Commit Graph

5977 Commits

Author SHA1 Message Date
Ingo Molnar
bdb1a9b62f x86, apic: rename genapic::apic_destination_logical to genapic::dest_logical
This field name was unreasonably long - shorten it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:19 +01:00
Ingo Molnar
0b06e734bf x86: clean up the APIC_DEST_LOGICAL logic
Impact: cleanup

The bigsmp and es7000 subarchitectures un-defined APIC_DEST_LOGICAL in
a rather nasty way by re-defining it to zero. That is infinitely
fragile and makes it very hard to see what to code really does in
a given context. The very same constant has different meanings and
values - depending on which subarch is enabled.

Untangle this mess by never undefining the constant, but instead
propagating the right values into the genapic driver templates.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:18 +01:00
Ingo Molnar
08125d3eda x86: rename ->ESR_DISABLE to ->disable_esr
the ->ESR_DISABLE shouting variant was used to enable the esr_disable
macro wrappers. Those ugly macros are removed now so we can rename
->ESR_DISABLE to ->disable_esr

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:18 +01:00
Ingo Molnar
f6f52baf26 x86: clean up esr_disable() methods
Impact: cleanup

Most subarchitectures want to disable the APIC ESR (Error Status Register),
because they generally have hardware hacks that wrap standard CPUs into
a bigger system and hence the APIC bus is quite non-standard and weirdnesses
(lockups) have been seen with ESR reporting.

Remove the esr_disable macros and put the desired flag into each
subarchitecture's genapic template directly.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:17 +01:00
Ingo Molnar
fe402e1f2b x86, apic: clean up / remove TARGET_CPUS
Impact: cleanup

use apic->target_cpus() directly instead of the TARGET_CPUS wrapper.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:17 +01:00
Ingo Molnar
0a9cc20b9c x86, apic: clean up target_cpus methods
Impact: cleanup

Clean up all the target_cpus() namespace overlap that exists
between bigsmp, es7000, mach-default, numaq and summit - by
separating the different functions into different names.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:17 +01:00
Ingo Molnar
7fe732862d x86, apic: remove IRQ_DEST_MODE
Remove leftover definition.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:16 +01:00
Ingo Molnar
38bd77a6c3 x86, apic: remove ES7000_IRQ_DELIVERY_MODE and ES7000_IRQ_DEST_MODE
Impact: cleanup

They were only used in a single place and obscured the apic_es7000
driver template.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:16 +01:00
Ingo Molnar
d8a3539e64 x86, apic: remove BIGSMP_IRQ_DELIVERY_MODE and BIGSMP_IRQ_DEST_MODE
Impact: cleanup

They were only used in a single place and obscured the apic_bigsmp
driver template.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:15 +01:00
Ingo Molnar
1b1bcb3ff4 x86, apic: remove NUMAQ_IRQ_DELIVERY_MODE and NUMAQ_IRQ_DEST_MODE
Impact: cleanup

They were only used in a single place and obscured the apic_numaq template.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:15 +01:00
Ingo Molnar
82daea6b08 x86, apic: remove SUMMIT_IRQ_DELIVERY_MODE and SUMMIT_IRQ_DEST_MODE
Impact: cleanup

They were only used in a single place and obscured the apic_summit template.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:14 +01:00
Ingo Molnar
dcafa4a8c9 x86, apic: remove DEFAULT_IRQ_DELIVERY_MODE and DEFAULT_IRQ_DEST_MODE
Impact: cleanup

They were only used in a single place and obscured the apic_default template.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:14 +01:00
Ingo Molnar
9b5bc8dc12 x86, apic: remove IRQ_DEST_MODE / IRQ_DELIVERY_MODE
Remove the wrapper macros IRQ_DEST_MODE and IRQ_DELIVERY_MODE.

The typical 32-bit and the 64-bit build all dereference via the genapic,
so it's pointless to hide that indirection via these ugly macros.

Furthermore, it also obscures subarchitecture details.

So replace it with apic->irq_dest_mode / etc. accesses.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:13 +01:00
Ingo Molnar
f8987a1093 x86, genapic: rename int_delivery_mode, et. al.
int_delivery_mode is supposed to mean 'interrupt delivery mode', but
it's quite a misnomer as 'int' we usually think of as an integer type ...

The standard naming for such attributes is 'irq' - so rename the following
fields and macros:

 int_delivery_mode => irq_delivery_mode
 INT_DELIVERY_MODE => IRQ_DELIVERY_MODE
 int_dest_mode     => irq_dest_mode
 INT_DEST_MODE     => IRQ_DEST_MODE

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:13 +01:00
Ingo Molnar
7ed248daa5 x86: clean up apic->apic_id_registered() methods
Impact: cleanup

x86 subarchitectures each defined a "apic_id_registered()" method,
which could be an inline function depending on which subarch we build
for, and which was also the name of a genapic field.

Untangle this namespace spaghetti by giving each of the instances
a separate name.

Also remove wrapper macro obfuscation.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:12 +01:00
Ingo Molnar
306db03b0d x86: clean up apic->acpi_madt_oem_check methods
Impact: refactor code

x86 subarchitectures each defined a "acpi_madt_oem_check()" method,
which could be an inline function, or an extern, or a static function,
and which was also the name of a genapic field.

