From: "George G. Davis" george_davis@mentor.com
As reported by Eugeniu Rosca, the newly added optional file argument does not validate if the file is indeed a watchdog, e.g.:
./watchdog-test -f /dev/zero Watchdog Ticking Away!
Fix it by confirming that the WDIOC_GETSUPPORT ioctl succeeds.
Reported-by: Eugeniu Rosca erosca@de.adit-jv.com Signed-off-by: George G. Davis george_davis@mentor.com Signed-off-by: Eugeniu Rosca erosca@de.adit-jv.com --- v1: Applied/tested on commit ce54eab71e210f ("kunit: fix failure to build without printk") of https://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest.git/lo...
tools/testing/selftests/watchdog/watchdog-test.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/tools/testing/selftests/watchdog/watchdog-test.c b/tools/testing/selftests/watchdog/watchdog-test.c index afff120c7be6..6ed822dc2222 100644 --- a/tools/testing/selftests/watchdog/watchdog-test.c +++ b/tools/testing/selftests/watchdog/watchdog-test.c @@ -97,6 +97,7 @@ int main(int argc, char *argv[]) int c; int oneshot = 0; char *file = "/dev/watchdog"; + struct watchdog_info info;
setbuf(stdout, NULL);
@@ -118,6 +119,16 @@ int main(int argc, char *argv[]) exit(-1); }
+ /* + * Validate that `file` is a watchdog device + */ + ret = ioctl(fd, WDIOC_GETSUPPORT, &info); + if (ret) { + printf("WDIOC_GETSUPPORT error '%s'\n", strerror(errno)); + close(fd); + exit(ret); + } + optind = 0;
while ((c = getopt_long(argc, argv, sopts, lopts, NULL)) != -1) {