linux-toradex.git/mm/madvise.c, branch v3.10.34

mm: madvise: complete input validation before taking lock

2013-04-29T22:54:37+00:00

In madvise(), there doesn't seem to be any reason for taking the
¤t->mm->mmap_sem before start and len_in have been validated.
Incidentally, this removes the need for the out: label.

[akpm@linux-foundation.org: s/out_plug/out/, per David]
Signed-off-by: Rasmus Villemoes 
Acked-by: KOSAKI Motohiro 
Acked-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: make madvise(MADV_WILLNEED) support swap file prefetch

2013-02-24T01:50:10+00:00

Make madvise(MADV_WILLNEED) support swap file prefetch.  If memory is
swapout, this syscall can do swapin prefetch.  It has no impact if the
memory isn't swapout.

[akpm@linux-foundation.org: fix CONFIG_SWAP=n build]
[sasha.levin@oracle.com: fix BUG on madvise early failure]
Signed-off-by: Shaohua Li 
Cc: Hugh Dickins 
Cc: Rik van Riel 
Signed-off-by: Sasha Levin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: prepare VM_DONTDUMP for using in drivers

2012-10-09T07:22:18+00:00

Rename VM_NODUMP into VM_DONTDUMP: this name matches other negative flags:
VM_DONTEXPAND, VM_DONTCOPY.  Currently this flag used only for
sys_madvise.  The next patch will use it for replacing the outdated flag
VM_RESERVED.

Also forbid madvise(MADV_DODUMP) for special kernel mappings VM_SPECIAL
(VM_IO | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP)

Signed-off-by: Konstantin Khlebnikov 
Cc: Alexander Viro 
Cc: Carsten Otte 
Cc: Chris Metcalf 
Cc: Cyrill Gorcunov 
Cc: Eric Paris 
Cc: H. Peter Anvin 
Cc: Hugh Dickins 
Cc: Ingo Molnar 
Cc: James Morris 
Cc: Jason Baron 
Cc: Kentaro Takeda 
Cc: Matt Helsley 
Cc: Nick Piggin 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Robert Richter 
Cc: Suresh Siddha 
Cc: Tetsuo Handa 
Cc: Venkatesh Pallipadi 
Acked-by: Linus Torvalds 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: Hold a file reference in madvise_remove

2012-07-06T17:34:38+00:00

Otherwise the code races with munmap (causing a use-after-free
of the vma) or with close (causing a use-after-free of the struct
file).

The bug was introduced by commit 90ed52ebe481 ("[PATCH] holepunch: fix
mmap_sem i_mutex deadlock")

Cc: Hugh Dickins 
Cc: Miklos Szeredi 
Cc: Badari Pulavarty 
Cc: Nick Piggin 
Cc: stable@vger.kernel.org
Signed-off-by: Andy Lutomirski 
Signed-off-by: Linus Torvalds

mm/fs: route MADV_REMOVE to FALLOC_FL_PUNCH_HOLE

2012-05-29T23:22:22+00:00

Now tmpfs supports hole-punching via fallocate(), switch madvise_remove()
to use do_fallocate() instead of vmtruncate_range(): which extends
madvise(,,MADV_REMOVE) support from tmpfs to ext4, ocfs2 and xfs.

There is one more user of vmtruncate_range() in our tree,
staging/android's ashmem_shrink(): convert it to use do_fallocate() too
(but if its unpinned areas are already unmapped - I don't know - then it
would do better to use shmem_truncate_range() directly).

