kernel_optimize_test/mm
Linus Torvalds 0988496433 mm: do not grow the stack vma just because of an overrun on preceding vma
The stack vma is designed to grow automatically (marked with VM_GROWSUP
or VM_GROWSDOWN depending on architecture) when an access is made beyond
the existing boundary.  However, particularly if you have not limited
your stack at all ("ulimit -s unlimited"), this can cause the stack to
grow even if the access was really just one past *another* segment.

And that's wrong, especially since we first grow the segment, but then
immediately later enforce the stack guard page on the last page of the
segment.  So _despite_ first growing the stack segment as a result of
the access, the kernel will then make the access cause a SIGSEGV anyway!

So do the same logic as the guard page check does, and consider an
access to within one page of the next segment to be a bad access, rather
than growing the stack to abut the next segment.

Reported-and-tested-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 08:36:04 -08:00
..
backing-dev.c bdi: allow block devices to say that they require stable page writes 2013-02-21 17:22:19 -08:00
balloon_compaction.c mm: introduce a common interface for balloon pages mobility 2012-12-11 17:22:26 -08:00
bootmem.c mm: Add alloc_bootmem_low_pages_nopanic() 2013-01-29 19:32:59 -08:00
bounce.c block: optionally snapshot page contents to provide stable pages during write 2013-02-21 17:22:20 -08:00
cleancache.c fs: encode_fh: return FILEID_INVALID if invalid fid_type 2013-02-26 02:46:10 -05:00
compaction.c mm: add & use zone_end_pfn() and zone_spans_pfn() 2013-02-23 17:50:20 -08:00
debug-pagealloc.c
dmapool.c dmapool: make DMAPOOL_DEBUG detect corruption of free marker 2012-12-11 17:22:24 -08:00
fadvise.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
failslab.c
filemap_xip.c
filemap.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
fremap.c mm: introduce VM_POPULATE flag to better deal with racy userspace programs 2013-02-23 17:50:11 -08:00
frontswap.c
highmem.c Some nice cleanups, and even a patch my wife did as a "live" demo for 2012-12-20 08:37:05 -08:00
huge_memory.c mm: use NUMA_NO_NODE 2013-02-23 17:50:21 -08:00
hugetlb_cgroup.c mm/hugetlb: create hugetlb cgroup file in hugetlb_init 2012-12-18 15:02:15 -08:00
hugetlb.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
hwpoison-inject.c
init-mm.c
internal.h mm: directly use __mlock_vma_pages_range() in find_extend_vma() 2013-02-23 17:50:11 -08:00
interval_tree.c
Kconfig memory-hotplug: implement register_page_bootmem_info_section of sparse-vmemmap 2013-02-23 17:50:12 -08:00
Kconfig.debug
kmemcheck.c
kmemleak-test.c
kmemleak.c mm: add & use zone_end_pfn() and zone_spans_pfn() 2013-02-23 17:50:20 -08:00
ksm.c ksm: allocate roots when needed 2013-02-23 17:50:24 -08:00
maccess.c
madvise.c mm: make madvise(MADV_WILLNEED) support swap file prefetch 2013-02-23 17:50:10 -08:00
Makefile mm: introduce a common interface for balloon pages mobility 2012-12-11 17:22:26 -08:00
memblock.c mm/memblock.c: use CONFIG_HAVE_MEMBLOCK_NODE_MAP to protect movablecore_map in memblock_overlaps_region(). 2013-02-23 17:50:14 -08:00
memcontrol.c memcg: stop warning on memcg_propagate_kmem 2013-02-23 17:50:22 -08:00
memory_hotplug.c mm/memory_hotplug: use pgdat_end_pfn() instead of open coding the same. 2013-02-23 17:50:21 -08:00
