There've been reports of problems with CONFIG_PREEMPT=y and the high
floating point partition. This is caused by the possibility of preemption
and rescheduling on a different processor while saving or restioirng the
high partition.
The only places where the FPU state is touched are in ptrace, in
switch_to(), and where handling a floating-point exception. In switch_to()
preemption is off. So it's only in trap.c and ptrace.c that we need to
prevent preemption.
Here is a patch that adds commentary to make the conditions clear, and adds
appropriate preempt_{en,dis}able() calls to make it so. In trap.c I use
preempt_enable_no_resched(), as we're about to return to user space where
the preemption flag will be checked anyway.
Signed-off-by: Peter Chubb <peterc@gelato.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove spurious MSR_SE reset during kprobe processing.
single_step_exception() already does it for us. Reset it to be safe when
executing the fault_handler.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add stricter checks during kprobe registration. Return correct error value so
insmod doesn't succeed. Also printk reason for registration failure.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Martin Bligh determined that this patch is causing his test box to not boot.
Revert.
Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
arch/i386/kernel/vsyscall-note.o is not listed as a target so its .cmd file
is neither considered as a target nor is it read on the next build. This
causes vsyscall-note.o to be rebuilt every time that you run make, which
causes vmlinux to be rebuilt every time.
Signed-off-by: Keith Owens <kaos@ocs.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add a definition for PPC 405EP which was lost somehow during 2.4 -> 2.6
transition.
Recent change to arch/ppc/kernel/misc.S ("Fix incorrect CPU_FTR fixup usage
for unified caches") triggered this bug and 405EP boards don't boot
anymore.
Signed-off-by: Eugene Surovegin <ebs@ebshome.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This cleans an error path which used to leak file descriptors by returning
without trying to tidy up.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It turns out that we need to check for pending signals when a newly forked
process is run for the first time. With strace -f, strace needs to know about
the forked process before it gets going. If it doesn't, then it ptraces some
bogus values into its registers, and the process segfaults. So, I added calls
to interrupt_end, which does that, plus checks for reschedules. There
shouldn't be any of those, but x86 does the same thing, so I'm copying that
behavior to be safe.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is a bunch of compile fixes provoked by building UML with gcc 4. There
are a bunch of signedness mismatches, a couple of uninitialized references,
and a botched C99 structure initialization which had somehow gone unnoticed.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This makes the minimal fixes needed to make the UML iomem driver work in 2.6.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
break.b does not store the break number in cr.iim, instead it stores 0,
which makes all break.b instructions look like BUG(). Extract the
break number from the instruction itself.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Christian Hildner pointed out that the comment did not match what the
code does in cpu_init() when we set up the default control register.
Patch based on suggestions from Ken Chen.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Some bits of the kernel assume that gp always points to valid memory,
in particular PHYSICAL_MODE_ENTER() assumes that both gp and sp are
valid virtual addresses with associated physical pages. The IA64
module loader puts gp well past the end of the module, with no physical
backing. Offsets on gp are still valid, but physical mode addressing
breaks for modules. Ensure that gp always falls within the module
body. Also ensure that gp is 8 byte aligned.
Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Patch from Nicolas Pitre
Not that there might be many of them on the planet, but at least RMK
apparently has one.
Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Kprobes was eating the hardware instruction and data address
breakpoint exceptions. This patch fixes it; kprobes doesn't use those
exceptions at all and should ignore them.
Signed-off-by: Ananth N Mavinakayanahalli <amavin@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
if num has a value of -1, accessing the digits[] array will fail and the
format string will be printed in funny way, or not at all. This happens if
one prints negative numbers.
Just change the code to match lib/vsprintf.c
asm/div64.h cant be used because u64 maps to u32 for this build.
Signed-off-by: Olaf Hering <olh@suse.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The ARM copypage changes in 2.6.12-rc4-git1 removed the preempt locking
from the copypage functions which broke the XScale implementation.