Based-on-patch-by: Cong Wang 
Signed-off-by: Hugh Dickins 
Cc: Christoph Hellwig 
Cc: Al Viro 
Cc: Colin Cross 
Cc: John Stultz 
Cc: Greg Kroah-Hartman 
Cc: "Theodore Ts'o" 
Cc: Andreas Dilger 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Dave Chinner 
Cc: Ben Myers 
Cc: Michael Kerrisk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

coredump: add VM_NODUMP, MADV_NODUMP, MADV_CLEAR_NODUMP

2012-03-23T23:58:42+00:00

Since we no longer need the VM_ALWAYSDUMP flag, let's use the freed bit
for 'VM_NODUMP' flag.  The idea is is to add a new madvise() flag:
MADV_DONTDUMP, which can be set by applications to specifically request
memory regions which should not dump core.

The specific application I have in mind is qemu: we can add a flag there
that wouldn't dump all of guest memory when qemu dumps core.  This flag
might also be useful for security sensitive apps that want to absolutely
make sure that parts of memory are not dumped.  To clear the flag use:
MADV_DODUMP.

[akpm@linux-foundation.org: s/MADV_NODUMP/MADV_DONTDUMP/, s/MADV_CLEAR_NODUMP/MADV_DODUMP/, per Roland]
[akpm@linux-foundation.org: fix up the architectures which broke]
Signed-off-by: Jason Baron 
Acked-by: Roland McGrath 
Cc: Chris Metcalf 
Cc: Avi Kivity 
Cc: Ralf Baechle 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Cc: Matt Turner 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

HWPOISON: Clean up memory_failure() vs. __memory_failure()

2012-01-03T20:06:32+00:00

There is only one caller of memory_failure(), all other users call
__memory_failure() and pass in the flags argument explicitly. The
lone user of memory_failure() will soon need to pass flags too.

Add flags argument to the callsite in mce.c. Delete the old memory_failure()
function, and then rename __memory_failure() without the leading "__".

Provide clearer message when action optional memory errors are ignored.

Acked-by: Borislav Petkov 
Signed-off-by: Tony Luck

fs: kill i_alloc_sem

2011-07-21T00:47:46+00:00

i_alloc_sem is a rather special rw_semaphore.  It's the last one that may
be released by a non-owner, and it's write side is always mirrored by
real exclusion.  It's intended use it to wait for all pending direct I/O
requests to finish before starting a truncate.

Replace it with a hand-grown construct:

 - exclusion for truncates is already guaranteed by i_mutex, so it can
   simply fall way
 - the reader side is replaced by an i_dio_count member in struct inode
   that counts the number of pending direct I/O requests.  Truncate can't
   proceed as long as it's non-zero
 - when i_dio_count reaches non-zero we wake up a pending truncate using
   wake_up_bit on a new bit in i_flags
 - new references to i_dio_count can't appear while we are waiting for
   it to read zero because the direct I/O count always needs i_mutex
   (or an equivalent like XFS's i_iolock) for starting a new operation.

This scheme is much simpler, and saves the space of a spinlock_t and a
struct list_head in struct inode (typically 160 bits on a non-debug 64-bit
system).

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

thp: khugepaged: make khugepaged aware about madvise

2011-01-14T01:32:47+00:00

MADV_HUGEPAGE and MADV_NOHUGEPAGE were fully effective only if run after
mmap and before touching the memory.  While this is enough for most
usages, it's little effort to make madvise more dynamic at runtime on an
existing mapping by making khugepaged aware about madvise.

MADV_HUGEPAGE: register in khugepaged immediately without waiting a page
fault (that may not ever happen if all pages are already mapped and the
"enabled" knob was set to madvise during the initial page faults).

MADV_NOHUGEPAGE: skip vmas marked VM_NOHUGEPAGE in khugepaged to stop
collapsing pages where not needed.

[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Andrea Arcangeli 
Cc: Michael Kerrisk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

thp: madvise(MADV_NOHUGEPAGE)

2011-01-14T01:32:47+00:00

Add madvise MADV_NOHUGEPAGE to mark regions that are not important to be
hugepage backed.  Return -EINVAL if the vma is not of an anonymous type,
or the feature isn't built into the kernel.  Never silently return
success.

Signed-off-by: Andrea Arcangeli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds