linux/mm
Dmitry Safonov b059a453b1 x86/vdso: Add mremap hook to vm_special_mapping
Add possibility for 32-bit user-space applications to move
the vDSO mapping.

Previously, when a user-space app called mremap() for the vDSO
address, in the syscall return path it would land on the previous
address of the vDSOpage, resulting in segmentation violation.

Now it lands fine and returns to userspace with a remapped vDSO.

This will also fix the context.vdso pointer for 64-bit, which does
not affect the user of vDSO after mremap() currently, but this
may change in the future.

As suggested by Andy, return -EINVAL for mremap() that would
split the vDSO image: that operation cannot possibly result in
a working system so reject it.

Renamed and moved the text_mapping structure declaration inside
map_vdso(), as it used only there and now it complements the
vvar_mapping variable.

There is still a problem for remapping the vDSO in glibc
applications: the linker relocates addresses for syscalls
on the vDSO page, so you need to relink with the new
addresses.

Without that the next syscall through glibc may fail:

  Program received signal SIGSEGV, Segmentation fault.
  #0  0xf7fd9b80 in __kernel_vsyscall ()
  #1  0xf7ec8238 in _exit () from /usr/lib32/libc.so.6

Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: 0x7f454c46@gmail.com
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160628113539.13606-2-dsafonov@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-08 14:17:51 +02:00
..
kasan mm: mempool: kasan: don't poot mempool objects in quarantine 2016-06-24 17:23:52 -07:00
backing-dev.c mm: throttle on IO only when there are too many dirty and writeback pages 2016-05-20 17:58:30 -07:00
balloon_compaction.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2016-03-17 21:38:27 -07:00
bootmem.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
cleancache.c cleancache: constify cleancache_ops structure 2016-01-27 09:09:57 -05:00
cma_debug.c
cma.c mm/cma: silence warnings due to max() usage 2016-05-27 14:49:37 -07:00
cma.h
compaction.c mm, compaction: abort free scanner if split fails 2016-06-24 17:23:52 -07:00
debug_page_ref.c mm/page_ref: add tracepoint to track down page reference manipulation 2016-03-17 15:09:34 -07:00
debug.c mm: introduce page reference manipulation functions 2016-03-17 15:09:34 -07:00
dmapool.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
early_ioremap.c
fadvise.c mm/fadvise.c: do not discard partial pages with POSIX_FADV_DONTNEED 2016-06-09 14:23:11 -07:00
failslab.c mm: fault-inject take over bootstrap kmem_cache check 2016-03-15 16:55:16 -07:00
filemap.c Revert "mm: make faultaround produce old ptes" 2016-06-24 17:23:52 -07:00
frame_vector.c mm/gup: Switch all callers of get_user_pages() to not pass tsk/mm 2016-02-16 10:11:12 +01:00
frontswap.c
gup.c Merge branch 'mm-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-04-14 19:31:34 -07:00
highmem.c mm/highmem: make nr_free_highpages() handles all highmem zones by itself 2016-05-19 19:12:14 -07:00
huge_memory.c libnvdimm for 4.7 2016-05-23 11:18:01 -07:00
hugetlb_cgroup.c mm, hugetlb_cgroup: round limit_in_bytes down to hugepage size 2016-05-20 17:58:30 -07:00
hugetlb.c mm/hugetlb: clear compound_mapcount when freeing gigantic pages 2016-06-24 17:23:52 -07:00
hwpoison-inject.c
init-mm.c
internal.h mm, sl[au]b: add __GFP_ATOMIC to the GFP reclaim mask 2016-06-24 17:23:52 -07:00
interval_tree.c
Kconfig mm: disable DEFERRED_STRUCT_PAGE_INIT on !NO_BOOTMEM 2016-05-27 14:49:37 -07:00
Kconfig.debug mm/page_ref: add tracepoint to track down page reference manipulation 2016-03-17 15:09:34 -07:00
kmemcheck.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
kmemleak-test.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
kmemleak.c mm: prevent KASAN false positives in kmemleak 2016-06-24 17:23:52 -07:00
ksm.c ksm: fix conflict between mmput and scan_get_next_rmap_item 2016-05-12 15:52:50 -07:00
list_lru.c mm: memcontrol: move kmem accounting code to CONFIG_MEMCG 2016-01-20 17:09:18 -08:00
maccess.c x86: remove more uaccess_32.h complexity 2016-05-22 17:21:27 -07:00
madvise.c mm: make mmap_sem for write waits killable for mm syscalls 2016-05-23 17:04:14 -07:00
Makefile z3fold: the 3-fold allocator for compressed pages 2016-05-20 17:58:30 -07:00
memblock.c mm/memblock.c: remove unnecessary always-true comparison 2016-05-20 17:58:30 -07:00
memcontrol.c memcg: css_alloc should return an ERR_PTR value on error 2016-06-24 17:23:52 -07:00
memory_hotplug.c mm: fix section mismatch warning 2016-05-27 15:23:32 -07:00
memory-failure.c mm/memory-failure.c: replace "MCE" with "Memory failure" 2016-05-20 17:58:30 -07:00
memory.c Revert "mm: disable fault around on emulated access bit architecture" 2016-06-24 17:23:52 -07:00
