREELIST(pm_targets); config_free(config); config = NULL; } -- 1.8.5.3
On 01/28/14 at 05:50pm, Silvan Jegen wrote:
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/pacman.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c index 7329f0f..1d821ef 100644 --- a/src/pacman/pacman.c +++ b/src/pacman/pacman.c @@ -262,13 +262,13 @@ static void setuseragent(void) static void cleanup(int ret) { /* free alpm library resources */
This comment applies specifically to the alpm_release call and either needs to be moved with it or deleted.
- if(config->handle && alpm_release(config->handle) == -1) { - pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); - } - - /* free memory */ - FREELIST(pm_targets); if(config) { + if(config->handle && alpm_release(config->handle) == -1) { + pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); + } + + /* free memory */ + FREELIST(pm_targets);
pm_targets is independent of config and needs to be freed whether config is NULL or not.
config_free(config); config = NULL; } -- 1.8.5.3
On Tue, Jan 28, 2014 at 12:32:13PM -0500, Andrew Gregory wrote:
On 01/28/14 at 05:50pm, Silvan Jegen wrote:
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/pacman.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c index 7329f0f..1d821ef 100644 --- a/src/pacman/pacman.c +++ b/src/pacman/pacman.c @@ -262,13 +262,13 @@ static void setuseragent(void) static void cleanup(int ret) { /* free alpm library resources */
This comment applies specifically to the alpm_release call and either needs to be moved with it or deleted.
My bad.
- if(config->handle && alpm_release(config->handle) == -1) { - pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); - } - - /* free memory */ - FREELIST(pm_targets); if(config) { + if(config->handle && alpm_release(config->handle) == -1) { + pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); + } + + /* free memory */ + FREELIST(pm_targets);
pm_targets is independent of config and needs to be freed whether config is NULL or not.
Ditto. A corrected version of the patch can be found below. Hope I got it right this time. -->8-- (for use with git am --scissors) Subject: [PATCH v2] Move NULL check before dereference Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/pacman.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c index 7329f0f..3ecced5 100644 --- a/src/pacman/pacman.c +++ b/src/pacman/pacman.c @@ -261,18 +261,18 @@ static void setuseragent(void) */ static void cleanup(int ret) { - /* free alpm library resources */ - if(config->handle && alpm_release(config->handle) == -1) { - pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); - } - - /* free memory */ - FREELIST(pm_targets); if(config) { + /* free alpm library resources */ + if(config->handle && alpm_release(config->handle) == -1) { + pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); + } + config_free(config); config = NULL; } + /* free memory */ + FREELIST(pm_targets); exit(ret); } -- 1.8.5.3
On 29/01/14 03:58, Silvan Jegen wrote:
On Tue, Jan 28, 2014 at 12:32:13PM -0500, Andrew Gregory wrote:
On 01/28/14 at 05:50pm, Silvan Jegen wrote:
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/pacman.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c index 7329f0f..1d821ef 100644 --- a/src/pacman/pacman.c +++ b/src/pacman/pacman.c @@ -262,13 +262,13 @@ static void setuseragent(void) static void cleanup(int ret) { /* free alpm library resources */
This comment applies specifically to the alpm_release call and either needs to be moved with it or deleted.
My bad.
- if(config->handle && alpm_release(config->handle) == -1) { - pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); - } - - /* free memory */ - FREELIST(pm_targets); if(config) { + if(config->handle && alpm_release(config->handle) == -1) { + pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); + } + + /* free memory */ + FREELIST(pm_targets);
pm_targets is independent of config and needs to be freed whether config is NULL or not.
Ditto.
A corrected version of the patch can be found below. Hope I got it right this time.
-->8-- (for use with git am --scissors) Subject: [PATCH v2] Move NULL check before dereference
Signed-off-by: Silvan Jegen <s.jegen@gmail.com> --- src/pacman/pacman.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c index 7329f0f..3ecced5 100644 --- a/src/pacman/pacman.c +++ b/src/pacman/pacman.c @@ -261,18 +261,18 @@ static void setuseragent(void) */ static void cleanup(int ret) { - /* free alpm library resources */ - if(config->handle && alpm_release(config->handle) == -1) { - pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); - } - - /* free memory */ - FREELIST(pm_targets); if(config) { + /* free alpm library resources */ + if(config->handle && alpm_release(config->handle) == -1) { + pm_printf(ALPM_LOG_ERROR, "error releasing alpm library\n"); + } + config_free(config); config = NULL; }
+ /* free memory */ + FREELIST(pm_targets); exit(ret); }
This version looks fine. Allan
participants (4)
-
Allan McRae
-
Andrew Gregory
-
Dan McGee
-
Silvan Jegen