Commit Graph

310457 Commits

Author SHA1 Message Date
Miklos Szeredi
050ac841ea vfs: do_last(): only return EISDIR for O_CREAT
This allows this code to be shared between O_CREAT and plain opens.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:11:59 -04:00
Miklos Szeredi
af2f55426d vfs: do_last(): check LOOKUP_DIRECTORY
Check for ENOTDIR before finishing open.  This allows this code to be shared
between O_CREAT and plain opens.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:11:58 -04:00
Miklos Szeredi
54c33e7f95 vfs: do_last(): make ENOENT exit RCU safe
This will allow this code to be used in RCU mode.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:11:58 -04:00
Miklos Szeredi
d45ea86792 vfs: make follow_link check RCU safe
This will allow this code to be used in RCU mode.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:11:58 -04:00
Miklos Szeredi
decf340087 vfs: do_last(): use inode variable
Use helper variable instead of path->dentry->d_inode before complete_walk().
This will allow this code to be used in RCU mode.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:11:57 -04:00
Miklos Szeredi
a1eb331530 vfs: do_last(): inline walk_component()
Copy walk_component() into do_lookup().

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:11:57 -04:00
Miklos Szeredi
e276ae672f vfs: do_last(): make exit RCU safe
Allow returning from do_last() with LOOKUP_RCU still set on the "out:" and
"exit:" labels.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:11:57 -04:00
Miklos Szeredi
697f514df1 vfs: split do_lookup()
Split do_lookup() into two functions:

  lookup_fast() - does cached lookup without i_mutex
  lookup_slow() - does lookup with i_mutex

Both follow managed dentries.

The new functions are needed by atomic_open.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:11:56 -04:00
Matt Fleming
0c7596621e x86, efi: Add EFI boot stub documentation
Since we can't expect every user to read the EFI boot stub code it
seems prudent to have a couple of paragraphs explaining what it is and
how it works.

The "initrd=" option in particular is tricky because it only
understands absolute EFI-style paths (backslashes as directory
separators), and until now this hasn't been documented anywhere. This
has tripped up a couple of users.

Cc: Matthew Garrett <mjg@redhat.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1331907517-3985-4-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-06-01 09:11:41 -07:00
Matt Fleming
9fa7dedad3 x86, efi; Add EFI boot stub console support
We need a way of printing useful messages to the user, for example
when we fail to open an initrd file, instead of just hanging the
machine without giving the user any indication of what went wrong. So
sprinkle some error messages throughout the EFI boot stub code to make
it easier for users to diagnose/report problems.

Reported-by: Keshav P R <the.ridikulus.rat@gmail.com>
Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1331907517-3985-3-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-06-01 09:11:26 -07:00
Matt Fleming
30dc0d0fe5 x86, efi: Only close open files in error path
The loop at the 'close_handles' label in handle_ramdisks() should be
using 'i', which represents the number of initrd files that were
successfully opened, not 'nr_initrds' which is the number of initrd=
arguments passed on the command line.

Currently, if we execute the loop to close all file handles and we
failed to open any initrds we'll try to call the close function on a
garbage pointer, causing the machine to hang.

Cc: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Link: http://lkml.kernel.org/r/1331907517-3985-2-git-send-email-matt@console-pimps.org
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2012-06-01 09:11:10 -07:00
Josef Bacik
e41f941a23 Btrfs: move over to use ->update_time
Btrfs had been doing it's own file_update_time so we could catch ENOSPC
properly, so just update our btrfs_update_time to work with the new stuff and
then we'll be fancy later.  Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-01 12:07:52 -04:00
Josef Bacik
c3b2da3148 fs: introduce inode operation ->update_time
Btrfs has to make sure we have space to allocate new blocks in order to modify
the inode, so updating time can fail.  We've gotten around this by having our
own file_update_time but this is kind of a pain, and Christoph has indicated he
would like to make xfs do something different with atime updates.  So introduce
->update_time, where we will deal with i_version an a/m/c time updates and
indicate which changes need to be made.  The normal version just does what it
has always done, updates the time and marks the inode dirty, and then
filesystems can choose to do something different.

