Commit Graph

17 Commits

Author SHA1 Message Date
David Howells 5d1c93ce21 Annotate hardware config module parameters in drivers/watchdog/
When the kernel is running in secure boot mode, we lock down the kernel to
prevent userspace from modifying the running kernel image.  Whilst this
includes prohibiting access to things like /dev/mem, it must also prevent
access by means of configuring driver modules in such a way as to cause a
device to access or modify the kernel image.

To this end, annotate module_param* statements that refer to hardware
configuration and indicate for future reference what type of parameter they
specify.  The parameter parser in the core sees this information and can
skip such parameters with an error message if the kernel is locked down.
The module initialisation then runs as normal, but just sees whatever the
default values for those parameters is.

Note that we do still need to do the module initialisation because some
drivers have viable defaults set in case parameters aren't specified and
some drivers support automatic configuration (e.g. PNP or PCI) in addition
to manually coded parameters.

This patch annotates drivers in drivers/watchdog/.

Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
cc: Wim Van Sebroeck <wim@iguana.be>
cc: Zwane Mwaikambo <zwanem@gmail.com>
cc: linux-watchdog@vger.kernel.org
2017-04-20 12:02:32 +01:00
Jean Delvare 487722cf2d watchdog: Get rid of MODULE_ALIAS_MISCDEV statements
I just can't find any value in MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR)
and MODULE_ALIAS_MISCDEV(TEMP_MINOR) statements.

Either the device is enumerated and the driver already has a module
alias (e.g. PCI, USB etc.) that will get the right driver loaded
automatically.

Or the device is not enumerated and loading its driver will lead to
more or less intrusive hardware poking. Such hardware poking should be
limited to a bare minimum, so the user should really decide which
drivers should be tried and in what order. Trying them all in
arbitrary order can't do any good.

On top of that, loading that many drivers at once bloats the kernel
log. Also many drivers will stay loaded afterward, bloating the output
of "lsmod" and wasting memory. Some modules (cs5535_mfgpt which gets
loaded as a dependency) can't even be unloaded!

If defining char-major-10-130 is needed then it should happen in
user-space.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Mike Frysinger <vapier.adi@gmail.com>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Cc: Jim Cromie <jim.cromie@gmail.com>
2013-11-17 19:38:13 +01:00
Linus Torvalds 0195c00244 Disintegrate and delete asm/system.h
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...
2012-03-28 15:58:21 -07:00
David Howells 9ffc93f203 Remove all #inclusions of asm/system.h
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`

Signed-off-by: David Howells <dhowells@redhat.com>
2012-03-28 18:30:03 +01:00
Wim Van Sebroeck 86a1e1896c watchdog: nowayout is bool
nowayout is actually a boolean value.
So make it bool for all watchdog device drivers.

Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27 20:06:02 +02:00
Joe Perches 27c766aaac watchdog: Use pr_<fmt> and pr_<level>
Use the current logging styles.

Make sure all output has a prefix.
Add missing newlines.
Remove now unnecessary PFX, NAME, and miscellaneous other #defines.
Coalesce formats.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2012-03-27 19:59:26 +02:00
Yong Zhang 86b5912880 watchdog: irq: Remove IRQF_DISABLED
This flag is a NOOP and can be removed now.

Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2011-11-05 21:16:15 +01:00
Wim Van Sebroeck 5f3b27569f watchdog: cleanup spaces before tabs
cleanup spaces before tabs in drivers/watchdog/

Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2011-03-15 16:02:27 +00:00
Randy Dunlap 4724ba575e watchdog: update/improve/consolidate watchdog driver
Move the limited watchdog driver help from kernel-parameters.txt
to Documentation/watchdog/watchdog-parameters.txt and add info to it
for all watchdog drivers except the ones that have driver-specific
files already.

Correct minor comments and MODULE_PARM_DESC() text in 2 places.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2010-05-25 09:05:34 +00:00
Andrew Morton c1bf3acffc [WATCHDOG] drivers/watchdog/wdt.c:wdt_ioctl(): make `ident' non-static
Making this instance static exposes the code to SMP races, etc.

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2010-03-07 10:31:05 +00:00
Alan Cox 04bedfa542 [WATCHDOG] wdt.c: remove #ifdef CONFIG_WDT_501
Change the wdt.c watchdog driver so that the code is the same for
both the WDT500 as the WDT501-P card. The selection of the card
is now being done via the module parameter: 'type' instead of the
config option CONFIG_WDT_501.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2009-03-25 09:08:16 +00:00
Alan Cox 29fa0586de [PATCH] Switch all my contributions stuff to a single common address
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2008-10-28 19:16:11 +00:00
Wim Van Sebroeck 0c06090c94 [WATCHDOG] Coding style - Indentation - part 2
This brings the watchdog drivers into line with coding style.
This patch takes cares of the indentation as described in chapter 1.
Main changes:
* Re-structure the ioctl switch call for all drivers as follows:
	switch (cmd) {
	case WDIOC_GETSUPPORT:
	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
	case WDIOC_GETTEMP:
	case WDIOC_SETOPTIONS:
	case WDIOC_KEEPALIVE:
	case WDIOC_SETTIMEOUT:
	case WDIOC_GETTIMEOUT:
	case WDIOC_GETTIMELEFT:
	default:
	}

This to make the migration from the drivers to the uniform watchdog
device driver easier in the future.

Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2008-08-06 13:21:09 +00:00
Alan Cox 9f2d1f0da7 wdt: Cleanup and sort out locking and inb_p
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-04 17:12:07 -07:00
Alan Cox 01c785dcb4 [WATCHDOG] wdt: fix locking
The audit of _p usage shows various drivers assume inb_p is somehow atomic.
 Of course it isn't and the delay can be split from the I/O cycle causing a
timing violation on chips that matter (eg this one)

With the proposed use of udelay() for some _p delays this will cease to be
a mostly theoretical bug (as the delay stall is unsplittable) and wants
fixing.

Lots of other drivers need fixing this way too.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2008-01-25 20:23:28 +00:00
Ilpo Jarvinen 59338d4cb6 [WATCHDOG] Add necessary braces to if (...) \n #if... cases
Signed-off-by: Ilpo Jarvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-10-25 08:47:29 +00:00
Wim Van Sebroeck b7e04f8c61 mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog.

Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
2007-10-18 10:39:03 +00:00