This patch fixes the locking on XScale and removes the now unneeded
minicache code.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Checked-by: Richard Purdie
Add a definition for PPC 405EP which was lost somehow during 2.4 -> 2.6
transition.
Recent change to arch/ppc/kernel/misc.S ("Fix incorrect CPU_FTR fixup usage
for unified caches") triggered this bug and 405EP boards don't boot
anymore.
Signed-off-by: Eugene Surovegin <ebs@ebshome.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Runtime feature support for unified caches was testing a userland feature
flag (PPC_FEATURE_UNIFIED_CACHE) instead of a cpu feature flag
(CPU_FTR_SPLIT_ID_CACHE). Luckily the current defined bit mask for cpu
features and userland features do not overlap so this only causes an issue
on machines with a unified cache, which is extremely rare on PPC today.
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The system might hang when using appldata_mem with high I/O traffic and a
large number of devices. The spinlocks bdev_lock and swaplock are acquired
via calls to si_meminfo() and si_swapinfo() from a tasklet, i.e. interrupt
context, which can lead to a deadlock. Replace tasklet with work queue.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The condition for no context in do_exception checks for hard and soft
interrupts by using in_interrupt() but not for preemption. This is bad for
the users of __copy_from/to_user_inatomic because the fault handler might call
schedule although the preemption count is != 0. Use in_atomic() instead
in_interrupt().
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
To make UML build and run on s390, I needed to do these two little
changes:
1) UML includes some of the subarch's (s390) headers. I had to
change one of them with the following one-liner, to make this
compile. AFAICS, this change doesn't break compilation of s390
itself.
2) UML needs to intercept syscalls via ptrace to invalidate the syscall,
read syscall's parameters and write the result with the result of
UML's syscall processing. Also, UML needs to make sure, that the host
does no syscall restart processing. On i386 for example, this can be
done by writing -1 to orig_eax on the 2nd syscall interception
(orig_eax is the syscall number, which after the interception is used
as a "interrupt was a syscall" flag only.
Unfortunately, s390 holds syscall number and syscall result in gpr2 and
its "interrupt was a syscall" flag (trap) is unreachable via ptrace.
So I changed the host to set trap to -1, if the syscall number is changed
to an invalid value on the first syscall interception.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The special cases of peek and poke on acrs[15] and the fpc register are not
handled correctly. A poke on acrs[15] will clobber the 4 bytes after the
access registers in the thread_info structure. That happens to be the kernel
stack pointer. A poke on the fpc with an invalid value is not caught by the
validity check. On the next context switch the broken fpc value will cause a
program check in the kernel. Improving the checks in peek and poke fixes
this.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Deepak Saxena
The IXDP2800 bootloader does not disable IRQs before jumping into
the kernel and this is causing the Grand Unified KGDB to crash
the system when we do an early call to trap_init() and irq handlers
have not yet been registered. This patch disables IRQs before we
jump into the kernel.
Signed-off-by: Deepak Saxena
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
A typo in prom_find_machine_type from Ben's recent patch "ppc64: Fix
result code handling in prom_init" prevents pSeries LPAR systems from
booting.
Tested on a pSeries 570 and OpenPower 720 (both Power5 LPAR).
Signed-off-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Todd Poynor
PXA27x sleep fixes:
* set additional sleep/wakeup registers for Mainstone boards.
* move CKEN=0 to pxa25x-specific code; that value is harmful on pxa27x.
* save/restore additional registers, including some found necessary for
C5 processors and/or newer blob versions.
* enable future support of additional sleep modes for PXA27x (eg,
standby, deep sleep).
* split off cpu-specific sleep processing between pxa27x and pxa25x into
separate files (partly in preparation for additional sleep modes).
Includes fixes from David Burrage.
Signed-off-by: Todd Poynor
Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Albrecht Dreß
Problem:
When a module requests a DMA channel via the function s3c2410_dma_request(), this function requests the appropriate irq under the name of the client module. When the client module is unloaded, it calls s3c2410_dma_free() which does not free the irq. Consequently, when e.g. running "cat /proc/interrupts", the irq owner points to freed memory, leading to a kernel oops.
