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  1. 14 12月, 2010 1 次提交
  3. 30 10月, 2010 2 次提交
  5. 14 10月, 2010 1 次提交
  7. 23 9月, 2010 1 次提交
    • J
      jump label: Base patch for jump label · bf5438fc
      由 Jason Baron 提交于 
      base patch to implement 'jump labeling'. Based on a new 'asm goto' inline
assembly gcc mechanism, we can now branch to labels from an 'asm goto'
statment. This allows us to create a 'no-op' fastpath, which can subsequently
be patched with a jump to the slowpath code. This is useful for code which
might be rarely used, but which we'd like to be able to call, if needed.
Tracepoints are the current usecase that these are being implemented for.
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NJason Baron <jbaron@redhat.com>
LKML-Reference: <ee8b3595967989fdaf84e698dc7447d315ce972a.1284733808.git.jbaron@redhat.com>

[ cleaned up some formating ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      bf5438fc
  9. 21 9月, 2010 2 次提交
  11. 14 7月, 2010 1 次提交
  13. 29 4月, 2010 1 次提交
  15. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      由 Tejun Heo 提交于 
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  17. 04 3月, 2010 1 次提交
  19. 26 2月, 2010 2 次提交
    • L
      x86: Add support for lock prefix in alternatives · b3ac891b
      由 Luca Barbieri 提交于 
      The current lock prefix UP/SMP alternative code doesn't allow
LOCK_PREFIX to be used in alternatives code.

This patch solves the problem by adding a new LOCK_PREFIX_ALTERNATIVE_PATCH
macro that only records the lock prefix location but does not emit
the prefix.

The user of this macro can then start any alternative sequence with
"lock" and have it UP/SMP patched.

To make this work, the UP/SMP alternative code is changed to do the
lock/DS prefix switching only if the byte actually contains a lock or
DS prefix.

Thus, if an alternative without the "lock" is selected, it will now do
nothing instead of clobbering the code.

Changes in v2:
- Naming change
- Change label to not conflict with alternatives
Signed-off-by: NLuca Barbieri <luca@luca-barbieri.com>
LKML-Reference: <1267005265-27958-2-git-send-email-luca@luca-barbieri.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      b3ac891b
    • M
      x86: Add text_poke_smp for SMP cross modifying code · 3d55cc8a
      由 Masami Hiramatsu 提交于 
      Add generic text_poke_smp for SMP which uses stop_machine()
to synchronize modifying code.
This stop_machine() method is officially described at "7.1.3
Handling Self- and Cross-Modifying Code" on the intel's
software developer's manual 3A.

Since stop_machine() can't protect code against NMI/MCE, this
function can not modify those handlers. And also, this function
is basically for modifying multibyte-single-instruction. For
modifying multibyte-multi-instructions, we need another special
trap & detour code.

This code originaly comes from immediate values with
stop_machine() version. Thanks Jason and Mathieu!
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Anders Kaseorg <andersk@ksplice.com>
Cc: Tim Abbott <tabbott@ksplice.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20100225133438.6725.80273.stgit@localhost6.localdomain6>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      3d55cc8a
  21. 08 2月, 2010 1 次提交
    • M
      x86/alternatives: Fix build warning · 076dc4a6
      由 Masami Hiramatsu 提交于 
      Fixes these warnings:

 arch/x86/kernel/alternative.c: In function 'alternatives_text_reserved':
 arch/x86/kernel/alternative.c:402: warning: comparison of distinct pointer types lacks a cast
 arch/x86/kernel/alternative.c:402: warning: comparison of distinct pointer types lacks a cast
 arch/x86/kernel/alternative.c:405: warning: comparison of distinct pointer types lacks a cast
 arch/x86/kernel/alternative.c:405: warning: comparison of distinct pointer types lacks a cast

Caused by:

  2cfa1978: ftrace/alternatives: Introducing *_text_reserved functions

Changes in v2:
  - Use local variables to compare, instead of type casts.
Reported-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
LKML-Reference: <20100205171647.15750.37221.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      076dc4a6
  23. 04 2月, 2010 1 次提交
    • M
      ftrace/alternatives: Introducing *_text_reserved functions · 2cfa1978
      由 Masami Hiramatsu 提交于 
      Introducing *_text_reserved functions for checking the text
address range is partially reserved or not. This patch provides
checking routines for x86 smp alternatives and dynamic ftrace.
Since both functions modify fixed pieces of kernel text, they
should reserve and protect those from other dynamic text
modifier, like kprobes.

