1. 02 1月, 2017 2 次提交
    • A
      USB: gadgetfs: fix unbounded memory allocation bug · faab5098
      Alan Stern 提交于
      Andrey Konovalov reports that fuzz testing with syzkaller causes a
      KASAN warning in gadgetfs:
      
      BUG: KASAN: slab-out-of-bounds in dev_config+0x86f/0x1190 at addr ffff88003c47e160
      Write of size 65537 by task syz-executor0/6356
      CPU: 3 PID: 6356 Comm: syz-executor0 Not tainted 4.9.0-rc7+ #19
      Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
       ffff88003c107ad8 ffffffff81f96aba ffffffff3dc11ef0 1ffff10007820eee
       ffffed0007820ee6 ffff88003dc11f00 0000000041b58ab3 ffffffff8598b4c8
       ffffffff81f96828 ffffffff813fb4a0 ffff88003b6eadc0 ffff88003c107738
      Call Trace:
       [<     inline     >] __dump_stack lib/dump_stack.c:15
       [<ffffffff81f96aba>] dump_stack+0x292/0x398 lib/dump_stack.c:51
       [<ffffffff817e4dec>] kasan_object_err+0x1c/0x70 mm/kasan/report.c:159
       [<     inline     >] print_address_description mm/kasan/report.c:197
       [<ffffffff817e5080>] kasan_report_error+0x1f0/0x4e0 mm/kasan/report.c:286
       [<ffffffff817e5705>] kasan_report+0x35/0x40 mm/kasan/report.c:306
       [<     inline     >] check_memory_region_inline mm/kasan/kasan.c:308
       [<ffffffff817e3fb9>] check_memory_region+0x139/0x190 mm/kasan/kasan.c:315
       [<ffffffff817e4044>] kasan_check_write+0x14/0x20 mm/kasan/kasan.c:326
       [<     inline     >] copy_from_user arch/x86/include/asm/uaccess.h:689
       [<     inline     >] ep0_write drivers/usb/gadget/legacy/inode.c:1135
       [<ffffffff83228caf>] dev_config+0x86f/0x1190 drivers/usb/gadget/legacy/inode.c:1759
       [<ffffffff817fdd55>] __vfs_write+0x5d5/0x760 fs/read_write.c:510
       [<ffffffff817ff650>] vfs_write+0x170/0x4e0 fs/read_write.c:560
       [<     inline     >] SYSC_write fs/read_write.c:607
       [<ffffffff81803a5b>] SyS_write+0xfb/0x230 fs/read_write.c:599
       [<ffffffff84f47ec1>] entry_SYSCALL_64_fastpath+0x1f/0xc2
      
      Indeed, there is a comment saying that the value of len is restricted
      to a 16-bit integer, but the code doesn't actually do this.
      
      This patch fixes the warning.  It replaces the comment with a
      computation that forces the amount of data copied from the user in
      ep0_write() to be no larger than the wLength size for the control
      transfer, which is a 16-bit quantity.
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Reported-by: NAndrey Konovalov <andreyknvl@google.com>
      Tested-by: NAndrey Konovalov <andreyknvl@google.com>
      CC: <stable@vger.kernel.org>
      Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
      faab5098
    • G
      usb: gadgetfs: restrict upper bound on device configuration size · 0994b0a2
      Greg Kroah-Hartman 提交于
      Andrey Konovalov reported that we were not properly checking the upper
      limit before of a device configuration size before calling
      memdup_user(), which could cause some problems.
      
      So set the upper limit to PAGE_SIZE * 4, which should be good enough for
      all devices.
      Reported-by: NAndrey Konovalov <andreyknvl@google.com>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
      0994b0a2
  2. 25 12月, 2016 1 次提交
  3. 06 12月, 2016 1 次提交
    • A
      [iov_iter] new primitives - copy_from_iter_full() and friends · cbbd26b8
      Al Viro 提交于
      copy_from_iter_full(), copy_from_iter_full_nocache() and
      csum_and_copy_from_iter_full() - counterparts of copy_from_iter()
      et.al., advancing iterator only in case of successful full copy
      and returning whether it had been successful or not.
      
