Hi Maciej,
On 9/29/2023 1:21 AM, Maciej Wieczor-Retman wrote: ...
diff --git a/tools/testing/selftests/resctrl/resctrlfs.c b/tools/testing/selftests/resctrl/resctrlfs.c index 3a8111362d26..342a3dbcdbb6 100644 --- a/tools/testing/selftests/resctrl/resctrlfs.c +++ b/tools/testing/selftests/resctrl/resctrlfs.c @@ -8,6 +8,7 @@
- Sai Praneeth Prakhya sai.praneeth.prakhya@intel.com,
- Fenghua Yu fenghua.yu@intel.com
*/ +#include <fcntl.h> #include <limits.h> #include "resctrl.h" @@ -490,9 +491,8 @@ int write_bm_pid_to_resctrl(pid_t bm_pid, char *ctrlgrp, char *mongrp, */ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val) {
- char controlgroup[1024], schema[1024], reason[64];
- int resource_id, ret = 0;
- FILE *fp;
- char controlgroup[1024], schema[1024], reason[128];
- int resource_id, fd, schema_len = 0, ret = 0;
if (strncmp(resctrl_val, MBA_STR, sizeof(MBA_STR)) && strncmp(resctrl_val, MBM_STR, sizeof(MBM_STR)) && @@ -520,27 +520,37 @@ int write_schemata(char *ctrlgrp, char *schemata, int cpu_no, char *resctrl_val) if (!strncmp(resctrl_val, CAT_STR, sizeof(CAT_STR)) || !strncmp(resctrl_val, CMT_STR, sizeof(CMT_STR)))
sprintf(schema, "%s%d%c%s", "L3:", resource_id, '=', schemata);
schema_len = snprintf(schema, sizeof(schema), "%s%d%c%s\n","L3:", resource_id, '=', schemata);
sprintf(schema, "%s%d%c%s", "MB:", resource_id, '=', schemata);
schema_len = snprintf(schema, sizeof(schema), "%s%d%c%s\n","MB:", resource_id, '=', schemata);- if (schema_len < 1) {
I find that this complicates the code since this is not the typical snprintf() error checking (0 is a valid snprintf() return). I think it will make the code easier to understand if it sticks to snprintf() error checking and initialize schema_len to match. What I mean with this is something like this:
int schema_len = -1;
if (...) schema_len = snprintf(...);
if (schema_len < 0 || schema_len >= sizeof(schema)) /* error handling */
snprintf(reason, sizeof(reason),"snprintf() failed with return value : %d", schema_len);ret = -1;goto out;- }
- fp = fopen(controlgroup, "w");
- if (!fp) {
sprintf(reason, "Failed to open control group");
- fd = open(controlgroup, O_WRONLY);
- if (fd < 0) {
snprintf(reason, sizeof(reason),"open() failed : %s", strerror(errno));goto out; }
- if (fprintf(fp, "%s\n", schema) < 0) {
sprintf(reason, "Failed to write schemata in control group");fclose(fp);
- if (write(fd, schema, schema_len) < 0) {
snprintf(reason, sizeof(reason),"write() failed : %s", strerror(errno));close(fd);goto out; }
- fclose(fp);
- close(fd);
- schema[schema_len - 1] = 0;
out: ksft_print_msg("Write schema "%s" to resctrl FS%s%s\n",
Also please note that _if_ there is an early exit then uninitialized schema will be printed. Maybe this also needs a schema[1024] = {} ?
Reinette