Граф коммитов

56 Коммитов

Автор SHA1 Сообщение Дата
Dan Streetman 3d9c637f4a module: export param_free_charp()
Change the param_free_charp() function from static to exported.

It is used by zswap in the next patch ("zswap: use charp for zswap param
strings").

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Seth Jennings <sjennings@variantweb.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
Linus Torvalds 02201e3f1b Minor merge needed, due to function move.
Main excitement here is Peter Zijlstra's lockless rbtree optimization to
 speed module address lookup.  He found some abusers of the module lock
 doing that too.
 
 A little bit of parameter work here too; including Dan Streetman's breaking
 up the big param mutex so writing a parameter can load another module (yeah,
 really).  Unfortunately that broke the usual suspects, !CONFIG_MODULES and
 !CONFIG_SYSFS, so those fixes were appended too.
 
 Cheers,
 Rusty.
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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module updates from Rusty Russell:
 "Main excitement here is Peter Zijlstra's lockless rbtree optimization
  to speed module address lookup.  He found some abusers of the module
  lock doing that too.

  A little bit of parameter work here too; including Dan Streetman's
  breaking up the big param mutex so writing a parameter can load
  another module (yeah, really).  Unfortunately that broke the usual
  suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were
  appended too"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits)
  modules: only use mod->param_lock if CONFIG_MODULES
  param: fix module param locks when !CONFIG_SYSFS.
  rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE()
  module: add per-module param_lock
  module: make perm const
  params: suppress unused variable error, warn once just in case code changes.
  modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'.
  kernel/module.c: avoid ifdefs for sig_enforce declaration
  kernel/workqueue.c: remove ifdefs over wq_power_efficient
  kernel/params.c: export param_ops_bool_enable_only
  kernel/params.c: generalize bool_enable_only
  kernel/module.c: use generic module param operaters for sig_enforce
  kernel/params: constify struct kernel_param_ops uses
  sysfs: tightened sysfs permission checks
  module: Rework module_addr_{min,max}
  module: Use __module_address() for module_address_lookup()
  module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING
  module: Optimize __module_address() using a latched RB-tree
  rbtree: Implement generic latch_tree
  seqlock: Introduce raw_read_seqcount_latch()
  ...
2015-07-01 10:49:25 -07:00
Dan Streetman b51d23e4e9 module: add per-module param_lock
Add a "param_lock" mutex to each module, and update params.c to use
the correct built-in or module mutex while locking kernel params.
Remove the kparam_block_sysfs_r/w() macros, replace them with direct
calls to kernel_param_[un]lock(module).

The kernel param code currently uses a single mutex to protect
modification of any and all kernel params.  While this generally works,
there is one specific problem with it; a module callback function
cannot safely load another module, i.e. with request_module() or even
with indirect calls such as crypto_has_alg().  If the module to be
loaded has any of its params configured (e.g. with a /etc/modprobe.d/*
config file), then the attempt will result in a deadlock between the
first module param callback waiting for modprobe, and modprobe trying to
lock the single kernel param mutex to set the new module's param.

This fixes that by using per-module mutexes, so that each individual module
is protected against concurrent changes in its own kernel params, but is
not blocked by changes to other module params.  All built-in modules
continue to use the built-in mutex, since they will always be loaded at
runtime and references (e.g. request_module(), crypto_has_alg()) to them
will never cause load-time param changing.

This also simplifies the interface used by modules to block sysfs access
to their params; while there are currently functions to block and unblock
sysfs param access which are split up by read and write and expect a single
kernel param to be passed, their actual operation is identical and applies
to all params, not just the one passed to them; they simply lock and unlock
the global param mutex.  They are replaced with direct calls to
kernel_param_[un]lock(THIS_MODULE), which locks THIS_MODULE's param_lock, or
if the module is built-in, it locks the built-in mutex.

Suggested-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-23 15:27:38 +09:30
Dan Streetman 5104b7d767 module: make perm const
Change the struct kernel_param.perm field to a const, as it should never
be changed.

Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cut from larger patch)
2015-06-23 15:27:37 +09:30
Luis R. Rodriguez d19f05d8a8 kernel/params.c: generalize bool_enable_only
This takes out the bool_enable_only implementation from
the module loading code and generalizes it so that others
can make use of it.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: cocci@systeme.lip6.fr
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:11 +09:30
Luis R. Rodriguez 9c27847dda kernel/params: constify struct kernel_param_ops uses
Most code already uses consts for the struct kernel_param_ops,
sweep the kernel for the last offending stragglers. Other than
include/linux/moduleparam.h and kernel/params.c all other changes
were generated with the following Coccinelle SmPL patch. Merge
conflicts between trees can be handled with Coccinelle.