Untangle this namespace spaghetti by setting ->acpi_madt_oem_check()
to NULL on those subarchitectures that have no detection quirks,
and rename the other ones (summit, es7000) that do.

Also change default_acpi_madt_oem_check() to handle NULL entries,
and clean its control flow up as well.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:12 +01:00
Ingo Molnar
9a6801da55 x86: remove APIC_INIT / APICFUNC / IPIFUNC
The APIC_INIT() / APICFUNC / IPIFUNC macros were ugly and obfuscated
the true identity of various APIC driver methods.

Now that they are not used anymore, remove them.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:11 +01:00
Ingo Molnar
491a50c4fb x86, genapic: cleanup 32-bit apic_summit template
Clean up the APIC driver template:

 - order fields properly
 - use the macro names explicitly (so that they can be renamed later)
 - fill in NULL entries as well

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:11 +01:00
Ingo Molnar
fed53ebf3c x86, genapic: cleanup 32-bit apic_es7000 template
Clean up the APIC driver template:

 - order fields properly
 - use the macro names explicitly (so that they can be renamed later)
 - fill in NULL entries as well

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:11 +01:00
Ingo Molnar
fea3437adf x86, genapic: cleanup 32-bit apic_numaq template
Clean up the APIC driver template:

 - order fields properly
 - use the macro names explicitly (so that they can be renamed later)
 - fill in NULL entries as well

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:10 +01:00
Ingo Molnar
d26b6d6660 x86, genapic: cleanup 32-bit apic_bigsmp template
Clean up the APIC driver template:

 - order fields properly
 - use the macro names explicitly (so that they can be renamed later)
 - fill in NULL entries as well

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:10 +01:00
Ingo Molnar
0a7e8c6414 x86, genapic: cleanup 32-bit apic_default template
Clean up the APIC driver template:

 - order fields properly
 - use the macro names explicitly (so that they can be renamed later)
 - fill in NULL entries as well

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:09 +01:00
Ingo Molnar
504a3c3ad4 x86: clean up apic_x2apic_cluster
- reorder fields so that they appear in struct genapic field ordering

- add zero-initialized fields too so that it's apparent which functionality
  is default / missing.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:09 +01:00
Ingo Molnar
05c155c235 x86: clean up apic_x2apic_phys
- reorder fields so that they appear in struct genapic field ordering

- add zero-initialized fields too so that it's apparent which functionality
  is default / missing.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:08 +01:00
Ingo Molnar
c796732991 x86: clean up apic_x2apic_uv_x
- reorder fields so that they appear in struct genapic field ordering

- add zero-initialized fields too so that it's apparent which functionality
  is default / missing.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:08 +01:00
Ingo Molnar
4c3e51e05a x86: clean up genapic_phys_flat
- reorder fields so that they appear in struct genapic field ordering

- add zero-initialized fields too so that it's apparent which functionality
  is default / missing.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:07 +01:00
Ingo Molnar
f2f05ee8b8 x86: clean up genapic_flat
- reorder fields so that they appear in struct genapic field ordering

- add zero-initialized fields too so that it's apparent which functionality
  is default / missing.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:07 +01:00
Ingo Molnar
c8d46cf06d x86: rename 'genapic' to 'apic'
Rename genapic-> to apic-> references because in a future chagne we'll
open-code all the indirect calls (instead of obscuring them via macros),
so we want this reference to be as short as possible.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:06 +01:00
Ingo Molnar
6781d948cc x86, genapic: provide IPI callbacks unconditionally
64-bit x86 uses the IPI callbacks even on UP - so provide them
generally.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:06 +01:00
Ingo Molnar
505deeb1a2 x86, genapic: cleanups
Unify genapic.h some more.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:05 +01:00
Ingo Molnar
ced733ec0b x86, genapic: finish unification
Unify remaining bits of genapic_32/64.h.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:05 +01:00
Ingo Molnar
ef7471b13f x86, genapic: unify struct genapic
Move over the (now identical) struct genapic definitions from
genapic_32/64.h to genapic.h.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:04 +01:00
Ingo Molnar
943d0f74d4 x86, genapic: refactor genapic_32.h
Impact: pre unification cleanup

Make genapic_32.h similar to genapic_64.h: reorder fields, unify types
and bring in new entries.

No existing functionality is affected.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:04 +01:00
Ingo Molnar
6e7a59944a x86, genapic: refactor genapic_64.h
Impact: pre unification cleanup

Make genapic_64.h similar to genapic_32.h: reorder fields, unify types
and bring in new entries.

No existing functionality is affected.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-28 23:20:03 +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
Peter Zijlstra
8f6d86dc41 x86: cpu_init(): remove ugly #ifdef construct around debug register clear
Impact: Cleanup

While I was looking through the new and improved bootstrap code - great
work that, thanks! I found the below a slight improvement.

