On Mon, 16 Jan 2023 11:30:07 +0800
Yulong Zhang <yulong.zhang@xxxxxxxxxx> wrote:
> 1. fopen sysfs without fclose.
> 2. asprintf filename without free.
> 3. if asprintf return error,do not need to free the buffer.
>
> Signed-off-by: Yulong Zhang <yulong.zhang@xxxxxxxxxx>
> ---
> Yes, you are right. Thanks you for the advice.
> I found another problem, when asprintf return error, still free the
> buffer.This is not correct,I've removed it.
>
> > sysfsfp = fopen(filename, "r");
> > if (!sysfsfp) {
> > ret = -errno;
> > fprintf(stderr, "failed to open %s\n",
> > filename);
> > free(filename);
> > goto error_cleanup_array;
> > }
> > free(filename);
> Because in if statement still use filename,so I can't free filename
> before it.And I am not sure it can be removed,so I free filename after if
> statement.
Agreed. My suggestion is drop that error print to simplify the code.
It isn't particularly important to know the full filename that we failed
to open so I think dropping it is a reasonable thing to do.
If you really care about the message then
fprintf(stderr, "failed to open %s/%s_index\n", scan_el_dir, current->name);
will work.
>
> tools/iio/iio_utils.c | 17 ++++-------------
> 1 file changed, 4 insertions(+), 13 deletions(-)
>
> diff --git a/tools/iio/iio_utils.c b/tools/iio/iio_utils.c
> index 8d35893b2fa8..abec4331701c 100644
> --- a/tools/iio/iio_utils.c
> +++ b/tools/iio/iio_utils.c
> @@ -264,6 +264,7 @@ int iioutils_get_param_float(float *output, const char *param_name,
> if (fscanf(sysfsfp, "%f", output) != 1)
> ret = errno ? -errno : -ENODATA;
>
> + fclose(sysfsfp);
> break;
> }
> error_free_filename:
> @@ -350,6 +351,7 @@ int build_channel_array(const char *device_dir, int buffer_idx,
> free(filename);
> goto error_close_dir;
> }
> + free(filename);
>
> errno = 0;
> if (fscanf(sysfsfp, "%i", &ret) != 1) {
> @@ -357,7 +359,6 @@ int build_channel_array(const char *device_dir, int buffer_idx,
> if (fclose(sysfsfp))
> perror("build_channel_array(): Failed to close file");
>
> - free(filename);
> goto error_close_dir;
> }
> if (ret == 1)
> @@ -365,11 +366,9 @@ int build_channel_array(const char *device_dir, int buffer_idx,
>
> if (fclose(sysfsfp)) {
> ret = -errno;
> - free(filename);
> goto error_close_dir;
> }
>
> - free(filename);
> }
>
> *ci_array = malloc(sizeof(**ci_array) * (*counter));
> @@ -395,9 +394,9 @@ int build_channel_array(const char *device_dir, int buffer_idx,
> }
>
> sysfsfp = fopen(filename, "r");
> + free(filename);
> if (!sysfsfp) {
> ret = -errno;
> - free(filename);
> count--;
> goto error_cleanup_array;
> }
> @@ -405,20 +404,17 @@ int build_channel_array(const char *device_dir, int buffer_idx,
> errno = 0;
> if (fscanf(sysfsfp, "%i", ¤t_enabled) != 1) {
> ret = errno ? -errno : -ENODATA;
> - free(filename);
> count--;
> goto error_cleanup_array;
> }
>
> if (fclose(sysfsfp)) {
> ret = -errno;
> - free(filename);
> count--;
> goto error_cleanup_array;
> }
>
> if (!current_enabled) {
> - free(filename);
> count--;
> continue;
> }
> @@ -429,7 +425,6 @@ int build_channel_array(const char *device_dir, int buffer_idx,
> strlen(ent->d_name) -
> strlen("_en"));
> if (!current->name) {
> - free(filename);
> ret = -ENOMEM;
> count--;
> goto error_cleanup_array;
> @@ -439,7 +434,6 @@ int build_channel_array(const char *device_dir, int buffer_idx,
> ret = iioutils_break_up_name(current->name,
> ¤t->generic_name);
> if (ret) {
> - free(filename);
> free(current->name);
> count--;
> goto error_cleanup_array;
> @@ -450,7 +444,6 @@ int build_channel_array(const char *device_dir, int buffer_idx,
> scan_el_dir,
> current->name);
> if (ret < 0) {
> - free(filename);
> ret = -ENOMEM;
> goto error_cleanup_array;
> }
> @@ -463,6 +456,7 @@ int build_channel_array(const char *device_dir, int buffer_idx,
> free(filename);
> goto error_cleanup_array;
> }
> + free(filename);
>
> errno = 0;
> if (fscanf(sysfsfp, "%u", ¤t->index) != 1) {
> @@ -470,17 +464,14 @@ int build_channel_array(const char *device_dir, int buffer_idx,
> if (fclose(sysfsfp))
> perror("build_channel_array(): Failed to close file");
>
> - free(filename);
> goto error_cleanup_array;
> }
>
> if (fclose(sysfsfp)) {
> ret = -errno;
> - free(filename);
> goto error_cleanup_array;
> }
>
> - free(filename);
> /* Find the scale */
> ret = iioutils_get_param_float(¤t->scale,
> "scale",