I've gone through all of the users of file_update_time and made them check for
errors with the exception of the fault code since it's complicated and I wasn't
quite sure what to do there, also Jan is going to be pushing the file time
updates into page_mkwrite for those who have it so that should satisfy btrfs and
make it not a big deal to check the file_update_time() return code in the
generic fault path. Thanks,

Signed-off-by: Josef Bacik <josef@redhat.com>
2012-06-01 12:07:25 -04:00
Adam Jackson
47819ba234 drm/edid: Make the header fixup threshold tunable
6 bytes seems to be a reasonable default so far, but for the desperate
it's worth exposing this.

[airlied: change include to module.h for this]

Bugzilla: https://bugzilla.redhat.com/582559
Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-06-01 17:00:23 +01:00
Alex Deucher
9b00147d9f drm/radeon: fix regression in UMS CS ioctl
radeon_cs_parser_init is called by both the legacy UMS
CS ioctl and the KMS CS ioctl.  Protect KMS specific
pieces of the code by checking that rdev is not NULL.

Reported-by: Michael Burian <michael.burian@sbg.at>

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-06-01 17:00:21 +01:00
Thomas Hellstrom
0824db38e5 drm/vmwgfx: Fix nasty write past alloced memory area
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-06-01 17:00:20 +01:00
Thomas Hellstrom
a8ff3ee211 drm/ttm: Fix spinlock imbalance
This imbalance may cause hangs when TTM is trying to swap out a buffer
that is already on the delayed delete list.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-06-01 17:00:19 +01:00
Alex Deucher
416a2bd274 drm/radeon: fixup tiling group size and backendmap on r6xx-r9xx (v4)
Tiling group size is always 256bits on r6xx/r7xx/r8xx/9xx. Also fix and
simplify render backend map. This now properly sets up the backend map
on r6xx-9xx which should improve 3D performance.

Vadim benchmarked also:
Some benchmarks on juniper (5750), fullscreen 1920x1080,
first result - kernel 3.4.0+ (fb21affa), second - with these patches:

Lightsmark:   91 fps => 123 fps    +35%
Doom3:        74 fps => 101 fps    +36%

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-06-01 17:00:14 +01:00
Linus Torvalds
51eab603f5 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "This includes a fairly large change from Josef around data writeback
  completion.  Before, the writeback wasn't completed until the metadata
  insertions for the extent were done, and this made for fairly large
  latency spikes on the last page of each ordered extent.

  We already had a separate mechanism for tracking pending metadata
  insertions, so Josef just needed to tweak things a little to end
  writeback earlier on the page.  Overall it makes us much friendly to
  memory reclaim and lowers latencies quite a lot for synchronous IO.

  Jan Schmidt has finished some background work required to track btree
  blocks as they go through changes in ownership.  It's the missing
  piece he needed for both btrfs send/receive and subvolume quotas.
  Neither of those are ready yet, but the new tracking code is included
  here.  Most of the time, the new code is off.  It is only used by
  scrub and other backref walkers.

  Stefan Behrens has added io failure tracking.  This includes counters
  for which drives are causing the most trouble so the admin (or an
  automated tool) can choose to kick them out.  We're tracking IO
  errors, crc errors, and generation checks we do on each metadata
  block.

  RAID5/6 did miss the cut this time because I'm having trouble with
  corruptions.  I'll nail it down next week and post as a beta testing
  before 3.6"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (58 commits)
  Btrfs: fix tree mod log rewinded level and rewinding of moved keys
  Btrfs: fix tree mod log del_ptr
  Btrfs: add tree_mod_dont_log helper
  Btrfs: add missing spin_lock for insertion into tree mod log
  Btrfs: add inodes before dropping the extent lock in find_all_leafs
  Btrfs: use delayed ref sequence numbers for all fs-tree updates
  Btrfs: fix false positive in check-integrity on unmount
  Btrfs: fix runtime warning in check-integrity check data mode
  Btrfs: set ioprio of scrub readahead to idle
  Btrfs: fix return code in drop_objectid_items
  Btrfs: check to see if the inode is in the log before fsyncing
  Btrfs: return value of btrfs_read_buffer is checked correctly
  Btrfs: read device stats on mount, write modified ones during commit
  Btrfs: add ioctl to get and reset the device stats
  Btrfs: add device counters for detected IO and checksum errors
  btrfs: Drop unused function btrfs_abort_devices()
  Btrfs: fix the same inode id problem when doing auto defragment
  Btrfs: fall back to non-inline if we don't have enough space
  Btrfs: fix how we deal with the orphan block rsv
  Btrfs: convert the inode bit field to use the actual bit operations
  ...
2012-06-01 08:37:31 -07:00
Linus Torvalds
419f431949 Merge branch 'for-3.5' of git://linux-nfs.org/~bfields/linux
Pull the rest of the nfsd commits from Bruce Fields:
 "... and then I cherry-picked the remainder of the patches from the
  head of my previous branch"

This is the rest of the original nfsd branch, rebased without the
delegation stuff that I thought really needed to be redone.

