Commit Graph

89 Commits

Author SHA1 Message Date
Roland Dreier
a1a08d1cb0 x86: Remove spurious printk level from segfault message
Since commit 5fd29d6c ("printk: clean up handling of log-levels
and newlines"), the kernel logs segfaults like:

    <6>gnome-power-man[24509]: segfault at 20 ip 00007f9d4950465a sp 00007fffbb50fc70 error 4 in libgobject-2.0.so.0.2103.0[7f9d494f7000+45000]

with the extra "<6>" being KERN_INFO.  This happens because the
printk in show_signal_msg() started with KERN_CONT and then
used "%s" to pass in the real level; and KERN_CONT is no longer
an empty string, and printk only pays attention to the level at
the very beginning of the format string.

Therefore, remove the KERN_CONT from this printk, since it is
now actively causing problems (and never really made any
sense).

Signed-off-by: Roland Dreier <roland@digitalvampire.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <874otjitkj.fsf@shaolin.home.digitalvampire.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-07-11 09:56:19 +02:00
Joe Perches
ad361c9884 Remove multiple KERN_ prefixes from printk formats
Commit 5fd29d6ccb ("printk: clean up
handling of log-levels and newlines") changed printk semantics.  printk
lines with multiple KERN_<level> prefixes are no longer emitted as
before the patch.

<level> is now included in the output on each additional use.

Remove all uses of multiple KERN_<level>s in formats.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-08 10:30:03 -07:00
Linus Torvalds
d06063cc22 Move FAULT_FLAG_xyz into handle_mm_fault() callers
This allows the callers to now pass down the full set of FAULT_FLAG_xyz
flags to handle_mm_fault().  All callers have been (mechanically)
converted to the new calling convention, there's almost certainly room
for architectures to clean up their code and then add FAULT_FLAG_RETRY
when that support is added.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-21 13:08:22 -07:00
Linus Torvalds
c4c5ab3089 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (45 commits)
  x86, mce: fix error path in mce_create_device()
  x86: use zalloc_cpumask_var for mce_dev_initialized
  x86: fix duplicated sysfs attribute
  x86: de-assembler-ize asm/desc.h
  i386: fix/simplify espfix stack switching, move it into assembly
  i386: fix return to 16-bit stack from NMI handler
  x86, ioapic: Don't call disconnect_bsp_APIC if no APIC present
  x86: Remove duplicated #include's
  x86: msr.h linux/types.h is only required for __KERNEL__
  x86: nmi: Add Intel processor 0x6f4 to NMI perfctr1 workaround
  x86, mce: mce_intel.c needs <asm/apic.h>
  x86: apic/io_apic.c: dmar_msi_type should be static
  x86, io_apic.c: Work around compiler warning
  x86: mce: Don't touch THERMAL_APIC_VECTOR if no active APIC present
  x86: mce: Handle banks == 0 case in K7 quirk
  x86, boot: use .code16gcc instead of .code16
  x86: correct the conversion of EFI memory types
  x86: cap iomem_resource to addressable physical memory
  x86, mce: rename _64.c files which are no longer 64-bit-specific
  x86, mce: mce.h cleanup
  ...

Manually fix up trivial conflict in arch/x86/mm/fault.c
2009-06-20 10:49:48 -07:00
Ingo Molnar
5dfaf90f80 x86: mm: Read cr2 before prefetching the mmap_lock
Prefetch instructions can generate spurious faults on certain
models of older CPUs. The faults themselves cannot be stopped
and they can occur pretty much anywhere - so the way we solve
them is that we detect certain patterns and ignore the fault.

There is one small path of code where we must not take faults
though: the #PF handler execution leading up to the reading
of the CR2 (the faulting address). If we take a fault there
then we destroy the CR2 value (with that of the prefetching
instruction's) and possibly mishandle user-space or
kernel-space pagefaults.

It turns out that in current upstream we do exactly that:

	prefetchw(&mm->mmap_sem);

	/* Get the faulting address: */
	address = read_cr2();

This is not good.

