All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, joe@perches.com, linux-mm@kvack.org,
	lukas.bulwahn@gmail.com, mm-commits@vger.kernel.org,
	mrinalmni@gmail.com, torvalds@linux-foundation.org
Subject: [patch 10/19] checkpatch: fix the usage of capture group ( ... )
Date: Fri, 04 Sep 2020 16:35:52 -0700	[thread overview]
Message-ID: <20200904233552.kLq6B7QPc%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200904163454.4db0e6ce0c4584d2653678a3@linux-foundation.org>

From: Mrinal Pandey <mrinalmni@gmail.com>
Subject: checkpatch: fix the usage of capture group ( ... )

The usage of "capture group (...)" in the immediate condition after `&&`
results in `$1` being uninitialized.  This issues a warning "Use of
uninitialized value $1 in regexp compilation at ./scripts/checkpatch.pl
line 2638".

I noticed this bug while running checkpatch on the set of commits from
v5.7 to v5.8-rc1 of the kernel on the commits with a diff content in their
commit message.

This bug was introduced in the script by commit e518e9a59ec3 ("checkpatch:
emit an error when there's a diff in a changelog").  It has been in the
script since then.

The author intended to store the match made by capture group in variable
`$1`.  This should have contained the name of the file as `[\w/]+`
matched.  However, this couldn't be accomplished due to usage of capture
group and `$1` in the same regular expression.

Fix this by placing the capture group in the condition before `&&`.  Thus,
`$1` can be initialized to the text that capture group matches thereby
setting it to the desired and required value.

Link: https://lkml.kernel.org/r/20200714032352.f476hanaj2dlmiot@mrinalpandey
Fixes: e518e9a59ec3 ("checkpatch: emit an error when there's a diff in a changelog")
Signed-off-by: Mrinal Pandey <mrinalmni@gmail.com>
Reviewed-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Tested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 scripts/checkpatch.pl |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/scripts/checkpatch.pl~checkpatch-fix-the-usage-of-capture-group
+++ a/scripts/checkpatch.pl
@@ -2639,8 +2639,8 @@ sub process {
 
 # Check if the commit log has what seems like a diff which can confuse patch
 		if ($in_commit_log && !$commit_log_has_diff &&
-		    (($line =~ m@^\s+diff\b.*a/[\w/]+@ &&
-		      $line =~ m@^\s+diff\b.*a/([\w/]+)\s+b/$1\b@) ||
+		    (($line =~ m@^\s+diff\b.*a/([\w/]+)@ &&
+		      $line =~ m@^\s+diff\b.*a/[\w/]+\s+b/$1\b@) ||
 		     $line =~ m@^\s*(?:\-\-\-\s+a/|\+\+\+\s+b/)@ ||
 		     $line =~ m/^\s*\@\@ \-\d+,\d+ \+\d+,\d+ \@\@/)) {
 			ERROR("DIFF_IN_COMMIT_MSG",
_

  parent reply	other threads:[~2020-09-04 23:35 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-04 23:34 incoming Andrew Morton
2020-09-04 23:35 ` [patch 01/19] memcg: fix use-after-free in uncharge_batch Andrew Morton
2020-09-04 23:35 ` [patch 02/19] mm: memcg: fix memcg reclaim soft lockup Andrew Morton
2020-09-04 23:35 ` [patch 03/19] mm: slub: fix conversion of freelist_corrupted() Andrew Morton
2020-09-04 23:35 ` [patch 04/19] MAINTAINERS: update Cavium/Marvell entries Andrew Morton
2020-09-04 23:35 ` [patch 05/19] MAINTAINERS: add LLVM maintainers Andrew Morton
2020-09-05 17:25   ` Masahiro Yamada
2020-09-04 23:35 ` [patch 06/19] MAINTAINERS: IA64: mark Status as Odd Fixes only Andrew Morton
2020-09-04 23:35 ` [patch 07/19] mm: track page table modifications in __apply_to_page_range() Andrew Morton
2020-09-04 23:35 ` [patch 08/19] ipc: adjust proc_ipc_sem_dointvec definition to match prototype Andrew Morton
2020-09-04 23:35 ` [patch 09/19] fork: adjust sysctl_max_threads " Andrew Morton
2020-09-04 23:35 ` Andrew Morton [this message]
2020-09-04 23:35 ` [patch 11/19] mm: madvise: fix vma user-after-free Andrew Morton
2020-09-04 23:35 ` [patch 12/19] mm/migrate: fixup setting UFFD_WP flag Andrew Morton
2020-09-04 23:36 ` [patch 13/19] mm/rmap: fixup copying of soft dirty and uffd ptes Andrew Morton
2020-09-04 23:36 ` [patch 14/19] mm/migrate: remove unnecessary is_zone_device_page() check Andrew Morton
2020-09-04 23:36 ` [patch 15/19] mm/migrate: preserve soft dirty in remove_migration_pte() Andrew Morton
2020-09-04 23:36 ` [patch 16/19] mm/hugetlb: try preferred node first when alloc gigantic page from cma Andrew Morton
2020-09-04 23:36 ` [patch 17/19] mm/hugetlb: fix a race between hugetlb sysctl handlers Andrew Morton
2020-09-04 23:36 ` [patch 18/19] mm/khugepaged.c: fix khugepaged's request size in collapse_file Andrew Morton
2020-09-04 23:36 ` [patch 19/19] include/linux/log2.h: add missing () around n in roundup_pow_of_two() Andrew Morton

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200904233552.kLq6B7QPc%akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=joe@perches.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lukas.bulwahn@gmail.com \
    --cc=mm-commits@vger.kernel.org \
    --cc=mrinalmni@gmail.com \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.