libswap.c: Improve calculate swap dev number

I encounter a dead loop on following code in our test on some non-intel archrs (aarch64, ppc64le, s390x): while ((c = fgetc(fp)) != EOF) Use fgets() instead of fgetc() can avoid the above issue. Link: https://lore.kernel.org/ltp/[email protected]/ Reviewed-by: Petr Vorel <[email protected]> Signed-off-by: Wei Gao <[email protected]>
SierraWireless · Mar 5, 2024 · 6f82542 · 6f82542
1 parent ee628ef
commit 6f82542
Showing 1 changed file with 4 additions and 5 deletions.
diff --git a/libs/libltpswap/libswap.c b/libs/libltpswap/libswap.c
@@ -13,6 +13,7 @@
 
 #define TST_NO_DEFAULT_MAIN
 #define DEFAULT_MAX_SWAPFILE 32
+#define BUFSIZE 200
 
 #include "tst_test.h"
 #include "libswap.h"
@@ -279,16 +280,14 @@ int tst_count_swaps(void)
 {
 	FILE *fp;
 	int used = -1;
-	char c;
+	char buf[BUFSIZE];
 
 	fp = SAFE_FOPEN("/proc/swaps", "r");
 	if (fp == NULL)
 		return -1;
 
-	while ((c = fgetc(fp)) != EOF) {
-		if (c == '\n')
-			used++;
-	}
+	while (fgets(buf, BUFSIZE, fp) != NULL)
+		used++;
 
 	SAFE_FCLOSE(fp);
 	if (used < 0)