This will also be extended when introducing other subsystems
which modify fixed pieces of kernel text. Dynamic text modifiers
should avoid those.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: przemyslaw@pawelczyk.it
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org>
Cc: Jason Baron <jbaron@redhat.com>
LKML-Reference: <20100202214911.4694.16587.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2cfa1978
  25. 30 12月, 2009 1 次提交
    • J
      x86-64: Modify copy_user_generic() alternatives mechanism · 1b1d9258
      由 Jan Beulich 提交于 
      In order to avoid unnecessary chains of branches, rather than
implementing copy_user_generic() as a function consisting of
just a single (possibly patched) branch, instead properly deal
with patching call instructions in the alternative instructions
framework, and move the patching into the callers.

As a follow-on, one could also introduce something like
__EXPORT_SYMBOL_ALT() to avoid patching call sites in modules.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4B2BB8180200007800026AE7@vpn.id2.novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1b1d9258
  27. 11 9月, 2009 1 次提交
  29. 22 8月, 2009 1 次提交
  31. 10 3月, 2009 1 次提交
  33. 06 3月, 2009 2 次提交
  35. 25 2月, 2009 1 次提交
  37. 18 2月, 2009 1 次提交
    • A
      x86, mce: don't disable machine checks during code patching · 123aa76e
      由 Andi Kleen 提交于 
      Impact: low priority bug fix

This removes part of a a patch I added myself some time ago. After some
consideration the patch was a bad idea. In particular it stopped machine check
exceptions during code patching.

To quote the comment:

        * MCEs only happen when something got corrupted and in this
        * case we must do something about the corruption.
        * Ignoring it is worse than a unlikely patching race.
        * Also machine checks tend to be broadcast and if one CPU
        * goes into machine check the others follow quickly, so we don't
        * expect a machine check to cause undue problems during to code
        * patching.

So undo the machine check related parts of
8f4e956b NMIs are still disabled.

This only removes code, the only additions are a new comment.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      123aa76e
  39. 13 10月, 2008 1 次提交
  41. 06 9月, 2008 1 次提交
  43. 19 8月, 2008 1 次提交
  45. 16 8月, 2008 1 次提交
    • M
      x86: alternatives : fix LOCK_PREFIX race with preemptible kernel and CPU hotplug · f88f07e0
      由 Mathieu Desnoyers 提交于 
      If a kernel thread is preempted in single-cpu mode right after the NOP (nop
about to be turned into a lock prefix), then we CPU hotplug a CPU, and then the
thread is scheduled back again, a SMP-unsafe atomic operation will be used on
shared SMP variables, leading to corruption. No corruption would happen in the
reverse case : going from SMP to UP is ok because we split a bit instruction
into tiny pieces, which does not present this condition.

Changing the 0x90 (single-byte nop) currently used into a 0x3E DS segment
override prefix should fix this issue. Since the default of the atomic
instructions is to use the DS segment anyway, it should not affect the
behavior.

The exception to this are references that use ESP/RSP and EBP/RBP as
the base register (they will use the SS segment), however, in Linux
(a) DS == SS at all times, and (b) we do not distinguish between
segment violations reported as #SS as opposed to #GP, so there is no
need to disassemble the instruction to figure out the suitable segment.

This patch assumes that the 0x3E prefix will leave atomic operations as-is (thus
assuming they normally touch data in the DS segment). Since there seem to be no
obvious ill-use of other segment override prefixes for atomic operations, it
should be safe. It can be verified with a quick

grep -r LOCK_PREFIX include/asm-x86/
grep -A 1 -r LOCK_PREFIX arch/x86/

Taken from

This source :
AMD64 Architecture Programmer's Manual Volume 3: General-Purpose and System
Instructions
States
"Instructions that Reference a Non-Stack Segment—If an instruction encoding
references any base register other than rBP or rSP, or if an instruction
contains an immediate offset, the default segment is the data segment (DS).
These instructions can use the segment-override prefix to select one of the
non-default segments, as shown in Table 1-5."