Remove unnecessary ugly #ifdef construct around debug register clear.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-27 14:54:44 -08:00
Andreas Schwab
042cbaf88a x86 setup: fix asm constraints in vesa_store_edid
Impact: fix potential miscompile (currently believed non-manifest)

As the comment explains, the VBE DDC call can clobber any register.
Tell the compiler about that fact.

Signed-off-by: Andreas Schwab <schwab@suse.de>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-27 14:48:46 -08:00
Ingo Molnar
4369f1fb7c Merge branch 'tj-percpu' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into core/percpu
Conflicts:
	arch/x86/kernel/setup_percpu.c

Semantic conflict:

	arch/x86/kernel/cpu/common.c

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-27 12:03:24 +01:00
Ingo Molnar
3ddeb51d9c Merge branch 'linus' into core/percpu
Conflicts:
	arch/x86/kernel/setup_percpu.c
2009-01-27 12:01:51 +01:00
Tejun Heo
cf3997f507 x86: clean up indentation in setup_per_cpu_areas()
Impact: cosmetic cleanup

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 14:25:05 +09:00
James Bottomley
22f25138c3 x86: fix build breakage on voyage
Impact: build fix

x86_cpu_to_apicid and x86_bios_cpu_apicid aren't defined for voyage.
Earlier patch forgot to conditionalize early percpu clearing.  Fix it.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 14:21:37 +09:00
Brian Gerst
2697fbd5fa x86: load new GDT after setting up boot cpu per-cpu area
Impact: sync 32 and 64-bit code

Merge load_gs_base() into switch_to_new_gdt().  Load the GDT and
per-cpu state for the boot cpu when its new area is set up.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:48 +09:00
Brian Gerst
1825b8edc2 x86: remove extra barriers from load_gs_base()
Impact: optimization

mb() generates an mfence instruction, which is not needed here.  Only
a compiler barrier is needed, and that is handled by the memory clobber
in the wrmsrl function.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:48 +09:00
Brian Gerst
b2d2f4312b x86: initialize per-cpu GDT segment in per-cpu setup
Impact: cleanup

Rename init_gdt() to setup_percpu_segment(), and move it to
setup_percpu.c.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:48 +09:00
Brian Gerst
89c9c4c58e x86: make Voyager use x86 per-cpu setup.
Impact: standardize all x86 platforms on same setup code

With the preceding changes, Voyager can use the same per-cpu setup
code as all the other x86 platforms.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:48 +09:00
Brian Gerst
34019be1cd x86: don't assume boot cpu is #0
Impact: minor cleanup

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:48 +09:00
Brian Gerst
1688401a0f x86: move this_cpu_offset
Impact: Small cleanup

Define BOOT_PERCPU_OFFSET and use it for this_cpu_offset and
__per_cpu_offset initializers.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:48 +09:00
Brian Gerst
996db817e3 x86: only compile setup_percpu.o on SMP
Impact: Minor build optimization

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:47 +09:00
Brian Gerst
ec70de8b04 x86: move apic variables to apic.c
Impact: Code movement

Move the variable definitions to apic.c.  Ifdef the copying of
the two early per-cpu variables, since Voyager doesn't use them.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:47 +09:00
Brian Gerst
74631a248d x86: always page-align per-cpu area start and size
Impact: cleanup

The way the code is written, align is always PAGE_SIZE.  Simplify
the code by removing the align variable.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:47 +09:00
Brian Gerst
2f2f52bad7 x86: move setup_cpu_local_masks()
Impact: Code movement, no functional change.

Move setup_cpu_local_masks() to kernel/cpu/common.c, where the
masks are defined.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:47 +09:00
Brian Gerst
6470aff619 x86: move 64-bit NUMA code
Impact: Code movement, no functional change.

Move the 64-bit NUMA code from setup_percpu.c to numa_64.c

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:47 +09:00
Brian Gerst
0d77e7f04d x86: merge setup_per_cpu_maps() into setup_per_cpu_areas()
Impact: minor optimization

Eliminates the need for two loops over possible cpus.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-27 12:56:47 +09:00
Linus Torvalds
cfb901bf84 Merge branch 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
  i2c: Warn on deprecated binding model use
  eeprom: More consistent symbol names
  eeprom: Move 93cx6 eeprom driver to /drivers/misc/eeprom
  spi: Move at25 (for SPI eeproms) to /drivers/misc/eeprom
  i2c: Move old eeprom driver to /drivers/misc/eeprom
  i2c: Move at24 to drivers/misc/eeprom
  i2c: Quilt tree has moved
  i2c: Delete many unused adapter IDs
  i2c: Delete 10 unused driver IDs
2009-01-26 15:11:41 -08:00
Linus Torvalds
2034563ca3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild-fixes:
  kbuild: fix kbuild.txt typos
  kbuild: print usage with no arguments in scripts/config
  Revert "kbuild: strip generated symbols from *.ko"
2009-01-26 15:10:37 -08:00
Jean Delvare
dd7f8dbe2b eeprom: More consistent symbol names
Now that all EEPROM drivers live in the same place, let's harmonize
their symbol names.