So turn around the order: first read the cr2 then prefetch
the lock address. Reading cr2 is plenty fast (2 cycles) so
delaying the prefetch by this amount shouldnt be a big issue
performance-wise.

[ And this might explain a mystery fault.c warning that sometimes
  occurs on one an old AMD/Semptron based test-system i have -
  which does have such prefetch problems. ]

Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
LKML-Reference: <20090616030522.GA22162@Krystal>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-16 10:23:32 +02:00
Vegard Nossum
f85612967c x86: add hooks for kmemcheck
The hooks that we modify are:
- Page fault handler (to handle kmemcheck faults)
- Debug exception handler (to hide pages after single-stepping
  the instruction that caused the page fault)

Also redefine memset() to use the optimized version if kmemcheck is
enabled.

(Thanks to Pekka Enberg for minimizing the impact on the page fault
handler.)

As kmemcheck doesn't handle MMX/SSE instructions (yet), we also disable
the optimized xor code, and rely instead on the generic C implementation
in order to avoid false-positive warnings.

Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>

[whitespace fixlet]
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
2009-06-15 12:40:02 +02:00
Ingo Molnar
940010c5a3 Merge branch 'linus' into perfcounters/core
Conflicts:
	arch/x86/kernel/irqinit.c
	arch/x86/kernel/irqinit_64.c
	arch/x86/kernel/traps.c
	arch/x86/mm/fault.c
	include/linux/sched.h
	kernel/exit.c
2009-06-11 17:55:42 +02:00
Peter Zijlstra
f4dbfa8f31 perf_counter: Standardize event names
Pure renames only, to PERF_COUNT_HW_* and PERF_COUNT_SW_*.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-06-11 17:54:15 +02:00
Linus Torvalds
be15f9d63b Merge branch 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-xen-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (42 commits)
  xen: cache cr0 value to avoid trap'n'emulate for read_cr0
  xen/x86-64: clean up warnings about IST-using traps
  xen/x86-64: fix breakpoints and hardware watchpoints
  xen: reserve Xen start_info rather than e820 reserving
  xen: add FIX_TEXT_POKE to fixmap
  lguest: update lazy mmu changes to match lguest's use of kvm hypercalls
  xen: honour VCPU availability on boot
  xen: add "capabilities" file
  xen: drop kexec bits from /sys/hypervisor since kexec isn't implemented yet
  xen/sys/hypervisor: change writable_pt to features
  xen: add /sys/hypervisor support
  xen/xenbus: export xenbus_dev_changed
  xen: use device model for suspending xenbus devices
  xen: remove suspend_cancel hook
  xen/dev-evtchn: clean up locking in evtchn
  xen: export ioctl headers to userspace
  xen: add /dev/xen/evtchn driver
  xen: add irq_from_evtchn
  xen: clean up gate trap/interrupt constants
  xen: set _PAGE_NX in __supported_pte_mask before pagetable construction
  ...
2009-06-10 16:16:27 -07:00
Ingo Molnar
a454ab3110 x86, mm: fault.c, use printk_once() in is_errata93()
Andrew pointed out that the 'once' variable has a needlessly
function-global scope. We can in fact eliminate it completely,
via the use of printk_once().

[ Impact: cleanup ]

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-03 10:09:03 +02:00
Peter Zijlstra
78f13e9525 perf_counter: allow for data addresses to be recorded
Paul suggested we allow for data addresses to be recorded along with
the traditional IPs as power can provide these.

For now, only the software pagefault events provide data addresses,
but in the future power might as well for some events.

x86 doesn't seem capable of providing this atm.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090408130409.394816925@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-08 19:05:56 +02:00
Peter Zijlstra
ac17dc8e58 perf_counter: provide major/minor page fault software events
Provide separate sw counters for major and minor page faults.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:29:40 +02:00
Peter Zijlstra
7dd1fcc258 perf_counter: provide pagefault software events
We use the generic software counter infrastructure to provide
page fault events.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-06 09:29:37 +02:00
Ingo Molnar
a2bcd4731f x86/mm: further cleanups of fault.c's include file section
Impact: cleanup

