linux.git/fs, branch v4.2-rc3

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2015-07-18T17:49:57+00:00

Pull x86 fixes from Ingo Molnar:
 "Two families of fixes:

   - Fix an FPU context related boot crash on newer x86 hardware with
     larger context sizes than what most people test.  To fix this
     without ugly kludges or extensive reverts we had to touch core task
     allocator, to allow x86 to determine the task size dynamically, at
     boot time.

     I've tested it on a number of x86 platforms, and I cross-built it
     to a handful of architectures:

                                        (warns)               (warns)
       testing     x86-64:  -git:  pass (    0),  -tip:  pass (    0)
       testing     x86-32:  -git:  pass (    0),  -tip:  pass (    0)
       testing        arm:  -git:  pass ( 1359),  -tip:  pass ( 1359)
       testing       cris:  -git:  pass ( 1031),  -tip:  pass ( 1031)
       testing       m32r:  -git:  pass ( 1135),  -tip:  pass ( 1135)
       testing       m68k:  -git:  pass ( 1471),  -tip:  pass ( 1471)
       testing       mips:  -git:  pass ( 1162),  -tip:  pass ( 1162)
       testing    mn10300:  -git:  pass ( 1058),  -tip:  pass ( 1058)
       testing     parisc:  -git:  pass ( 1846),  -tip:  pass ( 1846)
       testing      sparc:  -git:  pass ( 1185),  -tip:  pass ( 1185)

     ... so I hope the cross-arch impact 'none', as intended.

     (by Dave Hansen)

   - Fix various NMI handling related bugs unearthed by the big asm code
     rewrite and generally make the NMI code more robust and more
     maintainable while at it.  These changes are a bit late in the
     cycle, I hope they are still acceptable.

     (by Andy Lutomirski)"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86
  x86/fpu, sched: Dynamically allocate 'struct fpu'
  x86/entry/64, x86/nmi/64: Add CONFIG_DEBUG_ENTRY NMI testing code
  x86/nmi/64: Make the "NMI executing" variable more consistent
  x86/nmi/64: Minor asm simplification
  x86/nmi/64: Use DF to avoid userspace RSP confusing nested NMI detection
  x86/nmi/64: Reorder nested NMI checks
  x86/nmi/64: Improve nested NMI comments
  x86/nmi/64: Switch stacks on userspace NMI entry
  x86/nmi/64: Remove asm code that saves CR2
  x86/nmi: Enable nested do_nmi() handling for 64-bit kernels

Merge branch 'akpm' (patches from Andrew)

2015-07-18T17:01:04+00:00

Merge fixes from Andrew Morton:
 "25 fixes"

* emailed patches from Andrew Morton : (25 commits)
  lib/decompress: set the compressor name to NULL on error
  mm/cma_debug: correct size input to bitmap function
  mm/cma_debug: fix debugging alloc/free interface
  mm/page_owner: set correct gfp_mask on page_owner
  mm/page_owner: fix possible access violation
  fsnotify: fix oops in fsnotify_clear_marks_by_group_flags()
  /proc/$PID/cmdline: fixup empty ARGV case
  dma-debug: skip debug_dma_assert_idle() when disabled
  hexdump: fix for non-aligned buffers
  checkpatch: fix long line messages about patch context
  mm: clean up per architecture MM hook header files
  MAINTAINERS: uclinux-h8-devel is moderated for non-subscribers
  mailmap: update Sudeep Holla's email id
  Update Viresh Kumar's email address
  mm, meminit: suppress unused memory variable warning
  configfs: fix kernel infoleak through user-controlled format string
  include, lib: add __printf attributes to several function prototypes
  s390/hugetlb: add hugepages_supported define
  mm: hugetlb: allow hugepages_supported to be architecture specific
  revert "s390/mm: make hugepages_supported a boot time decision"
  ...

Merge branch 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

2015-07-18T04:46:57+00:00

Pull btrfs fixes from Chris Mason:
 "These are all from Filipe, and cover a few problems we've had reported
  on the list recently (along with ones he found on his own)"

* 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix file corruption after cloning inline extents
  Btrfs: fix order by which delayed references are run
  Btrfs: fix list transaction->pending_ordered corruption
  Btrfs: fix memory leak in the extent_same ioctl
  Btrfs: fix shrinking truncate when the no_holes feature is enabled

x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86

2015-07-18T01:42:51+00:00

Don't burden architectures without dynamic task_struct sizing
with the overhead of dynamic sizing.

Also optimize the x86 code a bit by caching task_struct_size.

