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  1. 31 8月, 2009 7 次提交
  3. 27 8月, 2009 17 次提交
  5. 26 8月, 2009 1 次提交
    • D
      sparc64: Validate linear D-TLB misses. · d8ed1d43
      由 David S. Miller 提交于 
      When page alloc debugging is not enabled, we essentially accept any
virtual address for linear kernel TLB misses.  But with kgdb, kernel
address probing, and other facilities we can try to access arbitrary
crap.

So, make sure the address we miss on will translate to physical memory
that actually exists.

In order to make this work we have to embed the valid address bitmap
into the kernel image.  And in order to make that less expensive we
make an adjustment, in that the max physical memory address is
decreased to "1 << 41", even on the chips that support a 42-bit
physical address space.  We can do this because bit 41 indicates
"I/O space" and thus covers non-memory ranges.

The result of this is that:

1) kpte_linear_bitmap shrinks from 2K to 1K in size

2) we need 64K more for the valid address bitmap

We can't let the valid address bitmap be dynamically allocated
once we start using it to validate TLB misses, otherwise we have
crazy issues to deal with wrt. recursive TLB misses and such.

If we're in a TLB miss it could be the deepest trap level that's legal
inside of the cpu.  So if we TLB miss referencing the bitmap, the cpu
will be out of trap levels and enter RED state.

To guard against out-of-range accesses to the bitmap, we have to check
to make sure no bits in the physical address above bit 40 are set.  We
could export and use last_valid_pfn for this check, but that's just an
unnecessary extra memory reference.

On the plus side of all this, since we load all of these translations
into the special 4MB mapping TSB, and we check the TSB first for TLB
misses, there should be absolutely no real cost for these new checks
in the TLB miss path.

Reported-by: heyongli@gmail.com
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d8ed1d43
  7. 25 8月, 2009 2 次提交
    • J
      x86: Fix build with older binutils and consolidate linker script · c62e4320
      由 Jan Beulich 提交于 
      binutils prior to 2.17 can't deal with the currently possible
situation of a new segment following the per-CPU segment, but
that new segment being empty - objcopy misplaces the .bss (and
perhaps also the .brk) sections outside of any segment.

However, the current ordering of sections really just appears
to be the effect of cumulative unrelated changes; re-ordering
things allows to easily guarantee that the segment following
the per-CPU one is non-empty, and at once eliminates the need
for the bogus data.init2 segment.

Once touching this code, also use the various data section
helper macros from include/asm-generic/vmlinux.lds.h.

-v2: fix !SMP builds.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Cc: <sam@ravnborg.org>
LKML-Reference: <4A94085D02000078000119A5@vpn.id2.novell.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      c62e4320
    • A
      x86: Fix an incorrect argument of reserve_bootmem() · a6a06f7b
      由 Amerigo Wang 提交于 
      This line looks suspicious, because if this is true, then the
'flags' parameter of function reserve_bootmem_generic() will be
unused when !CONFIG_NUMA. I don't think this is what we want.
Signed-off-by: NWANG Cong <amwang@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: akpm@linux-foundation.org
LKML-Reference: <20090821083709.5098.52505.sendpatchset@localhost.localdomain>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a6a06f7b
  9. 24 8月, 2009 4 次提交
  11. 22 8月, 2009 2 次提交
    • L
      x86: don't call '->send_IPI_mask()' with an empty mask · b04e6373
      由 Linus Torvalds 提交于 
      As noted in 83d349f3 ("x86: don't send
an IPI to the empty set of CPU's"), some APIC's will be very unhappy
with an empty destination mask.  That commit added a WARN_ON() for that
case, and avoided the resulting problem, but didn't fix the underlying
reason for why those empty mask cases happened.

This fixes that, by checking the result of 'cpumask_andnot()' of the
current CPU actually has any other CPU's left in the set of CPU's to be
sent a TLB flush, and not calling down to the IPI code if the mask is
empty.

The reason this started happening at all is that we started passing just
the CPU mask pointers around in commit 4595f962 ("x86: change
flush_tlb_others to take a const struct cpumask"), and when we did that,
the cpumask was no longer thread-local.