Eliminate more than 20 unnecessary #include lines in fault.c

Also fix include file dependency bug in asm/traps.h. (this was
masked before, by implicit inclusion)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <tip-56aea8468746e673a4bf50b6a13d97b2d1cbe1e8@git.kernel.org>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
2009-03-30 14:02:02 +02:00
Jeremy Fitzhardinge
b8bcfe997e x86/paravirt: remove lazy mode in interrupts
Impact: simplification, robustness

Make paravirt_lazy_mode() always return PARAVIRT_LAZY_NONE
when in an interrupt.  This prevents interrupt code from
accidentally inheriting an outer lazy state, and instead
does everything synchronously.  Outer batched operations
are left deferred.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
2009-03-29 23:35:38 -07:00
Ingo Molnar
b319eed0aa x86, mm: fault.c, simplify kmmio_fault(), cleanup
Clarify the kmmio_fault() comment.

Acked-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-22 10:24:18 +01:00
Ingo Molnar
f8eeb2e6be x86, mm: fault.c, update copyrights
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-20 23:13:36 +01:00
Ingo Molnar
cd1b68f08f x86, mm: fault.c, give another attempt at prefetch handing before SIGBUS
Impact: extend prefetch handling on 64-bit

Currently there's an extra is_prefetch() check done in do_sigbus(),
which we only do on 32 bits.

This is a last-ditch check before we terminate a task, so it's worth
giving prefetch instructions another chance - should none of our
existing quirks have caught a prefetch instruction related spurious
fault.

The only risk is if a prefetch causes a real sigbus, in that case
we'll not OOM but try another fault. But this code has been on
32-bit for a long time, so it should be fine in practice.

So do this on 64-bit too - and thus remove one more #ifdef.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:46 +01:00
Ingo Molnar
7c178a26d3 x86, mm: fault.c, remove #ifdef from fault_in_kernel_space()
Impact: cleanup

Removal of an #ifdef in fault_in_kernel_space(), by making
use of the new TASK_SIZE_MAX symbol which is now available
on 32-bit too.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:45 +01:00
Ingo Molnar
d951734654 x86, mm: rename TASK_SIZE64 => TASK_SIZE_MAX
Impact: cleanup

Rename TASK_SIZE64 to TASK_SIZE_MAX, and provide the
define on 32-bit too. (mapped to TASK_SIZE)

This allows 32-bit code to make use of the (former-) TASK_SIZE64
symbol as well, in a clean way.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:44 +01:00
Ingo Molnar
c3731c6866 x86, mm: fault.c, remove #ifdef from do_page_fault()
Impact: cleanup

do_page_fault() has this ugly #ifdef in its prototype:

  #ifdef CONFIG_X86_64
  asmlinkage
  #endif
  void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)

Replace it with 'dotraplinkage' which maps to exactly the above
construct: nothing on 32-bit and asmlinkage on 64-bit.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:44 +01:00
Ingo Molnar
1cc99544dd x86, mm: fault.c, unify oops handling
Impact: add oops-recursion check to 32-bit

Unify the oops state-machine, to the 64-bit version. It is
slightly more careful in that it does a recursion check
in oops_begin(), and is thus more likely to show the relevant
oops.

It also means that 32-bit will print one more line at the
end of pagefault triggered oopses:

 	printk(KERN_EMERG "CR2: %016lx\n", address);

Which is generally good information to be seen in partial-dump
digital-camera jpegs ;-)

The downside is the somewhat more complex critical path. Both
variants have been tested well meanwhile by kernel developers
crashing their boxes so i dont think this is a practical worry.

This removes 3 ugly #ifdefs from no_context() and makes the
function a lot nicer read.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:44 +01:00
Ingo Molnar
8f7661496c x86, mm: fault.c, unify oops printing
Impact: refine/extend page fault related oops printing on 64-bit

 - honor the pause_on_oops logic on 64-bit too
 - print out NX fault warnings on 64-bit as well
 - factor out the NX fault message to make it git-greppable and readable

Note that this means that we do the PF_INSTR check on 32-bit non-PAE
as well where it should not occur ... normally. Cannot hurt.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:43 +01:00
Ingo Molnar
f2f13a8535 x86, mm: fault.c, reorder functions
Impact: cleanup

Avoid a couple more #ifdefs by moving fundamentally non-unifiable
functions into a single #ifdef 32-bit / #else / #endif block in
fault.c: vmalloc*(), dump_pagetable(), check_vm8086_mode().

