Re: [igt-dev] [PATCH i-g-t 3/8] lib/params: overhaul param saving

Petri Latvala
2020-04-28T12:26:25Z

On Tue, Apr 21, 2020 at 07:17:20PM +0300, Juha-Pekka Heikkila wrote:
> From: Jani Nikula <jani.nikula@intel.com>
>
> More generic, use existing functions.
>
> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
> Signed-off-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
> ---
> lib/igt_params.c | 101 +++++++++++++++++++----------------------------
> 1 file changed, 41 insertions(+), 60 deletions(-)
>
> diff --git a/lib/igt_params.c b/lib/igt_params.c
> index f220e73b..b5ac1266 100644
> --- a/lib/igt_params.c
> +++ b/lib/igt_params.c
> @@ -34,92 +34,74 @@
> #include "igt_params.h"
> #include "igt_sysfs.h"
>
> -#define MODULE_PARAM_DIR "/sys/module/i915/parameters/"
> -#define PARAM_NAME_MAX_SZ 32
> -#define PARAM_VALUE_MAX_SZ 16
> -#define PARAM_FILE_PATH_MAX_SZ (strlen(MODULE_PARAM_DIR) + PARAM_NAME_MAX_SZ)
> -
> struct module_param_data {
> - char name[PARAM_NAME_MAX_SZ];
> - char original_value[PARAM_VALUE_MAX_SZ];
> + char *path;
> + char *name;
> + char *original_value;
>
> struct module_param_data *next;
> };
> struct module_param_data *module_params = NULL;
>
> -static void igt_module_param_exit_handler(int sig)
> +static void igt_params_exit_handler(int sig)
> {
> - const size_t dir_len = strlen(MODULE_PARAM_DIR);
> - char file_path[PARAM_FILE_PATH_MAX_SZ];
> struct module_param_data *data;
> - int fd;
> -
> - /* We don't need to assert string sizes on this function since they were
> - * already checked before being stored on the lists. Besides,
> - * igt_assert() is not AS-Safe. */
> - strcpy(file_path, MODULE_PARAM_DIR);
> + int dir;
>
> for (data = module_params; data != NULL; data = data->next) {
> - strcpy(file_path + dir_len, data->name);
> -
> - fd = open(file_path, O_RDWR);
> - if (fd >= 0) {
> - int size = strlen (data->original_value);
> -
> - if (size != write(fd, data->original_value, size)) {
> - const char msg[] = "WARNING: Module parameters "
> - "may not have been reset to their "
> - "original values\n";
> - assert(write(STDERR_FILENO, msg, sizeof(msg))
> - == sizeof(msg));
> - }
> -
> - close(fd);
> + dir = open(data->path, O_RDONLY);
> +
> + if (!igt_sysfs_set(dir, data->name, data->original_value)) {
> + const char msg[] = "WARNING: Module parameters "
> + "may not have been reset to their "
> + "original values\n";
> + assert(write(STDERR_FILENO, msg, sizeof(msg))
> + == sizeof(msg));
> }
> +
> + close(dir);
> }
> /* free() is not AS-Safe, so we can't call it here. */
> }
>
> /**
> - * igt_save_module_param:
> - * @name: name of the i915.ko module parameter
> - * @file_path: full sysfs file path for the parameter
> + * igt_params_save:
> + * @dir: file handle for path
> + * @path: full path to the sysfs directory
> + * @name: name of the sysfs attribute
> *
> - * Reads the current value of an i915.ko module parameter, saves it on an array,
> - * then installs an exit handler to restore it when the program exits.
> + * Reads the current value of a sysfs attribute, saves it on an array, then
> + * installs an exit handler to restore it when the program exits.
> *
> * It is safe to call this function multiple times for the same parameter.
> *
> * Notice that this function is called by igt_set_module_param(), so that one -
> * or one of its wrappers - is the only function the test programs need to call.
> */
> -static void igt_save_module_param(const char *name, const char *file_path)
> +static void igt_params_save(int dir, const char *path, const char *name)
> {
> struct module_param_data *data;
> - size_t n;
> - int fd;
>
> /* Check if this parameter is already saved. */
> for (data = module_params; data != NULL; data = data->next)
> - if (strncmp(data->name, name, PARAM_NAME_MAX_SZ) == 0)
> + if (strcmp(data->path, path) == 0 &&
> + strcmp(data->name, name) == 0)
> return;
>
> if (!module_params)
> - igt_install_exit_handler(igt_module_param_exit_handler);
> + igt_install_exit_handler(igt_params_exit_handler);
>
> data = calloc(1, sizeof (*data));
> igt_assert(data);
>
> - strncpy(data->name, name, PARAM_NAME_MAX_SZ - 1);
> -
> - fd = open(file_path, O_RDONLY);
> - igt_assert(fd >= 0);
> + data->path = strdup(path);
> + igt_assert(data->path);
>
> - n = read(fd, data->original_value, PARAM_VALUE_MAX_SZ);
> - igt_assert_f(n > 0 && n < PARAM_VALUE_MAX_SZ,
> - "Need to increase PARAM_VALUE_MAX_SZ\n");
> + data->name = strdup(name);
> + igt_assert(data->name);
>
> - igt_assert(close(fd) == 0);
> + data->original_value = igt_sysfs_get(dir, name);
> + igt_assert(data->original_value);
>
> data->next = module_params;
> module_params = data;
> @@ -205,22 +187,21 @@ bool igt_params_set(int device, const char *parameter, const char *fmt, ...)
> */
> void igt_set_module_param(const char *name, const char *val)
> {
> - char file_path[PARAM_FILE_PATH_MAX_SZ];
> - size_t len = strlen(val);
> - int fd;
> + const char *path = "/sys/module/i915/parameters";
> + int dir;
>
> - igt_assert_f(strlen(name) < PARAM_NAME_MAX_SZ,
> - "Need to increase PARAM_NAME_MAX_SZ\n");
> - strcpy(file_path, MODULE_PARAM_DIR);
> - strcpy(file_path + strlen(MODULE_PARAM_DIR), name);
> + dir = open(path, O_RDONLY);
> + igt_assert(dir >= 0);
>
> - igt_save_module_param(name, file_path);
> + igt_params_save(dir, path, name);
>
> - fd = open(file_path, O_RDWR);
> - igt_assert(write(fd, val, len) == len);
> - igt_assert(close(fd) == 0);
> + igt_assert(igt_sysfs_set(dir, name, val));
> +
> + igt_assert(close(dir) == 0);
> }
>
> +#define PARAM_VALUE_MAX_SZ 16
> +

Is this define still needed for something?

--
Petri Latvala