Before that commit, flush_tlb_mm() used to create it's own copy of
'mm->cpu_vm_mask' and pass that copy down to the low-level flush
routines after having tested that it was not empty.  But after changing
it to just pass down the CPU mask pointer, the lower level TLB flush
routines would now get a pointer to that 'mm->cpu_vm_mask', and that
could still change - and become empty - after the test due to other
CPU's having flushed their own TLB's.

See

	http://bugzilla.kernel.org/show_bug.cgi?id=13933

for details.
Tested-by: NThomas Björnell <thomas.bjornell@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b04e6373
    • L
      x86: don't send an IPI to the empty set of CPU's · 83d349f3
      由 Linus Torvalds 提交于 
      The default_send_IPI_mask_logical() function uses the "flat" APIC mode
to send an IPI to a set of CPU's at once, but if that set happens to be
empty, some older local APIC's will apparently be rather unhappy.  So
just warn if a caller gives us an empty mask, and ignore it.

This fixes a regression in 2.6.30.x, due to commit 4595f962 ("x86:
change flush_tlb_others to take a const struct cpumask"), documented
here:

	http://bugzilla.kernel.org/show_bug.cgi?id=13933

which causes a silent lock-up.  It only seems to happen on PPro, P2, P3
and Athlon XP cores.  Most developers sadly (or not so sadly, if you're
a developer..) have more modern CPU's.  Also, on x86-64 we don't use the
flat APIC mode, so it would never trigger there even if the APIC didn't
like sending an empty IPI mask.
Reported-by: NPavel Vilim <wylda@volny.cz>
Reported-and-tested-by: NThomas Björnell <thomas.bjornell@gmail.com>
Reported-and-tested-by: NMartin Rogge <marogge@onlinehome.de>
Cc: Mike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      83d349f3
  13. 21 8月, 2009 1 次提交
  15. 20 8月, 2009 3 次提交
    • J
      xen: rearrange things to fix stackprotector · ce2eef33
      由 Jeremy Fitzhardinge 提交于 
      Make sure the stack-protector segment registers are properly set up
before calling any functions which may have stack-protection compiled
into them.

[ Impact: prevent Xen early-boot crash when stack-protector is enabled ]
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      ce2eef33
    • J
      x86: make sure load_percpu_segment has no stackprotector · 5416c266
      由 Jeremy Fitzhardinge 提交于 
      load_percpu_segment() is used to set up the per-cpu segment registers,
which are also used for -fstack-protector.  Make sure that the
load_percpu_segment() function doesn't have stackprotector enabled.

[ Impact: allow percpu setup before calling stack-protected functions ]
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
      5416c266
    • S
      clockevent: Prevent dead lock on clockevents_lock · f833bab8
      由 Suresh Siddha 提交于 
      Currently clockevents_notify() is called with interrupts enabled at
some places and interrupts disabled at some other places.

This results in a deadlock in this scenario.

cpu A holds clockevents_lock in clockevents_notify() with irqs enabled
cpu B waits for clockevents_lock in clockevents_notify() with irqs disabled
cpu C doing set_mtrr() which will try to rendezvous of all the cpus.

This will result in C and A come to the rendezvous point and waiting
for B. B is stuck forever waiting for the spinlock and thus not
reaching the rendezvous point.

Fix the clockevents code so that clockevents_lock is taken with
interrupts disabled and thus avoid the above deadlock.

Also call lapic_timer_propagate_broadcast() on the destination cpu so
that we avoid calling smp_call_function() in the clockevents notifier
chain.

This issue left us wondering if we need to change the MTRR rendezvous
logic to use stop machine logic (instead of smp_call_function) or add
a check in spinlock debug code to see if there are other spinlocks
which gets taken under both interrupts enabled/disabled conditions.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: "Pallipadi Venkatesh" <venkatesh.pallipadi@intel.com>
Cc: "Brown Len" <len.brown@intel.com>
LKML-Reference: <1250544899.2709.210.camel@sbs-t61.sc.intel.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      f833bab8
  17. 19 8月, 2009 3 次提交