Also fix eeprom's dependencies, it definitely needs sysfs, and is no
longer experimental after many years in the kernel tree.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-01-26 21:19:57 +01:00
Linus Torvalds
3386c05bdb Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  debugobjects: add and use INIT_WORK_ON_STACK
  rcu: remove duplicate CONFIG_RCU_CPU_STALL_DETECTOR
  relay: fix lock imbalance in relay_late_setup_files
  oprofile: fix uninitialized use of struct op_entry
  rcu: move Kconfig menu
  softlock: fix false panic which can occur if softlockup_thresh is reduced
  rcu: add __cpuinit to rcu_init_percpu_data()
2009-01-26 09:47:56 -08:00
Linus Torvalds
1e70c7f7a9 Merge branch 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimers: fix inconsistent lock state on resume in hres_timers_resume
  time-sched.c: tick_nohz_update_jiffies should be static
  locking, hpet: annotate false positive warning
  kernel/fork.c: unused variable 'ret'
  itimers: remove the per-cpu-ish-ness
2009-01-26 09:47:43 -08:00
Linus Torvalds
810ee58de2 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: (29 commits)
  xen: unitialised return value in xenbus_write_transaction
  x86: fix section mismatch warning
  x86: unmask CPUID levels on Intel CPUs, fix
  x86: work around PAGE_KERNEL_WC not getting WC in iomap_atomic_prot_pfn.
  x86: use standard PIT frequency
  xen: handle highmem pages correctly when shrinking a domain
  x86, mm: fix pte_free()
  xen: actually release memory when shrinking domain
  x86: unmask CPUID levels on Intel CPUs
  x86: add MSR_IA32_MISC_ENABLE bits to <asm/msr-index.h>
  x86: fix PTE corruption issue while mapping RAM using /dev/mem
  x86: mtrr fix debug boot parameter
  x86: fix page attribute corruption with cpa()
  Revert "x86: signal: change type of paramter for sys_rt_sigreturn()"
  x86: use early clobbers in usercopy*.c
  x86: remove kernel_physical_mapping_init() from init section
  fix: crash: IP: __bitmap_intersects+0x48/0x73
  cpufreq: use work_on_cpu in acpi-cpufreq.c for drv_read and drv_write
  work_on_cpu: Use our own workqueue.
  work_on_cpu: don't try to get_online_cpus() in work_on_cpu.
  ...
2009-01-26 09:47:28 -08:00
H. Peter Anvin
30a0fb947a x86: correct the CPUID pattern for MSR_IA32_MISC_ENABLE availability
Impact: re-enable CPUID unmasking on affected processors

As far as I am capable of discerning from the documentation,
MSR_IA32_MISC_ENABLE should be available for all family 0xf CPUs, as
well as family 6 for model >= 0xd (newer Pentium M).

The documentation on this isn't ideal, so we need to be on the lookout
for errors, still.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-26 09:40:58 -08:00
Rakib Mullick
659d2618b3 x86: fix section mismatch warning
Here function vmi_activate calls a init function activate_vmi , which
causes the following section mismatch warnings:

  LD      arch/x86/kernel/built-in.o
WARNING: arch/x86/kernel/built-in.o(.text+0x13ba9): Section mismatch
in reference from the function vmi_activate() to the function
.init.text:vmi_time_init()
The function vmi_activate() references
the function __init vmi_time_init().
This is often because vmi_activate lacks a __init
annotation or the annotation of vmi_time_init is wrong.

WARNING: arch/x86/kernel/built-in.o(.text+0x13bd1): Section mismatch
in reference from the function vmi_activate() to the function
.devinit.text:vmi_time_bsp_init()
The function vmi_activate() references
the function __devinit vmi_time_bsp_init().
This is often because vmi_activate lacks a __devinit
annotation or the annotation of vmi_time_bsp_init is wrong.

WARNING: arch/x86/kernel/built-in.o(.text+0x13bdb): Section mismatch
in reference from the function vmi_activate() to the function
.devinit.text:vmi_time_ap_init()
The function vmi_activate() references
the function __devinit vmi_time_ap_init().
This is often because vmi_activate lacks a __devinit
annotation or the annotation of vmi_time_ap_init is wrong.

Fix it by marking vmi_activate() as __init too.

Signed-off-by: Rakib Mullick <rakib.mullick@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-26 14:27:18 +01:00
Ingo Molnar
d5e397cb49 x86: improve early fault/irq printout
Impact: add a stack dump to early IRQs/faults

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-26 14:22:00 +01:00
Ingo Molnar
34707bcd04 x86, debug: remove early_printk() #ifdefs from head_32.S
Impact: cleanup

Remove such constructs:

 #ifdef CONFIG_EARLY_PRINTK
        call early_printk
 #else
        call printk
 #endif

Not only are they ugly, they are also pointless: a call to printk()
maps to early_printk during early bootup anyway, if CONFIG_EARLY_PRINTK
is enabled.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-26 14:18:43 +01:00
Frederic Weisbecker
2d4d57db69 x86: micro-optimize __raw_read_trylock()
The current version of __raw_read_trylock starts with decrementing the lock
and read its new value as a separate operation after that.

