linux-stable.git/arch/x86/kernel/process.c, branch v3.3 Linux kernel stable tree x86: Fix rflags in FAKE_STACK_FRAME 2011-12-06T09:02:38+00:00 Seiichi Ikarashi s.ikarashi@jp.fujitsu.com 2011-12-06T08:58:14+00:00 1cf8343f55525c09c88da0a494a96e1b034f84e2 The x86_64 kernel pushes the fake kernel stack in arch/x86/kernel/entry_64.S:FAKE_STACK_FRAME, and rflags register in it does not conform to the specification. Although Intel's manual[1] says bit 1 of it shall be set to 1, this bit is cleared to 0 on pushing the fake stack. [1] Intel(R) 64 and IA-32 Architectures Software Developer's Manual Vol.1 3-21 Figure 3-8. EFLAGS Register If it is not on purpose, it is better to be fixed, because it can lead some tools misunderstanding the stack frame. For example, "crash" utility[2] actually detects it and warns you like below: RIP: ffffffff8005dfa2 RSP: ffff8104ce0c7f58 RFLAGS: 00000200 [...] bt: WARNING: possibly bogus exception frame Signed-off-by: Seiichi Ikarashi <s.ikarashi@jp.fujitsu.com> Tested-by: Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com> Cc: Jan Beulich <JBeulich@suse.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
The x86_64 kernel pushes the fake kernel stack in
arch/x86/kernel/entry_64.S:FAKE_STACK_FRAME, and
rflags register in it does not conform to the specification.

Although Intel's manual[1] says bit 1 of it shall be set to 1,
this bit is cleared to 0 on pushing the fake stack.

[1] Intel(R) 64 and IA-32 Architectures Software Developer's Manual
    Vol.1 3-21 Figure 3-8. EFLAGS Register

If it is not on purpose, it is better to be fixed, because
it can lead some tools misunderstanding the stack frame. For example,
"crash" utility[2] actually detects it and warns you like
below:

       RIP: ffffffff8005dfa2  RSP: ffff8104ce0c7f58  RFLAGS: 00000200
       [...]

       bt: WARNING: possibly bogus exception frame

Signed-off-by: Seiichi Ikarashi <s.ikarashi@jp.fujitsu.com>
Tested-by: Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
xen/pm_idle: Make pm_idle be default_idle under Xen. 2011-12-03T18:49:58+00:00 Konrad Rzeszutek Wilk konrad.wilk@oracle.com 2011-11-21T23:02:02+00:00 e5fd47bfab2df0c2184cc0bf4245d8e1bb7724fb The idea behind commit d91ee5863b71 ("cpuidle: replace xen access to x86 pm_idle and default_idle") was to have one call - disable_cpuidle() which would make pm_idle not be molested by other code. It disallows cpuidle_idle_call to be set to pm_idle (which is excellent). But in the select_idle_routine() and idle_setup(), the pm_idle can still be set to either: amd_e400_idle, mwait_idle or default_idle. This depends on some CPU flags (MWAIT) and in AMD case on the type of CPU. In case of mwait_idle we can hit some instances where the hypervisor (Amazon EC2 specifically) sets the MWAIT and we get: Brought up 2 CPUs invalid opcode: 0000 [#1] SMP Pid: 0, comm: swapper Not tainted 3.1.0-0.rc6.git0.3.fc16.x86_64 #1 RIP: e030:[<ffffffff81015d1d>] [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4 ... Call Trace: [<ffffffff8100e2ed>] cpu_idle+0xae/0xe8 [<ffffffff8149ee78>] cpu_bringup_and_idle+0xe/0x10 RIP [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4 RSP <ffff8801d28ddf10> In the case of amd_e400_idle we don't get so spectacular crashes, but we do end up making an MSR which is trapped in the hypervisor, and then follow it up with a yield hypercall. Meaning we end up going to hypervisor twice instead of just once. The previous behavior before v3.0 was that pm_idle was set to default_idle regardless of select_idle_routine/idle_setup. We want to do that, but only for one specific case: Xen. This patch does that. Fixes RH BZ #739499 and Ubuntu #881076 Reported-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
The idea behind commit d91ee5863b71 ("cpuidle: replace xen access to x86
pm_idle and default_idle") was to have one call - disable_cpuidle()
which would make pm_idle not be molested by other code.  It disallows
cpuidle_idle_call to be set to pm_idle (which is excellent).

But in the select_idle_routine() and idle_setup(), the pm_idle can still
be set to either: amd_e400_idle, mwait_idle or default_idle.  This
depends on some CPU flags (MWAIT) and in AMD case on the type of CPU.

