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: NMark Charlebois <charlebm@gmail.com>
Signed-off-by: NBehan Webster <behanw@converseincode.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

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: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

There is no such path as /sys/parameters, module parameters live in
/sys/module/*/parameters.
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Commit 026cee00 "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: NBenoît Thébaudeau <benoit.thebaudeau@advansee.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org

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: NJim Cromie <jim.cromie@gmail.com>
Acked-by: NJason Baron <jbaron@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NPawel Moll <pawel.moll@arm.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

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: NRusty Russell <rusty@rustcorp.com.au>

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: NRusty Russell <rusty@rustcorp.com.au>

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: NRusty Russell <rusty@rustcorp.com.au>

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: NRusty Russell <rusty@rustcorp.com.au>

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: NPaul Gortmaker <paul.gortmaker@windriver.com>

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=744545Signed-off-by: NMichal Schmidt <mschmidt@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (neatened implementations)

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: NRichard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

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: NLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

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: NJan Beulich <jbeulich@novell.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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: NRandy Dunlap <randy.dunlap@oracle.com>
Tested-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Also reorders the macros with the most common ones at the top.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Reviewed-by: NTakashi Iwai <tiwai@suse.de>
Tested-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>

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: NRusty Russell <rusty@rustcorp.com.au>
Reviewed-by: NTakashi Iwai <tiwai@suse.de>
Tested-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>

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: NRusty Russell <rusty@rustcorp.com.au>
Tested-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>

This allows us to generalize the KPARAM_KMALLOCED flag, by calling a function
on every parameter when a module is unloaded.
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Reviewed-by: NTakashi Iwai <tiwai@suse.de>
Tested-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>

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: NRusty Russell <rusty@rustcorp.com.au>
Reviewed-by: NTakashi Iwai <tiwai@suse.de>
Tested-by: NPhil 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

e180a6b7 "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: NTakashi 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: NRusty 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: NRusty 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: NRusty 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: NRusty 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: NSitsofe Wheeler <sitsofe@yahoo.com>
Diagnosed-by: NFrederic Weisbecker <fweisbec@gmail.com>
Tested-by: NFrederic Weisbecker <fweisbec@gmail.com>
Tested-by: NChristof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: NRusty 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: NRusty 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: NRusty 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=8964Signed-off-by: NIvan 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: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove the deprecated __attribute_used__.

[Introduce __section in a few places to silence checkpatch /sam]
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NSam 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: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Globally, s/driverfs/sysfs/g.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Fix source files to build with CONFIG_SYSFS=n.
module_subsys is not available.

SYSFS=n, MODULES=y:	T:y
SYSFS=n, MODULES=n:	T:y

SYSFS=y, MODULES=y:	T:y
SYSFS=y, MODULES=n:	T:y
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

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: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

param_array() in kernel/params.c can now become static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus 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: NSam 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!