That makes 3 dereferences (read, write (after sub), read) whereas
a single atomic_dec_return does only two pointers dereferences (read, write).

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-26 14:06:36 +01:00
Ingo Molnar
99fb4d349d x86: unmask CPUID levels on Intel CPUs, fix
Impact: fix boot hang on pre-model-15 Intel CPUs

rdmsrl_safe() does not work in very early bootup code yet, because we
dont have the pagefault handler installed yet so exception section
does not get parsed. rdmsr_safe() will just crash and hang the bootup.

So limit the MSR_IA32_MISC_ENABLE MSR read to those CPU types that
support it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-26 12:36:24 +01:00
Eric Anholt
ef5fa0ab24 x86: work around PAGE_KERNEL_WC not getting WC in iomap_atomic_prot_pfn.
In the absence of PAT, PAGE_KERNEL_WC ends up mapping to a memory type that
gets UC behavior even in the presence of a WC MTRR covering the area in
question.  By swapping to PAGE_KERNEL_UC_MINUS, we can get the actual
behavior the caller wanted (WC if you can manage it, UC otherwise).

This recovers the 40% performance improvement of using WC in the DRM
to upload vertex data.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-26 11:14:27 +01:00
Ingo Molnar
e1b4d11436 x86: use standard PIT frequency
the RDC and ELAN platforms use slighly different PIT clocks, resulting in
a timex.h hack that changes PIT_TICK_RATE during build time. But if a
tester enables any of these platform support .config options, the PIT
will be miscalibrated on standard PC platforms.

So use one frequency - in a subsequent patch we'll add a quirk to allow
x86 platforms to define different PIT frequencies.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-25 16:57:47 +01:00
H. Peter Anvin
b38b066590 x86: filter CPU features dependent on unavailable CPUID levels
Impact: Fixes potential crashes on misconfigured systems.

Some CPU features require specific CPUID levels to be available in
order to function, as they contain information about the operation of
a specific feature.  However, some BIOSes and virtualization software
provide the ability to mask CPUID levels in order to support legacy
operating systems.  We try to enable such CPUID levels when we know
how to do it, but for the remaining cases, filter out such CPU
features when there is no way for us to support them.

Do this in one place, in the CPUID code, with a table-driven approach.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-23 18:08:05 -08:00
H. Peter Anvin
75a048119e x86: handle PAT more like other CPU features
Impact: Cleanup

When PAT was originally introduced, it was handled specially for a few
reasons:

- PAT bugs are hard to track down, so we wanted to maintain a
  whitelist of CPUs.
- The i386 and x86-64 CPUID code was not yet unified.

Both of these are now obsolete, so handle PAT like any other features,
including ordinary feature blacklisting due to known bugs.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-23 18:07:45 -08:00
H. Peter Anvin
b1882e68d1 x86: clean up stray space in <asm/processor.h>
Impact: Whitespace cleanup only

Clean up a stray space character in arch/x86/include/asm/processor.h.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-23 17:54:17 -08:00
Hiroshi Shimamoto
3b4b75700a x86: ia32_signal: use {get|put}_user_try and catch
Impact: use new framework

Use {get|put}_user_try, catch, and _ex in arch/x86/ia32/ia32_signal.c.

Note: this patch contains "WARNING: line over 80 characters", because when
introducing new block I insert an indent to avoid mistakes by edit.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-23 17:17:39 -08:00
Hiroshi Shimamoto
98e3d45eda x86: signal: use {get|put}_user_try and catch
Impact: use new framework

Use {get|put}_user_try, catch, and _ex in arch/x86/kernel/signal.c.

Note: this patch contains "WARNING: line over 80 characters", because when
introducing new block I insert an indent to avoid mistakes by edit.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-23 17:17:38 -08:00
Hiroshi Shimamoto
fe40c0af3c x86: uaccess: introduce try and catch framework
Impact: introduce new uaccess exception handling framework

Introduce {get|put}_user_try and {get|put}_user_catch as new uaccess exception
handling framework.
{get|put}_user_try begins exception block and {get|put}_user_catch(err) ends
the block and gets err if an exception occured in {get|put}_user_ex() in the
block. The exception is stored thread_info->uaccess_err.

The example usage of this framework is below;
int func()
{
	int err = 0;

	get_user_try {
		get_user_ex(...);
		get_user_ex(...);
		:
	} get_user_catch(err);

	return err;
}

Note: get_user_ex() is not clear the value when an exception occurs, it's
different from the behavior of __get_user(), but I think it doesn't matter.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-23 17:17:36 -08:00
Peter Zijlstra
42ef73fe13 x86, mm: fix pte_free()
On -rt we were seeing spurious bad page states like:

Bad page state in process 'firefox'
page:c1bc2380 flags:0x40000000 mapping:c1bc2390 mapcount:0 count:0
Trying to fix it up, but a reboot is needed
Backtrace:
Pid: 503, comm: firefox Not tainted 2.6.26.8-rt13 #3
[<c043d0f3>] ? printk+0x14/0x19
[<c0272d4e>] bad_page+0x4e/0x79
[<c0273831>] free_hot_cold_page+0x5b/0x1d3
[<c02739f6>] free_hot_page+0xf/0x11
[<c0273a18>] __free_pages+0x20/0x2b
[<c027d170>] __pte_alloc+0x87/0x91
[<c027d25e>] handle_mm_fault+0xe4/0x733
[<c043f680>] ? rt_mutex_down_read_trylock+0x57/0x63
[<c043f680>] ? rt_mutex_down_read_trylock+0x57/0x63
[<c0218875>] do_page_fault+0x36f/0x88a

This is the case where a concurrent fault already installed the PTE and
we get to free the newly allocated one.