Therefore, forcing the DS segment on the atomic operations, which already use
the DS segment, should not change.

This source :
http://wiki.osdev.org/X86_Instruction_Encoding
States
"In 64-bit the CS, SS, DS and ES segment overrides are ignored."

Confirmed by "AMD 64-Bit Technology" A.7
http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/x86-64_overview.pdf

"In 64-bit mode, the DS, ES, SS and CS segment-override prefixes have no effect.
These four prefixes are no longer treated as segment-override prefixes in the
context of multipleprefix rules. Instead, they are treated as null prefixes."

This patch applies to 2.6.27-rc2, but would also have to be applied to earlier
kernels (2.6.26, 2.6.25, ...).

Performance impact of the fix : tests done on "xaddq" and "xaddl" shows it
actually improves performances on Intel Xeon, AMD64, Pentium M. It does not
change the performance on Pentium II, Pentium 3 and Pentium 4.

Xeon E5405 2.0GHz :
NR_TESTS                                    10000000
test empty cycles :                        162207948
test test 1-byte nop xadd cycles :         170755422
test test DS override prefix xadd cycles : 170000118 *
test test LOCK xadd cycles :               472012134

AMD64 2.0GHz :
NR_TESTS                                    10000000
test empty cycles :                        146674549
test test 1-byte nop xadd cycles :         150273860
test test DS override prefix xadd cycles : 149982382 *
test test LOCK xadd cycles :               270000690

Pentium 4 3.0GHz
NR_TESTS                                    10000000
test empty cycles :                        290001195
test test 1-byte nop xadd cycles :         310000560
test test DS override prefix xadd cycles : 310000575 *
test test LOCK xadd cycles :              1050103740

Pentium M 2.0GHz
NR_TESTS 10000000
test empty cycles :                        180000523
test test 1-byte nop xadd cycles :         320000345
test test DS override prefix xadd cycles : 310000374 *
test test LOCK xadd cycles :               480000357

Pentium 3 550MHz
NR_TESTS                                    10000000
test empty cycles :                        510000231
test test 1-byte nop xadd cycles :         620000128
test test DS override prefix xadd cycles : 620000110 *
test test LOCK xadd cycles :               800000088

Pentium II 350MHz
NR_TESTS                                    10000000
test empty cycles :                        200833494
test test 1-byte nop xadd cycles :         340000130
test test DS override prefix xadd cycles : 340000126 *
test test LOCK xadd cycles :               530000078

Speed test modules can be found at
http://ltt.polymtl.ca/svn/trunk/tests/kernel/test-prefix-speed-32.c
http://ltt.polymtl.ca/svn/trunk/tests/kernel/test-prefix-speed.c

Macro-benchmarks

2.0GHz E5405 Core 2 dual Quad-Core Xeon

Summary

* replace smp lock prefixes with DS segment selector prefixes
                  no lock prefix (s)   with lock prefix (s)    Speedup
make -j1 kernel/      33.94 +/- 0.07         34.91 +/- 0.27      2.8 %
hackbench 50           2.99 +/- 0.01          3.74 +/- 0.01     25.1 %

* replace smp lock prefixes with 0x90 nops
                  no lock prefix (s)   with lock prefix (s)    Speedup
make -j1 kernel/      34.16 +/- 0.32         34.91 +/- 0.27      2.2 %
hackbench 50           3.00 +/- 0.01          3.74 +/- 0.01     24.7 %

Detail :