No code changed:

   text	   data	    bss	    dec	    hex	filename
   4618	     32	     24	   4674	   1242	fault.o.before
   4618	     32	     24	   4674	   1242	fault.o.after

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:43 +01:00
Ingo Molnar
b18018126f x86, mm, kprobes: fault.c, simplify notify_page_fault()
Impact: cleanup

Remove an #ifdef from notify_page_fault(). The function still
compiles to nothing in the !CONFIG_KPROBES case.

Introduce kprobes_built_in() and kprobe_fault_handler() helpers
to allow this - they returns 0 if !CONFIG_KPROBES.

No code changed:

   text	   data	    bss	    dec	    hex	filename
   4618	     32	     24	   4674	   1242	fault.o.before
   4618	     32	     24	   4674	   1242	fault.o.after

Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:42 +01:00
Ingo Molnar
b814d41f09 x86, mm: fault.c, simplify kmmio_fault()
Impact: cleanup

Remove an #ifdef from kmmio_fault() - we can do this by
providing default implementations for is_kmmio_active()
and kmmio_handler(). The compiler optimizes it all away
in the !CONFIG_MMIOTRACE case.

Also, while at it, clean up mmiotrace.h a bit:

 - standard header guards
 - standard vertical spaces for structure definitions

No code changed (both with mmiotrace on and off in the config):

   text	   data	    bss	    dec	    hex	filename
   2947	     12	     12	   2971	    b9b	fault.o.before
   2947	     12	     12	   2971	    b9b	fault.o.after

Cc: Pekka Paalanen <pq@iki.fi>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:42 +01:00
Ingo Molnar
121d5d0a7e x86, mm: fault.c, enable PF_RSVD checks on 32-bit too
Impact: improve page fault handling robustness

The 'PF_RSVD' flag (bit 3) of the page-fault error_code is a
relatively recent addition to x86 CPUs, so the 32-bit do_fault()
implementation never had it. This flag gets set when the CPU
detects nonzero values in any reserved bits of the page directory
entries.

Extend the existing 64-bit check for PF_RSVD in do_page_fault()
to 32-bit too. If we detect such a fault then we print a more
informative oops and the pagetables.

This unifies the code some more, removes an ugly #ifdef and improves
the 32-bit page fault code robustness a bit. It slightly increases
the 32-bit kernel text size.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:41 +01:00
Ingo Molnar
8c938f9fae x86, mm: fault.c, factor out the vm86 fault check
Impact: cleanup

Instead of an ugly, open-coded, #ifdef-ed vm86 related legacy check
in do_page_fault(), put it into the check_v8086_mode() helper
function and merge it with an existing #ifdef.

Also, simplify the code flow a tiny bit in the helper.

No code changed:

arch/x86/mm/fault.o:

   text	   data	    bss	    dec	    hex	filename
   2711	     12	     12	   2735	    aaf	fault.o.before
   2711	     12	     12	   2735	    aaf	fault.o.after

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:41 +01:00
Ingo Molnar
107a03678c x86, mm: fault.c, refactor/simplify the is_prefetch() code
Impact: no functionality changed

Factor out the opcode checker into a helper inline.

