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()
...
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>
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>
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)
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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)
Userspace wants to manage module parameters with udev rules.
This currently only works for loaded modules, but not for
built-in ones.
To allow access to the built-in modules we need to
re-trigger all module load events that happened before any
userspace was running. We already do the same thing for all
devices, subsystems(buses) and drivers.
This adds the currently missing /sys/module/<name>/uevent files
to all module entries.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (split & trivial fix)
This simplifies the next patch, where we have an attribute on a
builtin module (ie. module == NULL).
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (split into 2)
In STANDARD_PARAM_DEF, param_set_* handles the case in which strtolfn
returns -EINVAL but it may return -ERANGE. If it returns -ERANGE,
param_set_* may set uninitialized value to the paramerter. We should handle
both cases.
The one of the cases in which strtolfn() returns -ERANGE is following:
*Type of module parameter is long
*Set the parameter more than LONG_MAX
Signed-off-by: Satoru Moriya <satoru.moriya@hds.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
On m68k natural alignment is 2-byte boundary but we are trying to
align structures in __modver section on sizeof(void *) boundary.
This causes trouble when we try to access elements in this section
in array-like fashion when create "version" attributes for built-in
modules.
Moreover, as DaveM said, we can't reliably put structures into
independent objects, put them into a special section, and then expect
array access over them (via the section boundaries) after linking the
objects together to just "work" due to variable alignment choices in
different situations. The only solution that seems to work reliably
is to make an array of plain pointers to the objects in question and
put those pointers in the special section.
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Currently only drivers that are built as modules have their versions
shown in /sys/module/<module_name>/version, but this information might
also be useful for built-in drivers as well. This especially important
for drivers that do not define any parameters - such drivers, if
built-in, are completely invisible from userspace.
This patch changes MODULE_VERSION() macro so that in case when we are
compiling built-in module, version information is stored in a separate
section. Kernel then uses this data to create 'version' sysfs attribute
in the same fashion it creates attributes for module parameters.
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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>
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>