I don't like rebasing things like this in general, but in this situation
this was the lesser of two evils.

* 'for-3.5' of git://linux-nfs.org/~bfields/linux: (50 commits)
  nfsd4: fix, consolidate client_has_state
  nfsd4: don't remove rebooted client record until confirmation
  nfsd4: remove some dprintk's and a comment
  nfsd4: return "real" sequence id in confirmed case
  nfsd4: fix exchange_id to return confirm flag
  nfsd4: clarify that renewing expired client is a bug
  nfsd4: simpler ordering of setclientid_confirm checks
  nfsd4: setclientid: remove pointless assignment
  nfsd4: fix error return in non-matching-creds case
  nfsd4: fix setclientid_confirm same_cred check
  nfsd4: merge 3 setclientid cases to 2
  nfsd4: pull out common code from setclientid cases
  nfsd4: merge last two setclientid cases
  nfsd4: setclientid/confirm comment cleanup
  nfsd4: setclientid remove unnecessary terms from a logical expression
  nfsd4: move rq_flavor into svc_cred
  nfsd4: stricter cred comparison for setclientid/exchange_id
  nfsd4: move principal name into svc_cred
  nfsd4: allow removing clients not holding state
  nfsd4: rearrange exchange_id logic to simplify
  ...
2012-06-01 08:32:58 -07:00
Matthew Garrett
53039f222c toshiba_acpi: Fix mis-merge
I managed to screw up the various backlight changes and ended up memsetting
the props structure after it had already been populated. This should fix it.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
2012-06-01 11:02:36 -04:00
Jerome Glisse
95c4b23ec4 drm/radeon: fix HD6790, HD6570 backend programming
Without this bit sets we get broken rendering and
lockups.

fglrx sets this bit.

Bugs that should be fixed by this patch :
https://bugs.freedesktop.org/show_bug.cgi?id=49792
https://bugzilla.kernel.org/show_bug.cgi?id=43207
https://bugs.freedesktop.org/show_bug.cgi?id=39282

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Cc: stable@vger.kernel.org
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-06-01 15:40:05 +01:00
Artem Bityutskiy
033369d1af reiserfs: get rid of resierfs_sync_super
This patch stops reiserfs using the VFS 'write_super()' method along with the
s_dirt flag, because they are on their way out.

The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblock using the '->write_super()' call-back.  But the
problem with this thread is that it wastes power by waking up the system every
5 seconds, even if there are no diry superblocks, or there are no client
file-systems which would need this (e.g., btrfs does not use
'->write_super()'). So we want to kill it completely and thus, we need to make
file-systems to stop using the '->write_super()' VFS service, and then remove
it together with the kernel thread.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:36 -04:00
Artem Bityutskiy
5c5fd81962 reiserfs: mark the superblock as dirty a bit later
The 'journal_mark_dirty()' function currently first marks the superblock as
dirty by setting 's_dirt' to 1, then does various sanity checks and returns,
then actuall does all the magic with the journal.

This is not an ideal order, though. It makes more sense to first do all the
checks, then do all the internal stuff, and at the end notify the VFS that the
superblock is now dirty.

This patch moves the 's_dirt = 1' assignment from the very beginning of this
function to the very end.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:36 -04:00
Artem Bityutskiy
717f03c4d7 reiserfs: remove useless superblock dirtying
The 'reiserfs_resize()' function marks the superblock as dirty by assigning 1
to 's_dirt' and then calls 'journal_mark_dirty()' which does the same. Thus,
we can remove the assignment from 'reiserfs_resize()'.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:36 -04:00
Artem Bityutskiy
25729b0e94 reiserfs: clean-up function return type
Turn 'reiserfs_flush_old_commits()' into a void function because the callers
do not cares about what it returns anyway.