memory-failure.c HWPOISON: change order of error_states[]'s elements 2013-02-23 17:50:22 -08:00
memory.c The sweeping change is to make add_taint() explicitly indicate whether to disable 2013-02-25 15:41:43 -08:00
mempolicy.c mm: use NUMA_NO_NODE 2013-02-23 17:50:21 -08:00
mempool.c
migrate.c mm: remove offlining arg to migrate_pages 2013-02-23 17:50:19 -08:00
mincore.c swap: make each swap partition have one address_space 2013-02-23 17:50:17 -08:00
mlock.c mm: use long type for page counts in mm_populate() and get_user_pages() 2013-02-23 17:50:22 -08:00
mm_init.c mm: init: report on last-nid information stored in page->flags 2013-02-23 17:50:18 -08:00
mmap.c mm: do not grow the stack vma just because of an overrun on preceding vma 2013-02-27 08:36:04 -08:00
mmu_context.c
mmu_notifier.c mm: export mmu notifier invalidates 2013-02-23 17:50:23 -08:00
mmzone.c mm: rename page struct field helpers 2013-02-23 17:50:18 -08:00
mprotect.c mm/mprotect.c: coding-style cleanups 2012-12-18 15:02:15 -08:00
mremap.c mm/rmap: rename anon_vma_unlock() => anon_vma_unlock_write() 2013-02-23 17:50:17 -08:00
msync.c
nobootmem.c mm: Add alloc_bootmem_low_pages_nopanic() 2013-01-29 19:32:59 -08:00
nommu.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
oom_kill.c memcg, oom: provide more precise dump info while memcg oom happening 2013-02-23 17:50:08 -08:00
page_alloc.c The sweeping change is to make add_taint() explicitly indicate whether to disable 2013-02-25 15:41:43 -08:00
page_cgroup.c memcontrol: use N_MEMORY instead N_HIGH_MEMORY 2012-12-12 17:38:32 -08:00
page_io.c
page_isolation.c mm: fix zone_watermark_ok_safe() accounting of isolated pages 2013-01-04 16:11:46 -08:00
page-writeback.c page-writeback.c: subtract min_free_kbytes from dirtyable memory 2013-02-23 17:50:17 -08:00
pagewalk.c thp: change split_huge_page_pmd() interface 2012-12-12 17:38:31 -08:00
percpu-km.c
percpu-vm.c
percpu.c mm, percpu: Make sure percpu_alloc early parameter has an argument 2012-12-02 06:23:04 -08:00
pgtable-generic.c mm: Only flush the TLB when clearing an accessible pte 2012-12-11 14:28:34 +00:00
process_vm_access.c
quicklist.c
readahead.c
rmap.c mm/rmap: rename anon_vma_unlock() => anon_vma_unlock_write() 2013-02-23 17:50:17 -08:00
shmem.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
slab_common.c slab: propagate tunable values 2012-12-18 15:02:14 -08:00
slab.c taint: add explicit flag to show whether lock dep is still OK. 2013-01-21 17:17:57 +10:30
slab.h slab: propagate tunable values 2012-12-18 15:02:14 -08:00
slob.c mm: rename page struct field helpers 2013-02-23 17:50:18 -08:00
slub.c The sweeping change is to make add_taint() explicitly indicate whether to disable 2013-02-25 15:41:43 -08:00
sparse-vmemmap.c
sparse.c memory-failure: use num_poisoned_pages instead of mce_bad_pages 2013-02-23 17:50:15 -08:00
swap_state.c swap: add per-partition lock for swapfile 2013-02-23 17:50:17 -08:00
swap.c swap: make each swap partition have one address_space 2013-02-23 17:50:17 -08:00
swapfile.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
truncate.c mm: drop vmtruncate 2012-12-20 18:46:29 -05:00
util.c swap: make each swap partition have one address_space 2013-02-23 17:50:17 -08:00
vmalloc.c mm: use NUMA_NO_NODE 2013-02-23 17:50:21 -08:00
vmscan.c vmscan: change type of vm_total_pages to unsigned long 2013-02-23 17:50:22 -08:00
vmstat.c mm: add & use zone_end_pfn() and zone_spans_pfn() 2013-02-23 17:50:20 -08:00