linux-toradex.git/arch/avr32/kernel/traps.c, branch v3.0.29

avr32: init cannot ignore signals sent by force_sig_info()

2011-04-13T13:46:55+00:00

We can delete the code that checks to see if we're sending an ignored
signal to init because force_sig_info() already handles this case.
force_sig_info() will kill init even if the signal handler is SIG_DFL
and the scenario described in the comment where init might "generate
the same exception over and over again" cannot occur (force_sig_info()
clears SIGNAL_UNKILLABLE to ensure that init will die).

Also, the use of is_global_init() is not correct in the multhreaded
case, as Oleg Nesterov explains,

	"is_global_init() is not right in theory, /sbin/init can be
	multithreaded. And, this doesn't cover the sub-namespace
	inits... I'd suggest to check SIGNAL_UNKILLABLE, but looking
	closer I think you can simply remove this code."

It seems this code was copied from arch/powerpc in March 2007 in commit

  623b0355d5b1 "[AVR32] Clean up exception handling code"

but the code was deleted from arch/powerpc in November 2009 in commit

  a0592d42fe3e "powerpc: kill the obsolete code under is_global_init()"

So catch up with powerpc and delete the bogus code.

Signed-off-by: Matt Fleming 
Signed-off-by: Hans-Christian Egtvedt

Remove multiple KERN_ prefixes from printk formats

2009-07-08T17:30:03+00:00

Commit 5fd29d6ccbc98884569d6f3105aeca70858b3e0f ("printk: clean up
handling of log-levels and newlines") changed printk semantics.  printk
lines with multiple KERN_ prefixes are no longer emitted as
before the patch.

 is now included in the output on each additional use.

Remove all uses of multiple KERN_s in formats.

Signed-off-by: Joe Perches 
Signed-off-by: Linus Torvalds

avr32: Fix oops on unaligned user access

2009-06-13T13:57:30+00:00

The unaligned address exception handler (and others) does not scan the
fixup tables before oopsing. This is bad because it means passing a
badly aligned pointer from user space might crash the kernel.

Fix this by scanning the fixup tables in _exception(). This should
resolve the issue for unaligned addresses as well as other less common
exceptions that might be happening during a userspace access. The page
fault handler already does fixup processing.

Signed-off-by: Haavard Skinnemoen

remove linux/hardirq.h from asm-generic/local.h

2009-01-06T23:59:13+00:00

While looking at reducing the amount of architecture namespace pollution
in the generic kernel, I found that asm/irq.h is included in the vast
majority of compilations on ARM (around 650 files.)

Since asm/irq.h includes a sub-architecture include file on ARM, this
causes a negative impact on the ccache's ability to re-use the build
results from other sub-architectures, so we have a desire to reduce the
dependencies on asm/irq.h.

It turns out that a major cause of this is the needless include of
linux/hardirq.h into asm-generic/local.h.  The patch below removes this
include, resulting in some 250 to 300 files (around half) of the kernel
then omitting asm/irq.h.

My test builds still succeed, provided two ARM files are fixed
(arch/arm/kernel/traps.c and arch/arm/mm/fault.c) - so there may be
negative impacts for this on other architectures.

Note that x86 does not include asm/irq.h nor linux/hardirq.h in its
asm/local.h, so this patch can be viewed as bringing the generic version
into line with the x86 version.

[kosaki.motohiro@jp.fujitsu.com: add #include  to acpi/processor_idle.c]
[adobriyan@gmail.com: fix sparc64]
Signed-off-by: Russell King 
Signed-off-by: KOSAKI Motohiro 
Cc: Steven Rostedt 
Cc: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

avr32: nmi_enter() without nmi_exit()

2008-09-19T18:08:08+00:00

While updating the rcu code, I noticed that do_nmi() for AVR32 is odd:
There is an nmi_enter() call without an nmi_exit().
This can't be correct, it breaks rcu (at least the preempt version) and
lockdep.

[haavard.skinnemoen@atmel.com: fixed another case that returned directly]
Signed-off-by: Haavard Skinnemoen

avr32: Build fix for CONFIG_BUG=n

2008-03-13T22:56:15+00:00

Don't include the BUG trap handling code when CONFIG_BUG is not set.
This fixes allnoconfig.

Signed-off-by: Haavard Skinnemoen

[AVR32] NMI debugging

2008-01-25T07:31:43+00:00

Change the NMI handler to use the die notifier chain to signal anyone
who cares. Add a simple "nmi debugger" which hooks into this chain and
that may dump registers, task state, etc. when it happens.

Signed-off-by: Haavard Skinnemoen

[AVR32] Clean up OCD register usage

2007-12-07T13:54:40+00:00

Generate a new set of OCD register definitions in asm/ocd.h and rename
__mfdr() and __mtdr() to ocd_read() and ocd_write() respectively.

The bitfield definitions are a lot more complete now, and they are
entirely based on bit numbers, not masks. This is because OCD
registers are frequently accessed from assembly code, where bit
numbers are a lot more useful (can be fed directly to sbr, bfins,
etc.)

Bitfields that consist of more than one bit have two definitions:
_START, which indicates the number of the first bit, and _SIZE, which
indicates the number of bits. These directly correspond to the
parameters taken by the bfextu, bfexts and bfins instructions.

Signed-off-by: Haavard Skinnemoen

pid namespaces: define is_global_init() and is_container_init()

2007-10-19T18:53:37+00:00

is_init() is an ambiguous name for the pid==1 check.  Split it into
is_global_init() and is_container_init().

A cgroup init has it's tsk->pid == 1.

A global init also has it's tsk->pid == 1 and it's active pid namespace
is the init_pid_ns.  But rather than check the active pid namespace,
compare the task structure with 'init_pid_ns.child_reaper', which is
initialized during boot to the /sbin/init process and never changes.

Changelog:

	2.6.22-rc4-mm2-pidns1:
	- Use 'init_pid_ns.child_reaper' to determine if a given task is the
	  global init (/sbin/init) process. This would improve performance
	  and remove dependence on the task_pid().

	2.6.21-mm2-pidns2:

	- [Sukadev Bhattiprolu] Changed is_container_init() calls in {powerpc,
	  ppc,avr32}/traps.c for the _exception() call to is_global_init().
	  This way, we kill only the cgroup if the cgroup's init has a
	  bug rather than force a kernel panic.

[akpm@linux-foundation.org: fix comment]
[sukadev@us.ibm.com: Use is_global_init() in arch/m32r/mm/fault.c]
[bunk@stusta.de: kernel/pid.c: remove unused exports]
[sukadev@us.ibm.com: Fix capability.c to work with threaded init]
Signed-off-by: Serge E. Hallyn 
Signed-off-by: Sukadev Bhattiprolu 
Acked-by: Pavel Emelianov 
Cc: Eric W. Biederman 
Cc: Cedric Le Goater 
Cc: Dave Hansen 
Cc: Herbert Poetzel 
Cc: Kirill Korotaev 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Report that kernel is tainted if there was an OOPS

2007-07-17T17:23:02+00:00

If the kernel OOPSed or BUGed then it probably should be considered as
tainted.  Thus, all subsequent OOPSes and SysRq dumps will report the
tainted kernel.  This saves a lot of time explaining oddities in the
calltraces.

Signed-off-by: Pavel Emelianov 
Acked-by: Randy Dunlap 
Cc: 
Signed-off-by: Andrew Morton 
[ Added parisc patch from Matthew Wilson  -Linus ]
Signed-off-by: Linus Torvalds