From: Ben Hutchings <ben@decadent.org.uk>
Date: Tue, 11 Sep 2018 03:07:28 +0100
Subject: tools: turbostat: Add checks for failure of fgets() and fscanf()
Forwarded: https://marc.info/?l=linux-pm&m=153711036626779

Most calls to fgets() and fscanf() are followed by error checks.
Add an exit-on-error in the remaining cases.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 tools/power/x86/turbostat/turbostat.c | 28 +++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

Index: linux/tools/power/x86/turbostat/turbostat.c
===================================================================
--- linux.orig/tools/power/x86/turbostat/turbostat.c
+++ linux/tools/power/x86/turbostat/turbostat.c
@@ -2554,7 +2554,8 @@ int get_thread_siblings(struct cpu_topol
 	filep = fopen_or_die(path, "r");
 	do {
 		offset -= BITMASK_SIZE;
-		fscanf(filep, "%lx%c", &map, &character);
+		if (fscanf(filep, "%lx%c", &map, &character) != 2)
+			err(1, "%s: failed to parse file", path);
 		for (shift = 0; shift < BITMASK_SIZE; shift++) {
 			if ((map >> shift) & 0x1) {
 				so = shift + offset;
@@ -3407,14 +3408,14 @@ dump_sysfs_cstate_config(void)
 		input = fopen(path, "r");
 		if (input == NULL)
 			continue;
-		fgets(name_buf, sizeof(name_buf), input);
+		if (!fgets(name_buf, sizeof(name_buf), input))
+			err(1, "%s: failed to read file", path);
 
 		 /* truncate "C1-HSW\n" to "C1", or truncate "C1\n" to "C1" */
 		sp = strchr(name_buf, '-');
 		if (!sp)
 			sp = strchrnul(name_buf, '\n');
 		*sp = '\0';
-
 		fclose(input);
 
 		sprintf(path, "/sys/devices/system/cpu/cpu%d/cpuidle/state%d/desc",
@@ -3422,7 +3423,8 @@ dump_sysfs_cstate_config(void)
 		input = fopen(path, "r");
 		if (input == NULL)
 			continue;
-		fgets(desc, sizeof(desc), input);
+		if (!fgets(desc, sizeof(desc), input))
+			err(1, "%s: failed to read file", path);
 
 		fprintf(outf, "cpu%d: %s: %s", base_cpu, name_buf, desc);
 		fclose(input);
@@ -3444,7 +3446,8 @@ dump_sysfs_pstate_config(void)
 		fprintf(stderr, "NSFOD %s\n", path);
 		return;
 	}
-	fgets(driver_buf, sizeof(driver_buf), input);
+	if (!fgets(driver_buf, sizeof(driver_buf), input))
+		err(1, "%s: failed to read file", path);
 	fclose(input);
 
 	sprintf(path, "/sys/devices/system/cpu/cpu%d/cpufreq/scaling_governor",
@@ -3454,7 +3457,8 @@ dump_sysfs_pstate_config(void)
 		fprintf(stderr, "NSFOD %s\n", path);
 		return;
 	}
-	fgets(governor_buf, sizeof(governor_buf), input);
+	if (!fgets(governor_buf, sizeof(governor_buf), input))
+		err(1, "%s: failed to read file", path);
 	fclose(input);
 
 	fprintf(outf, "cpu%d: cpufreq driver: %s", base_cpu, driver_buf);
@@ -3463,7 +3467,8 @@ dump_sysfs_pstate_config(void)
 	sprintf(path, "/sys/devices/system/cpu/cpufreq/boost");
 	input = fopen(path, "r");
 	if (input != NULL) {
-		fscanf(input, "%d", &turbo);
+		if (fscanf(input, "%d", &turbo) != 1)
+			err(1, "%s: failed to parse number from file", path);
 		fprintf(outf, "cpufreq boost: %d\n", turbo);
 		fclose(input);
 	}
@@ -3471,7 +3476,8 @@ dump_sysfs_pstate_config(void)
 	sprintf(path, "/sys/devices/system/cpu/intel_pstate/no_turbo");
 	input = fopen(path, "r");
 	if (input != NULL) {
-		fscanf(input, "%d", &turbo);
+		if (fscanf(input, "%d", &turbo) != 1)
+			err(1, "%s: failed to parse number from file", path);
 		fprintf(outf, "cpufreq intel_pstate no_turbo: %d\n", turbo);
 		fclose(input);
 	}
@@ -5296,7 +5302,8 @@ void probe_sysfs(void)
 		input = fopen(path, "r");
 		if (input == NULL)
 			continue;
-		fgets(name_buf, sizeof(name_buf), input);
+		if (!fgets(name_buf, sizeof(name_buf), input))
+			err(1, "%s: failed to read file", path);
 
 		 /* truncate "C1-HSW\n" to "C1", or truncate "C1\n" to "C1" */
 		sp = strchr(name_buf, '-');
@@ -5323,7 +5330,8 @@ void probe_sysfs(void)
 		input = fopen(path, "r");
 		if (input == NULL)
 			continue;
-		fgets(name_buf, sizeof(name_buf), input);
+		if (!fgets(name_buf, sizeof(name_buf), input))
+			err(1, "%s: failed to read file", path);
 		 /* truncate "C1-HSW\n" to "C1", or truncate "C1\n" to "C1" */
 		sp = strchr(name_buf, '-');
 		if (!sp)