linux-toradex.git/include/linux/moduleparam.h, branch v2.6.36-rc7

param: don't deref arg in __same_type() checks

2010-08-11T13:34:41+00:00

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 
Tested-by: Randy Dunlap 
Signed-off-by: Rusty Russell

param: add kerneldoc to moduleparam.h

2010-08-11T13:34:21+00:00

Also reorders the macros with the most common ones at the top.

Signed-off-by: Rusty Russell 
Reviewed-by: Takashi Iwai 
Tested-by: Phil Carmody

param: locking for kernel parameters

2010-08-11T13:34:20+00:00

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 
Reviewed-by: Takashi Iwai 
Tested-by: Phil Carmody

param: make param sections const.

2010-08-11T13:34:19+00:00

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 
Tested-by: Phil Carmody

param: add a free hook to kernel_param_ops.

2010-08-11T13:34:18+00:00

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 
Reviewed-by: Takashi Iwai 
Tested-by: Phil Carmody

param: use ops in struct kernel_param, rather than get and set fns directly

2010-08-11T13:34:13+00:00

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 
Reviewed-by: Takashi Iwai 
Tested-by: Phil Carmody 
Cc: "David S. Miller" 
Cc: Ville Syrjala 
Cc: Dmitry Torokhov 
Cc: Alessandro Rubini 
Cc: Michal Januszewski 
Cc: Trond Myklebust 
Cc: "J. Bruce Fields" 
Cc: Neil Brown 
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

param: fix lots of bugs with writing charp params from sysfs, by leaking mem.

2009-10-28T22:26:17+00:00

e180a6b7759a "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 
Cc: Sitsofe Wheeler 
Cc: Frederic Weisbecker 
Cc: Christof Schmitt 
Signed-off-by: Rusty Russell 
Cc: stable@kernel.org

module_param: allow 'bool' module_params to be bool, not just int.

2009-06-12T12:16:58+00:00

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

module_param: split perm field into flags and perm

2009-06-12T12:16:56+00:00

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

module_param: invbool should take a 'bool', not an 'int'

2009-06-12T12:16:56+00:00

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 
Cc: Michal Januszewski 
Signed-off-by: Rusty Russell