We are going to remove the 'sb->s_dirt' field completely and this patch is a
small step towards this direction.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:36 -04:00
Artem Bityutskiy
efaa33eb13 reiserfs: cleanup reiserfs_fill_super a bit
We have the reiserfs superblock pointer in the 'sbi' variable in this
function, no need to use the 'REISERFS_SB(s)' macro which is the same.
This is jut a small clean-up.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:36 -04:00
Al Viro
d58367515f sch_atm.c: get rid of poinless extern
sockfd_lookup() is declared in linux/net.h, which is pulled by
linux/skbuff.h (and needed for a lot of other stuff in sch_atm.c
anyway).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:18 -04:00
Al Viro
17d1587f55 unexport do_munmap()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:18 -04:00
Al Viro
eb36c5873b new helper: vm_mmap_pgoff()
take it to mm/util.c, convert vm_mmap() to use of that one and
take it to mm/util.c as well, convert both sys_mmap_pgoff() to
use of vm_mmap_pgoff()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:18 -04:00
Al Viro
dc982501d9 kill do_mmap() completely
just pull into vm_mmap()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:17 -04:00
Al Viro
e3fc629d7b switch aio and shm to do_mmap_pgoff(), make do_mmap() static
after all, 0 bytes and 0 pages is the same thing...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:17 -04:00
Al Viro
98de59bfe4 take calculation of final prot in security_mmap_file() into a helper
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:17 -04:00
Al Viro
9ac4ed4bd0 move security_mmap_addr() to saner place
it really should be done by get_unmapped_area(); that cuts down on
the amount of callers considerably and it's the right place for
that stuff anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:16 -04:00
Al Viro
8b3ec6814c take security_mmap_file() outside of ->mmap_sem
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 10:37:01 -04:00
Alex Deucher
0b8c30bc49 drm/radeon: properly program gart on rv740, juniper, cypress, barts, hemlock
Need to program an additional VM register.  This doesn't not currently
cause any problems, but allows us to program the proper backend
map in a subsequent patch which should improve performance on these
asics.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-06-01 15:36:54 +01:00
Alex Deucher
29d654067a drm/radeon: fix bank information in tiling config
While there are cards with more than 8 mem banks, the max
number of banks from a tiling perspective is 8, so cap
the tiling config at 8 banks.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=43448

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-06-01 15:36:31 +01:00
Dave Airlie
08ef8e41a6 drm/mgag200: kick off conflicting framebuffers earlier.
It appears grub2 can pass framebuffer info via efifb, so
we need to kick it off earlier to reserve the vram allocation.

(just a fixup same as for cirrus)

Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-06-01 11:12:39 +01:00
Dave Airlie
dedc14e2a6 drm/cirrus: kick out conflicting framebuffers earlier
It appears that grub2 will pass framebuffer info via EFI,
this causes the vram reserve to fail, so kick out efifb
earlier before cirrus loads.

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=826983
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-06-01 11:11:09 +01:00
Hugh Dickins
5e44f8c374 ext4: hole-punch use truncate_pagecache_range
When truncating a file, we unmap pages from userspace first, as that's
usually more efficient than relying, page by page, on the fallback in
truncate_inode_page() - particularly if the file is mapped many times.

Do the same when punching a hole: 3.4 added truncate_pagecache_range()
to do the unmap and trunc, so use it in ext4_ext_punch_hole(), instead
of calling truncate_inode_pages_range() directly.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-06-01 00:15:28 -04:00
Wanlong Gao
b2f4edb335 jbd2: use kmem_cache_zalloc wrapper instead of flag
Use kmem_cache_zalloc wrapper instead of flag __GFP_ZERO.

Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-06-01 00:10:32 -04:00
Salman Qazi
95599968d1 ext4: remove mb_groups before tearing down the buddy_cache
We can't have references held on pages in the s_buddy_cache while we are
trying to truncate its pages and put the inode.  All the pages must be
gone before we reach clear_inode.  This can only be gauranteed if we
can prevent new users from grabbing references to s_buddy_cache's pages.