mempolicy.c mm, page_alloc: avoid looking up the first zone in a zonelist twice 2016-05-19 19:12:14 -07:00
mempool.c mm: mempool: kasan: don't poot mempool objects in quarantine 2016-06-24 17:23:52 -07:00
memtest.c
migrate.c mm: Export migrate_page_move_mapping and migrate_page_copy 2016-06-23 00:29:45 +02:00
mincore.c mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage 2016-04-04 10:41:08 -07:00
mlock.c mm: make mmap_sem for write waits killable for mm syscalls 2016-05-23 17:04:14 -07:00
mm_init.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
mmap.c x86/vdso: Add mremap hook to vm_special_mapping 2016-07-08 14:17:51 +02:00
mmu_context.c mm/mmu_context, sched/core: Fix mmu_context.h assumption 2016-04-28 11:44:19 +02:00
mmu_notifier.c fix Christoph's email addresses 2016-03-17 15:09:34 -07:00
mmzone.c mm, page_alloc: inline the fast path of the zonelist iterator 2016-05-19 19:12:14 -07:00
mprotect.c mm: make mmap_sem for write waits killable for mm syscalls 2016-05-23 17:04:14 -07:00
mremap.c mm: make mmap_sem for write waits killable for mm syscalls 2016-05-23 17:04:14 -07:00
msync.c
nobootmem.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
nommu.c mm: remove more IS_ERR_VALUE abuses 2016-05-27 15:57:31 -07:00
oom_kill.c oom_reaper: avoid pointless atomic_inc_not_zero usage. 2016-06-24 17:23:52 -07:00
page_alloc.c mm, page_alloc: recalculate the preferred zoneref if the context can ignore memory policies 2016-06-03 16:02:57 -07:00
page_counter.c
page_ext.c mm: use early_pfn_to_nid in page_ext_init 2016-05-27 14:49:37 -07:00
page_idle.c
page_io.c Merge branch 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-17 15:05:23 -07:00
page_isolation.c mm/memory_hotplug: add comment to some functions related to memory hotplug 2016-05-19 19:12:14 -07:00
page_owner.c mm/page_owner: avoid null pointer dereference 2016-06-24 17:23:52 -07:00
page_poison.c mm: check the return value of lookup_page_ext for all call sites 2016-06-03 15:06:22 -07:00
page-writeback.c writeback: use higher precision calculation in domain_dirty_limits() 2016-05-30 08:54:40 -06:00
pagewalk.c
percpu-km.c mm: percpu: use pr_fmt to prefix output 2016-03-17 15:09:34 -07:00
percpu-vm.c
percpu.c percpu: fix synchronization between synchronous map extension and chunk destruction 2016-05-25 11:48:25 -04:00
pgtable-generic.c mm/thp/migration: switch from flush_tlb_range to flush_pmd_tlb_range 2016-03-17 15:09:34 -07:00
process_vm_access.c mm/gup: Introduce get_user_pages_remote() 2016-02-16 10:04:09 +01:00
quicklist.c fix Christoph's email addresses 2016-03-17 15:09:34 -07:00
readahead.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
rmap.c mm: thp: avoid false positive VM_BUG_ON_PAGE in page_move_anon_rmap() 2016-05-27 14:49:37 -07:00
shmem.c tmpfs: don't undo fallocate past its last page 2016-06-24 17:23:52 -07:00
slab_common.c mm: kasan: initial memory quarantine implementation 2016-05-20 17:58:30 -07:00
slab.c mm, kasan: don't call kasan_krealloc() from ksize(). 2016-05-20 17:58:30 -07:00
slab.h mm: kasan: initial memory quarantine implementation 2016-05-20 17:58:30 -07:00
slob.c mm: slab: free kmem_cache_node after destroy sysfs file 2016-02-18 16:23:24 -08:00
slub.c mm, kasan: don't call kasan_krealloc() from ksize(). 2016-05-20 17:58:30 -07:00
sparse-vmemmap.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
sparse.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
swap_cgroup.c mm: convert printk(KERN_<LEVEL> to pr_<level> 2016-03-17 15:09:34 -07:00
swap_state.c mm: thp: broken page count after commit aa88b68c3b 2016-06-09 14:23:11 -07:00
swap.c mm/swap.c: flush lru pvecs on compound page arrival 2016-06-24 17:23:52 -07:00
swapfile.c mm: thp: calculate the mapcount correctly for THP pages during WP faults 2016-05-12 15:52:50 -07:00
truncate.c dax: New fault locking 2016-05-19 15:20:54 -06:00
userfaultfd.c mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros 2016-04-04 10:41:08 -07:00
util.c mm: make vm_mmap killable 2016-05-23 17:04:14 -07:00
vmacache.c
vmalloc.c mm: fix overflow in vm_map_ram() 2016-06-03 15:06:22 -07:00
vmpressure.c mm/vmpressure.c: fix subtree pressure detection 2016-02-03 08:28:43 -08:00
vmscan.c mm, oom: rework oom detection 2016-05-20 17:58:30 -07:00
vmstat.c mm: check the return value of lookup_page_ext for all call sites 2016-06-03 15:06:22 -07:00
workingset.c mm: workingset: make shadow node shrinker memcg aware 2016-03-17 15:09:34 -07:00
z3fold.c mm/z3fold.c: avoid modifying HEADLESS page and minor cleanup 2016-06-03 16:02:55 -07:00
zbud.c
zpool.c
zsmalloc.c update "mm/zsmalloc: don't fail if can't create debugfs info" 2016-05-26 15:35:44 -07:00
zswap.c mm/zswap: use workqueue to destroy pool 2016-05-20 17:58:30 -07:00