| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <44CFFDF1.6030909@gmail.com>
Date: Wed, 02 Aug 2006 09:20:49 +0800
From: "Antonino A. Daplas" <adaplas@...il.com>
To: Alan Cox <alan@...rguk.ukuu.org.uk>
CC: Roland Dreier <rdreier@...co.com>, Dave Jones <davej@...hat.com>,
Linux Kernel <linux-kernel@...r.kernel.org>,
Andrew Morton <akpm@...l.org>
Subject: [PATCH] fbcon: Use persistent allocation for cursor blinking.
From: Dave Jones <davej@...hat.com>
Every time the console cursor blinks, we do a kmalloc/kfree pair.
This patch turns that into a single allocation.
This allocation was the most frequent kmalloc I saw on my test box.
[adaplas]
Per Alan's suggestion, move global variables to fbcon's private structure.
This would also avoid resource leaks when fbcon is unloaded.
Signed-off-by: Dave Jones <davej@...hat.com>
Acked-by: Alan Cox <alan@...hat.com>
Signed-off-by: Antonino Daplas <adaplas@....net>
---
Alan Cox wrote:
> Ar Maw, 2006-08-01 am 12:15 -0700, ysgrifennodd Roland Dreier:
>> > Every time the console cursor blinks, we do a kmalloc/kfree pair.
>> > This patch turns that into a single allocation.
Thanks for doing this.
>>
>> A naiive question from someone who knows nothing about this subsystem:
>> is there any possibility of concurrent calls into this function, for
>> example if there are multiple cursors on a multiheaded system?
>
> We don't do console multihead so its basically OK. Moving all the
> console globals into a struct so we can have multiple instances would be
> a good thing [tm] and it would make sense for the variable to end up in
> said structure if it was done.
>
Here's an update. Taking Alan's cue, I just moved the global variables
to struct fbcon_ops.
Tony
drivers/video/console/fbcon.c | 3 +++
drivers/video/console/fbcon.h | 2 ++
drivers/video/console/softcursor.c | 31 +++++++++++++++++++++----------
3 files changed, 26 insertions(+), 10 deletions(-)
diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index 390439b..6165fd9 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -3225,7 +3225,10 @@ #endif
module_put(info->fbops->owner);
if (info->fbcon_par) {
+ struct fbcon_ops *ops = info->fbcon_par;
+
fbcon_del_cursor_timer(info);
+ kfree(ops->cursor_src);
kfree(info->fbcon_par);
info->fbcon_par = NULL;
}
diff --git a/drivers/video/console/fbcon.h b/drivers/video/console/fbcon.h
index f244ad0..0b73ae9 100644
--- a/drivers/video/console/fbcon.h
+++ b/drivers/video/console/fbcon.h
@@ -80,6 +80,8 @@ struct fbcon_ops {
char *cursor_data;
u8 *fontbuffer;
u8 *fontdata;
+ u8 *cursor_src;
+ u8 cursor_size;
u32 fd_size;
};
/*
diff --git a/drivers/video/console/softcursor.c b/drivers/video/console/softcursor.c
index 557c563..7d07d83 100644
--- a/drivers/video/console/softcursor.c
+++ b/drivers/video/console/softcursor.c
@@ -20,11 +20,12 @@ #include "fbcon.h"
int soft_cursor(struct fb_info *info, struct fb_cursor *cursor)
{
+ struct fbcon_ops *ops = info->fbcon_par;
unsigned int scan_align = info->pixmap.scan_align - 1;
unsigned int buf_align = info->pixmap.buf_align - 1;
unsigned int i, size, dsize, s_pitch, d_pitch;
struct fb_image *image;
- u8 *dst, *src;
+ u8 *dst;
if (info->state != FBINFO_STATE_RUNNING)
return 0;
@@ -32,11 +33,19 @@ int soft_cursor(struct fb_info *info, st
s_pitch = (cursor->image.width + 7) >> 3;
dsize = s_pitch * cursor->image.height;
- src = kmalloc(dsize + sizeof(struct fb_image), GFP_ATOMIC);
- if (!src)
- return -ENOMEM;
+ if (dsize + sizeof(struct fb_image) != ops->cursor_size) {
+ if (ops->cursor_src != NULL)
+ kfree(ops->cursor_src);
+ ops->cursor_size = dsize + sizeof(struct fb_image);
- image = (struct fb_image *) (src + dsize);
+ ops->cursor_src = kmalloc(ops->cursor_size, GFP_ATOMIC);
+ if (!ops->cursor_src) {
+ ops->cursor_size = 0;
+ return -ENOMEM;
+ }
+ }
+
+ image = (struct fb_image *) (ops->cursor_src + dsize);
*image = cursor->image;
d_pitch = (s_pitch + scan_align) & ~scan_align;
@@ -48,21 +57,23 @@ int soft_cursor(struct fb_info *info, st
switch (cursor->rop) {
case ROP_XOR:
for (i = 0; i < dsize; i++)
- src[i] = image->data[i] ^ cursor->mask[i];
+ ops->cursor_src[i] = image->data[i] ^
+ cursor->mask[i];
break;
case ROP_COPY:
default:
for (i = 0; i < dsize; i++)
- src[i] = image->data[i] & cursor->mask[i];
+ ops->cursor_src[i] = image->data[i] &
+ cursor->mask[i];
break;
}
} else
- memcpy(src, image->data, dsize);
+ memcpy(ops->cursor_src, image->data, dsize);
- fb_pad_aligned_buffer(dst, d_pitch, src, s_pitch, image->height);
+ fb_pad_aligned_buffer(dst, d_pitch, ops->cursor_src, s_pitch,
+ image->height);
image->data = dst;
info->fbops->fb_imageblit(info, image);
- kfree(src);
return 0;
}
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists