linux-toradex.git/kernel/kprobes.c, branch v3.0.16

Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu

2011-01-08T01:02:58+00:00

* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (30 commits)
  gameport: use this_cpu_read instead of lookup
  x86: udelay: Use this_cpu_read to avoid address calculation
  x86: Use this_cpu_inc_return for nmi counter
  x86: Replace uses of current_cpu_data with this_cpu ops
  x86: Use this_cpu_ops to optimize code
  vmstat: User per cpu atomics to avoid interrupt disable / enable
  irq_work: Use per cpu atomics instead of regular atomics
  cpuops: Use cmpxchg for xchg to avoid lock semantics
  x86: this_cpu_cmpxchg and this_cpu_xchg operations
  percpu: Generic this_cpu_cmpxchg() and this_cpu_xchg support
  percpu,x86: relocate this_cpu_add_return() and friends
  connector: Use this_cpu operations
  xen: Use this_cpu_inc_return
  taskstats: Use this_cpu_ops
  random: Use this_cpu_inc_return
  fs: Use this_cpu_inc_return in buffer.c
  highmem: Use this_cpu_xx_return() operations
  vmstat: Use this_cpu_inc_return for vm statistics
  x86: Support for this_cpu_add, sub, dec, inc_return
  percpu: Generic support for this_cpu_add, sub, dec, inc_return
  ...

Fixed up conflicts: in arch/x86/kernel/{apic/nmi.c, apic/x2apic_uv_x.c, process.c}
as per Tejun.

kprobes: Use this_cpu_ops

2010-12-17T14:07:19+00:00

Use this_cpu ops in various places to optimize per cpu data access.

Cc: Jason Baron 
Cc: Namhyung Kim 
Acked-by: H. Peter Anvin 
Signed-off-by: Christoph Lameter 
Signed-off-by: Tejun Heo

kprobes: Use text_poke_smp_batch for unoptimizing

2010-12-06T16:59:32+00:00

Use text_poke_smp_batch() on unoptimization path for reducing
the number of stop_machine() issues. If the number of
unoptimizing probes is more than MAX_OPTIMIZE_PROBES(=256),
kprobes unoptimizes first MAX_OPTIMIZE_PROBES probes and kicks
optimizer for remaining probes.

Signed-off-by: Masami Hiramatsu 
Cc: Rusty Russell 
Cc: Frederic Weisbecker 
Cc: Ananth N Mavinakayanahalli 
Cc: Jason Baron 
Cc: Mathieu Desnoyers 
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
LKML-Reference: <20101203095434.2961.22657.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar

kprobes: Use text_poke_smp_batch for optimizing

2010-12-06T16:59:31+00:00

Use text_poke_smp_batch() in optimization path for reducing
the number of stop_machine() issues. If the number of optimizing
probes is more than MAX_OPTIMIZE_PROBES(=256), kprobes optimizes
first MAX_OPTIMIZE_PROBES probes and kicks optimizer for
remaining probes.

Changes in v5:
- Use kick_kprobe_optimizer() instead of directly calling
  schedule_delayed_work().
- Rescheduling optimizer outside of kprobe mutex lock.

Changes in v2:
- Allocate code buffer and parameters in arch_init_kprobes()
  instead of using static arraies.
- Merge previous max optimization limit patch into this patch.
  So, this patch introduces upper limit of optimization at
  once.

Signed-off-by: Masami Hiramatsu 
Cc: Rusty Russell 
Cc: Frederic Weisbecker 
Cc: Ananth N Mavinakayanahalli 
Cc: Jason Baron 
Cc: Mathieu Desnoyers 
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Peter Zijlstra 
Cc: Steven Rostedt 
LKML-Reference: <20101203095428.2961.8994.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar

kprobes: Reuse unused kprobe

2010-12-06T16:59:31+00:00

Reuse unused (waiting for unoptimizing and no user handler)
kprobe on given address instead of returning -EBUSY for
registering a new kprobe.

Signed-off-by: Masami Hiramatsu 
Cc: Rusty Russell 
Cc: Frederic Weisbecker 
Cc: Ananth N Mavinakayanahalli 
Cc: Jason Baron 
Cc: Mathieu Desnoyers 
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095416.2961.39080.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar

kprobes: Support delayed unoptimizing

2010-12-06T16:59:30+00:00

Unoptimization occurs when a probe is unregistered or disabled,
and is heavy because it recovers instructions by using
stop_machine(). This patch delays unoptimization operations and
unoptimize several probes at once by using
text_poke_smp_batch(). This can avoid unexpected system slowdown
coming from stop_machine().

Changes in v5:
- Split this patch into several cleanup patches and this patch.
- Fix some text_mutex lock miss.
- Use bool instead of int for behavior flags.
- Add additional comment for (un)optimizing path.

Changes in v2:
- Use dynamic allocated buffers and params.

Signed-off-by: Masami Hiramatsu 
Cc: Rusty Russell 
Cc: Frederic Weisbecker 
Cc: Ananth N Mavinakayanahalli 
Cc: Jason Baron 
Cc: Mathieu Desnoyers 
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095409.2961.82733.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar

kprobes: Separate kprobe optimizing code from optimizer

2010-12-06T16:59:30+00:00

Separate kprobe optimizing code from optimizer, this
will make easy to introducing unoptimizing code in
optimizer.

Signed-off-by: Masami Hiramatsu 
Cc: Rusty Russell 
Cc: Frederic Weisbecker 
Cc: Ananth N Mavinakayanahalli 
Cc: Jason Baron 
Cc: Mathieu Desnoyers 
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095403.2961.91201.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar

kprobes: Cleanup disabling and unregistering path

2010-12-06T16:59:29+00:00

Merge disabling kprobe to unregistering kprobe function
and add comments for disabing/unregistring process.

Current unregistering code disables(disarms) kprobes after
checking target kprobe status. This patch changes it to
disabling kprobe first after that it changing the kprobe's
state. This allows to share probe disabling code between
disable_kprobe() and unregister_kprobe().

Signed-off-by: Masami Hiramatsu 
Cc: Rusty Russell 
Cc: Frederic Weisbecker 
Cc: Ananth N Mavinakayanahalli 
Cc: Jason Baron 
Cc: Mathieu Desnoyers 
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095356.2961.30152.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar

kprobes: Rename old_p to more appropriate name

2010-12-06T16:59:29+00:00

Rename irrelevant uses of "old_p" to more appropriate names.
Originally, "old_p" just meant "the old kprobe on given address"
but current code uses that name as "just another kprobe" or
something like that. This patch renames those pointer names
to more appropriate one for maintainability.

Signed-off-by: Masami Hiramatsu 
Cc: Rusty Russell 
Cc: Frederic Weisbecker 
Cc: Ananth N Mavinakayanahalli 
Cc: Jason Baron 
Cc: Mathieu Desnoyers 
Cc: 2nddept-manager@sdl.hitachi.co.jp
LKML-Reference: <20101203095350.2961.48110.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Ingo Molnar

jump label: Fix error with preempt disable holding mutex

2010-10-29T16:55:55+00:00

Kprobes and jump label were having a race between mutexes that
was fixed by reordering the jump label. But this reordering
moved the jump label mutex into a preempt disable location.

This patch does a little fiddling to move the grabbing of
the jump label mutex from inside the preempt disable section
and still keep the order correct between the mutex and the
kprobes lock.

Reported-by: Ingo Molnar 
Acked-by: Masami Hiramatsu 
Cc: Jason Baron 
Signed-off-by: Steven Rostedt