linux_dsm_epyc7002/arch/x86
Peter Zijlstra 20273941f2 mm: fix race in kunmap_atomic()
Christoph reported a nice splat which illustrated a race in the new stack
based kmap_atomic implementation.

The problem is that we pop our stack slot before we're completely done
resetting its state -- in particular clearing the PTE (sometimes that's
CONFIG_DEBUG_HIGHMEM).  If an interrupt happens before we actually clear
the PTE used for the last slot, that interrupt can reuse the slot in a
dirty state, which triggers a BUG in kmap_atomic().

Fix this by introducing kmap_atomic_idx() which reports the current slot
index without actually releasing it and use that to find the PTE and delay
the _pop() until after we're completely done.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Christoph Hellwig <hch@infradead.org>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:05 -07:00
..
boot x86, setup: Use string copy operation to optimze copy in kernel compression 2010-10-07 21:23:09 -07:00
configs defconfig reduction 2010-08-14 22:26:53 +02:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 2010-05-03 11:28:58 +08:00
ia32 Don't dump task struct in a.out core-dumps 2010-10-14 10:57:40 -07:00
include/asm Merge branches 'upstream/xenfs' and 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2010-10-26 18:20:19 -07:00
kernel Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 2010-10-26 17:28:37 -07:00
kvm Merge branch 'kvm-updates/2.6.37' of git://git.kernel.org/pub/scm/virt/kvm/kvm 2010-10-24 12:47:25 -07:00
lguest x86: lguest: Use new irq allocator 2010-10-12 16:53:45 +02:00
lib x86, mem: Optimize memmove for small size and unaligned cases 2010-09-24 18:57:11 -07:00
math-emu x86, fpu: Unbreak FPU emulation 2010-05-10 13:37:16 -07:00
mm mm: fix race in kunmap_atomic() 2010-10-27 18:03:05 -07:00
oprofile Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 14:11:46 -07:00
pci x86, olpc: Only enable PCI configuration type override on XO-1 2010-09-23 11:14:18 -07:00
power x86, tsc, sched: Recompute cyc2ns_offset's during resume from sleep states 2010-08-20 14:59:02 +02:00
tools x86: Remove trailing spaces in messages 2010-02-07 17:47:51 +01:00
vdso Merge branches 'x86-cleanups-for-linus', 'x86-vmware-for-linus', 'x86-mtrr-for-linus', 'x86-apic-for-linus', 'x86-fpu-for-linus' and 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-08-06 16:22:59 -07:00
video
xen Merge branches 'upstream/xenfs' and 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2010-10-26 18:20:19 -07:00
.gitignore add random binaries to .gitignore 2010-04-08 11:34:34 +02:00
Kbuild
Kconfig Merge branch 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 18:52:11 -07:00
Kconfig.cpu Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-05-18 08:58:16 -07:00
Kconfig.debug Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-22 08:54:21 -07:00
Makefile Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-10-21 13:06:00 -07:00
Makefile_32.cpu