      Convert some obvious users.  *NOTE* - do not blindly assume that
      something is a good candidate for those unless you are sure that
      not advancing iov_iter in failure case is the right thing in
      this case.  Anything that does short read/short write kind of
      stuff (or is in a loop, etc.) is unlikely to be a good one.
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      cbbd26b8
  4. 28 9月, 2016 1 次提交
  5. 11 8月, 2016 2 次提交
  6. 31 5月, 2016 1 次提交
    • B
      usb: gadget: fix spinlock dead lock in gadgetfs · d246dcb2
      Bin Liu 提交于
      [   40.467381] =============================================
      [   40.473013] [ INFO: possible recursive locking detected ]
      [   40.478651] 4.6.0-08691-g7f3db9a #37 Not tainted
      [   40.483466] ---------------------------------------------
      [   40.489098] usb/733 is trying to acquire lock:
      [   40.493734]  (&(&dev->lock)->rlock){-.....}, at: [<bf129288>] ep0_complete+0x18/0xdc [gadgetfs]
      [   40.502882]
      [   40.502882] but task is already holding lock:
      [   40.508967]  (&(&dev->lock)->rlock){-.....}, at: [<bf12a420>] ep0_read+0x20/0x5e0 [gadgetfs]
      [   40.517811]
      [   40.517811] other info that might help us debug this:
      [   40.524623]  Possible unsafe locking scenario:
      [   40.524623]
      [   40.530798]        CPU0
      [   40.533346]        ----
      [   40.535894]   lock(&(&dev->lock)->rlock);
      [   40.540088]   lock(&(&dev->lock)->rlock);
      [   40.544284]
      [   40.544284]  *** DEADLOCK ***
      [   40.544284]
      [   40.550461]  May be due to missing lock nesting notation
      [   40.550461]
      [   40.557544] 2 locks held by usb/733:
      [   40.561271]  #0:  (&f->f_pos_lock){+.+.+.}, at: [<c02a6114>] __fdget_pos+0x40/0x48
      [   40.569219]  #1:  (&(&dev->lock)->rlock){-.....}, at: [<bf12a420>] ep0_read+0x20/0x5e0 [gadgetfs]
      [   40.578523]
      [   40.578523] stack backtrace:
      [   40.583075] CPU: 0 PID: 733 Comm: usb Not tainted 4.6.0-08691-g7f3db9a #37
      [   40.590246] Hardware name: Generic AM33XX (Flattened Device Tree)
      [   40.596625] [<c010ffbc>] (unwind_backtrace) from [<c010c1bc>] (show_stack+0x10/0x14)
      [   40.604718] [<c010c1bc>] (show_stack) from [<c04207fc>] (dump_stack+0xb0/0xe4)
      [   40.612267] [<c04207fc>] (dump_stack) from [<c01886ec>] (__lock_acquire+0xf68/0x1994)
      [   40.620440] [<c01886ec>] (__lock_acquire) from [<c0189528>] (lock_acquire+0xd8/0x238)
      [   40.628621] [<c0189528>] (lock_acquire) from [<c06ad6b4>] (_raw_spin_lock_irqsave+0x38/0x4c)
      [   40.637440] [<c06ad6b4>] (_raw_spin_lock_irqsave) from [<bf129288>] (ep0_complete+0x18/0xdc [gadgetfs])
      [   40.647339] [<bf129288>] (ep0_complete [gadgetfs]) from [<bf10a728>] (musb_g_giveback+0x118/0x1b0 [musb_hdrc])
      [   40.657842] [<bf10a728>] (musb_g_giveback [musb_hdrc]) from [<bf108768>] (musb_g_ep0_queue+0x16c/0x188 [musb_hdrc])
      [   40.668772] [<bf108768>] (musb_g_ep0_queue [musb_hdrc]) from [<bf12a944>] (ep0_read+0x544/0x5e0 [gadgetfs])
      [   40.678963] [<bf12a944>] (ep0_read [gadgetfs]) from [<c0284470>] (__vfs_read+0x20/0x110)
      [   40.687414] [<c0284470>] (__vfs_read) from [<c0285324>] (vfs_read+0x88/0x114)
      [   40.694864] [<c0285324>] (vfs_read) from [<c0286150>] (SyS_read+0x44/0x9c)
      [   40.702051] [<c0286150>] (SyS_read) from [<c0107820>] (ret_fast_syscall+0x0/0x1c)
      