In case of mwait_idle we can hit some instances where the hypervisor
(Amazon EC2 specifically) sets the MWAIT and we get:

  Brought up 2 CPUs
  invalid opcode: 0000 [#1] SMP

  Pid: 0, comm: swapper Not tainted 3.1.0-0.rc6.git0.3.fc16.x86_64 #1
  RIP: e030:[<ffffffff81015d1d>]  [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
  ...
  Call Trace:
   [<ffffffff8100e2ed>] cpu_idle+0xae/0xe8
   [<ffffffff8149ee78>] cpu_bringup_and_idle+0xe/0x10
  RIP  [<ffffffff81015d1d>] mwait_idle+0x6f/0xb4
   RSP <ffff8801d28ddf10>

In the case of amd_e400_idle we don't get so spectacular crashes, but we
do end up making an MSR which is trapped in the hypervisor, and then
follow it up with a yield hypercall.  Meaning we end up going to
hypervisor twice instead of just once.

The previous behavior before v3.0 was that pm_idle was set to
default_idle regardless of select_idle_routine/idle_setup.

We want to do that, but only for one specific case: Xen.  This patch
does that.

Fixes RH BZ #739499 and Ubuntu #881076
Reported-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
x86, mm, trivial: Remove unnecessary get_order() in free_thread_info() 2011-08-23T19:49:35+00:00 Zhao Jin cronozhj@gmail.com 2011-08-20T13:24:57+00:00 c812d8f7ad27bd5f1ed1c790eea8527b6f8ff1c7 Because THREAD_SIZE is defined as PAGE_SIZE << THREAD_ORDER on x86, the call of get_order(THREAD_SIZE) can be replaced with THREAD_ORDER. Signed-off-by: Zhao Jin <cronozhj@gmail.com> Link: http://lkml.kernel.org/r/4E4FB5A9.700@gmail.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> 
Because THREAD_SIZE is defined as PAGE_SIZE << THREAD_ORDER on x86, the
call of get_order(THREAD_SIZE) can be replaced with THREAD_ORDER.

Signed-off-by: Zhao Jin <cronozhj@gmail.com>
Link: http://lkml.kernel.org/r/4E4FB5A9.700@gmail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
x86 idle: move mwait_idle_with_hints() to where it is used 2011-08-03T23:06:36+00:00 Len Brown len.brown@intel.com 2011-03-31T03:52:29+00:00 4bfc8288bc4a64529c5547d17349a2a1f4675507 ...and make it static no functional change cc: x86@kernel.org Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com> 
...and make it static

no functional change

cc: x86@kernel.org
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
x86 idle: APM requires pm_idle/default_idle unconditionally when a module 2011-06-14T20:42:20+00:00 Andy Whitcroft apw@canonical.com 2011-06-14T19:45:10+00:00 60b8b1de0dd2bf246f0e074d287bb3f0bc42a755 [ Also from Ben Hutchings <ben@decadent.org.uk> and Vitaliy Ivanov <vitalivanov@gmail.com> ] Commit 06ae40ce073d ("x86 idle: EXPORT_SYMBOL(default_idle, pm_idle) only when APM demands it") removed the export for pm_idle/default_idle unless the apm module was modularised and CONFIG_APM_CPU_IDLE was set. But the apm module uses pm_idle/default_idle unconditionally, CONFIG_APM_CPU_IDLE only affects the bios idle threshold. Adjust the export accordingly. [ Used #ifdef instead of #if defined() as it's shorter, and what both Ben and Vitaliy used.. Andy, you're out-voted ;) - Linus ] Reported-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Len Brown <len.brown@intel.com> Signed-off-by: Andy Whitcroft <apw@canonical.com> Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
[ Also from Ben Hutchings <ben@decadent.org.uk> and Vitaliy Ivanov
  <vitalivanov@gmail.com> ]

Commit 06ae40ce073d ("x86 idle: EXPORT_SYMBOL(default_idle, pm_idle)
only when APM demands it") removed the export for pm_idle/default_idle
unless the apm module was modularised and CONFIG_APM_CPU_IDLE was set.

But the apm module uses pm_idle/default_idle unconditionally,
CONFIG_APM_CPU_IDLE only affects the bios idle threshold.  Adjust the
export accordingly.

[ Used #ifdef instead of #if defined() as it's shorter, and what both
  Ben and Vitaliy used.. Andy, you're out-voted ;)    - Linus ]

Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-05-31T17:07:22+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-05-31T17:07:22+00:00 af0d6a0a3a30946f7df69c764791f1b0643f7cd6 * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Fix mwait_play_dead() faulting on mwait-incapable cpus x86 idle: Fix mwait deprecation warning message Evil merge to remove extra quote noticed by Joe Perches 
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix mwait_play_dead() faulting on mwait-incapable cpus
  x86 idle: Fix mwait deprecation warning message

