On Nov 16 2004 a change to intelfbdrv.c was commited (as part of 0.9.2 it
looks like) that added __initdata to all of the module param variables that
seems to create the opportunity for an oops.

I've recently been chasing an OOPS
(http://marc.theaimsgroup.com/?l=linux-kernel&m=111552250920370&w=2) I
created by reading every file on the /sys file system and I've traced it
back to this code in the intelfbdrv.  Though I had root privs in my initial
problem report, it turns out they are un-necessary to generate the oops -
all you've got to do is "cat /sys/module/intelfb/parameters/mode" enough
times and eventually it will oops.

This is because sysfs automatically exports all module_param declarations
to the sysfs file system..  which means those variables can be dynamically
evaluated at any later time, which of course means marking them __initdata
is a bad idea ;)..  when they happen to be char *'s it is an especially bad
idea ;).

Applying the patch below clears up the OOPS for me.

Signed-off-by: Patrick McManus <mcmanus@ducksong.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Patrick McManus 2005-05-28 15:51:46 -07:00 коммит произвёл Linus Torvalds
Родитель c1e4c8d3ee
Коммит 346e399b2a
1 изменённых файлов: 11 добавлений и 11 удалений

Просмотреть файл

@ -228,17 +228,17 @@ MODULE_DESCRIPTION(
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DEVICE_TABLE(pci, intelfb_pci_table);
static int accel __initdata = 1;
static int vram __initdata = 4;
static int hwcursor __initdata = 1;
static int mtrr __initdata = 1;
static int fixed __initdata = 0;
static int noinit __initdata = 0;
static int noregister __initdata = 0;
static int probeonly __initdata = 0;
static int idonly __initdata = 0;
static int bailearly __initdata = 0;
static char *mode __initdata = NULL;
static int accel = 1;
static int vram = 4;
static int hwcursor = 1;
static int mtrr = 1;
static int fixed = 0;
static int noinit = 0;
static int noregister = 0;
static int probeonly = 0;
static int idonly = 0;
static int bailearly = 0;
static char *mode = NULL;
module_param(accel, bool, S_IRUGO);
MODULE_PARM_DESC(accel, "Enable console acceleration");