Acked-and-Tested-by: Dave Hansen 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Denys Vlasenko 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1437128892-9831-3-git-send-email-mingo@kernel.org
Signed-off-by: Ingo Molnar

x86/fpu, sched: Dynamically allocate 'struct fpu'

2015-07-18T01:42:35+00:00

The FPU rewrite removed the dynamic allocations of 'struct fpu'.
But, this potentially wastes massive amounts of memory (2k per
task on systems that do not have AVX-512 for instance).

Instead of having a separate slab, this patch just appends the
space that we need to the 'task_struct' which we dynamically
allocate already.  This saves from doing an extra slab
allocation at fork().

The only real downside here is that we have to stick everything
and the end of the task_struct.  But, I think the
BUILD_BUG_ON()s I stuck in there should keep that from being too
fragile.

Signed-off-by: Dave Hansen 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1437128892-9831-2-git-send-email-mingo@kernel.org
Signed-off-by: Ingo Molnar

fsnotify: fix oops in fsnotify_clear_marks_by_group_flags()

2015-07-17T23:39:54+00:00

fsnotify_clear_marks_by_group_flags() can race with
fsnotify_destroy_marks() so when fsnotify_destroy_mark_locked() drops
mark_mutex, a mark from the list iterated by
fsnotify_clear_marks_by_group_flags() can be freed and we dereference free
memory in the loop there.

Fix the problem by keeping mark_mutex held in
fsnotify_destroy_mark_locked().  The reason why we drop that mutex is that
we need to call a ->freeing_mark() callback which may acquire mark_mutex
again.  To avoid this and similar lock inversion issues, we move the call
to ->freeing_mark() callback to the kthread destroying the mark.

Signed-off-by: Jan Kara 
Reported-by: Ashish Sangwan 
Suggested-by: Lino Sanfilippo 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

/proc/$PID/cmdline: fixup empty ARGV case

2015-07-17T23:39:54+00:00

/proc/*/cmdline code checks if it should look at ENVP area by checking
last byte of ARGV area:

	rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0);
	if (rv <= 0)
		goto out_free_page;

If ARGV is somehow made empty (by doing execve(..., NULL, ...) or
manually setting ->arg_start and ->arg_end to equal values), the decision
will be based on byte which doesn't even belong to ARGV/ENVP.

So, quickly check if ARGV area is empty and report 0 to match previous
behaviour.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

configfs: fix kernel infoleak through user-controlled format string

2015-07-17T23:39:53+00:00

Some modules call config_item_init_type_name() and config_group_init_type_name()
with parameter "name" directly controlled by userspace.  These two
functions call config_item_set_name() with this name used as a format
string, which can be used to leak information such as content of the
stack to userspace.

For example, make_netconsole_target() in netconsole module calls
config_item_init_type_name() with the name of a newly-created directory.
This means that the following commands give some unexpected output, with
configfs mounted in /sys/kernel/config/ and on a system with a
configured eth0 ethernet interface:

    # modprobe netconsole
    # mkdir /sys/kernel/config/netconsole/target_%lx
    # echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name
    # echo 1 > /sys/kernel/config/netconsole/target_%lx/enabled
    # echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name
    # dmesg |tail -n1
    [  142.697668] netconsole: target (target_ffffffffc0ae8080) is
    enabled, disable to update parameters

The directory name is correct but %lx has been interpreted in the
internal item name, displayed here in the error message used by
store_dev_name() in drivers/net/netconsole.c.

To fix this, update every caller of config_item_set_name to use "%s"
when operating on untrusted input.

This issue was found using -Wformat-security gcc flag, once a __printf
attribute has been added to config_item_set_name().

Signed-off-by: Nicolas Iooss 
Acked-by: Greg Kroah-Hartman 
Acked-by: Felipe Balbi 
Acked-by: Joel Becker 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs, proc: add help for CONFIG_PROC_CHILDREN

2015-07-17T23:39:52+00:00

The purpose of the option was documented in
Documentation/filesystems/proc.txt but the help text was missing.

Add small help text that also points to the documentation.

Signed-off-by: Iago López Galeiras 
Reviewed-by: Jean Delvare 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'jfs-4.2' of git://github.com/kleikamp/linux-shaggy

2015-07-16T23:28:28+00:00

Pull jfs fixes from David Kleikamp:
 "A couple trivial fixes and an error path fix"

* tag 'jfs-4.2' of git://github.com/kleikamp/linux-shaggy:
  jfs: clean up jfs_rename and fix out of order unlock
  jfs: fix indentation on if statement
  jfs: removed a prohibited space after opening parenthesis