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  1. 27 2月, 2009 3 次提交
  3. 23 2月, 2009 3 次提交
  5. 22 2月, 2009 2 次提交
  7. 21 2月, 2009 4 次提交
  9. 20 2月, 2009 9 次提交
    • I
      x86: use the right protections for split-up pagetables · 07a66d7c
      由 Ingo Molnar 提交于 
      Steven Rostedt found a bug in where in his modified kernel
ftrace was unable to modify the kernel text, due to the PMD
itself having been marked read-only as well in
split_large_page().

The fix, suggested by Linus, is to not try to 'clone' the
reference protection of a huge-page, but to use the standard
(and permissive) page protection bits of KERNPG_TABLE.

The 'cloning' makes sense for the ptes but it's a confused and
incorrect concept at the page table level - because the
pagetable entry is a set of all ptes and hence cannot
'clone' any single protection attribute - the ptes can be any
mixture of protections.

With the permissive KERNPG_TABLE, even if the pte protections
get changed after this point (due to ftrace doing code-patching
or other similar activities like kprobes), the resulting combined
protections will still be correct and the pte's restrictive
(or permissive) protections will control it.

Also update the comment.

This bug was there for a long time but has not caused visible
problems before as it needs a rather large read-only area to
trigger. Steve possibly hacked his kernel with some really
large arrays or so. Anyway, the bug is definitely worth fixing.

[ Huang Ying also experienced problems in this area when writing
  the EFI code, but the real bug in split_large_page() was not
  realized back then. ]
Reported-by: NSteven Rostedt <rostedt@goodmis.org>
Reported-by: NHuang Ying <ying.huang@intel.com>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      07a66d7c
    • A
      x86, vmi: TSC going backwards check in vmi clocksource · 48ffc70b
      由 Alok N Kataria 提交于 
      Impact: fix time warps under vmware

Similar to the check for TSC going backwards in the TSC clocksource,
we also need this check for VMI clocksource.
Signed-off-by: NAlok N Kataria <akataria@vmware.com>
Cc: Zachary Amsden <zach@vmware.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Cc: stable@kernel.org
      48ffc70b
    • T
      [IA64] xen_domu build fix · ec8148de
      由 Tony Luck 提交于 
      arch/ia64/xen/xen_pv_ops.c:156: error: xen_init_ops causes a section type conflict
arch/ia64/xen/xen_pv_ops.c:340: error: xen_iosapic_ops causes a section type conflict
Signed-off-by: NTony Luck <tony.luck@intel.com>
      ec8148de
    • I
      [IA64] fixes configs and add default config for ia64 xen domU · 1d5b20f4
      由 Isaku Yamahata 提交于 
      This patch fixes xen related Kconfigs and add default config
file for ia64 xen domU.
Signed-off-by: NIsaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: NTony Luck <aegl@agluck-desktop.(none)>
      1d5b20f4
    • A
      [IA64] Remove redundant cpu_clear() in __cpu_disable path · c0acdea2
      由 Alex Chiang 提交于 
      The second call to cpu_clear() is redundant, as we've already removed
the CPU from cpu_online_map before calling migrate_platform_irqs().
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NTony Luck <aegl@agluck-desktop.(none)>
      c0acdea2
    • A
      [IA64] Revert "prevent ia64 from invoking irq handlers on offline CPUs" · 66db2e63
      由 Alex Chiang 提交于 
      This reverts commit e7b14036.

Commit e7b14036 removes the targetted disabled CPU from the
cpu_online_map after calls to migrate_platform_irqs and fixup_irqs.

Paul McKenney states that the reasoning behind the patch was to
prevent irq handlers from running on CPUs marked offline because:

	RCU happily ignores CPUs that don't have their bits set in
	cpu_online_map, so if there are RCU read-side critical sections
	in the irq handlers being run, RCU will ignore them.  If the
	other CPUs were running, they might sequence through the RCU
	state machine, which could result in data structures being
	yanked out from under those irq handlers, which in turn could
	result in oopses or worse.

Unfortunately, both ia64 functions above look at cpu_online_map to find
a new CPU to migrate interrupts onto. This means we can potentially
migrate an interrupt off ourself back to... ourself. Uh oh.

This causes an oops when we finally try to process pending interrupts on
the CPU we want to disable. The oops results from calling __do_IRQ with
a NULL pt_regs:

