linux.git/arch/xtensa/kernel/process.c, branch v3.7-rc2

xtensa: minor compiler warning fix

2012-10-19T17:24:20+00:00

Fix two compiler warnings complaining about truncating a value on
a 64-bit host, and about declaring an unused variable that is only
used for a specific configuration.

Signed-off-by: Chris Zankel

xtensa: copy_thread with CLONE_VM must not copy live parent AR windows

2012-10-16T04:42:27+00:00

When doing a fork (new VM), the new task has a mirror image of the
parent's stack, so keeps the same live register windows etc.
However when doing a clone with CLONE_VM, keeping the same VM
(eg. when creating a new thread), the child starts afresh on a new
stack -- it cannot share any part of the parent stack.  It
especially cannot have the same live AR windows as the parent,
otherwise it will overwrite the parent stack on overflow, likely
causing corruption.  (and so it did...)

Effectively, the register windows need to be spilled.
Turns out it's much easier to simply not copy parent register
windows when CLONE_VM is set.

Signed-off-by: Marc Gauthier 
Signed-off-by: Max Filippov 
Signed-off-by: Chris Zankel

vfs: define struct filename and have getname() return it

2012-10-13T00:14:55+00:00

getname() is intended to copy pathname strings from userspace into a
kernel buffer. The result is just a string in kernel space. It would
however be quite helpful to be able to attach some ancillary info to
the string.

For instance, we could attach some audit-related info to reduce the
amount of audit-related processing needed. When auditing is enabled,
we could also call getname() on the string more than once and not
need to recopy it from userspace.

This patchset converts the getname()/putname() interfaces to return
a struct instead of a string. For now, the struct just tracks the
string in kernel space and the original userland pointer for it.

Later, we'll add other information to the struct as it becomes
convenient.

Signed-off-by: Jeff Layton 
Signed-off-by: Al Viro

xtensa: Add missing RCU idle APIs on idle loop

2012-09-23T14:44:51+00:00

In the old times, the whole idle task was considered
as an RCU quiescent state. But as RCU became more and
more successful overtime, some RCU read side critical
section have been added even in the code of some
architectures idle tasks, for tracing for example.

So nowadays, rcu_idle_enter() and rcu_idle_exit() must
be called by the architecture to tell RCU about the part
in the idle loop that doesn't make use of rcu read side
critical sections, typically the part that puts the CPU
in low power mode.

This is necessary for RCU to find the quiescent states in
idle in order to complete grace periods.

Add this missing pair of calls in the xtensa's idle loop.

Reported-by: Paul E. McKenney 
Signed-off-by: Frederic Weisbecker 
Cc: Chris Zankel 
Cc:  # 3.3+
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett

xtensa: fix incorrect memset

2012-07-11T23:04:49+00:00

Addresses: https://bugzilla.kernel.org/show_bug.cgi?id=43871

Reported-by: 
Signed-off-by: Alan Cox 
Signed-off-by: Chris Zankel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fork: move the real prepare_to_copy() users to arch_dup_task_struct()

2012-05-16T22:16:26+00:00

Historical prepare_to_copy() is mostly a no-op, duplicated for majority of
the architectures and the rest following the x86 model of flushing the extended
register state like fpu there.

Remove it and use the arch_dup_task_struct() instead.

Suggested-by: Oleg Nesterov 
Suggested-by: Linus Torvalds 
Signed-off-by: Suresh Siddha 
Link: http://lkml.kernel.org/r/1336692811-30576-1-git-send-email-suresh.b.siddha@intel.com
Acked-by: Benjamin Herrenschmidt 
Cc: David Howells 
Cc: Koichi Yasutake 
Cc: Paul Mackerras 
Cc: Paul Mundt 
Cc: Chris Zankel 
Cc: Richard Henderson 
Cc: Russell King 
Cc: Haavard Skinnemoen 
Cc: Mike Frysinger 
Cc: Mark Salter 
Cc: Aurelien Jacquiot 
Cc: Mikael Starvik 
Cc: Yoshinori Sato 
Cc: Richard Kuo 
Cc: Tony Luck 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: Jonas Bonn 
Cc: James E.J. Bottomley 
Cc: Helge Deller 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Chen Liqin 
Cc: Lennox Wu 
Cc: David S. Miller 
Cc: Chris Metcalf 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Guan Xuetao 
Signed-off-by: H. Peter Anvin

Disintegrate asm/system.h for Xtensa

2012-03-28T17:30:03+00:00

Disintegrate asm/system.h for Xtensa.

Signed-off-by: David Howells 
cc: Chris Zankel

sched/rt: Use schedule_preempt_disabled()

2012-03-01T09:28:03+00:00

Coccinelle based conversion.

Signed-off-by: Thomas Gleixner 
Acked-by: Peter Zijlstra 
Link: http://lkml.kernel.org/n/tip-24swm5zut3h9c4a6s46x8rws@git.kernel.org
Signed-off-by: Ingo Molnar

atomic: use

2011-07-26T23:49:47+00:00

This allows us to move duplicated code in 
(atomic_inc_not_zero() for now) to 

Signed-off-by: Arun Sharma 
Reviewed-by: Eric Dumazet 
Cc: Ingo Molnar 
Cc: David Miller 
Cc: Eric Dumazet 
Acked-by: Mike Frysinger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Make do_execve() take a const filename pointer

2010-08-18T01:07:43+00:00

Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:

arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type

This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to.  This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel().  A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().

do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.

Further kernel_execve() and sys_execve() need to be changed to match.

This has been test built on x86_64, frv, arm and mips.

Signed-off-by: David Howells 
Tested-by: Ralf Baechle 
Acked-by: Russell King 
Signed-off-by: Linus Torvalds