e180a6b775 "param: fix charp parameters set via sysfs" fixed the case
where charp parameters written via sysfs were freed, leaving drivers
accessing random memory.
Unfortunately, storing a flag in the kparam struct was a bad idea: it's
rodata so setting it causes an oops on some archs. But that's not all:
1) module_param_array() on charp doesn't work reliably, since we use an
uninitialized temporary struct kernel_param.
2) there's a fundamental race if a module uses this parameter and then
it's changed: they will still access the old, freed, memory.
The simplest fix (ie. for 2.6.32) is to never free the memory. This
prevents all these problems, at cost of a memory leak. In practice, there
are only 18 places where a charp is writable via sysfs, and all are
root-only writable.
Reported-by: Takashi Iwai <tiwai@suse.de>
Cc: Sitsofe Wheeler <sitsofe@yahoo.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
Impact: API cleanup
For historical reasons, 'bool' parameters must be an int, not a bool.
But there are around 600 users, so a conversion seems like useless churn.
So we use __same_type() to distinguish, and handle both cases.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: cleanup
Rather than hack KPARAM_KMALLOCED into the perm field, separate it out.
Since the perm field was 32 bits and only needs 16, we don't add bloat.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
It takes an 'int' for historical reasons, and there are only two
users: simply switch it over to bool.
The other user (uvesafb.c) will get a (harmless-on-x86) warning until
the next patch is applied.
Cc: Brad Douglas <brad@neruo.com>
Cc: Michal Januszewski <spock@gentoo.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Impact: fix crash on reading from /sys/module/.../ieee80211_default_rc_algo
The module_param type "charp" simply sets a char * pointer in the
module to the parameter in the commandline string: this is why we keep
the (mangled) module command line around. But when set via sysfs (as
about 11 charp parameters can be) this memory is freed on the way
out of the write(). Future reads hit random mem.
So we kstrdup instead: we have to check we're not in early commandline
parsing, and we have to note when we've used it so we can reliably
kfree the parameter when it's next overwritten, and also on module
unload.
(Thanks to Randy Dunlap for CONFIG_SYSFS=n fixes)
Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Diagnosed-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Frederic Weisbecker <fweisbec@gmail.com>
Tested-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
There are a lot of one-liner uses of __setup() in the kernel: they're
cumbersome and not queryable (definitely not settable) via /sys. Yet
it's ugly to simplify them to module_param(), because by default that
inserts a prefix of the module name (usually filename).
So, introduce a "core_param". The parameter gets no prefix, but
appears in /sys/module/kernel/parameters/ (if non-zero perms arg). I
thought about using the name "core", but that's more common than
"kernel". And if you create a module called "kernel", you will die
a horrible death.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The kparam code tries to handle over-length parameter prefixes at
runtime. Not only would I bet this has never been tested, it's not
clear that truncating names is a good idea either.
So let's check at compile time. We need to move the #define to
moduleparam.h to do this, though.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
On alpha, ia64 and ppc64 only relocations to local data can go into
read-only sections. The vast majority of module parameters use the global
generic param_set_*/param_get_* functions, so the 'const' attribute for
struct kernel_param is not only useless, but it also causes compile
failures due to 'section type conflict' in those rare cases where
param_set/get are local functions.
This fixes http://bugzilla.kernel.org/show_bug.cgi?id=8964
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Adrian Bunk <bunk@stusta.de>
Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the deprecated __attribute_used__.
[Introduce __section in a few places to silence checkpatch /sam]
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
.. in an effort to make read-only whatever can be made, so that
CONFIG_DEBUG_RODATA can catch as many issues as possible.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One of the mistakes a module_param() user can make is to supply default
value of module parameter as the last argument. module_param() accepts
permissions instead. If default value is, say, 3 (-------wx), parameter
becomes world-writeable.
So far, the only remedy was to apply grep(1) and read drivers submitted
to -mm. BTDT.
With this patch applied, compiler will finally do some job.
*) bounds checking on permissions
*) world-writeable bit checking on permissions
*) compile breakage if checks trigger
First version of this check (only "& 2" part) directly caught 4 out of 7
places during my last grep.
Subject: Neverending module_param() bugs
[X] drivers/acpi/sbs.c:101:module_param(capacity_mode, int, CAPACITY_UNIT);
[X] drivers/acpi/sbs.c:102:module_param(update_mode, int, UPDATE_MODE);
[ ] drivers/acpi/sbs.c:103:module_param(update_info_mode, int, UPDATE_INFO_MODE);
[ ] drivers/acpi/sbs.c:104:module_param(update_time, int, UPDATE_TIME);
[ ] drivers/acpi/sbs.c:105:module_param(update_time2, int, UPDATE_TIME2);
[X] drivers/char/watchdog/sbc8360.c:203:module_param(timeout, int, 27);
[X] drivers/media/video/tuner-simple.c:13:module_param(offset, int, 0666);
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
param_array() in kernel/params.c can now become static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Now when kbuild passes KBUILD_MODNAME with "" do not __stringify it when
used. Remove __stringnify for all users.
This also fixes the output of:
$ ls -l /sys/module/
drwxr-xr-x 4 root root 0 2006-01-05 14:24 pcmcia
drwxr-xr-x 4 root root 0 2006-01-05 14:24 pcmcia_core
drwxr-xr-x 3 root root 0 2006-01-05 14:24 "processor"
drwxr-xr-x 3 root root 0 2006-01-05 14:24 "psmouse"
The quoting of the module names will be gone again.
Thanks to GregKH + Kay Sievers for reproting this.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Rusty Russell