linux.git/arch/powerpc/kernel/process.c, branch v2.6.16

[PATCH] powerpc: Fix runlatch performance issues

2006-02-24T00:36:31+00:00

The runlatch SPR can take a lot of time to write. My original runlatch
code would set it on every exception entry even though most of the time
this was not required. It would also continually set it in the idle
loop, which is an issue on an SMT capable processor.

Now we cache the runlatch value in a threadinfo bit, and only check for
it in decrementer and hardware interrupt exceptions as well as the idle
loop. Boot on POWER3, POWER5 and iseries, and compile tested on pmac32.

Signed-off-by: Anton Blanchard 
Signed-off-by: Paul Mackerras

Merge git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc-merge

2006-01-12T18:21:22+00:00

Fix up delete/modify conflict of arch/ppc/kernel/process.c by hand (it's
gone, gone, gone).

Signed-off-by: Linus Torvalds

[PATCH] powerpc: task_stack_page()

2006-01-12T17:08:57+00:00

Signed-off-by: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] powerpc: task_thread_info()

2006-01-12T17:08:57+00:00

Signed-off-by: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

powerpc: make ARCH=ppc use arch/powerpc/kernel/process.c

2006-01-12T10:22:34+00:00

Commit 5388fb1025443ec223ba556b10efc4c5f83f8682 made signal_32.c
use discard_lazy_cpu_state, which broke ARCH=ppc because that
uses the common signal_32.c but has its own process.c.  Make ARCH=ppc
use the common process.c to fix this and to reduce the amount
of duplicated code.

Signed-off-by: Paul Mackerras

[PATCH] powerpc: Avoid potential FP corruption with preempt and UP

2006-01-12T09:09:29+00:00

Heikki Lindholm pointed out that there was a potential race with the
lazy CPU state (FP, VR, EVR) stuff if preempt is enabled.  The race
is that in the process of restoring FP state on sigreturn, the task
gets preempted by a user task that wants to use the FPU.  It will take
an FP unavailable exception, which will write the current FPU state
to the thread_struct, overwriting the values which sigreturn has
stored.  Note that this can only happen on UP since we don't implement
lazy CPU state on SMP.

The fix is to flush the lazy CPU state before updating the
thread_struct.  To do this we re-use the flush_lazy_cpu_state()
function from process.c.

Signed-off-by: Paul Mackerras

powerpc: Fix bug causing FP registers corruption on UP + preempt

2005-11-30T02:20:54+00:00

This fixes a bug noticed by Paolo Galtieri and fixed for ARCH=ppc in
the previous commit (ppc: fix floating point register corruption).
This fixes the arch/powerpc code by adding preempt_disable/enable,
and also cleans it up a bit by pulling out the code that discards
any lazily-switched CPU register state into a new function, rather
than having that code repeated in three places.

Signed-off-by: Paul Mackerras

[PATCH] kprobes: Fix return probes on sys_execve

2005-11-24T00:08:39+00:00

Fix a bug in kprobes that can cause an Oops or even a crash when a return
probe is installed on one of the following functions: sys_execve,
do_execve, load_*_binary, flush_old_exec, or flush_thread.  The fix is to
remove the call to kprobe_flush_task() in flush_thread().  This fix has
been tested on all architectures for which the return-probes feature has
been implemented (i386, x86_64, ppc64, ia64).  Please apply.

BACKGROUND

Up to now, we have called kprobe_flush_task() under two situations: when a
task exits, and when it execs.  Flushing kretprobe_instances on exit is
correct because (a) do_exit() doesn't return, and (b) one or more
return-probed functions may be active when a task calls do_exit().  Neither
is the case for sys_execve() and its callees.

Initially, the mistaken call to kprobe_flush_task() on exec was harmless
because we put the "real" return address of each active probed function
back in the stack, just to be safe, when we recycled its
kretprobe_instance.  When support for ppc64 and ia64 was added, this safety
measure couldn't be employed, and was eventually dropped even for i386 and
x86_64.  sys_execve() and its callees were informally blacklisted for
return probes until this fix was developed.

Acked-by: Prasanna S Panchamukhi 
Signed-off-by: Jim Keniston 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge ../linux-2.6

2005-11-07T03:42:09+00:00

[PATCH] powerpc: Make ppc_md.set_dabr non 64-bit specific

2005-11-07T02:31:13+00:00

Define ppc_md.set_dabr for both 32 + 64 bit. Cleanup the implementation for
pSeries also, it was needlessly complex. Now we just do two firmware tests at
setup time, and use one of two functions, rather than using one function and
testing on every call.

Signed-off-by: Michael Ellerman 
Signed-off-by: Paul Mackerras