Unable to handle kernel NULL pointer dereference (address 0000000000000040)
Call Trace:
 [<a000000100016930>] show_stack+0x50/0xa0
                                sp=e0000009c922fa00 bsp=e0000009c92214d0
 [<a0000001000171a0>] show_regs+0x820/0x860
                                sp=e0000009c922fbd0 bsp=e0000009c9221478
 [<a00000010003c700>] die+0x1a0/0x2e0
                                sp=e0000009c922fbd0 bsp=e0000009c9221438
 [<a0000001006e92f0>] ia64_do_page_fault+0x950/0xa80
                                sp=e0000009c922fbd0 bsp=e0000009c92213d8
 [<a00000010000c7a0>] ia64_native_leave_kernel+0x0/0x270
                                sp=e0000009c922fc60 bsp=e0000009c92213d8
 [<a0000001000ecdb0>] profile_tick+0xd0/0x1c0
                                sp=e0000009c922fe30 bsp=e0000009c9221398
 [<a00000010003bb90>] timer_interrupt+0x170/0x3e0
                                sp=e0000009c922fe30 bsp=e0000009c9221330
 [<a00000010013a800>] handle_IRQ_event+0x80/0x120
                                sp=e0000009c922fe30 bsp=e0000009c92212f8
 [<a00000010013aa00>] __do_IRQ+0x160/0x4a0
                                sp=e0000009c922fe30 bsp=e0000009c9221290
 [<a000000100012290>] ia64_process_pending_intr+0x2b0/0x360
                                sp=e0000009c922fe30 bsp=e0000009c9221208
 [<a0000001000112d0>] fixup_irqs+0xf0/0x2a0
                                sp=e0000009c922fe30 bsp=e0000009c92211a8
 [<a00000010005bd80>] __cpu_disable+0x140/0x240
                                sp=e0000009c922fe30 bsp=e0000009c9221168
 [<a0000001006c5870>] take_cpu_down+0x50/0xa0
                                sp=e0000009c922fe30 bsp=e0000009c9221148
 [<a000000100122610>] stop_cpu+0xd0/0x200
                                sp=e0000009c922fe30 bsp=e0000009c92210f0
 [<a0000001000e0440>] kthread+0xc0/0x140
                                sp=e0000009c922fe30 bsp=e0000009c92210c8
 [<a000000100014ab0>] kernel_thread_helper+0xd0/0x100
                                sp=e0000009c922fe30 bsp=e0000009c92210a0
 [<a00000010000a4c0>] start_kernel_thread+0x20/0x40
                                sp=e0000009c922fe30 bsp=e0000009c92210a0

I don't like this revert because it is fragile. ia64 is getting lucky
because we seem to only ever process timer interrupts in this path, but
if we ever race with an IPI here, we definitely use RCU and have the
potential of hitting an oops that Paul describes above.

Patching ia64's timer_interrupt() to check for NULL pt_regs is
insufficient though, as we still hit the above oops.

As a short term solution, I do think that this revert is the right
answer. The revert hold up under repeated testing (24+ hour test runs)
with this setup:

	- 8-way rx6600
	- randomly toggling CPU online/offline state every 2 seconds
	- running CPU exercisers, memory hog, disk exercisers, and
	  network stressors
	- average system load around ~160

In the long term, we really need to figure out why we set pt_regs = NULL
in ia64_process_pending_intr(). If it turns out that it is unnecessary
to do so, then we could safely re-introduce e7b14036 (along with some
other logic to be smarter about migrating interrupts).

One final note: x86 also removes the disabled CPU from cpu_online_map
and then re-enables interrupts for 1ms, presumably to handle any pending
interrupts:

arch/x86/kernel/irq_32.c (and irq_64.c):
cpu_disable_common:
	[remove cpu from cpu_online_map]

	fixup_irqs():
		for_each_irq:
			[break CPU affinities]

		local_irq_enable();
		mdelay(1);
		local_irq_disable();

So they are doing implicitly what ia64 is doing explicitly.
Signed-off-by: NAlex Chiang <achiang@hp.com>
Signed-off-by: NTony Luck <aegl@agluck-desktop.(none)>
      66db2e63
    • R
      [IA64] bte_copy of BTE_MAX_XFER trips BUG_ON. · 39d481cb
      由 Robin Holt 提交于 
      BTE_MAX_XFER is wrong.  It is one greater than the number of cache
lines the BTE is actually able to transfer.  If you request a transfer
of exactly BTE_MAX_XFER size, you trip a very cryptic BUG_ON() which
should certainly be made more clear.

This patch fixes that constant and also cleans up the BUG_ON()s in
arch/ia64/sn/kernel/bte.c to test one condition per line.
Signed-off-by: NRobin Holt <holt@sgi.com>
Signed-off-by: NTony Luck <aegl@agluck-desktop.(none)>
      39d481cb
    • T
      [IA64] Build fix for __early_pfn_to_nid() undefined link error · 334f85b6
      由 Tony Luck 提交于 
      ia64 only defines __early_pfn_to_nid() for SPARSEMEM && NUMA configurations,
so the recent:

	commit: f2dbcfa7
	mm: clean up for early_pfn_to_nid()

ends up with some link problems for certain configuration files.