In the future git could get Coccinelle merge support to deal with
patch --> fail --> grammar --> Coccinelle --> new patch conflicts
automatically for us on patches where the grammar is available and
the patch is of high confidence. Consider this a feature request.

Test compiled on x86_64 against:

	* allnoconfig
	* allmodconfig
	* allyesconfig

@ const_found @
identifier ops;
@@

const struct kernel_param_ops ops = {
};

@ const_not_found depends on !const_found @
identifier ops;
@@

-struct kernel_param_ops ops = {
+const struct kernel_param_ops ops = {
};

Generated-by: Coccinelle SmPL
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Junio C Hamano <gitster@pobox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: cocci@systeme.lip6.fr
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:10 +09:30
Dmitry Torokhov ec0ccc16a0 module: add core_param_unsafe
Similarly to module_param_unsafe(), add the helper to be used by core
code wishing to expose unsafe debugging or testing parameters that taint
the kernel when set.

Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20 00:25:25 -07:00
Luis R. Rodriguez ecc8617053 module: add extra argument for parse_params() callback
This adds an extra argument onto parse_params() to be used
as a way to make the unused callback a bit more useful and
generic by allowing the caller to pass on a data structure
of its choice. An example use case is to allow us to easily
make module parameters for every module which we will do
next.

@ parse @
identifier name, args, params, num, level_min, level_max;
identifier unknown, param, val, doing;
type s16;
@@
 extern char *parse_args(const char *name,
 			 char *args,
 			 const struct kernel_param *params,
 			 unsigned num,
 			 s16 level_min,
 			 s16 level_max,
+			 void *arg,
 			 int (*unknown)(char *param, char *val,
					const char *doing
+					, void *arg
					));

@ parse_mod @
identifier name, args, params, num, level_min, level_max;
identifier unknown, param, val, doing;
type s16;
@@
 char *parse_args(const char *name,
 			 char *args,
 			 const struct kernel_param *params,
 			 unsigned num,
 			 s16 level_min,
 			 s16 level_max,
+			 void *arg,
 			 int (*unknown)(char *param, char *val,
					const char *doing
+					, void *arg
					))
{
	...
}

@ parse_args_found @
expression R, E1, E2, E3, E4, E5, E6;
identifier func;
@@

(
	R =
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   func);
|
	R =
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   &func);
|
	R =
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   NULL);
|
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   func);
|
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   &func);
|
	parse_args(E1, E2, E3, E4, E5, E6,
+		   NULL,
		   NULL);
)

@ parse_args_unused depends on parse_args_found @
identifier parse_args_found.func;
@@

int func(char *param, char *val, const char *unused
+		 , void *arg
		 )
{
	...
}

@ mod_unused depends on parse_args_found @
identifier parse_args_found.func;
expression A1, A2, A3;
@@

-	func(A1, A2, A3);
+	func(A1, A2, A3, NULL);

Generated-by: Coccinelle SmPL
Cc: cocci@systeme.lip6.fr
Cc: Tejun Heo <tj@kernel.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Felipe Contreras <felipe.contreras@gmail.com>
Cc: Ewan Milne <emilne@redhat.com>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20 00:25:24 -07:00
Geert Uytterhoeven 63a12d9d01 kernel/param: consolidate __{start,stop}___param[] in <linux/moduleparam.h>
Consolidate the various external const and non-const declarations of
__start___param[] and __stop___param in <linux/moduleparam.h>.  This
requires making a few struct kernel_param pointers in kernel/params.c
const.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:28 +02:00
Mark Rustad 184c3fc3f5 moduleparam: Resolve missing-field-initializer warning
Resolve a missing-field-initializer warning, that is produced
by every reference to module_param_call, by using designated
initialization for the first field. That is enough to silence
the complaint.

The message is only seen when doing a W=2 build. I happened to be using gcc
4.8.3, but I think most versions would produce the warning when it is
enabled. It can either be silenced by using even a single designated
initializer as I did here, or providing values for all of the fields. Because
of the number of references to the macro, this change silences many warnings
in W=2 builds.