1 CPU, replace smp lock prefixes with DS segment selector prefixes

make -j1 kernel/

real	0m34.067s
user	0m30.630s
sys	0m2.980s

real	0m33.867s
user	0m30.582s
sys	0m3.024s

real	0m33.939s
user	0m30.738s
sys	0m2.876s

real	0m33.913s
user	0m30.806s
sys	0m2.808s

avg : 33.94s
std. dev. : 0.07s

hackbench 50

Time: 2.978
Time: 2.982
Time: 3.010
Time: 2.984
Time: 2.982

avg : 2.99
std. dev. : 0.01

1 CPU, noreplace-smp

make -j1 kernel/

real	0m35.326s
user	0m30.630s
sys	0m3.260s

real	0m34.325s
user	0m30.802s
sys	0m3.084s

real	0m35.568s
user	0m30.722s
sys	0m3.168s

real	0m34.435s
user	0m30.886s
sys	0m2.996s

avg.: 34.91s
std. dev. : 0.27s

hackbench 50

Time: 3.733
Time: 3.750
Time: 3.761
Time: 3.737
Time: 3.741

avg : 3.74
std. dev. : 0.01

1 CPU, replace smp lock prefixes with 0x90 nops

make -j1 kernel/

real	0m34.139s
user	0m30.782s
sys	0m2.820s

real	0m34.010s
user	0m30.630s
sys	0m2.976s

real	0m34.777s
user	0m30.658s
sys	0m2.916s

real	0m33.924s
user	0m30.634s
sys	0m2.924s

real	0m33.962s
user	0m30.774s
sys	0m2.800s

real	0m34.141s
user	0m30.770s
sys	0m2.828s

avg : 34.16
std. dev. : 0.32

hackbench 50

Time: 2.999
Time: 2.994
Time: 3.004
Time: 2.991
Time: 2.988

avg : 3.00
std. dev. : 0.01

I did more runs (20 runs of each) to compare the nop case to the DS
prefix case. Results in seconds. They actually does not seems to show a
significant difference.

NOP

34.155
33.955
34.012
35.299
35.679
34.141
33.995
35.016
34.254
33.957
33.957
34.008
35.013
34.494
33.893
34.295
34.314
34.854
33.991
34.132

DS

34.080
34.304
34.374
35.095
34.291
34.135
33.940
34.208
35.276
34.288
33.861
33.898
34.610
34.709
33.851
34.256
35.161
34.283
33.865
35.078

Used http://www.graphpad.com/quickcalcs/ttest1.cfm?Format=C to do the
T-test (yeah, I'm lazy) :

 Group      Group One (DS prefix)       Group Two (nops)
 Mean                    34.37815               34.37070
 SD                       0.46108                0.51905
 SEM                      0.10310                0.11606
 N                             20                     20

P value and statistical significance:
  The two-tailed P value equals 0.9620
  By conventional criteria, this difference is considered to be not statistically significant.

Confidence interval:
  The mean of Group One minus Group Two equals 0.00745
  95% confidence interval of this difference: From -0.30682 to 0.32172

Intermediate values used in calculations:
  t = 0.0480
  df = 38
  standard error of difference = 0.155

So, unless these calculus are completely bogus, the difference between the nop
and the DS case seems not to be statistically significant.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
CC: Linus Torvalds <torvalds@linux-foundation.org>
CC: Jeremy Fitzhardinge <jeremy@goop.org>
CC: Roland McGrath <roland@redhat.com>
CC: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
CC: Steven Rostedt <srostedt@redhat.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: David Miller <davem@davemloft.net>
CC: Ulrich Drepper <drepper@redhat.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Gregory Haskins <ghaskins@novell.com>
CC: Arnaldo Carvalho de Melo <acme@redhat.com>
CC: "Luis Claudio R. Goncalves" <lclaudio@uudg.org>
CC: Clark Williams <williams@redhat.com>
CC: Christoph Lameter <cl@linux-foundation.org>
CC: Andi Kleen <andi@firstfloor.org>
CC: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
      f88f07e0
  47. 24 5月, 2008 2 次提交
  49. 26 4月, 2008 3 次提交
  51. 17 4月, 2008 3 次提交
    • M
      x86: fix test_poke for vmalloced pages · 15a601eb
      由 Mathieu Desnoyers 提交于 
      * Ingo Molnar (mingo@elte.hu) wrote:
>
> * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> wrote:
>
> > The shadow vmap for DEBUG_RODATA kernel text modification uses
> > virt_to_page to get the pages from the pointer address.
> >
> > However, I think vmalloc_to_page would be required in case the page is
> > used for modules.
> >
> > Since only the core kernel text is marked read-only, use
> > kernel_text_address() to make sure we only shadow map the core kernel
> > text, not modules.
>
> actually, i think we should mark module text readonly too.
>

Yes, but in the meantime, the x86 tree would need this patch to make
kprobes work correctly on modules.

