Commit graph

122 commits

Author SHA1 Message Date
Chris Wilson
edc41b3c54 kernel/params.c: downgrade warning for unsafe parameters
As using an unsafe module parameter is, by its very definition, an
expected user action, emitting a warning is overkill.  Nothing has yet
gone wrong, and we add a taint flag for any future oops should something
actually go wrong.  So instead of having a user controllable pr_warn,
downgrade it to a pr_notice for "a normal, but significant condition".

We make use of unsafe kernel parameters in igt
(https://cgit.freedesktop.org/drm/igt-gpu-tools/) (we have not yet
succeeded in removing all such debugging options), which generates a
warning and taints the kernel.  The warning is unhelpful as we then need
to filter it out again as we check that every test themselves do not
provoke any kernel warnings.

Link: http://lkml.kernel.org/r/20180226151919.9674-1-chris@chris-wilson.co.uk
Fixes: 91f9d330cc ("module: make it possible to have unsafe, tainting module params")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Petri Latvala <petri.latvala@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-11 10:28:37 -07:00
Jean Delvare
e0596c80f4 kernel/params.c: improve STANDARD_PARAM_DEF readability
Align the parameters passed to STANDARD_PARAM_DEF for clarity.

Link: http://lkml.kernel.org/r/20170928162728.756143cc@endymion
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Suggested-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
Jean Delvare
96802e6b1d kernel/params.c: fix an overflow in param_attr_show
Function param_attr_show could overflow the buffer it is operating on.

The buffer size is PAGE_SIZE, and the string returned by
attribute->param->ops->get is generated by scnprintf(buffer, PAGE_SIZE,
...) so it could be PAGE_SIZE - 1 long, with the terminating '\0' at the
very end of the buffer.  Calling strcat(..., "\n") on this isn't safe, as
the '\0' will be replaced by '\n' (OK) and then another '\0' will be added
past the end of the buffer (not OK.)

Simply add the trailing '\n' when writing the attribute contents to the
buffer originally.  This is safe, and also faster.

Credits to Teradata for discovering this issue.

Link: http://lkml.kernel.org/r/20170928162602.60c379c7@endymion
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
Jean Delvare
90ceb2a3ad kernel/params.c: fix the maximum length in param_get_string
The length parameter of strlcpy() is supposed to reflect the size of the
target buffer, not of the source string.  Harmless in this case as the
buffer is PAGE_SIZE long and the source string is always much shorter than
this, but conceptually wrong, so let's fix it.

Link: http://lkml.kernel.org/r/20170928162515.24846b4f@endymion
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-10-03 17:54:26 -07:00
Jean Delvare
630cc2b30a kernel/params.c: align add_sysfs_param documentation with code
This parameter is named kp, so the documentation should use that.

Fixes: 9b473de872 ("param: Fix duplicate module prefixes")
Link: http://lkml.kernel.org/r/20170919142656.64aea59e@endymion
Signed-off-by: Jean Delvare <jdelvare@suse.de>
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>
2017-10-03 17:54:23 -07:00
Baoquan He
f51b17c8d9 boot/param: Move next_arg() function to lib/cmdline.c for later reuse
next_arg() will be used to parse boot parameters in the x86/boot/compressed code,
so move it to lib/cmdline.c for better code reuse.

No change in functionality.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Cc: Jens Axboe <axboe@fb.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dan.j.williams@intel.com
Cc: dave.jiang@intel.com
Cc: dyoung@redhat.com
Cc: keescook@chromium.org
Cc: zijun_hu <zijun_hu@htc.com>
Link: http://lkml.kernel.org/r/1492436099-4017-2-git-send-email-bhe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-18 10:37:13 +02:00
Linus Torvalds
50c36504fc Nothing exciting, minor tweaks and cleanups.
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:
 "Nothing exciting, minor tweaks and cleanups"

* tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  scripts: [modpost] add new sections to white list
  modpost: Add flag -E for making section mismatches fatal
  params: don't ignore the rest of cmdline if parse_one() fails
  modpost: abort if a module symbol is too long
2015-11-09 15:53:39 -08:00
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
Oleg Nesterov
74b22c465c params: don't ignore the rest of cmdline if parse_one() fails
parse_args() just aborts after it hits an error, so other args
at the same initcall level are simply ignored. This can lead to
other hard-to-understand problems, for example my testing machine
panics during the boot if I pass "locktorture.verbose=true".