One instance of the full warning message looks like this:

/home/share/git/nn-mdr/include/linux/moduleparam.h:198:16: warning: missing
initializer for field ‘free’ of ‘struct kernel_param_ops’
[-Wmissing-field-initializers]
  static struct kernel_param_ops __param_ops_##name =  \
		  ^
/home/share/git/nn-mdr/fs/fuse/inode.c:35:1: note: in expansion of macro
‘module_param_call’
 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
 ^
/home/share/git/nn-mdr/include/linux/moduleparam.h:56:9: note: ‘free’
declared here
  void (*free)(void *arg);

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-09-11 09:59:25 +09:30
Rusty Russell 7a486d3781 param: check for tainting before calling set op.
This means every set op doesn't need to call it, and it can move into
params.c.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 21:54:10 +09:30
Jani Nikula 3baee201b0 module: add module_param_unsafe and module_param_named_unsafe
Add the helpers to be used by modules wishing to expose unsafe debugging
or testing module parameters that taint the kernel when set.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Jon Mason <jon.mason@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 21:54:08 +09:30
Jani Nikula 91f9d330cc module: make it possible to have unsafe, tainting module params
Add flags field to struct kernel_params, and add the first flag: unsafe
parameter. Modifying a kernel parameter with the unsafe flag set, either
via the kernel command line or sysfs, will issue a warning and taint the
kernel.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Jon Mason <jon.mason@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 21:54:08 +09:30
Jani Nikula 6a4c264313 module: rename KERNEL_PARAM_FL_NOARG to avoid confusion
Make it clear this is about kernel_param_ops, not kernel_param (which
will soon have a flags field of its own). No functional changes.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Jon Mason <jon.mason@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-08-27 21:54:07 +09:30
Hannes Reinecke b4210b810e Add module param type 'ullong'
Some driver might want to pass in an 64-bit value, so introduce
a module param type 'ullong'.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ewan Milne <emilne@redhat.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-07-17 22:07:37 +02:00
Rusty Russell 51e158c12a param: hand arguments after -- straight to init
The kernel passes any args it doesn't need through to init, except it
assumes anything containing '.' belongs to the kernel (for a module).
This change means all users can clearly distinguish which arguments
are for init.

For example, the kernel uses debug ("dee-bug") to mean log everything to
the console, where systemd uses the debug from the Scandinavian "day-boog"
meaning "fail to boot".  If a future versions uses argv[] instead of
reading /proc/cmdline, this confusion will be avoided.

eg: test 'FOO="this is --foo"' -- 'systemd.debug="true true true"'

Gives:
argv[0] = '/debug-init'
argv[1] = 'test'
argv[2] = 'systemd.debug=true true true'
envp[0] = 'HOME=/'
envp[1] = 'TERM=linux'
envp[2] = 'FOO=this is --foo'

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-04-28 11:48:34 +09:30
Rusty Russell 58f86cc89c VERIFY_OCTAL_PERMISSIONS: stricter checking for sysfs perms.
Summary of http://lkml.org/lkml/2014/3/14/363 :

  Ted: module_param(queue_depth, int, 444)
  Joe: 0444!
  Rusty: User perms >= group perms >= other perms?
  Joe: CLASS_ATTR, DEVICE_ATTR, SENSOR_ATTR and SENSOR_ATTR_2?

Side effect of stricter permissions means removing the unnecessary
S_IFREG from several callers.

Note that the BUILD_BUG_ON_ZERO((perm) & 2) test was removed: a fair
number of drivers fail this test, so that will be the debate for a
future patch.

Suggested-by: Joe Perches <joe@perches.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> for drivers/pci/slot.c
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-03-24 12:21:00 +10:30
Mark Charlebois 0283f9a529 module: LLVMLinux: Remove unused function warning from __param_check macro
This code makes a compile time type check that is optimized away. Clang
complains that it generates an unused function:

linux/kernel/panic.c:471:1: warning: unused function '__check_panic'
      [-Wunused-function]
core_param(panic, panic_timeout, int, 0644);
^
linux/moduleparam.h:283:2: note: expanded from macro
      'core_param'
        param_check_##type(name, &(var));                               \
        ^
<scratch space>:87:1: note: expanded from here
param_check_int
^
linux/moduleparam.h:369:34: note: expanded from macro
      'param_check_int'
#define param_check_int(name, p) __param_check(name, p, int)
                                 ^
linux/moduleparam.h:349:22: note: expanded from macro
      '__param_check'
        static inline type *__check_##name(void) { return(p); }
                            ^
<scratch space>:88:1: note: expanded from here
__check_panic

GCC won't complain for a static inline function but would if it was just
a static function.

