util/inteltool: Remove duplicated error message, switch to snprintf

Passing a string containing output from strerror() to perror() causes
double error message display. It is also causing segfaults when the
error message is longer than temp_string capacity.

To fix the problems, sterror() call has been removed so the error
message is printed only once. This could be enough to avoid segfaults,
but it is a good practice to limit output size with snprintf().

Change-Id: I5ccc37e404f278cafae0a451c5acaa27d7907cce
Signed-off-by: Maciej Suminski <maciej.suminski@cern.ch>
Reviewed-on: https://review.coreboot.org/21025
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

1 files changed, 5 insertions, 7 deletions

diff --git a/util/inteltool/cpu.c b/util/inteltool/cpu.c
index 7b2e503757..360b86b9d0 100644
--- a/util/inteltool/cpu.c
+++ b/util/inteltool/cpu.c
@@ -117,14 +117,13 @@ static int open_and_seek(int cpu, unsigned long msr, int mode, int *fd)
 	*fd = open(dev, mode);
 
 	if (*fd < 0) {
-		sprintf(temp_string,
-			"open(\"%s\"): %s\n", dev, strerror(errno));
+		snprintf(temp_string, sizeof(temp_string), "open(\"%s\")", dev);
 		perror(temp_string);
 		return -1;
 	}
 
 	if (lseek(*fd, msr, SEEK_SET) == (off_t)-1) {
-		sprintf(temp_string, "lseek(%lu): %s\n", msr, strerror(errno));
+		snprintf(temp_string, sizeof(temp_string), "lseek(%lu)", msr);
 		perror(temp_string);
 		close(*fd);
 		return -1;
@@ -141,7 +140,8 @@ msr_t rdmsr_from_cpu(int cpu, unsigned long addr)
 	char temp_string[50];
 
 	if (open_and_seek(cpu, addr, O_RDONLY, &fd) < 0) {
-		sprintf(temp_string, "Could not read MSR for CPU#%d", cpu);
+		snprintf(temp_string, sizeof(temp_string),
+			"Could not read MSR for CPU#%d", cpu);
 		perror(temp_string);
 	}
 
@@ -194,13 +194,11 @@ int print_sgx(void)
 #ifndef __DARWIN__
 	int ncpus = get_number_of_cpus();
 	int i = 0;
-	char temp_string[50];
 
 	printf("\n============= Dumping INTEL SGX status =============");
 
 	if (ncpus < 1) {
-		sprintf(temp_string, "Failed to get number of CPUs\n");
-		perror(temp_string);
+		perror("Failed to get number of CPUs");
 		error = -1;
 	} else {
 		printf("\nNumber of CPUs = %d\n", ncpus);