From: Jiri Slaby <jslaby@suse.cz>
To: gregkh@linuxfoundation.org
Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
Jiri Slaby <jslaby@suse.cz>
Subject: [PATCH 33/36] tty/vt: consolemap: change refcount only if needed in con_do_clear_unimap()
Date: Tue, 7 Jun 2022 12:49:43 +0200 [thread overview]
Message-ID: <20220607104946.18710-33-jslaby@suse.cz> (raw)
In-Reply-To: <20220607104946.18710-1-jslaby@suse.cz>
con_do_clear_unimap() currently decreases and increases refcount of old
dictionary in a back and forth fashion. This makes the code really hard
to follow. Decrease the refcount only if everything went well and we
really allocated a new one and decoupled from the old dictionary.
I sincerelly hope I did not make a mistake in this (ill) logic.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/tty/vt/consolemap.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c
index 01b7e49f1f91..4d8efe74315c 100644
--- a/drivers/tty/vt/consolemap.c
+++ b/drivers/tty/vt/consolemap.c
@@ -535,22 +535,23 @@ static int con_do_clear_unimap(struct vc_data *vc)
{
struct uni_pagedict *old = *vc->vc_uni_pagedir_loc;
- if (!old || --old->refcount) {
+ if (!old || old->refcount > 1) {
struct uni_pagedict *new = kzalloc(sizeof(*new), GFP_KERNEL);
- if (!new) {
- if (old)
- old->refcount++;
+ if (!new)
return -ENOMEM;
- }
+
new->refcount = 1;
*vc->vc_uni_pagedir_loc = new;
+
+ if (old)
+ old->refcount--;
} else {
if (old == dflt)
dflt = NULL;
- old->refcount++;
old->sum = 0;
con_release_unimap(old);
}
+
return 0;
}
--
2.36.1
next prev parent reply other threads:[~2022-06-07 10:54 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-07 10:49 [PATCH 01/36] tty/vt: consolemap: use ARRAY_SIZE() Jiri Slaby
2022-06-07 10:49 ` [PATCH 02/36] tty/vt: consolemap: rename and document struct uni_pagedir Jiri Slaby
2022-06-07 12:36 ` Ilpo Järvinen
2022-06-08 5:42 ` Jiri Slaby
2022-06-07 10:49 ` [PATCH 03/36] tty/vt: consolemap: define UNI_* macros for constants Jiri Slaby
2022-06-07 13:21 ` Ilpo Järvinen
2022-06-08 6:55 ` Jiri Slaby
2022-06-08 9:54 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 04/36] tty/vt: consolemap: decrypt inverse_translate() Jiri Slaby
2022-06-07 12:54 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 05/36] tty/vt: consolemap: remove extern from function decls Jiri Slaby
2022-06-07 13:33 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 06/36] tty/vt: consolemap: convert macros to static inlines Jiri Slaby
2022-06-07 13:31 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 07/36] tty/vt: consolemap: make parameters of inverse_translate() saner Jiri Slaby
2022-06-07 13:32 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 08/36] tty/vt: consolemap: one line = one statement Jiri Slaby
2022-06-07 13:35 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 09/36] tty/vt: consolemap: use | for binary addition Jiri Slaby
2022-06-07 13:36 ` Ilpo Järvinen
2022-06-07 13:40 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 10/36] tty/vt: consolemap: introduce UNI_*() macros Jiri Slaby
2022-06-07 13:47 ` Ilpo Järvinen
2022-06-08 6:59 ` Jiri Slaby
2022-06-08 7:30 ` Jiri Slaby
2022-06-08 8:02 ` Ilpo Järvinen
2022-06-08 8:18 ` Jiri Slaby
2022-06-07 10:49 ` [PATCH 11/36] tty/vt: consolemap: zero uni_pgdir using kcalloc() Jiri Slaby
2022-06-07 13:51 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 12/36] tty/vt: consolemap: use sizeof(*pointer) instead of sizeof(type) Jiri Slaby
2022-06-07 14:00 ` Ilpo Järvinen
2022-06-07 18:13 ` Jiri Slaby
