As reported by Eugeniu Rosca, a side of affect of commit c3f2490d6e92
("selftests: watchdog: Add optional file argument") is that arbitrary files
may be opened for watchdog testing, e.g../watchdog-test -f /dev/zero Watchdog Ticking Away! To prevent watchdog-test from operating on non-watchdog device files, validate that a file is indeed a watchdog device via an ioctl(WDIOC_GETSUPPORT) call. While we're at it, since the watchdog_info is available as a result of the ioctl(WDIOC_GETSUPPORT) call, add a command line option to optionally show the watchdog_info. Reported-by: Eugeniu Rosca <[email protected]> Tested-by: Eugeniu Rosca <[email protected]> Signed-off-by: George G. Davis <[email protected]> Signed-off-by: Eugeniu Rosca <[email protected]> --- 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/log/?h=next v2: Squashed [1] and [2], and update commit description as discussed in [3]. [1] https://patchwork.kernel.org/patch/11136283/ [2] https://patchwork.kernel.org/patch/11136285/ [3] https://patchwork.kernel.org/patch/11136285/#22883573 --- tools/testing/selftests/watchdog/watchdog-test.c | 27 +++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/watchdog/watchdog-test.c b/tools/testing/selftests/watchdog/watchdog-test.c index afff120c7be6..f45e510500c0 100644 --- a/tools/testing/selftests/watchdog/watchdog-test.c +++ b/tools/testing/selftests/watchdog/watchdog-test.c @@ -19,7 +19,7 @@ int fd; const char v = 'V'; -static const char sopts[] = "bdehp:t:Tn:NLf:"; +static const char sopts[] = "bdehp:t:Tn:NLf:i"; static const struct option lopts[] = { {"bootstatus", no_argument, NULL, 'b'}, {"disable", no_argument, NULL, 'd'}, @@ -32,6 +32,7 @@ static const struct option lopts[] = { {"getpretimeout", no_argument, NULL, 'N'}, {"gettimeleft", no_argument, NULL, 'L'}, {"file", required_argument, NULL, 'f'}, + {"info", no_argument, NULL, 'i'}, {NULL, no_argument, NULL, 0x0} }; @@ -72,6 +73,7 @@ static void usage(char *progname) printf("Usage: %s [options]\n", progname); printf(" -f, --file\t\tOpen watchdog device file\n"); printf("\t\t\tDefault is /dev/watchdog\n"); + printf(" -i, --info\t\tShow watchdog_info\n"); printf(" -b, --bootstatus\tGet last boot status (Watchdog/POR)\n"); printf(" -d, --disable\t\tTurn off the watchdog timer\n"); printf(" -e, --enable\t\tTurn on the watchdog timer\n"); @@ -97,6 +99,7 @@ int main(int argc, char *argv[]) int c; int oneshot = 0; char *file = "/dev/watchdog"; + struct watchdog_info info; setbuf(stdout, NULL); @@ -118,6 +121,16 @@ 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) { @@ -205,6 +218,18 @@ int main(int argc, char *argv[]) case 'f': /* Handled above */ break; + case 'i': + /* + * watchdog_info was obtained as part of file open + * validation. So we just show it here. + */ + oneshot = 1; + printf("watchdog_info:\n"); + printf(" identity:\t\t%s\n", info.identity); + printf(" firmware_version:\t%u\n", + info.firmware_version); + printf(" options:\t\t%08x\n", info.options); + break; default: usage(argv[0]); -- 2.7.4
