linux/mm
Linus Torvalds a1fde08c74 VM: skip the stack guard page lookup in get_user_pages only for mlock
The logic in __get_user_pages() used to skip the stack guard page lookup
whenever the caller wasn't interested in seeing what the actual page
was.  But Michel Lespinasse points out that there are cases where we
don't care about the physical page itself (so 'pages' may be NULL), but
do want to make sure a page is mapped into the virtual address space.

So using the existence of the "pages" array as an indication of whether
to look up the guard page or not isn't actually so great, and we really
should just use the FOLL_MLOCK bit.  But because that bit was only set
for the VM_LOCKED case (and not all vma's necessarily have it, even for
mlock()), we couldn't do that originally.

Fix that by moving the VM_LOCKED check deeper into the call-chain, which
actually simplifies many things.  Now mlock() gets simpler, and we can
also check for FOLL_MLOCK in __get_user_pages() and the code ends up
much more straightforward.

Reported-and-reviewed-by: Michel Lespinasse <walken@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-04 21:30:28 -07:00
..
Kconfig mm: compaction: don't depend on HUGETLB_PAGE 2011-01-26 10:50:02 +10:00
Kconfig.debug mm: debug-pagealloc: fix kconfig dependency warning 2011-03-22 17:44:02 -07:00
Makefile bootmem: Separate out CONFIG_NO_BOOTMEM code into nobootmem.c 2011-02-24 14:43:05 +01:00
backing-dev.c Fix common misspellings 2011-03-31 11:26:23 -03:00
bootmem.c crash_dump: export is_kdump_kernel to modules, consolidate elfcorehdr_addr, setup_elfcorehdr and saved_max_pfn 2011-03-23 19:47:19 -07:00
bounce.c bounce: call flush_dcache_page() after bounce_copy_vec() 2010-09-09 18:57:25 -07:00
compaction.c mm: compaction: minimise the time IRQs are disabled while isolating pages for migration 2011-03-22 17:44:05 -07:00
debug-pagealloc.c
dmapool.c mm/dmapool.c: use TASK_UNINTERRUPTIBLE in dma_pool_alloc() 2011-01-13 17:32:48 -08:00
fadvise.c readahead: introduce FMODE_RANDOM for POSIX_FADV_RANDOM 2010-03-06 11:26:25 -08:00
failslab.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
filemap.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2011-03-24 19:01:30 -07:00
filemap_xip.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fremap.c Avoid pgoff overflow in remap_file_pages 2010-09-25 09:34:58 -07:00
highmem.c mm,x86: fix kmap_atomic_push vs ioremap_32.c 2010-10-27 18:03:05 -07:00
huge_memory.c mm: thp: fix /dev/zero MAP_PRIVATE and vm_flags cleanups 2011-04-28 11:28:20 -07:00
hugetlb.c Fix common misspellings 2011-03-31 11:26:23 -03:00
hwpoison-inject.c Fix common misspellings 2011-03-31 11:26:23 -03:00
init-mm.c mm: provide init_mm mm_context initializer 2010-08-09 20:44:54 -07:00
internal.h Fix common misspellings 2011-03-31 11:26:23 -03:00
kmemcheck.c kmemcheck: Fix build errors due to missing slab.h 2010-03-30 22:02:32 +09:00
kmemleak-test.c kmemleak: remove memset by using kzalloc 2011-01-27 18:31:51 +00:00
kmemleak.c Fix common misspellings 2011-03-31 11:26:23 -03:00
ksm.c Fix common misspellings 2011-03-31 11:26:23 -03:00
maccess.c MN10300: Save frame pointer in thread_info struct rather than global var 2010-10-27 17:29:01 +01:00
madvise.c thp: khugepaged: make khugepaged aware about madvise 2011-01-13 17:32:47 -08:00
memblock.c mm/memblock: properly handle overlaps and fix error path 2011-03-22 17:44:09 -07:00
memcontrol.c Fix common misspellings 2011-03-31 11:26:23 -03:00
memory-failure.c Fix common misspellings 2011-03-31 11:26:23 -03:00
memory.c VM: skip the stack guard page lookup in get_user_pages only for mlock 2011-05-04 21:30:28 -07:00
memory_hotplug.c mm: optimize pfn calculation in online_page() 2011-04-14 16:06:54 -07:00
mempolicy.c mempolicy: remove redundant check in __mpol_equal() 2011-03-22 17:44:04 -07:00
mempool.c
migrate.c Fix common misspellings 2011-03-31 11:26:23 -03:00
mincore.c thp: mincore transparent hugepage support 2011-01-13 17:32:44 -08:00
mlock.c VM: skip the stack guard page lookup in get_user_pages only for mlock 2011-05-04 21:30:28 -07:00
mm_init.c
mmap.c brk: COMPAT_BRK: fix detection of randomized brk 2011-04-14 16:06:55 -07:00
mmu_context.c exit: fix oops in sync_mm_rss 2010-03-24 16:31:21 -07:00
mmu_notifier.c thp: mmu_notifier_test_young 2011-01-13 17:32:46 -08:00
mmzone.c mm: page allocator: adjust the per-cpu counter threshold when memory is low 2011-01-13 17:32:31 -08:00
mprotect.c thp: mprotect: transparent huge page support 2011-01-13 17:32:44 -08:00
mremap.c mm: avoid wrapping vm_pgoff in mremap() 2011-04-07 07:35:51 -07:00
msync.c sanitize vfs_fsync calling conventions 2010-05-21 18:31:21 -04:00
nobootmem.c Fix common misspellings 2011-03-31 11:26:23 -03:00
nommu.c NOMMU: implement access_remote_vm 2011-03-29 14:05:12 +01:00
oom_kill.c oom: use pte pages in OOM score 2011-04-28 11:28:21 -07:00
page-writeback.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
page_alloc.c mm/page_alloc.c: silence build_all_zonelists() section mismatch 2011-04-14 16:06:54 -07:00
page_cgroup.c Fix common misspellings 2011-03-31 11:26:23 -03:00
page_io.c block: kill off REQ_UNPLUG 2011-03-10 08:52:27 +01:00
page_isolation.c mm: page_isolation: codeclean fix comment and rm unneeded val init 2010-10-26 16:52:11 -07:00
pagewalk.c pagewalk: only split huge pages when necessary 2011-03-22 17:44:04 -07:00
percpu-km.c percpu: clear memory allocated with the km allocator 2010-10-02 10:28:42 +03:00
percpu-vm.c mm: remove gfp mask from pcpu_get_vm_areas 2011-01-13 17:32:34 -08:00
percpu.c Fix common misspellings 2011-03-31 11:26:23 -03:00
pgtable-generic.c mm/pgtable-generic.c: fix CONFIG_SWAP=n build 2011-01-26 10:49:58 +10:00
prio_tree.c
quicklist.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
readahead.c read-ahead: use plugging 2011-03-10 08:52:26 +01:00
rmap.c fs: move i_wb_list out from under inode_lock 2011-03-24 21:17:51 -04:00
shmem.c tmpfs: fix off-by-one in max_blocks checks 2011-04-14 16:06:55 -07:00
slab.c Fix common misspellings 2011-03-31 11:26:23 -03:00
slob.c mm: Remove support for kmem_cache_name() 2011-01-23 21:00:05 +02:00
slub.c slub: Fix the lockless code on 32-bit platforms with no 64-bit cmpxchg 2011-05-04 14:20:20 -07:00
sparse-vmemmap.c tree-wide: fix comment/printk typos 2010-11-01 15:38:34 -04:00
sparse.c Fix common misspellings 2011-03-31 11:26:23 -03:00
swap.c mm: simplify code of swap.c 2011-03-22 17:44:09 -07:00
swap_state.c block: remove per-queue plugging 2011-03-10 08:52:07 +01:00
swapfile.c Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block 2011-03-24 10:16:26 -07:00
thrash.c
truncate.c mm: deactivate invalidated pages 2011-03-22 17:44:03 -07:00
util.c Fix common misspellings 2011-03-31 11:26:23 -03:00
vmalloc.c vmalloc: remove confusing comment on vwrite() 2011-03-22 17:44:09 -07:00
vmscan.c vmscan: all_unreclaimable() use zone->all_unreclaimable as a name 2011-04-14 16:06:56 -07:00
vmstat.c mm: add VM counters for transparent hugepages 2011-04-14 16:06:55 -07:00