Adding the unused attribute to the function declaration removes the warning.
Per request from Rusty Russell it is marked as __always_unused as the code
is meant to be optimized away.

This code works for both GCC and clang.

Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-03-17 14:54:50 +10:30
Steven Rostedt ab013c5f60 module: Add flag to allow mod params to have no arguments
Currently the params.c code allows only two "set" functions to have
no arguments. If a parameter does not have an argument, then it
looks at the set function and tests if it is either param_set_bool()
or param_set_bint(). If it is not one of these functions, then it
fails the loading of the module.

But there may be module parameters that have different set functions
and still allow no arguments. But unless each of these cases adds
their function to the if statement, it wont be allowed to have no
arguments. This method gets rather messing and does not scale.

Instead, introduce a flags field to the kernel_param_ops, where if
the flag KERNEL_PARAM_FL_NOARG is set, the parameter will not fail
if it does not contain an argument. It will be expected that the
corresponding set function can handle a NULL pointer as "val".

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-08-20 15:37:42 +09:30
Jean Delvare b634d130e4 There is no /sys/parameters
There is no such path as /sys/parameters, module parameters live in
/sys/module/*/parameters.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-07-02 15:38:19 +09:30
Rusty Russell 34182eea36 moduleparam: use __UNIQUE_ID()
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-12-14 13:06:40 +10:30
Rusty Russell ae82fdb140 module_param: stop double-calling parameters.
Commit 026cee0086 "params:
<level>_initcall-like kernel parameters" set old-style module
parameters to level 0.  And we call those level 0 calls where we used
to, early in start_kernel().

We also loop through the initcall levels and call the levelled
module_params before the corresponding initcall.  Unfortunately level
0 is early_init(), so we call the standard module_param calls twice.

(Turns out most things don't care, but at least ubi.mtd does).

Change the level to -1 for standard module_param calls.

Reported-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
2012-06-08 14:58:13 +09:30
Jim Cromie 9fb48c744b params: add 3rd arg to option handler callback signature
Add a 3rd arg, named "doing", to unknown-options callbacks invoked
from parse_args(). The arg is passed as:

  "Booting kernel" from start_kernel(),
  initcall_level_names[i] from do_initcall_level(),
  mod->name from load_module(), via parse_args(), parse_one()

parse_args() already has the "name" parameter, which is renamed to
"doing" to better reflect current uses 1,2 above.  parse_args() passes
it to an altered parse_one(), which now passes it down into the
unknown option handler callbacks.

The mod->name will be needed to handle dyndbg for loadable modules,
since params passed by modprobe are not qualified (they do not have a
"$modname." prefix), and by the time the unknown-param callback is
called, the module name is not otherwise available.

Minor tweaks:

Add param-name to parse_one's pr_debug(), current message doesnt
identify the param being handled, add it.

Add a pr_info to print current level and level_name of the initcall,
and number of registered initcalls at that level.  This adds 7 lines
to dmesg output, like:

   initlevel:6=device, 172 registered initcalls

Drop "parameters" from initcall_level_names[], its unhelpful in the
pr_info() added above.  This array is passed into parse_args() by
do_initcall_level().

CC: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Acked-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-30 14:05:27 -04:00
Pawel Moll 026cee0086 params: <level>_initcall-like kernel parameters
This patch adds a set of macros that can be used to declare
kernel parameters to be parsed _before_ initcalls at a chosen
level are executed.  We rename the now-unused "flags" field of
struct kernel_param as the level.  It's signed, for when we
use this for early params as well, in future.

Linker macro collating init calls had to be modified in order
to add additional symbols between levels that are later used
by the init code to split the calls into blocks.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-03-26 12:50:51 +10:30
Rusty Russell 8b8252813d module_param: remove support for bool parameters which are really int.
module_param(bool) used to counter-intuitively take an int.  In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

This eliminates that code (though leaves the flags field in the struct,
for impending use).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-03-26 12:50:51 +10:30
Rusty Russell 72db395ffa module_param: check that bool parameters really are bool.
module_param(bool) used to counter-intuitively take an int.  In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.

This tightens the check (you'll get a warning about incompatible
return type) but still allows it.  Next kernel version, we'll remove
it.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-13 09:32:28 +10:30
Rusty Russell 69116f279a module_param: avoid bool abuse, add bint for special cases.
For historical reasons, we allow module_param(bool) to take an int (or
an unsigned int).  That's going away.