Evil merge to remove extra quote noticed by Joe Perches
x86 idle: Fix mwait deprecation warning message 2011-05-30T11:02:04+00:00 Borislav Petkov bp@alien8.de 2011-05-30T09:38:06+00:00 598e887d8b01655780c81cc86a9e7820ed091580 Fix: arch/x86/kernel/process.c:645:1: warning: unknown escape sequence '\i' due to missing escape backslash, introduced by this commit: 5d4c47e0195b: x86 idle: deprecate mwait_idle() and "idle=mwait" cmdline param Signed-off-by: Borislav Petkov <bp@alien8.de> Cc: Len Brown <len.brown@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1306748286-24701-1-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@elte.hu> 
Fix:

  arch/x86/kernel/process.c:645:1: warning: unknown escape sequence '\i'

due to missing escape backslash, introduced by this commit:

  5d4c47e0195b: x86 idle: deprecate mwait_idle() and "idle=mwait" cmdline param

Signed-off-by: Borislav Petkov <bp@alien8.de>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1306748286-24701-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merge branch 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6 2011-05-29T18:18:09+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-05-29T18:18:09+00:00 f310642123e0d32d919c60ca3fab5acd130c4ba3 * 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6: x86 idle: deprecate mwait_idle() and "idle=mwait" cmdline param x86 idle: deprecate "no-hlt" cmdline param x86 idle APM: deprecate CONFIG_APM_CPU_IDLE x86 idle floppy: deprecate disable_hlt() x86 idle: EXPORT_SYMBOL(default_idle, pm_idle) only when APM demands it x86 idle: clarify AMD erratum 400 workaround idle governor: Avoid lock acquisition to read pm_qos before entering idle cpuidle: menu: fixed wrapping timers at 4.294 seconds 
* 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6:
  x86 idle: deprecate mwait_idle() and "idle=mwait" cmdline param
  x86 idle: deprecate "no-hlt" cmdline param
  x86 idle APM: deprecate CONFIG_APM_CPU_IDLE
  x86 idle floppy: deprecate disable_hlt()
  x86 idle: EXPORT_SYMBOL(default_idle, pm_idle) only when APM demands it
  x86 idle: clarify AMD erratum 400 workaround
  idle governor: Avoid lock acquisition to read pm_qos before entering idle
  cpuidle: menu: fixed wrapping timers at 4.294 seconds
x86 idle: deprecate mwait_idle() and "idle=mwait" cmdline param 2011-05-29T07:39:17+00:00 Len Brown len.brown@intel.com 2011-04-01T19:46:09+00:00 5d4c47e0195b989f284907358bd5c268a44b91c7 mwait_idle() is a C1-only idle loop intended to be more efficient than HLT on SMP hardware that supports it. But mwait_idle() has been replaced by the more general mwait_idle_with_hints(), which handles both C1 and deeper C-states. ACPI uses only mwait_idle_with_hints(), and never uses mwait_idle(). Deprecate mwait_idle() and the "idle=mwait" cmdline param to simplify the x86 idle code. After this change, kernels configured with (!CONFIG_ACPI=n && !CONFIG_INTEL_IDLE=n) when run on hardware that support MWAIT will simply use HLT. If MWAIT is desired on those systems, cpuidle and the cpuidle drivers above can be used. cc: x86@kernel.org cc: stable@kernel.org # .39.x Signed-off-by: Len Brown <len.brown@intel.com> 
mwait_idle() is a C1-only idle loop intended to be more efficient
than HLT on SMP hardware that supports it.

But mwait_idle() has been replaced by the more general
mwait_idle_with_hints(), which handles both C1 and deeper C-states.
ACPI uses only mwait_idle_with_hints(), and never uses mwait_idle().

Deprecate mwait_idle() and the "idle=mwait" cmdline param
to simplify the x86 idle code.

After this change, kernels configured with
(!CONFIG_ACPI=n && !CONFIG_INTEL_IDLE=n) when run on hardware
that support MWAIT will simply use HLT.  If MWAIT is desired
on those systems, cpuidle and the cpuidle drivers above
can be used.

cc: x86@kernel.org
cc: stable@kernel.org # .39.x
Signed-off-by: Len Brown <len.brown@intel.com>
x86 idle: EXPORT_SYMBOL(default_idle, pm_idle) only when APM demands it 2011-05-29T07:39:14+00:00 Len Brown len.brown@intel.com 2011-04-01T19:28:09+00:00 06ae40ce073daf233607a3c54a489f2c1e44683e In the long run, we don't want default_idle() or (pm_idle)() to be exported outside of process.c. Start by not exporting them to modules, unless the APM build demands it. cc: x86@kernel.org cc: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Len Brown <len.brown@intel.com> 
In the long run, we don't want default_idle() or (pm_idle)() to
be exported outside of process.c.  Start by not exporting them
to modules, unless the APM build demands it.

cc: x86@kernel.org
cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Len Brown <len.brown@intel.com>