From: Emily Shaffer <emilyshaffer@google.com>
To: git@vger.kernel.org
Cc: jrn@google.com, Emily Shaffer <emilyshaffer@google.com>
Subject: [RFC PATCH] grep: provide sane default to grep_source struct
Date: Wed, 15 May 2019 19:00:23 -0700 [thread overview]
Message-ID: <20190516020023.61161-1-emilyshaffer@google.com> (raw)
grep_buffer creates a struct grep_source gs and calls grep_source()
with it. However, gs.name is null, which eventually produces a
segmentation fault in
grep_source()->grep_source_1()->show_line() when grep_opt.status_only is
not set.
This seems to be unreachable from existing commands but is reachable in
the event that someone rolls their own revision walk and neglects to set
rev_info->grep_filter->status_only. Conceivably, someone might want to
print all changed lines of all commits which match some regex.
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
---
Hiya,
I ran into this issue while I was working on a tutorial on rolling your
own revision walk. I didn't want to print all the lines associated with
a matching change, but it didn't seem good that a seemingly-sane
grep_filter config was segfaulting.
I don't know if adding a placeholder name is the right answer (hence RFC
patch).
Jonathan Nieder proposed alternatively adding some check to grep_source()
to ensure that if opt->status_only is unset, gs->name must be non-NULL
(and yell about it if not), as well as some extra comments indicating
what assumptions are made about the data coming into functions like
grep_source(). I'm fine with that as well (although I'm not sure it
makes sense semantically to require a name which the user probably can't
easily set, or else ban the user from printing LOC during grep). Mostly
I'm happy with any solution besides a segfault with no error logging :)
Thanks in advance for everyone's thoughts.
Emily
grep.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/grep.c b/grep.c
index 0d50598acd..fd84454faf 100644
--- a/grep.c
+++ b/grep.c
@@ -2045,7 +2045,7 @@ int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
struct grep_source gs;
int r;
- grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
+ grep_source_init(&gs, GREP_SOURCE_BUF, _("(in memory)"), NULL, NULL);
gs.buf = buf;
gs.size = size;
--
2.21.0.1020.gf2820cf01a-goog
next reply other threads:[~2019-05-16 2:00 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-16 2:00 Emily Shaffer [this message]
2019-05-16 3:07 ` [RFC PATCH] grep: provide sane default to grep_source struct Junio C Hamano
2019-05-16 3:13 ` Jonathan Nieder
2019-05-16 3:11 ` Jonathan Nieder
2019-05-16 21:05 ` Emily Shaffer
2019-05-16 21:44 ` [PATCH v2] " Emily Shaffer
2019-05-16 22:02 ` Jeff King
2019-05-21 23:52 ` Emily Shaffer
2019-05-22 0:17 ` Jonathan Nieder
2019-05-22 0:34 ` [PATCH v3] " Emily Shaffer
2019-05-22 0:58 ` Jonathan Nieder
2019-05-22 4:01 ` Jeff King
2019-05-23 20:23 ` [PATCH v4] grep: fail if call could output and name is null Emily Shaffer
2019-05-23 20:34 ` Jonathan Nieder
2019-05-28 17:57 ` Junio C Hamano
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