A few drivers really want an int: they set it to -1 and a parameter
will set it to 0 or 1.  This sucks: reading them from sysfs will give
'Y' for both -1 and 1, but if we change it to an int, then the users
might be broken (if they did "param" instead of "param=1").

Use a new 'bint' parser for them.

(ntfs has a different problem: it needs an int for debug_msgs because
it's also exposed via sysctl.)

Cc: Steve Glendinning <steve.glendinning@smsc.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
Cc: Christoph Raisch <raisch@de.ibm.com>
Cc: Roland Dreier <roland@kernel.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: linux390@de.ibm.com
Cc: Anton Altaparmakov <anton@tuxera.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: lm-sensors@lm-sensors.org
Cc: linux-rdma@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-ntfs-dev@lists.sourceforge.net
Cc: alsa-devel@alsa-project.org
Acked-by: Takashi Iwai <tiwai@suse.de> (For the sound part)
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com> (For the hwmon driver)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-13 09:32:17 +10:30
Rusty Russell bafeafeab9 module_param: check type correctness for module_param_array
module_param_array(), unlike its non-array cousins, didn't check the type
of the variable.  Fixing this found two bugs.

Cc: Luca Risolia <luca.risolia@studio.unibo.it>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Eric Piel <eric.piel@tremplin-utc.net>
Cc: linux-media@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-13 09:32:16 +10:30
Paul Gortmaker 639938eb60 module.h: relocate MODULE_PARM_DESC into moduleparam.h
There are files which use module_param and MODULE_PARM_DESC
back to back.  They only include moduleparam.h which makes sense,
but the implicit presence of module.h everywhere hid the fact
that MODULE_PARM_DESC wasn't in moduleparam.h at all.  Relocate
the macro to moduleparam.h so that the moduleparam infrastructure
can be used independently of module.h

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 09:20:11 -04:00
Michal Schmidt b1e4d20cbf params: make dashes and underscores in parameter names truly equal
The user may use "foo-bar" for a kernel parameter defined as "foo_bar".
Make sure it works the other way around too.

Apply the equality of dashes and underscores on early_params and __setup
params as well.

The example given in Documentation/kernel-parameters.txt indicates that
this is the intended behaviour.

With the patch the kernel accepts "log-buf-len=1M" as expected.
https://bugzilla.redhat.com/show_bug.cgi?id=744545

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (neatened implementations)
2011-10-26 13:10:39 +10:30
Richard Kennedy c5be0b2eb1 module: reorder kparam_array to remove alignment padding on 64 bit builds
Reorder structure kparam_array to remove 8 bytes of alignment padding on
64 bit builds, dropping its size from 40 to 32 bytes.

Also update the macro module_param_array_named to initialise the
structure using its member names to allow it to be changed without
touching all its call sites.

'git grep' finds module_param_array in 1037 places so this patch will
save a small amount of data space across many modules.

Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-05-19 16:55:25 +09:30
Linus Walleij b75be4204e param: add null statement to compiled-in module params
Add an unused struct declaration statement requiring a
terminating semicolon to the compile-in case to provoke an
error if __MODULE_INFO() is used without the terminating
semicolon. Previously MODULE_ALIAS("foo") (no semicolon)
compiled fine if MODULE was not selected.

Cc: Dan Carpenter <error27@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2011-01-24 14:32:52 +10:30
Jan Beulich b647277681 modules: no need to align .modinfo strings
gcc aligns strings as a performance consideration for those cases where
strings are being used a lot.

Their use is not performance critical, and hence it seems better to save
some space.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 16:52:13 -07:00
Rusty Russell a6de51b278 param: don't deref arg in __same_type() checks
gcc allows this when arg is a function, but sparse complains:

drivers/char/ipmi/ipmi_watchdog.c:303:1: error: cannot dereference this type
drivers/char/ipmi/ipmi_watchdog.c:307:1: error: cannot dereference this type
drivers/char/ipmi/ipmi_watchdog.c:311:1: error: cannot dereference this type

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Tested-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-08-11 23:04:41 +09:30
Rusty Russell 546970bc6a param: add kerneldoc to moduleparam.h
Also reorders the macros with the most common ones at the top.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
2010-08-11 23:04:21 +09:30
Rusty Russell 907b29eb41 param: locking for kernel parameters
There may be cases (most obviously, sysfs-writable charp parameters) where
a module needs to prevent sysfs access to parameters.