This is due to pgtable_page_ctor() doing the spin_lock_init(&page->ptl)
which is overlaid with the {private, mapping} struct.

union {
    struct {
        unsigned long private;
        struct address_space *mapping;
    };
    spinlock_t ptl;
    struct kmem_cache *slab;
    struct page *first_page;
};

Normally the spinlock is small enough to not stomp on page->mapping, but
PREEMPT_RT=y has huge 'spin'locks.

But lockdep kernels should also be able to trigger this splat, as the
lock tracking code grows the spinlock to cover page->mapping.

The obvious fix is calling pgtable_page_dtor() like the regular pte free
path __pte_free_tlb() does.

It seems all architectures except x86 and nm10300 already do this, and
nm10300 doesn't seem to use pgtable_page_ctor(), which suggests it
doesn't do SMP or simply doesnt do MMU at all or something.

Signed-off-by: Peter Zijlstra <a.p.zijlsta@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: <stable@kernel.org>
2009-01-23 18:42:06 +01:00
Ingo Molnar
99d0000f71 x86, xen: fix hardirq.h merge fallout
Impact: build fix

This build error:

 arch/x86/xen/suspend.c:22: error: implicit declaration of function 'fix_to_virt'
 arch/x86/xen/suspend.c:22: error: 'FIX_PARAVIRT_BOOTMAP' undeclared (first use in this function)
 arch/x86/xen/suspend.c:22: error: (Each undeclared identifier is reported only once
 arch/x86/xen/suspend.c:22: error: for each function it appears in.)

triggers because the hardirq.h unification removed an implicit fixmap.h
include - on which arch/x86/xen/suspend.c depended. Add the fixmap.h
include explicitly.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-23 11:09:15 +01:00
Brian Gerst
2de3a5f795 x86: make irq_cpustat_t fields conditional
Impact: shrink size of irq_cpustat_t when possible

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-23 11:03:32 +09:00
Brian Gerst
22da7b3df3 x86: merge hardirq_{32,64}.h into hardirq.h
Impact: cleanup

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-23 11:03:31 +09:00
Brian Gerst
658a9a2c34 x86: sync hardirq_{32,64}.h
Impact: better code generation and removal of unused field for 32bit

In general, use the 64-bit version.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-23 11:03:31 +09:00
Brian Gerst
3819cd489e x86: remove include of apic.h from hardirq_64.h
Impact: cleanup

APIC definitions aren't needed here.  Remove the include and fix
up the fallout.

tj: added include to mce_intel_64.c.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-23 11:03:29 +09:00
Brian Gerst
03d2989df9 x86: remove idle_timestamp from 32bit irq_cpustat_t
Impact: bogus irq_cpustat field removed

idle_timestamp is left over from the removed irqbalance code.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-01-23 11:03:28 +09:00
Jeremy Fitzhardinge
6522869c34 x86: add pte_set_flags/clear_flags for pte flag manipulation
It's not necessary to deconstruct and reconstruct a pte every time its
flags are being updated.  Introduce pte_set_flags and pte_clear_flags
to set and clear flags in a pte.  This allows the flag manipulation
code to be inlined, and avoids calls via paravirt-ops.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-22 23:35:21 +01:00
Jeremy Fitzhardinge
ab897d2013 x86/pvops: remove pte_flags pvop
pte_flags() was introduced as a new pvop in order to extract just the
flags portion of a pte, which is a potentially cheaper operation than
extracting the page number as well.  It turns out this operation is
not needed, because simply using a mask to extract the flags from a
pte is sufficient for all current users.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-22 23:35:20 +01:00
venkatesh.pallipadi@intel.com
d639bab8da x86 PAT: ioremap_wc should take resource_size_t parameter
Impact: fix/extend ioremap_wc() beyond 4GB aperture on 32-bit

ioremap_wc() was taking in unsigned long parameter, where as it should take
64-bit resource_size_t parameter like other ioremap variants.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-22 11:53:42 +01:00
Thomas Gleixner
336f6c322d debugobjects: add and use INIT_WORK_ON_STACK
Impact: Fix debugobjects warning

debugobject enabled kernels spit out a warning in hpet code due to a
workqueue which is initialized on stack.

Add INIT_WORK_ON_STACK() which calls init_timer_on_stack() and use it
in hpet.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-01-22 10:02:07 +01:00
H. Peter Anvin
066941bd4e x86: unmask CPUID levels on Intel CPUs
Impact: Fixes crashes with misconfigured BIOSes on XSAVE hardware

Avuton Olrich reported early boot crashes with v2.6.28 and
bisected it down to dc1e35c6e9
("x86, xsave: enable xsave/xrstor on cpus with xsave support").