File:
linux/arch/arm/mach-s3c2410/dma.c
Fix:
trivial, below
Signed-off-by: Albrecht Dreß
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix a bug in which shub_1_1_found is not being properly initialized or set,
resulting in the improper setting of sn_hub_info->shub_1_1_found.
Signed-off-by: Dean Nelson <dcn@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Re-work the m68knommu specific idle code according to suggestions
from Nick Piggin <nickpiggin@yahoo.com.au>.
A couple of rules that we need to follow:
1. Preempt should now disabled over idle routines. Should only be enabled
to call schedule() then disabled again.
3. When cpu_idle finds (need_resched() == 'true'), it should call schedule().
It should not call schedule() otherwise.
Also fix interrupt locking around the need_resched() and cpu stop state
so that there is no race condition.
Signed-off-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Now that we have HZ=1000 there is much less of a need for decr_overclock.
Remove it.
Leave spread_lpevents but move it into iSeries_setup.c. We should look at
making event spreading the default some day.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The iseries has a bar graph on the front panel that shows how busy it is.
The operating system sets and clears a bit in the CTRL register to control
it.
Instead of going to the complexity of using a thread info bit, just set and
clear it in the idle loop.
Also create two helper functions, ppc64_runlatch_on and ppc64_runlatch_off.
Finally don't use the short form of the SPR defines.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
prom_init(), the trampoline code that "talks" to Open Firmware during
early boot, has various issues with managing OF result codes. Some of my
recent fixups in fact made the problem worse on some platforms.
This patch reworks it all. Tested on g5, Maple, POWER3 and POWER5.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This gets rid of an unused variable `error' in sys_ia32.c:sys32_epoll_wait()
Getting rid of this one makes parsing the output of the kernecomp
autobuild easier --- searching for `Error' to find a problem kept
hitting this one, even though it's only a warning.
Signed-off-by: Tony Luck <tony.luck@intel.com>
The attached patch cleans up a compilation warning when ACPI
is turned off (i.e., when compiling for the Ski simulator).
Signed-off-by: Tony Luck <tony.luck@intel.com>
This cleans up the /proc/device-tree representation of the Open Firmware
device-tree on ppc and ppc64. It does the following things:
- Workaround an issue in some Apple device-trees where a property may
exist with the same name as a child node of the parent. We now
simply "drop" the property instead of creating duplicate entries in
/proc with random result...
- Do not try to chop off the "@0" at the end of a node name whose unit
address is 0. This is not useful, inconsistent, and the code was
buggy and didn't always work anyway.
- Do not create symlinks for the short name and unit address parts of a
node. These were never really used, bloated the memory footprint of
the device-tree with useless struct proc_dir_entry and their matching
dentry and inode cache bloat.
This results in smaller code, smaller memory footprint, and a more
accurate view of the tree presented to userland.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is the ppc32 patch equivalent to the just posted ppc64 one working
around a bug in Apple device-trees regarding the "cpus" nodes.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Apple's Open Firmware has a funny bug when creating the /cpus nodes
where it leaves a dangling '\0' character in the CPU name which ends up
appearing in the full path of the node. This is bogus and
confuses /proc/device-tree badly.
This patch strips those bogus zero's from the node full path when
reading the device-tree from Open Firmware. The "name" property is not
modified and still contains the spurrious 0 (it basically contains 0
tailing 0 instead of one) but that shouldn't be a problem.
An equivalent patch for ppc32 will follow shortly
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The initial peek read PIO of the match register is just a waste.
Just do the flush writes first, as that is more efficient.
Signed-off-by: David S. Miller <davem@davemloft.net>
As mandated by the spec, disable timer around transitions.
From code by : Ken Staton <ken_staton@agilent.com
Signed-off-by: Dave Jones <davej@redhat.com>
The spec states that we have to do this, which is *horrid*.
Based on code from: Ken Staton <ken_staton@agilent.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Peter Chubb