The code got a tiny bit smaller:

   text	   data	    bss	    dec	    hex	filename
   4632	     32	     24	   4688	   1250	fault.o.before
   4618	     32	     24	   4674	   1242	fault.o.after

And it got cleaner / easier to review as well.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:40 +01:00
Ingo Molnar
2d4a71676f x86, mm: fault.c cleanup
Impact: cleanup, no code changed

Clean up various small details, which can be correctness checked
automatically:

 - tidy up the include file section
 - eliminate unnecessary includes
 - introduce show_signal_msg() to clean up code flow
 - standardize the code flow
 - standardize comments and other style details
 - more cleanups, pointed out by checkpatch

No code changed on either 32-bit nor 64-bit:

arch/x86/mm/fault.o:

   text	   data	    bss	    dec	    hex	filename
   4632	     32	     24	   4688	   1250	fault.o.before
   4632	     32	     24	   4688	   1250	fault.o.after

the md5 changed due to a change in a single instruction:

   2e8a8241e7f0d69706776a5a26c90bc0  fault.o.before.asm
   c5c3d36e725586eb74f0e10692f0193e  fault.o.after.asm

Because a __LINE__ reference in a WARN_ONCE() has changed.

On 32-bit a few stack offsets changed - no code size difference
nor any functionality difference.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-21 00:09:39 +01:00
Ingo Molnar
c9e1585b1b Merge branch 'tip/x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into x86/mm 2009-02-20 18:51:43 +01:00
Steven Rostedt
3c3e5694ad x86: check PMD in spurious_fault handler
Impact: fix to prevent hard lockup on bad PMD permissions

If the PMD does not have the correct permissions for a page access,
but the PTE does, the spurious fault handler will mistake the fault
as a lazy TLB transaction. This will result in an infinite loop of:

 fault -> spurious_fault check (pass) -> return to code -> fault

This patch adds a check and a warn on if the PTE passes the permissions
but the PMD does not.

[ Updated: Ingo Molnar suggested using WARN_ONCE with some text ]

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2009-02-20 11:44:47 -05:00
Ingo Molnar
b233969eaa Merge branch 'x86/untangle2' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen into x86/headers
Conflicts:
	arch/x86/include/asm/page.h
	arch/x86/include/asm/pgtable.h
	arch/x86/mach-voyager/voyager_smp.c
	arch/x86/mm/fault.c
2009-02-13 13:09:00 +01:00
Ingo Molnar
f268fe7333 Merge branch 'x86/mm' into x86/core 2009-02-13 09:47:24 +01:00
Ingo Molnar
f8a6b2b9ce Merge branch 'linus' into x86/apic
Conflicts:
	arch/x86/kernel/acpi/boot.c
	arch/x86/mm/fault.c
2009-02-13 09:44:22 +01:00
Jeremy Fitzhardinge
9049a11de7 Merge commit 'remotes/tip/x86/paravirt' into x86/untangle2
* commit 'remotes/tip/x86/paravirt': (175 commits)
  xen: use direct ops on 64-bit
  xen: make direct versions of irq_enable/disable/save/restore to common code
  xen: setup percpu data pointers
  xen: fix 32-bit build resulting from mmu move
  x86/paravirt: return full 64-bit result
  x86, percpu: fix kexec with vmlinux
  x86/vmi: fix interrupt enable/disable/save/restore calling convention.
  x86/paravirt: don't restore second return reg
  xen: setup percpu data pointers
  x86: split loading percpu segments from loading gdt
  x86: pass in cpu number to switch_to_new_gdt()
  x86: UV fix uv_flush_send_and_wait()
  x86/paravirt: fix missing callee-save call on pud_val
  x86/paravirt: use callee-saved convention for pte_val/make_pte/etc
  x86/paravirt: implement PVOP_CALL macros for callee-save functions
  x86/paravirt: add register-saving thunks to reduce caller register pressure
  x86/paravirt: selectively save/restore regs around pvops calls
  x86: fix paravirt clobber in entry_64.S
  x86/pvops: add a paravirt_ident functions to allow special patching
  xen: move remaining mmu-related stuff into mmu.c
  ...