2022-06-08 7:23 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 13/36] tty/vt: consolemap: make con_set_unimap() more readable Jiri Slaby
2022-06-07 14:06 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 14/36] tty/vt: consolemap: make con_get_unimap() " Jiri Slaby
2022-06-07 14:11 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 15/36] tty/vt: consolemap: make p1 increment less confusing in con_get_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 16/36] tty/vt: consolemap: check put_user() " Jiri Slaby
2022-06-07 14:19 ` Ilpo Järvinen
2022-06-08 7:40 ` Jiri Slaby
2022-06-08 8:13 ` Ilpo Järvinen
2022-06-08 10:38 ` Andy Shevchenko
2022-06-08 10:43 ` Greg Kroah-Hartman
2022-06-08 8:02 ` David Laight
2022-06-08 8:11 ` Jiri Slaby
2022-06-08 8:13 ` Jiri Slaby
2022-06-09 8:51 ` Jiri Slaby
2022-06-07 10:49 ` [PATCH 17/36] tty/vt: consolemap: introduce enum translation_map and use it Jiri Slaby
2022-06-07 10:49 ` [PATCH 18/36] tty/vt: consolemap: remove glyph < 0 check from set_inverse_trans_unicode() Jiri Slaby
2022-06-07 10:49 ` [PATCH 19/36] tty/vt: consolemap: extract dict unsharing to con_unshare_unimap() Jiri Slaby
2022-06-07 14:30 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 20/36] tty/vt: consolemap: saner variable names in set_inverse_trans_unicode() Jiri Slaby
2022-06-07 14:34 ` Ilpo Järvinen
2022-06-07 10:49 ` [PATCH 21/36] tty/vt: consolemap: saner variable names in conv_uni_to_pc() Jiri Slaby
2022-06-07 10:49 ` [PATCH 22/36] tty/vt: consolemap: saner variable names in con_insert_unipair() Jiri Slaby
2022-06-07 10:49 ` [PATCH 23/36] tty/vt: consolemap: saner variable names in con_unify_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 24/36] tty/vt: consolemap: saner variable names in con_do_clear_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 25/36] tty/vt: consolemap: saner variable names in con_unshare_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 26/36] tty/vt: consolemap: saner variable names in con_release_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 27/36] tty/vt: consolemap: saner variable names in con_copy_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 28/36] tty/vt: consolemap: saner variable names in con_get_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 29/36] tty/vt: consolemap: saner variable names in con_set_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 30/36] tty/vt: consolemap: saner variable names in con_set_default_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 31/36] tty/vt: consolemap: make conv_uni_to_pc() more readable Jiri Slaby
2022-06-07 10:49 ` [PATCH 32/36] tty/vt: consolemap: remove superfluous whitespace Jiri Slaby
2022-06-07 10:49 ` Jiri Slaby [this message]
2022-06-07 15:31 ` [PATCH 33/36] tty/vt: consolemap: change refcount only if needed in con_do_clear_unimap() Ilpo Järvinen
2022-06-08 7:44 ` Jiri Slaby
2022-06-07 10:49 ` [PATCH 34/36] tty/vt: consolemap: extract con_allocate_new() from con_do_clear_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 35/36] tty/vt: consolemap: use con_allocate_new() in con_unshare_unimap() Jiri Slaby
2022-06-07 10:49 ` [PATCH 36/36] tty/vt: consolemap: walk the buffer only once in con_set_trans_old() Jiri Slaby
2022-06-07 16:25 ` Ilpo Järvinen
2022-06-07 12:36 ` [PATCH 01/36] tty/vt: consolemap: use ARRAY_SIZE() Ilpo Järvinen
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=20220607104946.18710-33-jslaby@suse.cz \
--to=jslaby@suse.cz \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-serial@vger.kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).