If the CPUID limit bit in MSR_IA32_MISC_ENABLE is set, clear it to
make all CPUID information available.  This is required for some
features to work, in particular XSAVE.

Reported-and-bisected-by: Avuton Olrich <avuton@gmail.com>
Tested-by: Avuton Olrich <avuton@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-22 09:24:02 +01:00
H. Peter Anvin
bdf21a49ba x86: add MSR_IA32_MISC_ENABLE bits to <asm/msr-index.h>
Impact: None (new bit definitions currently unused)

Add bit definitions for the MSR_IA32_MISC_ENABLE MSRs to
<asm/msr-index.h>.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2009-01-21 15:13:53 -08:00
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
Suresh Siddha
9597134218 x86: fix PTE corruption issue while mapping RAM using /dev/mem
Beschorner Daniel reported:
> hwinfo problem since 2.6.28, showing this in the oops:
>	Corrupted page table at address 7fd04de3ec00

Also, PaX Team reported a regression with this commit:

>	commit 9542ada803
>	Author: Suresh Siddha <suresh.b.siddha@intel.com>
>	Date:   Wed Sep 24 08:53:33 2008 -0700
>
>	    x86: track memtype for RAM in page struct

This commit breaks mapping any RAM page through /dev/mem, as the
reserve_memtype() was not initializing the return attribute type and as such
corrupting the PTE entry that was setup with the return attribute type.

Because of this bug, application mapping this RAM page through /dev/mem
will die with "Corrupted page table at address xxxx" message in the kernel
log and also the kernel identity mapping which maps the underlying RAM
page gets converted to UC.

Fix this by initializing the return attribute type before calling
reserve_ram_pages_type()

Reported-by: PaX Team <pageexec@freemail.hu>
Reported-and-tested-by: Beschorner Daniel <Daniel.Beschorner@facton.com>
Tested-and-Acked-by: PaX Team <pageexec@freemail.hu>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 18:42:32 +01:00
Nick Piggin
03b486322e x86: make UV support configurable
Make X86 SGI Ultraviolet support configurable. Saves about 13K of text size
on my modest config.

   text    data     bss     dec     hex filename
6770537 1158680  694356 8623573  8395d5 vmlinux
6757492 1157664  694228 8609384  835e68 vmlinux.nouv

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 13:00:42 +01:00
Hiroshi Shimamoto
cc86c9e0dc x86: uaccess: rename __put_user_u64() to __put_user_asm_u64()
Impact: cleanup

rename __put_user_u64() to __put_user_asm_u64() like __get_user_asm_u64().

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 12:34:44 +01:00
Hiroshi Shimamoto
4d5d783896 x86: uaccess: fix style problems
Impact: cleanup

Fix coding style problems in arch/x86/include/asm/uaccess.h.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 12:34:44 +01:00
Thomas Renninger
731f1872f4 x86: mtrr fix debug boot parameter
while looking at:

  http://bugzilla.kernel.org/show_bug.cgi?id=11541

I realized that the mtrr.show param cannot work, because
the code is processed much too early.

This patch:
 - Declares mtrr.show as early_param
 - Stays consistent with the previous param (which I doubt
   that it ever worked), so mtrr.show=1 would still work
 - Declares mtrr_show as initdata

Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 12:26:42 +01:00
Suresh Siddha
a1e46212a4 x86: fix page attribute corruption with cpa()
Impact: fix sporadic slowdowns and warning messages

This patch fixes a performance issue reported by Linus on his
Nehalem system. While Linus reverted the PAT patch (commit
58dab916df) which exposed the issue,
existing cpa() code can potentially still cause wrong(page attribute
corruption) behavior.

This patch also fixes the "WARNING: at arch/x86/mm/pageattr.c:560" that
various people reported.

In 64bit kernel, kernel identity mapping might have holes depending
on the available memory and how e820 reports the address range
covering the RAM, ACPI, PCI reserved regions. If there is a 2MB/1GB hole
in the address range that is not listed by e820 entries, kernel identity
mapping will have a corresponding hole in its 1-1 identity mapping.

If cpa() happens on the kernel identity mapping which falls into these holes,
existing code fails like this:

	__change_page_attr_set_clr()
		__change_page_attr()
			returns 0 because of if (!kpte). But doesn't
			set cpa->numpages and cpa->pfn.
		cpa_process_alias()
			uses uninitialized cpa->pfn (random value)
			which can potentially lead to changing the page
			attribute of kernel text/data, kernel identity
			mapping of RAM pages etc. oops!

This bug was easily exposed by another PAT patch which was doing
cpa() more often on kernel identity mapping holes (physical range between
max_low_pfn_mapped and 4GB), where in here it was setting the
cache disable attribute(PCD) for kernel identity mappings aswell.

