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kernel-fxtec-pro1x/mm
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Cyril Hrubis e8420a8ece mm/mmap: check for RLIMIT_AS before unmapping 
Fix a corner case for MAP_FIXED when requested mapping length is larger
than rlimit for virtual memory.  In such case any overlapping mappings
are unmapped before we check for the limit and return ENOMEM.

The check is moved before the loop that unmaps overlapping parts of
existing mappings.  When we are about to hit the limit (currently mapped
pages + len > limit) we scan for overlapping pages and check again
accounting for them.

This fixes situation when userspace program expects that the previous
mappings are preserved after the mmap() syscall has returned with error.
(POSIX clearly states that successfull mapping shall replace any
previous mappings.)

This corner case was found and can be tested with LTP testcase:

testcases/open_posix_testsuite/conformance/interfaces/mmap/24-2.c

In this case the mmap, which is clearly over current limit, unmaps
dynamic libraries and the testcase segfaults right after returning into
userspace.

I've also looked at the second instance of the unmapping loop in the
do_brk().  The do_brk() is called from brk() syscall and from vm_brk().
The brk() syscall checks for overlapping mappings and bails out when
there are any (so it can't be triggered from the brk syscall).  The
vm_brk() is called only from binmft handlers so it shouldn't be
triggered unless binmft handler created overlapping mappings.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
Reviewed-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-29 15:54:38 -07:00
..
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 mm: make snapshotting pages for stable writes a per-bio operation 2013-04-29 15:54:33 -07:00
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 mm, x86: Remove debug_pagealloc_enabled 2011-12-06 09:24:07 +01:00
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 switch debugfs to umode_t 2012-01-03 22:54:56 -05:00
filemap.c mm: trace filemap add and del 2013-04-29 15:54:28 -07:00
filemap_xip.c mm: move all mmu notifier invocations to be done outside the PT lock 2012-10-09 16:22:58 +09:00
fremap.c Revert "mm: introduce VM_POPULATE flag to better deal with racy userspace programs" 2013-03-28 17:45:51 -07:00
frontswap.c frontswap: support exclusive gets if tmem backend is capable 2012-09-21 10:38:12 -04:00
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 THP: fix comment about memory barrier 2013-04-29 15:54:37 -07:00
hugetlb.c mm, hugetlb: include hugepages in meminfo 2013-04-29 15:54:35 -07:00
hugetlb_cgroup.c mm/hugetlb: create hugetlb cgroup file in hugetlb_init 2012-12-18 15:02:15 -08:00
hwpoison-inject.c memcg: rename config variables 2012-07-31 18:42:43 -07:00
init-mm.c
internal.h mm: accelerate munlock() treatment of THP pages 2013-02-27 19:10:09 -08:00
interval_tree.c mm: add CONFIG_DEBUG_VM_RB build option 2012-10-09 16:22:42 +09:00
Kconfig Select VIRT_TO_BUS directly where needed 2013-03-12 11:16:40 -07:00
Kconfig.debug mm: more intensive memory corruption debugging 2012-01-10 16:30:42 -08:00
kmemcheck.c
kmemleak-test.c
kmemleak.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -08:00
ksm.c ksm: fix m68k build: only NUMA needs pfn_to_nid 2013-03-08 15:05:34 -08:00
maccess.c
madvise.c mm: madvise: complete input validation before taking lock 2013-04-29 15:54:37 -07:00
Makefile memcg: add memory.pressure_level events 2013-04-29 15:54:38 -07:00
memblock.c memblock: add assertion for zero allocation alignment 2013-04-29 15:54:28 -07:00
memcontrol.c memcg: add memory.pressure_level events 2013-04-29 15:54:38 -07:00
memory-failure.c HWPOISON: check dirty flag to match against clean page 2013-04-29 15:54:28 -07:00
memory.c THP: fix comment about memory barrier 2013-04-29 15:54:37 -07:00
memory_hotplug.c mm, hotplug: avoid compiling memory hotremove functions when disabled 2013-04-29 15:54:37 -07:00
mempolicy.c mm/mempolicy.c: fix sp_node_init() argument ordering 2013-03-08 15:05:34 -08:00
mempool.c mempool: add @gfp_mask to mempool_create_node() 2012-06-25 11:53:47 +02:00
migrate.c mm: rewrite the comment over migrate_pages() more comprehensibly 2013-04-29 15:54:37 -07:00
mincore.c swap: make each swap partition have one address_space 2013-02-23 17:50:17 -08:00
mlock.c Revert "mm: introduce VM_POPULATE flag to better deal with racy userspace programs" 2013-03-28 17:45:51 -07:00
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/mmap: check for RLIMIT_AS before unmapping 2013-04-29 15:54:38 -07:00
mmu_context.c mm, counters: remove task argument to sync_mm_rss() and __sync_task_rss_stat() 2012-03-21 17:54:59 -07:00
mmu_notifier.c hlist: drop the node parameter from iterators 2013-02-27 19:10:24 -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 mm: replace hardcoded 3% with admin_reserve_pages knob 2013-04-29 15:54:36 -07:00
oom_kill.c memcg, oom: provide more precise dump info while memcg oom happening 2013-02-23 17:50:08 -08:00
page-writeback.c mm: make snapshotting pages for stable writes a per-bio operation 2013-04-29 15:54:33 -07:00
page_alloc.c page_alloc: make setup_nr_node_ids() usable for arch init code 2013-04-29 15:54:36 -07:00
page_cgroup.c memcontrol: use N_MEMORY instead N_HIGH_MEMORY 2012-12-12 17:38:32 -08:00
page_io.c mm: add support for direct_IO to highmem pages 2012-07-31 18:42:47 -07:00
page_isolation.c mm: fix zone_watermark_ok_safe() accounting of isolated pages 2013-01-04 16:11:46 -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 mm: fix kernel-doc warnings 2012-06-20 14:39:36 -07:00
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 Fix: compat_rw_copy_check_uvector() misuse in aio, readv, writev, and security keys 2013-03-12 11:05:45 -07:00
quicklist.c
readahead.c switch simple cases of fget_light to fdget 2012-09-26 22:20:08 -04:00
rmap.c rmap: recompute pgoff for unmapping huge page 2013-04-29 15:54:28 -07:00
shmem.c mm/shmem.c: remove an ifdef 2013-04-29 15:54:28 -07:00
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
slab_common.c 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 mm/slub.c: use register_hotmemory_notifier() 2013-04-29 15:54:36 -07:00
sparse-vmemmap.c sparse-vmemmap: specify vmemmap population range in bytes 2013-04-29 15:54:35 -07:00
sparse.c mm, hotplug: avoid compiling memory hotremove functions when disabled 2013-04-29 15:54:37 -07:00
swap.c swap: make each swap partition have one address_space 2013-02-23 17:50:17 -08:00
swap_state.c swap: add per-partition lock for swapfile 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 kexec, vmalloc: export additional vmalloc layer information 2013-04-29 15:54:34 -07:00
vmpressure.c memcg: add memory.pressure_level events 2013-04-29 15:54:38 -07:00
vmscan.c memcg: add memory.pressure_level events 2013-04-29 15:54:38 -07:00
vmstat.c mm: remove CONFIG_HOTPLUG ifdefs 2013-04-29 15:54:37 -07:00