      This is caused by the spinlock bug in ep0_read().
      Fix the two other deadlock sources in gadgetfs_setup() too.
      
      Cc: <stable@vger.kernel.org> # v3.16+
      Signed-off-by: NBin Liu <b-liu@ti.com>
      Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
      d246dcb2
  7. 05 4月, 2016 1 次提交
    • K
      mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros · 09cbfeaf
      Kirill A. Shutemov 提交于
      PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
      ago with promise that one day it will be possible to implement page
      cache with bigger chunks than PAGE_SIZE.
      
      This promise never materialized.  And unlikely will.
      
      We have many places where PAGE_CACHE_SIZE assumed to be equal to
      PAGE_SIZE.  And it's constant source of confusion on whether
      PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
      especially on the border between fs and mm.
      
      Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
      breakage to be doable.
      
      Let's stop pretending that pages in page cache are special.  They are
      not.
      
      The changes are pretty straight-forward:
      
       - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
      
       - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
      
       - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
      
       - page_cache_get() -> get_page();
      
       - page_cache_release() -> put_page();
      
      This patch contains automated changes generated with coccinelle using
      script below.  For some reason, coccinelle doesn't patch header files.
      I've called spatch for them manually.
      
      The only adjustment after coccinelle is revert of changes to
      PAGE_CAHCE_ALIGN definition: we are going to drop it later.
      
      There are few places in the code where coccinelle didn't reach.  I'll
      fix them manually in a separate patch.  Comments and documentation also
      will be addressed with the separate patch.
      
      virtual patch
      
      @@
      expression E;
      @@
      - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
      + E
      
      @@
      expression E;
      @@
      - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
      + E
      
      @@
      @@
      - PAGE_CACHE_SHIFT
      + PAGE_SHIFT
      
      @@
      @@
      - PAGE_CACHE_SIZE
      + PAGE_SIZE
      
      @@
      @@
      - PAGE_CACHE_MASK
      + PAGE_MASK
      
      @@
      expression E;
      @@
      - PAGE_CACHE_ALIGN(E)
      + PAGE_ALIGN(E)
      
      @@
      expression E;
      @@
      - page_cache_get(E)
      + get_page(E)
      
      @@
      expression E;
      @@
      - page_cache_release(E)
      + put_page(E)
      Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Acked-by: NMichal Hocko <mhocko@suse.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      09cbfeaf
  8. 04 3月, 2016 1 次提交
  9. 23 2月, 2016 1 次提交
  10. 23 1月, 2016 1 次提交
    • A
      wrappers for ->i_mutex access · 5955102c
      Al Viro 提交于
      parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
      inode_foo(inode) being mutex_foo(&inode->i_mutex).
      
      Please, use those for access to ->i_mutex; over the coming cycle
      ->i_mutex will become rwsem, with ->lookup() done with it held
      only shared.
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      5955102c
  11. 17 12月, 2015 1 次提交
  12. 10 5月, 2015 1 次提交
  13. 16 4月, 2015 1 次提交
  14. 12 4月, 2015 1 次提交
  15. 26 3月, 2015 1 次提交
  16. 14 3月, 2015 1 次提交
    • C
      fs: split generic and aio kiocb · 04b2fa9f
      Christoph Hellwig 提交于
      Most callers in the kernel want to perform synchronous file I/O, but
      still have to bloat the stack with a full struct kiocb.  Split out
      the parts needed in filesystem code from those in the aio code, and
      only allocate those needed to pass down argument on the stack.  The
      aio code embedds the generic iocb in the one it allocates and can
      easily get back to it by using container_of.
      