Fix arch/ia64/Kconfig to only define HAVE_ARCH_EARLY_PFN_TO_NID in the
cases where we do provide this function.
Signed-off-by: NTony Luck <tony.luck@intel.com>
      334f85b6
    • H
      [ARM] 5405/1: ep93xx: remove unused gesbc9312.h header · 9dd446f6
      由 Hartley Sweeten 提交于 
      Remove the gesbc9312.h header since it is unused.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      9dd446f6
  11. 19 2月, 2009 7 次提交
  13. 18 2月, 2009 5 次提交
    • A
      x86, mce: fix ifdef for 64bit thermal apic vector clear on shutdown · 07db1c14
      由 Andi Kleen 提交于 
      Impact: Bugfix

The ifdef for the apic clear on shutdown for the 64bit intel thermal
vector was incorrect and never triggered. Fix that.
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>
      07db1c14
    • A
      x86, mce: use force_sig_info to kill process in machine check · 380851bc
      由 Andi Kleen 提交于 
      Impact: bug fix (with tolerant == 3)

do_exit cannot be called directly from the exception handler because
it can sleep and the exception handler runs on the exception stack.
Use force_sig() instead.

Based on a earlier patch by Ying Huang who debugged the problem.
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>
      380851bc
    • A
      x86, mce: reinitialize per cpu features on resume · 6ec68bff
      由 Andi Kleen 提交于 
      Impact: Bug fix

This fixes a long standing bug in the machine check code. On resume the
boot CPU wouldn't get its vendor specific state like thermal handling
reinitialized. This means the boot cpu wouldn't ever get any thermal
events reported again.

Call the respective initialization functions on resume

v2: Remove ancient init because they don't have a resume device anyways.
    Pointed out by Thomas Gleixner.
v3: Now fix the Subject too to reflect v2 change
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>
      6ec68bff
    • N
      [ARM] 5401/1: Orion: fix edge triggered GPIO interrupt support · fd4b9b36
      由 Nicolas Pitre 提交于 
      The GPIO interrupts can be configured as either level triggered or edge
triggered, with a default of level triggered.  When an edge triggered
interrupt is requested, the gpio_irq_set_type method is called which
currently switches the given IRQ descriptor between two struct irq_chip
instances: orion_gpio_irq_level_chip and orion_gpio_irq_edge_chip. This
happens via __setup_irq() which also calls irq_chip_set_defaults() to
assign default methods to uninitialized ones.  The problem is that
irq_chip_set_defaults() is called before the irq_chip reference is
switched, leaving the new irq_chip (orion_gpio_irq_edge_chip in this
case) with uninitialized methods such as chip->startup() causing a kernel
oops.

Many solutions are possible, such as making irq_chip_set_defaults() global
and calling it from gpio_irq_set_type(), or calling __irq_set_trigger()
before irq_chip_set_defaults() in __setup_irq().  But those require
modifications to the generic IRQ code which might have adverse effect on
other architectures, and that would still be a fragile arrangement.
Manually copying the missing methods from within gpio_irq_set_type()
would be really ugly and it would break again the day new methods with
automatic defaults are added.

A better solution is to have a single irq_chip instance which can deal
with both edge and level triggered interrupts.  It is also a good idea
to switch the IRQ handler instead, as the edge IRQ handler allows for
one edge IRQ event to be queued as the IRQ is actually masked only when
that second IRQ is received, at which point the hardware can queue an
additional IRQ event, making edge triggered interrupts a bit more
reliable.
Tested-by: NMartin Michlmayr <tbm@cyrius.com>
Signed-off-by: NNicolas Pitre <nico@marvell.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
      fd4b9b36
    • P
      x86, rcu: fix strange load average and ksoftirqd behavior · bf51935f
      由 Paul E. McKenney 提交于 
      Damien Wyart reported high ksoftirqd CPU usage (20%) on an
otherwise idle system.

The function-graph trace Damien provided:

>   799.521187 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.521371 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.521555 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.521738 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.521934 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.522068 |   1)  ksoftir-2324  |               |                rcu_check_callbacks() {
>   799.522208 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.522392 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.522575 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.522759 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.522956 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.523074 |   1)  ksoftir-2324  |               |                  rcu_check_callbacks() {
>   799.523214 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.523397 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.523579 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.523762 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.523960 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.524079 |   1)  ksoftir-2324  |               |                  rcu_check_callbacks() {
>   799.524220 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.524403 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.524587 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
>   799.524770 |   1)    <idle>-0    |               |  rcu_check_callbacks() {
> [ . . . ]

Shows rcu_check_callbacks() being invoked way too often. It should be called
once per jiffy, and here it is called no less than 22 times in about
3.5 milliseconds, meaning one call every 160 microseconds or so.

Why do we need to call rcu_pending() and rcu_check_callbacks() from the
idle loop of 32-bit x86, especially given that no other architecture does
this?

The following patch removes the call to rcu_pending() and
rcu_check_callbacks() from the x86 32-bit idle loop in order to
reduce the softirq load on idle systems.
Reported-by: NDamien Wyart <damien.wyart@free.fr>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      bf51935f
  15. 17 2月, 2009 1 次提交
  17. 16 2月, 2009 3 次提交
  19. 15 2月, 2009 3 次提交