The original bug can be reproduced and the bug fix can be verified by:

while true; do mount -t ext4 /dev/ram0 /export/hda3/ram0; \
	umount /export/hda3/ram0; done &

while true; do cat /proc/fs/ext4/ram0/mb_groups; done

Signed-off-by: Salman Qazi <sqazi@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2012-05-31 23:52:14 -04:00
Salman Qazi
02b7831019 ext4: add ext4_mb_unload_buddy in the error path
ext4_free_blocks fails to pair an ext4_mb_load_buddy with a matching
ext4_mb_unload_buddy when it fails a memory allocation.

Signed-off-by: Salman Qazi <sqazi@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2012-05-31 23:51:27 -04:00
Theodore Ts'o
79906964a1 ext4: don't trash state flags in EXT4_IOC_SETFLAGS
In commit 353eb83c we removed i_state_flags with 64-bit longs, But
when handling the EXT4_IOC_SETFLAGS ioctl, we replace i_flags
directly, which trashes the state flags which are stored in the high
32-bits of i_flags on 64-bit platforms.  So use the the
ext4_{set,clear}_inode_flags() functions which use atomic bit
manipulation functions instead.

Reported-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2012-05-31 23:46:01 -04:00
Steven Rostedt
5963e317b1 ftrace/x86: Do not change stacks in DEBUG when calling lockdep
When both DYNAMIC_FTRACE and LOCKDEP are set, the TRACE_IRQS_ON/OFF
will call into the lockdep code. The lockdep code can call lots of
functions that may be traced by ftrace. When ftrace is updating its
code and hits a breakpoint, the breakpoint handler will call into
lockdep. If lockdep happens to call a function that also has a breakpoint
attached, it will jump back into the breakpoint handler resetting
the stack to the debug stack and corrupt the contents currently on
that stack.

The 'do_sym' call that calls do_int3() is protected by modifying the
IST table to point to a different location if another breakpoint is
hit. But the TRACE_IRQS_OFF/ON are outside that protection, and if
a breakpoint is hit from those, the stack will get corrupted, and
the kernel will crash:

[ 1013.243754] BUG: unable to handle kernel NULL pointer dereference at 0000000000000002
[ 1013.272665] IP: [<ffff880145cc0000>] 0xffff880145cbffff
[ 1013.285186] PGD 1401b2067 PUD 14324c067 PMD 0
[ 1013.298832] Oops: 0010 [#1] PREEMPT SMP
[ 1013.310600] CPU 2
[ 1013.317904] Modules linked in: ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables crc32c_intel ghash_clmulni_intel microcode usb_debug serio_raw pcspkr iTCO_wdt i2c_i801 iTCO_vendor_support e1000e nfsd nfs_acl auth_rpcgss lockd sunrpc i915 video i2c_algo_bit drm_kms_helper drm i2c_core [last unloaded: scsi_wait_scan]
[ 1013.401848]
[ 1013.407399] Pid: 112, comm: kworker/2:1 Not tainted 3.4.0+ #30
[ 1013.437943] RIP: 8eb8:[<ffff88014630a000>]  [<ffff88014630a000>] 0xffff880146309fff
[ 1013.459871] RSP: ffffffff8165e919:ffff88014780f408  EFLAGS: 00010046
[ 1013.477909] RAX: 0000000000000001 RBX: ffffffff81104020 RCX: 0000000000000000
[ 1013.499458] RDX: ffff880148008ea8 RSI: ffffffff8131ef40 RDI: ffffffff82203b20
[ 1013.521612] RBP: ffffffff81005751 R08: 0000000000000000 R09: 0000000000000000
[ 1013.543121] R10: ffffffff82cdc318 R11: 0000000000000000 R12: ffff880145cc0000
[ 1013.564614] R13: ffff880148008eb8 R14: 0000000000000002 R15: ffff88014780cb40
[ 1013.586108] FS:  0000000000000000(0000) GS:ffff880148000000(0000) knlGS:0000000000000000
[ 1013.609458] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1013.627420] CR2: 0000000000000002 CR3: 0000000141f10000 CR4: 00000000001407e0
[ 1013.649051] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1013.670724] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 1013.692376] Process kworker/2:1 (pid: 112, threadinfo ffff88013fe0e000, task ffff88014020a6a0)
[ 1013.717028] Stack:
[ 1013.724131]  ffff88014780f570 ffff880145cc0000 0000400000004000 0000000000000000
[ 1013.745918]  cccccccccccccccc ffff88014780cca8 ffffffff811072bb ffffffff81651627
[ 1013.767870]  ffffffff8118f8a7 ffffffff811072bb ffffffff81f2b6c5 ffffffff81f11bdb
[ 1013.790021] Call Trace:
[ 1013.800701] Code: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a <e7> d7 64 81 ff ff ff ff 01 00 00 00 00 00 00 00 65 d9 64 81 ff
[ 1013.861443] RIP  [<ffff88014630a000>] 0xffff880146309fff
[ 1013.884466]  RSP <ffff88014780f408>
[ 1013.901507] CR2: 0000000000000002

