From: Li Xi <lixi@ddn.com>
Date: Tue, 11 Jun 2019 12:28:30 +0000 (+0800)
Subject: LU-12420 utils: llog_reader handles uninitialized mountdata
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=c8f270a7d7ed92ca408a8ca39c200332042227eb;p=fs%2Flustre-release.git

LU-12420 utils: llog_reader handles uninitialized mountdata

When reading an mountdata that has never been used, "llog_reader
CONFIGS/mountdata" command crashes with following output:

Header size : 500170753
Time : Wed Sep  4 00:57:37 6869
Number of records: 65534
Target uuid :
-----------------------
Segmentation fault

After apply this patch, llog_reader will print following message
and quit under this circumstance:

Header size : 500170753
Time : Wed Sep  4 00:57:37 6869
Number of records: 65534
Target uuid :
-----------------------
uninitialized llog record at index 0

Lustre-change: https://review.whamcloud.com/35178
Lustre-commit: 46f53da979344c88ab985de7227a81240a8107bf

Change-Id: I25147f7fd09c6d59ff0049bdb20ac1979cf43ee4
Signed-off-by: Li Xi <lixi@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Wang Shilong <wshilong@ddn.com>
Reviewed-by: Li Dongyang <dongyangli@ddn.com>
Signed-off-by: Etienne AUJAMES <eaujames@ddn.com>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/48303
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
---

diff --git a/lustre/utils/llog_reader.c b/lustre/utils/llog_reader.c
index 6e7064f..b4e4757 100644
--- a/lustre/utils/llog_reader.c
+++ b/lustre/utils/llog_reader.c
@@ -278,7 +278,7 @@ int llog_pack_buffer(int fd, struct llog_log_hdr **llog,
 	/* the llog header not countable here.*/
 	recs_num = count - 1;
 
-	recs_buf = malloc(recs_num * sizeof(**recs_pr));
+	recs_buf = calloc(recs_num, sizeof(**recs_pr));
 	if (recs_buf == NULL) {
 		rc = -ENOMEM;
 		llapi_error(LLAPI_MSG_ERROR, rc,
@@ -934,6 +934,12 @@ static void print_records(struct llog_rec_hdr **recs,
 	int i, skip = 0;
 
 	for (i = 0; i < rec_number; i++) {
+		if (recs[i] == NULL) {
+			llapi_printf(LLAPI_MSG_NORMAL,
+				     "uninitialized llog record at index %d\n",
+				     i);
+			break;
+		}
 		printf("#%.2d (%.3d)", __le32_to_cpu(recs[i]->lrh_index),
 		       __le32_to_cpu(recs[i]->lrh_len));