pstore: fs superblock limits

[ Upstream commit 83b8a3fbe3aa82ac3c253b698ae6a9be2dbdd5e0 ]

Leaving granularity at 1ns because it is dependent on the specific
attached backing pstore module. ramoops has microsecond resolution.

Fix the readback of ramoops fractional timestamp microseconds,
which has incorrectly been reporting the value as nanoseconds.

Fixes: 3f8f80f0 ("pstore/ram: Read and write to the 'compressed' flag of pstore").
Signed-off-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Acked-by: NKees Cook <keescook@chromium.org>
Acked-by: NJeff Layton <jlayton@kernel.org>
Cc: anton@enomsg.org
Cc: ccross@android.com
Cc: keescook@chromium.org
Cc: tony.luck@intel.com
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

fs/pstore/ram.c

@@ -162,6 +162,7 @@ static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
 	if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu-%c\n%n",
 		   (time64_t *)&time->tv_sec, &time->tv_nsec, &data_type,
 		   &header_length) == 3) {
+		time->tv_nsec *= 1000;
 		if (data_type == 'C')
 			*compressed = true;
 		else
@@ -169,6 +170,7 @@ static int ramoops_read_kmsg_hdr(char *buffer, struct timespec64 *time,
 	} else if (sscanf(buffer, RAMOOPS_KERNMSG_HDR "%lld.%lu\n%n",
 			  (time64_t *)&time->tv_sec, &time->tv_nsec,
 			  &header_length) == 2) {
+		time->tv_nsec *= 1000;
 		*compressed = false;
 	} else {
 		time->tv_sec = 0;