      Also add a ->ki_complete method to struct kiocb, this is used to call
      into the aio code and thus removes the dependency on aio for filesystems
      impementing asynchronous operations.  It will also allow other callers
      to substitute their own completion callback.
      
      We also add a new ->ki_flags field to work around the nasty layering
      violation recently introduced in commit 5e33f6 ("usb: gadget: ffs: add
      eventfd notification about ffs events").
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      04b2fa9f
  17. 09 3月, 2015 2 次提交
    • A
      gadgetfs: really get rid of switching ->f_op · 96b62a57
      Alan Stern 提交于
      ... for ep0 as well
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      96b62a57
    • A
      gadgetfs: get rid of flipping ->f_op in ep_config() · d4461a60
      Al Viro 提交于
      Final methods start with get_ready_ep(), which will fail unless we have
      ->state == STATE_EP_ENABLED.  So they'd be failing just fine until that
      first write() anyway.  Let's do the following:
      	* get_ready_ep() gets a new argument - true when called from
      ep_write_iter(), false otherwise.
      	* make it quiet when it finds STATE_EP_READY (no printk, that is;
      the case won't be impossible after that change).
      	* when that new argument is true, treat STATE_EP_READY the same
      way as STATE_EP_ENABLED (i.e. return zero and do not unlock).
      	* in ep_write_iter(), after success of get_ready_ep() turn
      	if (!usb_endpoint_dir_in(&epdata->desc)) {
      into
      	if (epdata->state == STATE_EP_ENABLED &&
      	    !usb_endpoint_dir_in(&epdata->desc)) {
      - that logics only applies after config.
      	* have ep_config() take kernel-side buffer (i.e. use memcpy()
      instead of copy_from_user() in there) and in the "let's call ep_io or
      ep_aio" (again, in ep_write_iter()) add "... or ep_config() in case it's
      not configured yet"
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      d4461a60
  18. 18 2月, 2015 2 次提交
  19. 10 1月, 2015 1 次提交
  20. 23 12月, 2014 1 次提交
  21. 09 10月, 2014 1 次提交
  22. 09 9月, 2014 1 次提交
  23. 19 8月, 2014 1 次提交
  24. 17 7月, 2014 1 次提交
  25. 19 6月, 2014 1 次提交
  26. 28 5月, 2014 1 次提交
  27. 13 5月, 2014 1 次提交
  28. 16 4月, 2014 1 次提交
    • L
      usb: gadget: gadgetfs: Initialize CHIP to NULL before UDC probe · 5cdf7d5b
      Lubomir Rintel 提交于
      Otherwise the value from the last probe would be retained that possibly is
      freed since (the UDC is removed) and therefore no longer relevant. Reproducible
      with the dummy UDC:
      
        modprobe dummy_hcd
        mount -t gadgetfs gadgetfs /dev/gadget
        umount /dev/gadget
        rmmod dummy_hcd
        mount -t gadgetfs gadgetfs /dev/gadget
      
      BUG: unable to handle kernel paging request at ffffffffa066fd9d
      Call Trace:
       [<ffffffff811d0cd2>] ? d_alloc_name+0x22/0x50
       [<ffffffff812b74dc>] ? selinux_d_instantiate+0x1c/0x20
       [<ffffffffa067d687>] gadgetfs_create_file+0x27/0xa0 [gadgetfs]
       [<ffffffffa067da70>] ? setup_req.isra.4+0x80/0x80 [gadgetfs]
       [<ffffffffa067dbac>] gadgetfs_fill_super+0x13c/0x180 [gadgetfs]
       [<ffffffff811bc832>] mount_single+0x92/0xc0
       [<ffffffffa067d0f8>] gadgetfs_mount+0x18/0x20 [gadgetfs]
       [<ffffffff811bc8f9>] mount_fs+0x39/0x1b0
       [<ffffffff8116b220>] ? __alloc_percpu+0x10/0x20
       [<ffffffff811d6da3>] vfs_kern_mount+0x63/0xf0
       [<ffffffff811d93be>] do_mount+0x23e/0xac0
       [<ffffffff811660eb>] ? strndup_user+0x4b/0xf0
       [<ffffffff811d9f63>] SyS_mount+0x83/0xc0
       [<ffffffff81695b69>] system_call_fastpath+0x16/0x1b
      Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
      Signed-off-by: NFelipe Balbi <balbi@ti.com>
      5cdf7d5b
  29. 18 3月, 2014 1 次提交
  30. 28 8月, 2013 1 次提交
  31. 30 7月, 2013 2 次提交
    • K
      aio: Kill aio_rw_vect_retry() · 73a7075e
      Kent Overstreet 提交于
      This code doesn't serve any purpose anymore, since the aio retry
      infrastructure has been removed.
      