Change parse_args() to save the err code for return and continue.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-08-26 10:36:19 +09:30
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
Stephen Rothwell
20bdc2cfdb modules: only use mod->param_lock if CONFIG_MODULES
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-28 14:50:12 +09:30
Rusty Russell
cf2fde7b39 param: fix module param locks when !CONFIG_SYSFS.
As Dan Streetman points out, the entire point of locking for is to
stop sysfs accesses, so they're elided entirely in the !SYSFS case.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-28 14:46:14 +09:30
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
Rusty Russell
74c3dea355 params: suppress unused variable error, warn once just in case code changes.
It shouldn't fail due to OOM (it's boot time), and already warns if we
get two identical names.  But you never know what the future holds, and
WARN_ON_ONCE() keeps gcc happy with minimal code.

Reported-by: Louis Langholtz <lou_langholtz@me.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-06-23 15:27:37 +09:30
Luis R. Rodriguez
154be21c58 kernel/params.c: export param_ops_bool_enable_only
This will grant access to this helper to code built as modules.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Kyle McMartin <kyle@kernel.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-05-28 11:32:12 +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
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
Rusty Russell
b9cc4489c6 params: handle quotes properly for values not of form foo="bar".
When starting kernel with arguments like:
  init=/bin/sh -c "echo arguments"
the trailing double quote is not removed which results in following command
being executed:
  /bin/sh -c 'echo arguments"'

Reported-by: Arthur Gautier <baloo@gandi.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-04-15 13:31:23 +09:30
Rusty Russell
c772be5231 param: fix uninitialized read with CONFIG_DEBUG_LOCK_ALLOC
ignore_lockdep is uninitialized, and sysfs_attr_init() doesn't initialize
it, so memset to 0.

Reported-by: Huang Ying <ying.huang@intel.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-20 11:38:31 +10:30
Rusty Russell
574732c73d param: initialize store function to NULL if not available.
I rebased Kees' 'param: do not set store func without write perm'
on top of my 'params: cleanup sysfs allocation'.  However, my patch
uses krealloc which doesn't zero memory, leaving .store unset.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-12-23 15:07:41 +10:30
Kees Cook
b0a65b0ccc param: do not set store func without write perm
When a module_param is defined without DAC write permissions, it can
still be changed at runtime and updated. Drivers using a 0444 permission
may be surprised that these values can still be changed.

For drivers that want to allow updates, any S_IW* flag will set the
"store" function as before. Drivers without S_IW* flags will have the
"store" function unset, unforcing a read-only value. Drivers that wish
neither "store" nor "get" can continue to use "0" for perms to stay out
of sysfs entirely.

Old behavior:
  # cd /sys/module/snd/parameters
  # ls -l
  total 0
  -r--r--r-- 1 root root 4096 Dec 11 13:55 cards_limit
  -r--r--r-- 1 root root 4096 Dec 11 13:55 major
  -r--r--r-- 1 root root 4096 Dec 11 13:55 slots
  # cat major
  116
  # echo -1 > major
  -bash: major: Permission denied
  # chmod u+w major
  # echo -1 > major
  # cat major
  -1

New behavior:
  ...
  # chmod u+w major
  # echo -1 > major
  -bash: echo: write error: Input/output error

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-12-18 12:38:51 +10:30
Rusty Russell
18eb74fa94 params: cleanup sysfs allocation
commit 63662139e5 attempted to patch a
leak (which would only happen on OOM, ie. never), but it didn't quite
work.

This rewrites the code to be as simple as possible.  add_sysfs_param()
adds a parameter.  If it fails, it's the caller's responsibility to
clean up the parameters which already exist.

The kzalloc-then-always-krealloc pattern is perhaps overly simplistic,
but this code has clearly confused people.  It worked on me...

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11 17:07:47 +10:30
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
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
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
Felipe Contreras
88a88b320a params: improve standard definitions
We are repeating the functionality of kstrtol in param_set_long, and the
same for kstrtoint. We can get rid of the extra code by using the right
functions.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-12-04 14:09:46 +10:30
Jean Delvare
3a126f85e0 kernel/params: fix handling of signed integer types
Commit 6072ddc852 ("kernel: replace strict_strto*() with kstrto*()")
broke the handling of signed integer types, fix it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Reported-by: Christian Kujau <lists@nerdbynature.de>
Tested-by: Christian Kujau <lists@nerdbynature.de>
Cc: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-28 12:35:52 -07:00
Jingoo Han
6072ddc852 kernel: replace strict_strto*() with kstrto*()
The usage of strict_strto*() is not preferred, because strict_strto*() is
obsolete.  Thus, kstrto*() should be used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 15:38:03 -07:00
Li Zhong
942e443127 module: Fix mod->mkobj.kobj potentially freed too early
DEBUG_KOBJECT_RELEASE helps to find the issue attached below.

After some investigation, it seems the reason is:
The mod->mkobj.kobj(ffffffffa01600d0 below) is freed together with mod
itself in free_module(). However, its children still hold references to
it, as the delay caused by DEBUG_KOBJECT_RELEASE. So when the
child(holders below) tries to decrease the reference count to its parent
in kobject_del(), BUG happens as it tries to access already freed memory.

This patch tries to fix it by waiting for the mod->mkobj.kobj to be
really released in the module removing process (and some error code
paths).

[ 1844.175287] kobject: 'holders' (ffff88007c1f1600): kobject_release, parent ffffffffa01600d0 (delayed)
[ 1844.178991] kobject: 'notes' (ffff8800370b2a00): kobject_release, parent ffffffffa01600d0 (delayed)
[ 1845.180118] kobject: 'holders' (ffff88007c1f1600): kobject_cleanup, parent ffffffffa01600d0
[ 1845.182130] kobject: 'holders' (ffff88007c1f1600): auto cleanup kobject_del
[ 1845.184120] BUG: unable to handle kernel paging request at ffffffffa01601d0
[ 1845.185026] IP: [<ffffffff812cda81>] kobject_put+0x11/0x60
[ 1845.185026] PGD 1a13067 PUD 1a14063 PMD 7bd30067 PTE 0
[ 1845.185026] Oops: 0000 [#1] PREEMPT
[ 1845.185026] Modules linked in: xfs libcrc32c [last unloaded: kprobe_example]
[ 1845.185026] CPU: 0 PID: 18 Comm: kworker/0:1 Tainted: G           O 3.11.0-rc6-next-20130819+ #1
[ 1845.185026] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
[ 1845.185026] Workqueue: events kobject_delayed_cleanup
[ 1845.185026] task: ffff88007ca51f00 ti: ffff88007ca5c000 task.ti: ffff88007ca5c000
[ 1845.185026] RIP: 0010:[<ffffffff812cda81>]  [<ffffffff812cda81>] kobject_put+0x11/0x60
[ 1845.185026] RSP: 0018:ffff88007ca5dd08  EFLAGS: 00010282
[ 1845.185026] RAX: 0000000000002000 RBX: ffffffffa01600d0 RCX: ffffffff8177d638
[ 1845.185026] RDX: ffff88007ca5dc18 RSI: 0000000000000000 RDI: ffffffffa01600d0
[ 1845.185026] RBP: ffff88007ca5dd18 R08: ffffffff824e9810 R09: ffffffffffffffff
[ 1845.185026] R10: ffff8800ffffffff R11: dead4ead00000001 R12: ffffffff81a95040
[ 1845.185026] R13: ffff88007b27a960 R14: ffff88007c1f1600 R15: 0000000000000000
[ 1845.185026] FS:  0000000000000000(0000) GS:ffffffff81a23000(0000) knlGS:0000000000000000
[ 1845.185026] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1845.185026] CR2: ffffffffa01601d0 CR3: 0000000037207000 CR4: 00000000000006b0
[ 1845.185026] Stack:
[ 1845.185026]  ffff88007c1f1600 ffff88007c1f1600 ffff88007ca5dd38 ffffffff812cdb7e
[ 1845.185026]  0000000000000000 ffff88007c1f1640 ffff88007ca5dd68 ffffffff812cdbfe
[ 1845.185026]  ffff88007c974800 ffff88007c1f1640 ffff88007ff61a00 0000000000000000
[ 1845.185026] Call Trace:
[ 1845.185026]  [<ffffffff812cdb7e>] kobject_del+0x2e/0x40
[ 1845.185026]  [<ffffffff812cdbfe>] kobject_delayed_cleanup+0x6e/0x1d0
[ 1845.185026]  [<ffffffff81063a45>] process_one_work+0x1e5/0x670
[ 1845.185026]  [<ffffffff810639e3>] ? process_one_work+0x183/0x670
[ 1845.185026]  [<ffffffff810642b3>] worker_thread+0x113/0x370
[ 1845.185026]  [<ffffffff810641a0>] ? rescuer_thread+0x290/0x290
[ 1845.185026]  [<ffffffff8106bfba>] kthread+0xda/0xe0
[ 1845.185026]  [<ffffffff814ff0f0>] ? _raw_spin_unlock_irq+0x30/0x60
[ 1845.185026]  [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130
[ 1845.185026]  [<ffffffff8150751a>] ret_from_fork+0x7a/0xb0
[ 1845.185026]  [<ffffffff8106bee0>] ? kthread_create_on_node+0x130/0x130
[ 1845.185026] Code: 81 48 c7 c7 28 95 ad 81 31 c0 e8 9b da 01 00 e9 4f ff ff ff 66 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 83 ec 08 48 85 ff 74 1d <f6> 87 00 01 00 00 01 74 1e 48 8d 7b 38 83 6b 38 01 0f 94 c0 84
[ 1845.185026] RIP  [<ffffffff812cda81>] kobject_put+0x11/0x60
[ 1845.185026]  RSP <ffff88007ca5dd08>
[ 1845.185026] CR2: ffffffffa01601d0
[ 1845.185026] ---[ end trace 49a70afd109f5653 ]---

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-09-03 16:35:47 +09:30
Chen Gang
f4940ab7c5 kernel/params.c: use scnprintf() instead of sprintf()
For some strings (e.g. version string), they are permitted to be larger
than PAGE_SIZE (although meaningless), so recommend to use scnprintf()
instead of sprintf().

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-08-20 15:37:46 +09:30
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
Christoph Jaeger
79ac6834c2 module: fix sprintf format specifier in param_get_byte()
In param_get_byte(), to which the macro STANDARD_PARAM_DEF(byte, ...) expands,
"%c" is used to print an unsigned char. So it gets printed as a character what
is not intended here. Use "%hhu" instead.

[Rusty: note drivers which would be effected:
 drivers/net/wireless/cw1200/main.c
 drivers/ntb/ntb_transport.c:68
 drivers/scsi/lpfc/lpfc_attr.c
 drivers/usb/atm/speedtch.c
 drivers/usb/gadget/g_ffs.c
]

Acked-by: Jon Mason <jon.mason@intel.com> (for ntb)
Acked-by: Michal Nazarewicz <mina86@mina86.com> (for g_ffs.c)
Signed-off-by: Christoph Jaeger <christophjaeger@linux.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-08-20 15:37:28 +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
David Woodhouse
63662139e5 params: Fix potential memory leak in add_sysfs_param()
On allocation failure, it would fail to free the old attrs array which
was no longer referenced by anything (since it would free the old
module_param_attrs struct on the way out).

Comment the suspicious-looking krealloc() usage to explain why it *isn't*
actually buggy, despite looking like a classic realloc() usage bug.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2013-03-18 11:40:21 +00:00
Jim Cromie
b5f3abf950 params: replace printk(KERN_<LVL>...) with pr_<lvl>(...)
I left 1 printk which uses __FILE__, __LINE__ explicitly, which should
not be subject to generic preferences expressed via pr_fmt().

+ tweaks suggested by Joe Perches:
- add doing to irq-enabled warning, like others.  It wont happen often..
- change sysfs failure crit, not just err, make it 1 line in logs.
- coalese 2 format fragments into 1 >80 char line

cc: Joe Perches <joe@perches.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-04 17:28:18 -07:00
Jim Cromie
1ef9eaf2bf params.c: fix Smack complaint about parse_args
In commit 9fb48c744: "params: add 3rd arg to option handler callback
signature", the if-guard added to the pr_debug was overzealous; no
callers pass NULL, and existing code above and below the guard assumes
as much.  Change the if-guard to match, and silence the Smack
complaint.

CC: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-04 17:24:22 -07:00
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
Paul Gortmaker
13ae246db4 includecheck: delete any duplicate instances of module.h
Different tree maintainers picked up independently generated
trivial compile fixes based on linux-next testing, resulting
in some cases where a file would have got more than one addition
of module.h once everything was all merged together.

Delete any duplicates so includecheck isn't complaining about
anything related to module.h/export.h changes.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-02-28 19:31:56 -05:00
Dave Young
10f296cbfe module: make module param bint handle nul value
Allow bint param accept nul values, just do same as bool param.

Signed-off-by: Dave Young <dyoung@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-02-14 11:02:15 +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
Jim Cromie
8487bfd954 kernel/params: replace DEBUGP with pr_debug
Use more flexible pr_debug.  This allows:

  echo "module params +p" > /dbg/dynamic_debug/control

to turn on debug messages when needed.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-01-13 09:32:15 +10:30
Paul Gortmaker
72a59aaada kernel: params.c needs module.h not moduleparam.h
Through various other implicit include paths, some files were
getting the full module.h file, and hence living the illusion
that they really only needed moduleparam.h -- but the reality
is that once you remove the module.h presence, these show up:

kernel/params.c:583: warning: ‘struct module_kobject’ declared inside parameter list

Such files really require module.h so simply make it so.  As the
file module.h grabs moduleparam.h on the fly, all will be well.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 09:20:13 -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