linux/mm
David Vrabel 461ae488ec mm: sync vmalloc address space page tables in alloc_vm_area()
Xen backend drivers (e.g., blkback and netback) would sometimes fail to
map grant pages into the vmalloc address space allocated with
alloc_vm_area().  The GNTTABOP_map_grant_ref would fail because Xen could
not find the page (in the L2 table) containing the PTEs it needed to
update.

(XEN) mm.c:3846:d0 Could not find L1 PTE for address fbb42000

netback and blkback were making the hypercall from a kernel thread where
task->active_mm != &init_mm and alloc_vm_area() was only updating the page
tables for init_mm.  The usual method of deferring the update to the page
tables of other processes (i.e., after taking a fault) doesn't work as a
fault cannot occur during the hypercall.

This would work on some systems depending on what else was using vmalloc.

Fix this by reverting ef691947d8 ("vmalloc: remove vmalloc_sync_all()
from alloc_vm_area()") and add a comment to explain why it's needed.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Cc: Keir Fraser <keir.xen@gmail.com>
Cc: <stable@kernel.org>		[3.0.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-09-14 18:09:38 -07:00
..
Kconfig
Kconfig.debug
Makefile
backing-dev.c
bootmem.c
bounce.c
cleancache.c
compaction.c
debug-pagealloc.c
dmapool.c
fadvise.c
failslab.c fault-injection: add ability to export fault_attr in arbitrary directory 2011-08-03 14:25:20 -10:00
filemap.c mm: clarify the radix_tree exceptional cases 2011-08-03 14:25:24 -10:00
filemap_xip.c
fremap.c
highmem.c mm: make HASHED_PAGE_VIRTUAL page_address' struct page argument const. 2011-08-17 13:00:20 -07:00
huge_memory.c
hugetlb.c
hwpoison-inject.c
init-mm.c
internal.h
kmemcheck.c
kmemleak-test.c
kmemleak.c
ksm.c
maccess.c
madvise.c
memblock.c
memcontrol.c memcg: Revert "memcg: add memory.vmscan_stat" 2011-09-14 18:09:38 -07:00
memory-failure.c HWPoison: add memory_failure_queue() 2011-08-03 11:15:58 -04:00
memory.c
memory_hotplug.c
mempolicy.c mm/mempolicy.c: make copy_from_user() provably correct 2011-09-14 18:09:36 -07:00
mempool.c
migrate.c
mincore.c mm: clarify the radix_tree exceptional cases 2011-08-03 14:25:24 -10:00
mlock.c
mm_init.c
mmap.c
mmu_context.c
mmu_notifier.c
mmzone.c
mprotect.c
mremap.c
msync.c
nobootmem.c
nommu.c
oom_kill.c
page-writeback.c squeeze max-pause area and drop pass-good area 2011-08-19 22:42:07 +08:00
page_alloc.c fault-injection: add ability to export fault_attr in arbitrary directory 2011-08-03 14:25:20 -10:00
page_cgroup.c
page_io.c
page_isolation.c
pagewalk.c
percpu-km.c
percpu-vm.c
percpu.c
pgtable-generic.c
prio_tree.c
quicklist.c
readahead.c
rmap.c
shmem.c mm: clarify the radix_tree exceptional cases 2011-08-03 14:25:24 -10:00
slab.c slab, lockdep: Annotate the locks before using them 2011-08-04 10:18:00 +02:00
slob.c
slub.c slub: Fix partial count comparison confusion 2011-08-09 21:12:31 +03:00
sparse-vmemmap.c
sparse.c
swap.c
swap_state.c
swapfile.c mm: let swap use exceptional entries 2011-08-03 14:25:22 -10:00
thrash.c
truncate.c mm: a few small updates for radix-swap 2011-08-03 14:25:24 -10:00
util.c
vmalloc.c mm: sync vmalloc address space page tables in alloc_vm_area() 2011-09-14 18:09:38 -07:00
vmscan.c memcg: Revert "memcg: add memory.vmscan_stat" 2011-09-14 18:09:38 -07:00
vmstat.c numa: fix NUMA compile error when sysfs and procfs are disabled 2011-09-14 18:09:37 -07:00