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  1. 14 Sep, 2010 3 commits
    • Steven Rostedt's avatar
      tracing: Keep track of set_ftrace_filter position and allow lseek again · 98c4fd04
      Steven Rostedt authored 
      This patch keeps track of the index within the elements of
set_ftrace_filter and if the position goes backwards, it nicely
resets and starts from the beginning again.

This allows for lseek and pread to work properly now.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      98c4fd04
    • Steven Rostedt's avatar
      tracing: Replace typecasted void pointer in set_ftrace_filter code · 4aeb6967
      Steven Rostedt authored 
      The set_ftrace_filter uses seq_file and reads from two lists. The
pointer returned by t_next() can either be of type struct dyn_ftrace
or struct ftrace_func_probe. If there is a bug (there was one)
the wrong pointer may be used and the reference can cause an oops.

This patch makes t_next() and friends only return the iterator structure
which now has a pointer of type struct dyn_ftrace and struct
ftrace_func_probe. The t_show() can now test if the pointer is NULL or
not and if the pointer exists, it is guaranteed to be of the correct type.

Now if there's a bug, only wrong data will be shown but not an oops.

Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      4aeb6967
    • Steven Rostedt's avatar
      tracing: Do not reset *pos in set_ftrace_filter · 2bccfffd
      Steven Rostedt authored 
      After the filtered functions are read, the probed functions are read
from the hash in set_ftrace_filter. When the hashed probed functions
are read, the *pos passed in is reset. Instead of modifying the pos
given to the read function, just record the pos where the filtered
functions ended and subtract from that.
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      2bccfffd
  3. 13 Sep, 2010 14 commits
  5. 12 Sep, 2010 1 commit
  7. 11 Sep, 2010 13 commits
  9. 10 Sep, 2010 9 commits
    • mark gross's avatar
      PM QoS: Correct pr_debug() misuse and improve parameter checks · 0109c2c4
      mark gross authored 
      Correct some pr_debug() misuse and add a stronger parameter check to
pm_qos_write() for the ASCII hex value case.  Thanks to Dan Carpenter
for pointing out the problem!
Signed-off-by: default avatarmark gross <markgross@thegnar.org>
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
      0109c2c4
    • Dave Chinner's avatar
      xfs: log IO completion workqueue is a high priority queue · 51749e47
      Dave Chinner authored 
      The workqueue implementation in 2.6.36-rcX has changed, resulting
in the workqueues no longer having dedicated threads for work
processing. This has caused severe livelocks under heavy parallel
create workloads because the log IO completions have been getting
held up behind metadata IO completions.  Hence log commits would
stall, memory allocation would stall because pages could not be
cleaned, and lock contention on the AIL during inode IO completion
processing was being seen to slow everything down even further.

By making the log Io completion workqueue a high priority workqueue,
they are queued ahead of all data/metadata IO completions and
processed before the data/metadata completions. Hence the log never
gets stalled, and operations needed to clean memory can continue as
quickly as possible. This avoids the livelock conditions and allos
the system to keep running under heavy load as per normal.
Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAlex Elder <aelder@sgi.com>
      51749e47
    • Roland McGrath's avatar
      execve: make responsive to SIGKILL with large arguments · 9aea5a65
      Roland McGrath authored 
      An execve with a very large total of argument/environment strings
can take a really long time in the execve system call.  It runs
uninterruptibly to count and copy all the strings.  This change
makes it abort the exec quickly if sent a SIGKILL.

Note that this is the conservative change, to interrupt only for
SIGKILL, by using fatal_signal_pending().  It would be perfectly
correct semantics to let any signal interrupt the string-copying in
execve, i.e. use signal_pending() instead of fatal_signal_pending().
We'll save that change for later, since it could have user-visible
consequences, such as having a timer set too quickly make it so that
an execve can never complete, though it always happened to work before.
Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Reviewed-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9aea5a65
    • Roland McGrath's avatar
      execve: improve interactivity with large arguments · 7993bc1f
      Roland McGrath authored 
      This adds a preemption point during the copying of the argument and
environment strings for execve, in copy_strings().  There is already
a preemption point in the count() loop, so this doesn't add any new
points in the abstract sense.

