This is a note to let you know that I've just added the patch titled
kdb: Fix pager search for multi-line strings
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kdb-fix-pager-search-for-multi-line-strings.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 72f08330f4d8f1a9688003ec012a01c62525a304
Author: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Date: Wed Sep 9 15:17:08 2020 +0100
kdb: Fix pager search for multi-line strings
[ Upstream commit d081a6e353168f15e63eb9e9334757f20343319f ]
Currently using forward search doesn't handle multi-line strings correctly.
The search routine replaces line breaks with \0 during the search and, for
regular searches ("help | grep Common\n"), there is code after the line
has been discarded or printed to replace the break character.
However during a pager search ("help\n" followed by "/Common\n") when the
string is matched we will immediately return to normal output and the code
that should restore the \n becomes unreachable. Fix this by restoring the
replaced character when we disable the search mode and update the comment
accordingly.
Fixes: fb6daa7520f9d ("kdb: Provide forward search at more prompt")
Link: https://lore.kernel.org/r/20200909141708.338273-1-daniel.thompson@xxxxxxxxxx
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Signed-off-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 3a5184eb6977d..46821793637a1 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -679,12 +679,16 @@ int vkdb_printf(enum kdb_msgsrc src, const char *fmt, va_list ap)
size_avail = sizeof(kdb_buffer) - len;
goto kdb_print_out;
}
- if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH)
+ if (kdb_grepping_flag >= KDB_GREPPING_FLAG_SEARCH) {
/*
* This was a interactive search (using '/' at more
- * prompt) and it has completed. Clear the flag.
+ * prompt) and it has completed. Replace the \0 with
+ * its original value to ensure multi-line strings
+ * are handled properly, and return to normal mode.
*/
+ *cphold = replaced_byte;
kdb_grepping_flag = 0;
+ }
/*
* at this point the string is a full line and
* should be printed, up to the null.