      This change should be safe because aio_read/write are also used for
      synchronous IO, and called from do_sync_read()/do_sync_write() - and
      there's no looping done in the sync case (the read and write syscalls).
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>
      73a7075e
    • K
      aio: io_cancel() no longer returns the io_event · bec68faa
      Kent Overstreet 提交于
      Originally, io_event() was documented to return the io_event if
      cancellation succeeded - the io_event wouldn't be delivered via the ring
      buffer like it normally would.
      
      But this isn't what the implementation was actually doing; the only
      driver implementing cancellation, the usb gadget code, never returned an
      io_event in its cancel function. And aio_complete() was recently changed
      to no longer suppress event delivery if the kiocb had been cancelled.
      
      This gets rid of the unused io_event argument to kiocb_cancel() and
      kiocb->ki_cancel(), and changes io_cancel() to return -EINPROGRESS if
      kiocb->ki_cancel() returned success.
      
      Also tweak the refcounting in kiocb_cancel() to make more sense.
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>
      bec68faa
  32. 08 5月, 2013 3 次提交
    • K
      aio: use cancellation list lazily · 0460fef2
      Kent Overstreet 提交于
      Cancelling kiocbs requires adding them to a per kioctx linked list,
      which is one of the few things we need to take the kioctx lock for in
      the fast path.  But most kiocbs can't be cancelled - so if we just do
      this lazily, we can avoid quite a bit of locking overhead.
      
      While we're at it, instead of using a flag bit switch to using ki_cancel
      itself to indicate that a kiocb has been cancelled/completed.  This lets
      us get rid of ki_flags entirely.
      
      [akpm@linux-foundation.org: remove buggy BUG()]
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0460fef2
    • K
      aio: move private stuff out of aio.h · 4e179bca
      Kent Overstreet 提交于
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Zach Brown <zab@redhat.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Acked-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4e179bca
    • Z
      gadget: remove only user of aio retry · a80bf61e
      Zach Brown 提交于
      This removes the only in-tree user of aio retry.  This will let us
      remove the retry code from the aio core.
      
      Removing retry is relatively easy as the USB gadget wasn't using it to
      retry IOs at all.  It always fully submitted the IO in the context of
      the initial io_submit() call.  It only used the AIO retry facility to
      get the submitter's mm context for copying the result of a read back to
      user space.  This is easy to implement with use_mm() and a work struct,
      much like kvm does with async_pf_execute() for get_user_pages().
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NZach Brown <zab@redhat.com>
      Signed-off-by: NKent Overstreet <koverstreet@google.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Mark Fasheh <mfasheh@suse.com>
      Cc: Joel Becker <jlbec@evilplan.org>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Jens Axboe <axboe@kernel.dk>
      Cc: Asai Thambi S P <asamymuthupa@micron.com>
      Cc: Selvan Mani <smani@micron.com>
      Cc: Sam Bradshaw <sbradshaw@micron.com>
      Acked-by: NJeff Moyer <jmoyer@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Benjamin LaHaise <bcrl@kvack.org>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a80bf61e
  33. 10 4月, 2013 1 次提交