I suspect that without this fix, with the enhanced hotplug and kprobes
patch, kprobes will use text_poke to insert breakpoints in modules
(vmalloced pages used), which will map the wrong pages and corrupt
random kernel locations instead of updating the correct page.

Work that would write protect the module pages should clearly be done,
but it can come in a later time. We have to make sure we interact
correctly with the page allocation debugging, as an example.

Here is the patch against x86.git 2.6.25-rc5 :

The shadow vmap for DEBUG_RODATA kernel text modification uses virt_to_page to
get the pages from the pointer address.

However, I think vmalloc_to_page would be required in case the page is used for
modules.

Since only the core kernel text is marked read-only, use kernel_text_address()
to make sure we only shadow map the core kernel text, not modules.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: akpm@linux-foundation.org
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      15a601eb
    • M
      x86: enhance DEBUG_RODATA support - alternatives · e587cadd
      由 Mathieu Desnoyers 提交于 
      Fix a memcpy that should be a text_poke (in apply_alternatives).

Use kernel_wp_save/kernel_wp_restore in text_poke to support DEBUG_RODATA
correctly and so the CPU HOTPLUG special case can be removed.

Add text_poke_early, for alternatives and paravirt boot-time and module load
time patching.

Changelog:

- Fix text_set and text_poke alignment check (mixed up bitwise and and or)
- Remove text_set
- Export add_nops, so it can be used by others.
- Document text_poke_early.
- Remove clflush, since it breaks some VIA architectures and is not strictly
  necessary.
- Add kerneldoc to text_poke and text_poke_early.
- Create a second vmap instead of using the WP bit to support Xen and VMI.
- Move local_irq disable within text_poke and text_poke_early to be able to
  be sleepable in these functions.
Signed-off-by: NMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Andi Kleen <andi@firstfloor.org>
CC: pageexec@freemail.hu
CC: H. Peter Anvin <hpa@zytor.com>
CC: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      e587cadd
    • H
      x86: replace remaining __FUNCTION__ occurances · 77bf90ed
      由 Harvey Harrison 提交于 
      __FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      77bf90ed
  53. 10 4月, 2008 1 次提交
    • S
      pop previous section in alternative.c · f4be31ec
      由 Steven Rostedt 提交于 
      gcc expects all toplevel assembly to return to the original section type.
The code in alteranative.c does not do this. This caused some strange bugs
in sched-devel where code would end up in the .rodata section and when
the kernel sets the NX bit on all .rodata, the kernel would crash when
executing this code.

This patch adds a .previous marker to return the code back to the
original section.

Credit goes to Andrew Pinski for telling me it wasn't a gcc bug but a
bug in the toplevel asm code in the kernel.  ;-)
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f4be31ec
  55. 30 1月, 2008 3 次提交
  57. 20 10月, 2007 1 次提交
    • M
      x86: convert cpuinfo_x86 array to a per_cpu array · 92cb7612
      由 Mike Travis 提交于 
      cpu_data is currently an array defined using NR_CPUS.  This means that
we overallocate since we will rarely really use maximum configured cpus.
When NR_CPU count is raised to 4096 the size of cpu_data becomes
3,145,728 bytes.

These changes were adopted from the sparc64 (and ia64) code.  An
additional field was added to cpuinfo_x86 to be a non-ambiguous cpu
index.  This corresponds to the index into a cpumask_t as well as the
per_cpu index.  It's used in various places like show_cpuinfo().

cpu_data is defined to be the boot_cpu_data structure for the NON-SMP
case.
Signed-off-by: NMike Travis <travis@sgi.com>
Acked-by: NChristoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@suse.de>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      92cb7612