The solution was to reuse the NMI functions that change the IDT table to make the debug
stack keep its current stack (in kernel mode) when hitting a breakpoint:

  call debug_stack_set_zero
  TRACE_IRQS_ON
  call debug_stack_reset

If the TRACE_IRQS_ON happens to hit a breakpoint then it will keep the current stack
and not crash the box.

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-31 23:12:22 -04:00
Steven Rostedt
f8988175fd x86: Allow nesting of the debug stack IDT setting
When the NMI handler runs, it checks if it preempted a debug handler
and if that handler is using the debug stack. If it is, it changes the
IDT table not to update the stack, otherwise it will reset the debug
stack and corrupt the debug handler it preempted.

Now that ftrace uses breakpoints to change functions from nops to
callers, many more places may hit a breakpoint. Unfortunately this
includes some of the calls that lockdep performs. Which causes issues
with the debug stack. It too needs to change the debug stack before
tracing (if called from the debug handler).

Allow the debug_stack_set_zero() and debug_stack_reset() to be nested
so that the debug handlers can take advantage of them too.

[ Used this_cpu_*() over __get_cpu_var() as suggested by H. Peter Anvin ]

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-31 23:12:21 -04:00
Steven Rostedt
c0525a6972 x86: Reset the debug_stack update counter
When an NMI goes off and it sees that it preempted the debug stack,
to keep the debug stack safe, it changes the IDT to point to one that
does not modify the stack on breakpoint (to allow breakpoints in NMIs).

But the variable that gets set to know to undo it on exit never gets
cleared on exit. Thus every NMI will reset it on exit the first time
it is done even if it does not need to be reset.

[ Added H. Peter Anvin's suggestion to use this_cpu_read/write ]

Cc: <stable@vger.kernel.org> # v3.3
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-31 23:12:20 -04:00
Steven Rostedt
8a4d0a687a ftrace: Use breakpoint method to update ftrace caller
On boot up and module load, it is fine to modify the code directly,
without the use of breakpoints. This is because boot up modification
is done before SMP is initialized, thus the modification is serial,
and module load is done before the module executes.

But after that we must use a SMP safe method to modify running code.
Otherwise, if we are running the function tracer and update its
function (by starting off the stack tracer, or perf tracing)
the change of the function called by the ftrace trampoline is done
directly. If this is being executed on another CPU, that CPU may
take a GPF and crash the kernel.

The breakpoint method is used to change the nops at all the functions, but
the change of the ftrace callback handler itself was still using a
direct modification. If tracing was enabled and the function callback
was changed then another CPU could fault if it was currently calling
the original callback. This modification must use the breakpoint method
too.

Note, the direct method is still used for boot up and module load.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-31 23:12:19 -04:00
Steven Rostedt
a192cd0413 ftrace: Synchronize variable setting with breakpoints
When the function tracer starts modifying the code via breakpoints
it sets a variable (modifying_ftrace_code) to inform the breakpoint
handler to call the ftrace int3 code.

But there's no synchronization between setting this code and the
handler, thus it is possible for the handler to be called on another
CPU before it sees the variable. This will cause a kernel crash as
the int3 handler will not know what to do with it.

I originally added smp_mb()'s to force the visibility of the variable
but H. Peter Anvin suggested that I just make it atomic.

[ Added comments as suggested by Peter Zijlstra ]

Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2012-05-31 23:12:17 -04:00
Tao Ma
9660755100 ext4: let getattr report the right blocks in delalloc+bigalloc
In delayed allocation, i_reserved_data_blocks now indicates
clusters, not blocks. So report it in the right number.

This can be easily exposed by the following command:
echo foo > blah; du -hc blah; sync; du -hc blah

Reported-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2012-05-31 22:54:16 -04:00