When the total argument+environment strings are very large, the time
spent copying them can be much more than a normal user time slice.
So this change improves the interactivity of the rest of the system
when one process is doing an execve with very large arguments.
Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Reviewed-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      7993bc1f
    • Roland McGrath's avatar
      setup_arg_pages: diagnose excessive argument size · 1b528181
      Roland McGrath authored 
      The CONFIG_STACK_GROWSDOWN variant of setup_arg_pages() does not
check the size of the argument/environment area on the stack.
When it is unworkably large, shift_arg_pages() hits its BUG_ON.
This is exploitable with a very large RLIMIT_STACK limit, to
create a crash pretty easily.

Check that the initial stack is not too large to make it possible
to map in any executable.  We're not checking that the actual
executable (or intepreter, for binfmt_elf) will fit.  So those
mappings might clobber part of the initial stack mapping.  But
that is just userland lossage that userland made happen, not a
kernel problem.
Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Reviewed-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1b528181
    • Linus Torvalds's avatar
      Merge branch 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm · be6200aa
      Linus Torvalds authored 
      * 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86: Perform hardware_enable in CPU_STARTING callback
  KVM: i8259: fix migration
  KVM: fix i8259 oops when no vcpus are online
  KVM: x86 emulator: fix regression with cmpxchg8b on i386 hosts
      be6200aa
    • Linus Torvalds's avatar
      Merge branch 'perf-fixes-for-linus' of... · f2955b49
      Linus Torvalds authored 
      Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  tracing: t_start: reset FTRACE_ITER_HASH in case of seek/pread
  perf symbols: Fix multiple initialization of symbol system
  perf: Fix CPU hotplug
  perf, trace: Fix module leak
  tracing/kprobe: Fix handling of C-unlike argument names
  tracing/kprobes: Fix handling of argument names
  perf probe: Fix handling of arguments names
  perf probe: Fix return probe support
  tracing/kprobe: Fix a memory leak in error case
  tracing: Do not allow llseek to set_ftrace_filter
      f2955b49
    • David Howells's avatar
      KEYS: Fix bug in keyctl_session_to_parent() if parent has no session keyring · 3d96406c
      David Howells authored 
      Fix a bug in keyctl_session_to_parent() whereby it tries to check the ownership
of the parent process's session keyring whether or not the parent has a session
keyring [CVE-2010-2960].

This results in the following oops:

  BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0
  IP: [<ffffffff811ae4dd>] keyctl_session_to_parent+0x251/0x443
  ...
  Call Trace:
   [<ffffffff811ae2f3>] ? keyctl_session_to_parent+0x67/0x443
   [<ffffffff8109d286>] ? __do_fault+0x24b/0x3d0
   [<ffffffff811af98c>] sys_keyctl+0xb4/0xb8
   [<ffffffff81001eab>] system_call_fastpath+0x16/0x1b

if the parent process has no session keyring.

If the system is using pam_keyinit then it mostly protected against this as all
processes derived from a login will have inherited the session keyring created
by pam_keyinit during the log in procedure.

To test this, pam_keyinit calls need to be commented out in /etc/pam.d/.
Reported-by: default avatarTavis Ormandy <taviso@cmpxchg8b.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarTavis Ormandy <taviso@cmpxchg8b.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      3d96406c
    • David Howells's avatar
      KEYS: Fix RCU no-lock warning in keyctl_session_to_parent() · 9d1ac65a
      David Howells authored 
      There's an protected access to the parent process's credentials in the middle
of keyctl_session_to_parent().  This results in the following RCU warning:

  ===================================================
  [ INFO: suspicious rcu_dereference_check() usage. ]
  ---------------------------------------------------
  security/keys/keyctl.c:1291 invoked rcu_dereference_check() without protection!

  other info that might help us debug this:

  rcu_scheduler_active = 1, debug_locks = 0
  1 lock held by keyctl-session-/2137:
   #0:  (tasklist_lock){.+.+..}, at: [<ffffffff811ae2ec>] keyctl_session_to_parent+0x60/0x236

  stack backtrace:
  Pid: 2137, comm: keyctl-session- Not tainted 2.6.36-rc2-cachefs+ #1
  Call Trace:
   [<ffffffff8105606a>] lockdep_rcu_dereference+0xaa/0xb3
   [<ffffffff811ae379>] keyctl_session_to_parent+0xed/0x236
   [<ffffffff811af77e>] sys_keyctl+0xb4/0xb6
   [<ffffffff81001eab>] system_call_fastpath+0x16/0x1b

The code should take the RCU read lock to make sure the parents credentials
don't go away, even though it's holding a spinlock and has IRQ disabled.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9d1ac65a
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