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authorMarti Raudsepp <marti@juffo.org>2012-03-09 16:45:36 +0200
committerLennart Poettering <lennart@poettering.net>2012-03-14 17:55:55 +0100
commit189f6d82eef8bccb733f735281bed4588dccbbd9 (patch)
tree7e7f60f4050e574399f664cb2d5f3b3b337ca300
parent8af0fcdb909b87ef4dcef34d50df814656acec81 (diff)
journal: Don't hold pointers to journal while remapping
Hi! I was trying out the journal and the journalctl utility sometimes crashed on me. After some debugging, I tracked it down to the fact that next_with_matches() holds the "c" object pointer through the journal_file_next_entry_for_data() call -- which apparently may re-map the journal file, invalidating the pointer. The attached patch fixes this crash for me, but being unfamiliar with the code, I don't know if I'm doing the right thing. This patch is also available from my github repository: git://github.com/intgr/systemd.git https://github.com/intgr/systemd Regards, Marti For the record, here's the original stack trace at the time of remapping: ret=0x7fff1d5cdec0) at src/journal/journal-file.c:330 ret=0x7fff1d5cdf28) at src/journal/journal-file.c:414 ret=0x7fff1d5ce0a0, offset=0x7fff1d5ce098) at src/journal/journal-file.c:1101 i=5705, ret=0x7fff1d5ce0a0, offset=0x7fff1d5ce098) at src/journal/journal-file.c:1147 p=6413608, data_offset=66600, direction=DIRECTION_DOWN, ret=0x7fff1d5ce0a0, offset=0x7fff1d5ce098) at src/journal/journal-file.c:1626 direction=DIRECTION_DOWN, ret=0x7fff1d5ce120, offset=0x7fff1d5ce128) at src/journal/sd-journal.c:533 direction=DIRECTION_DOWN, ret=0x7fff1d5ce170, offset=0x7fff1d5ce178) at src/journal/sd-journal.c:595 src/journal/sd-journal.c:651 From 9266fc6a58065a7c5dab67430fd78925e519dce9 Mon Sep 17 00:00:00 2001 From: Marti Raudsepp <marti@juffo.org> Date: Fri, 9 Mar 2012 16:23:00 +0200 Subject: [PATCH] journal: Don't hold pointers to journal while remapping This would cause a segfault otherwise.
-rw-r--r--src/journal/sd-journal.c12
1 files changed, 11 insertions, 1 deletions
diff --git a/src/journal/sd-journal.c b/src/journal/sd-journal.c
index baf51db1a8..86ac267de4 100644
--- a/src/journal/sd-journal.c
+++ b/src/journal/sd-journal.c
@@ -527,6 +527,9 @@ static int next_with_matches(sd_journal *j, JournalFile *f, direction_t directio
* matches are not OK */
r = journal_file_next_entry_for_data(f, c, cp, le64toh(c->entry.items[k].object_offset), direction, &qo, &q);
+ /* This pointer is invalidated if the window was
+ * remapped. May need to re-fetch it later */
+ c = NULL;
if (r < 0)
return r;
@@ -552,8 +555,15 @@ static int next_with_matches(sd_journal *j, JournalFile *f, direction_t directio
/* Did this entry match against all matches? */
if (found) {
- if (ret)
+ if (ret) {
+ if (c == NULL) {
+ /* Re-fetch the entry */
+ r = journal_file_move_to_object(f, OBJECT_ENTRY, cp, &c);
+ if (r < 0)
+ return r;
+ }
*ret = c;
+ }
if (offset)
*offset = cp;
return 1;