Conflicts:
	arch/x86/mach-voyager/voyager_smp.c
	arch/x86/mm/fault.c
2009-02-11 11:52:22 -08:00
Ingo Molnar
0464ac9ebd Merge branch 'linus' into x86/mm
Conflicts:
	arch/x86/mm/fault.c
2009-02-06 14:42:54 +01:00
Masami Hiramatsu
9be260a646 prevent kprobes from catching spurious page faults
Prevent kprobes from catching spurious faults which will cause infinite
recursive page-fault and memory corruption by stack overflow.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-05 17:01:50 -08:00
Hiroshi Shimamoto
0973a06cde x86: mm: introduce helper function in fault.c
Impact: cleanup

Introduce helper function fault_in_kernel_address() to make editors happy.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-02-04 16:16:55 -08:00
Peter Zijlstra
010060741a x86: add might_sleep() to do_page_fault()
Impact: widen debug checks

VirtualBox calls do_page_fault() from an atomic context but runs into a
might_sleep() way pas this point, cure that.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-29 16:03:34 +01:00
Ingo Molnar
74b6eb6b93 Merge branches 'x86/asm', 'x86/cleanups', 'x86/cpudetect', 'x86/debug', 'x86/doc', 'x86/header-fixes', 'x86/mm', 'x86/paravirt', 'x86/pat', 'x86/setup-v2', 'x86/subarch', 'x86/uaccess' and 'x86/urgent' into x86/core 2009-01-28 23:13:53 +01:00
Johannes Weiner
fb746d0e13 x86: optimise page fault entry, cleanup
tsk is already assigned to current, drop the redundant second
assignment.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 21:36:54 +01:00
Ingo Molnar
198030782c Merge branch 'x86/mm' into core/percpu
Conflicts:
	arch/x86/mm/fault.c
2009-01-21 10:39:51 +01:00
Nick Piggin
92181f190b x86: optimise x86's do_page_fault (C entry point for the page fault path)
Impact: cleanup, restructure code to improve assembly

gcc isn't _all_ that smart about spilling registers to stack or reusing
stack slots, even with branch annotations. do_page_fault contained a lot
of functionality, so split unlikely paths into their own functions, and
mark them as noinline just to be sure. I consider this actually to be
somewhat of a cleanup too: the main function now contains about half
the number of lines so the normal path is easier to read, while the error
cases are also nicely split away.

Also, ensure the order of arguments to functions is always the same: regs,
addr, error_code. This can reduce code size a tiny bit, and just looks neater
too.

And add a couple of branch annotations.

Before:
  do_page_fault:
          subq    $360, %rsp      #,

After:
  do_page_fault:
          subq    $56, %rsp       #,

bloat-o-meter:
  add/remove: 8/0 grow/shrink: 0/1 up/down: 2222/-1680 (542)
  function                                     old     new   delta
  __bad_area_nosemaphore                         -     506    +506
  no_context                                     -     474    +474
  vmalloc_fault                                  -     424    +424
  spurious_fault                                 -     358    +358
  mm_fault_error                                 -     272    +272
  bad_area_access_error                          -      89     +89
  bad_area                                       -      89     +89
  bad_area_nosemaphore                           -      10     +10
  do_page_fault                               2464     784   -1680

Yes, the total size increases by 542 bytes, due to the extra function calls.
But these will very rarely be called (except for vmalloc_fault) in a normal
workload. Importantly, do_page_fault is less than 1/3rd it's original size,
and touches far less stack.

Existing gotos and branch hints did move a lot of the infrequently used text
out of the fastpath, but that's even further improved after this patch.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-20 13:14:23 +01:00
Ingo Molnar
b2b062b816 Merge branch 'core/percpu' into stackprotector
Conflicts:
	arch/x86/include/asm/pda.h
	arch/x86/include/asm/system.h

Also, moved include/asm-x86/stackprotector.h to arch/x86/include/asm.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-18 18:37:14 +01:00
Andi Kleen
f313e12308 x86: avoid theoretical vmalloc fault loop
Ajith Kumar noticed:

 I was going through the vmalloc fault handling for x86_64 and am unclear
 about the following lines in the vmalloc_fault() function.

 pgd = pgd_offset(current->mm ?: &init_mm, address);
 pgd_ref = pgd_offset_k(address);

 Here the intention is to get the pgd corresponding to the current process
 and sync it up with the pgd in init_mm(obtained from pgd_offset_k).
 However, for kernel threads current->mm is NULL and hence pgd =
 pgd_offset(init_mm, address) = pgd_ref which means the fault handler
 returns without setting the pgd entry in the MM structure in the context
 of which the kernel thread has faulted.  This could lead to never-ending
 faults and busy looping of kernel threads like pdflush.  So, shouldn't the
 pgd = pgd_offset(current->mm ?: &init_mm, address); be pgd =
 pgd_offset(current->active_mm ?: &init_mm, address);

We can use active_mm unconditionally because it should be always set.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-12 19:24:21 +01:00
Nick Piggin
1c0fe6e3bd mm: invoke oom-killer from page fault
Rather than have the pagefault handler kill a process directly if it gets
a VM_FAULT_OOM, have it call into the OOM killer.

