[LTP] [PATCH v1] madvise11.c:Check loadable module before rmmod

[Wei Gao]

Signed-off-by: Wei Gao <wegao@suse.com>
---
 testcases/kernel/syscalls/madvise/madvise11.c | 32 +++++++++++++++++--
 1 file changed, 30 insertions(+), 2 deletions(-)

diff --git a/testcases/kernel/syscalls/madvise/madvise11.c b/testcases/kernel/syscalls/madvise/madvise11.c
index 7e291d571..bac077fc8 100644
--- a/testcases/kernel/syscalls/madvise/madvise11.c
+++ b/testcases/kernel/syscalls/madvise/madvise11.c
@@ -33,6 +33,7 @@
 #define NUM_LOOPS	5
 #define NUM_PAGES	32
 #define NUM_PAGES_OFFSET	5
+#define MAX_BUF 4094
 
 /* Needed module to online back memory pages */
 #define HW_MODULE	"hwpoison_inject"
@@ -291,6 +292,31 @@ static void unpoison_this_pfn(unsigned long pfn, int fd)
 	SAFE_WRITE(0, fd, pfn_str, strlen(pfn_str));
 }
 
+static int is_loadable_module(const char *modname)
+{
+	char command[MAX_BUF];
+	char line[MAX_BUF];
+	char *token;
+
+	sprintf(command, "lsmod | grep '^%s'", modname);
+
+	FILE *fp = popen(command, "r");
+
+	if (fp == NULL)
+		tst_brk(TBROK, "Popen command %s failed", command);
+
+	if (fgets(line, MAX_BUF, fp) != NULL) {
+		token = strtok(line, " \t\n");
+		if (strcmp(token, modname) == 0) {
+			pclose(fp);
+			return 1;
+		}
+	}
+
+	pclose(fp);
+	return 0;
+}
+
 /* Find and open the <debugfs>/hwpoison/unpoison-pfn special file */
 static int open_unpoison_pfn(void)
 {
@@ -337,6 +363,7 @@ static void unpoison_pfn(char *begin_tag)
 	unsigned long *pfns;
 	const char *const cmd_rmmod[] = {"rmmod", HW_MODULE, NULL};
 	int found_pfns, fd;
+	int is_loadable = -1;
 
 	pfns = SAFE_MALLOC(sizeof(pfns) * maximum_pfns * run_iterations);
 
@@ -351,8 +378,9 @@ static void unpoison_pfn(char *begin_tag)
 
 		SAFE_CLOSE(fd);
 	}
-	/* remove hwpoison only if we probed it */
-	if (hwpoison_probe)
+	/* remove hwpoison only if we probed it and not built in*/
+	is_loadable = is_loadable_module(HW_MODULE);
+	if (hwpoison_probe && (is_loadable == 1))
 		SAFE_CMD(cmd_rmmod, NULL, NULL);
 }
 
-- 
2.35.3