Rather than express this in terms of a big lock, the functions are
expressed in terms of what they protect against.  This is clearer, esp.
if the implementation changes to a module-level or even param-level lock.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
2010-08-11 23:04:20 +09:30
Rusty Russell 914dcaa84c param: make param sections const.
Since this section can be read-only (they're in .rodata), they should
always have been const.  Minor flow-through various functions.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
2010-08-11 23:04:19 +09:30
Rusty Russell e6df34a442 param: add a free hook to kernel_param_ops.
This allows us to generalize the KPARAM_KMALLOCED flag, by calling a function
on every parameter when a module is unloaded.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
2010-08-11 23:04:18 +09:30
Rusty Russell 9bbb9e5a33 param: use ops in struct kernel_param, rather than get and set fns directly
This is more kernel-ish, saves some space, and also allows us to
expand the ops without breaking all the callers who are happy for the
new members to be NULL.

The few places which defined their own param types are changed to the
new scheme (more which crept in recently fixed in following patches).

Since we're touching them anyway, we change get() and set() to take a
const struct kernel_param (which they really are).  This causes some
harmless warnings until we fix them (in following patches).

To reduce churn, module_param_call creates the ops struct so the callers
don't have to change (and casts the functions to reduce warnings).
The modern version which takes an ops struct is called module_param_cb.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ville Syrjala <syrjala@sci.fi>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Alessandro Rubini <rubini@ipvvis.unipv.it>
Cc: Michal Januszewski <spock@gentoo.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: linux-kernel@vger.kernel.org
Cc: linux-input@vger.kernel.org
Cc: linux-fbdev-devel@lists.sourceforge.net
Cc: linux-nfs@vger.kernel.org
Cc: netdev@vger.kernel.org
2010-08-11 23:04:13 +09:30
Rusty Russell 65afac7d80 param: fix lots of bugs with writing charp params from sysfs, by leaking mem.
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
2009-10-29 08:56:17 +10:30
Rusty Russell fddd520122 module_param: allow 'bool' module_params to be bool, not just int.
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>
2009-06-12 21:46:58 +09:30
Rusty Russell 45fcc70c0b module_param: split perm field into flags and perm
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>
2009-06-12 21:46:56 +09:30
Rusty Russell 9a71af2c36 module_param: invbool should take a 'bool', not an 'int'
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>
2009-06-12 21:46:56 +09:30
Rusty Russell e180a6b775 param: fix charp parameters set via sysfs
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>
2009-03-31 13:05:30 +10:30
Rusty Russell 67e67ceaac core_param() for genuinely core kernel parameters
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>
2008-10-22 10:00:23 +11:00
Rusty Russell 730b69d225 module: check kernel param length at compile time, not runtime
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>
2008-10-22 10:00:22 +11:00
Ivan Kokshaysky 91d35dd93e moduleparam: fix alpha, ia64 and ppc64 compile failures
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>
2008-02-13 16:21:19 -08:00
Adrian Bunk 3ff6eecca4 remove __attribute_used__
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>
2008-01-28 23:21:18 +01:00
Jan Beulich 22e48eaf58 constify string/array kparam tracking structures
.. 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>
2007-10-17 08:42:56 -07:00
Linus Torvalds 874ff01bd9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (25 commits)
  Documentation/kernel-docs.txt update.
  arch/cris: typo in KERN_INFO
  Storage class should be before const qualifier
  kernel/printk.c: comment fix
  update I/O sched Kconfig help texts - CFQ is now default, not AS.
  Remove duplicate listing of Cris arch from README
  kbuild: more doc. cleanups
  doc: make doc. for maxcpus= more visible
  drivers/net/eexpress.c: remove duplicate comment
  add a help text for BLK_DEV_GENERIC
  correct a dead URL in the IP_MULTICAST help text
  fix the BAYCOM_SER_HDX help text
  fix SCSI_SCAN_ASYNC help text
  trivial documentation patch for platform.txt
  Fix typos concerning hierarchy
  Fix comment typo "spin_lock_irqrestore".
  Fix misspellings of "agressive".
  drivers/scsi/a100u2w.c: trivial typo patch
  Correct trivial typo in log2.h.
  Remove useless FIND_FIRST_BIT() macro from cardbus.c.
  ...
2007-02-19 13:29:02 -08:00