With increasingly sophisticated oom behaviour (cpusets, memory cgroups,
oom killing throttling, oom priority adjustment or selective disabling,
panic on oom, etc), it's silly to unconditionally kill the faulting
process at page fault time.  Create a hook for pagefault oom path to call
into instead.

Only converted x86 and uml so far.

[akpm@linux-foundation.org: make __out_of_memory() static]
[akpm@linux-foundation.org: fix comment]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Jeff Dike <jdike@addtoit.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:58:58 -08:00
Ingo Molnar
a9de18eb76 Merge branch 'linus' into stackprotector
Conflicts:
	arch/x86/include/asm/pda.h
	kernel/fork.c
2008-12-31 08:31:57 +01:00
Linus Torvalds
b0f4b285d7 Merge branch 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (241 commits)
  sched, trace: update trace_sched_wakeup()
  tracing/ftrace: don't trace on early stage of a secondary cpu boot, v3
  Revert "x86: disable X86_PTRACE_BTS"
  ring-buffer: prevent false positive warning
  ring-buffer: fix dangling commit race
  ftrace: enable format arguments checking
  x86, bts: memory accounting
  x86, bts: add fork and exit handling
  ftrace: introduce tracing_reset_online_cpus() helper
  tracing: fix warnings in kernel/trace/trace_sched_switch.c
  tracing: fix warning in kernel/trace/trace.c
  tracing/ring-buffer: remove unused ring_buffer size
  trace: fix task state printout
  ftrace: add not to regex on filtering functions
  trace: better use of stack_trace_enabled for boot up code
  trace: add a way to enable or disable the stack tracer
  x86: entry_64 - introduce FTRACE_ frame macro v2
  tracing/ftrace: add the printk-msg-only option
  tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()
  x86, bts: correctly report invalid bts records
  ...

Fixed up trivial conflict in scripts/recordmcount.pl due to SH bits
being already partly merged by the SH merge.
2008-12-28 12:21:10 -08:00
Linus Torvalds
be9c5ae4ee Merge branch 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (246 commits)
  x86: traps.c replace #if CONFIG_X86_32 with #ifdef CONFIG_X86_32
  x86: PAT: fix address types in track_pfn_vma_new()
  x86: prioritize the FPU traps for the error code
  x86: PAT: pfnmap documentation update changes
  x86: PAT: move track untrack pfnmap stubs to asm-generic
  x86: PAT: remove follow_pfnmap_pte in favor of follow_phys
  x86: PAT: modify follow_phys to return phys_addr prot and return value
  x86: PAT: clarify is_linear_pfn_mapping() interface
  x86: ia32_signal: remove unnecessary declaration
  x86: common.c boot_cpu_stack and boot_exception_stacks should be static
  x86: fix intel x86_64 llc_shared_map/cpu_llc_id anomolies
  x86: fix warning in arch/x86/kernel/microcode_amd.c
  x86: ia32.h: remove unused struct sigfram32 and rt_sigframe32
  x86: asm-offset_64: use rt_sigframe_ia32
  x86: sigframe.h: include headers for dependency
  x86: traps.c declare functions before they get used
  x86: PAT: update documentation to cover pgprot and remap_pfn related changes - v3
  x86: PAT: add pgprot_writecombine() interface for drivers - v3
  x86: PAT: change pgprot_noncached to uc_minus instead of strong uc - v3
  x86: PAT: implement track/untrack of pfnmap regions for x86 - v3
  ...
2008-12-28 12:07:57 -08:00