Fix cpa() to handle the kernel identity mapping holes. Retain
the WARN() for cpa() calls to other not present address ranges
(kernel-text/data, ioremap() addresses)

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 12:24:54 +01:00
Ingo Molnar
ace6c6c840 x86: make x86_32 use tlb_64.c, build fix, clean up X86_L1_CACHE_BYTES
Fix:

  arch/x86/mm/tlb.c:47: error: ‘CONFIG_X86_INTERNODE_CACHE_BYTES’ undeclared here (not in a function)

The CONFIG_X86_INTERNODE_CACHE_BYTES symbol is only defined on 64-bit,
because vsmp support is 64-bit only. Define it on 32-bit too - where it
will always be equal to X86_L1_CACHE_BYTES.

Also move the default of X86_L1_CACHE_BYTES (which is separate from the
more commonly used L1_CACHE_SHIFT kconfig symbol) from 128 bytes to
64 bytes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 11:17:11 +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
Ingo Molnar
4ec71fa2d2 x86: uv cleanup, build fix
Fix:

 arch/x86/mm/srat_64.c: In function ‘acpi_numa_processor_affinity_init’:
 arch/x86/mm/srat_64.c:141: error: implicit declaration of function ‘get_uv_system_type’
 arch/x86/mm/srat_64.c:141: error: ‘UV_X2APIC’ undeclared (first use in this function)
 arch/x86/mm/srat_64.c:141: error: (Each undeclared identifier is reported only once
 arch/x86/mm/srat_64.c:141: error: for each function it appears in.)

A couple of UV definitions were moved to asm/uv/uv.h, but srat_64.c did
not include that header. Add it.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 10:24:27 +01:00
Ingo Molnar
55f4949f57 x86, mm: move tlb.c to arch/x86/mm/
Impact: cleanup

Now that it's unified, move the (SMP) TLB flushing code from arch/x86/kernel/
to arch/x86/mm/, where it belongs logically.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 10:16:19 +01:00
Ingo Molnar
3eb3963fd1 Merge branch 'cpus4096' into core/percpu
Conflicts:
	arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
	arch/x86/kernel/tlb_32.c

Merge it here because both the cpumask changes and the ongoing percpu
work is touching the TLB code. The percpu changes take precedence, as
they eliminate tlb_32.c altogether.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 10:14:17 +01:00
Ingo Molnar
552b8aa4d1 Revert "x86: signal: change type of paramter for sys_rt_sigreturn()"
This reverts commit 4217458daf.

Justin Madru bisected this commit, it was causing weird Firefox
crashes.

The reason is that GCC mis-optimizes (re-uses) the on-stack parameters of
the calling frame, which corrupts the syscall return pt_regs state and
thus corrupts user-space register state.

So we go back to the slightly less clean but more optimization-safe
method of getting to pt_regs. Also add a comment to explain this.

Resolves: http://bugzilla.kernel.org/show_bug.cgi?id=12505

Reported-and-bisected-by: Justin Madru <jdm64@gawab.com>
Tested-by: Justin Madru <jdm64@gawab.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 09:43:18 +01:00
Andi Kleen
e0a96129db x86: use early clobbers in usercopy*.c
Impact: fix rare (but currently harmless) miscompile with certain configs and gcc versions

Hugh Dickins noticed that strncpy_from_user() was miscompiled
in some circumstances with gcc 4.3.

Thanks to Hugh's excellent analysis it was easy to track down.

Hugh writes:

> Try building an x86_64 defconfig 2.6.29-rc1 kernel tree,
> except not quite defconfig, switch CONFIG_PREEMPT_NONE=y
> and CONFIG_PREEMPT_VOLUNTARY off (because it expands a
> might_fault() there, which hides the issue): using a
> gcc 4.3.2 (I've checked both openSUSE 11.1 and Fedora 10).
>
> It generates the following:
>
> 0000000000000000 <__strncpy_from_user>:
>    0:   48 89 d1                mov    %rdx,%rcx
>    3:   48 85 c9                test   %rcx,%rcx
>    6:   74 0e                   je     16 <__strncpy_from_user+0x16>
>    8:   ac                      lods   %ds:(%rsi),%al
>    9:   aa                      stos   %al,%es:(%rdi)
>    a:   84 c0                   test   %al,%al
>    c:   74 05                   je     13 <__strncpy_from_user+0x13>
>    e:   48 ff c9                dec    %rcx
>   11:   75 f5                   jne    8 <__strncpy_from_user+0x8>
>   13:   48 29 c9                sub    %rcx,%rcx
>   16:   48 89 c8                mov    %rcx,%rax
>   19:   c3                      retq
>
> Observe that "sub %rcx,%rcx; mov %rcx,%rax", whereas gcc 4.2.1
> (and many other configs) say "sub %rcx,%rdx; mov %rdx,%rax".
> Isn't it returning 0 when it ought to be returning strlen?

The asm constraints for the strncpy_from_user() result were missing an
early clobber, which tells gcc that the last output arguments
are written before all input arguments are read.

Also add more early clobbers in the rest of the file and fix 32-bit
usercopy.c in the same way.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
[ since this API is rarely used and no in-kernel user relies on a 'len'
  return value (they only rely on negative return values) this miscompile
  was never noticed in the field. But it's worth fixing it nevertheless. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-21 09:43:17 +01:00