linux-toradex.git/include/linux/kprobes.h, branch v3.7.3

kprobes/x86: ftrace based optimization for x86

2012-07-31T14:29:59+00:00

Add function tracer based kprobe optimization support
handlers on x86. This allows kprobes to use function
tracer for probing on mcount call.

Link: http://lkml.kernel.org/r/20120605102838.27845.26317.stgit@localhost.localdomain

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Ananth N Mavinakayanahalli 
Cc: "Frank Ch. Eigler" 
Cc: Andrew Morton 
Cc: Frederic Weisbecker 
Signed-off-by: Masami Hiramatsu 

[ Updated to new port of ftrace save regs functions ]

Signed-off-by: Steven Rostedt

kprobes: introduce ftrace based optimization

2012-07-31T14:29:58+00:00

Introduce function trace based kprobes optimization.

With using ftrace optimization, kprobes on the mcount calling
address, use ftrace's mcount call instead of breakpoint.
Furthermore, this optimization works with preemptive kernel
not like as current jump-based optimization. Of cource,
this feature works only if the probe is on mcount call.

Only if kprobe.break_handler is set, that probe is not
optimized with ftrace (nor put on ftrace). The reason why this
limitation comes is that this break_handler may be used only
from jprobes which changes ip address (for fetching the function
arguments), but function tracer ignores modified ip address.

Changes in v2:
 - Fix ftrace_ops registering right after setting its filter.
 - Unregister ftrace_ops if there is no kprobe using.
 - Remove notrace dependency from __kprobes macro.

Link: http://lkml.kernel.org/r/20120605102832.27845.63461.stgit@localhost.localdomain

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Ananth N Mavinakayanahalli 
Cc: "Frank Ch. Eigler" 
Cc: Andrew Morton 
Cc: Frederic Weisbecker 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Steven Rostedt

BUG: headers with BUG/BUG_ON etc. need linux/bug.h

2012-03-04T22:54:34+00:00

If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
other BUG variant in a static inline (i.e. not in a #define) then
that header really should be including  and not just
expecting it to be implicitly present.

We can make this change risk-free, since if the files using these
headers didn't have exposure to linux/bug.h already, they would have
been causing compile failures/warnings.

Signed-off-by: Paul Gortmaker

locking, kprobes: Annotate the hash locks and kretprobe.lock as raw

2011-09-13T09:11:45+00:00

The kprobe locks can be taken in atomic context and therefore
cannot be preempted on -rt - annotate it.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar

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: Jump optimization sysctl interface

2010-02-25T16:49:25+00:00

Add /proc/sys/debug/kprobes-optimization sysctl which enables
and disables kprobes jump optimization on the fly for debugging.

Changes in v7:
 - Remove ctl_name = CTL_UNNUMBERED for upstream compatibility.

Changes in v6:
- Update comments and coding style.

Signed-off-by: Masami Hiramatsu 
Cc: systemtap 
Cc: DLE 
Cc: Ananth N Mavinakayanahalli 
Cc: Jim Keniston 
Cc: Srikar Dronamraju 
Cc: Christoph Hellwig 
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
Cc: Anders Kaseorg 
Cc: Tim Abbott 
Cc: Andi Kleen 
Cc: Jason Baron 
Cc: Mathieu Desnoyers 
Cc: Frederic Weisbecker 
Cc: Ananth N Mavinakayanahalli 
LKML-Reference: <20100225133415.6725.8274.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar

kprobes: Introduce kprobes jump optimization

2010-02-25T16:49:24+00:00

Introduce kprobes jump optimization arch-independent parts.
Kprobes uses breakpoint instruction for interrupting execution
flow, on some architectures, it can be replaced by a jump
instruction and interruption emulation code. This gains kprobs'
performance drastically.

To enable this feature, set CONFIG_OPTPROBES=y (default y if the
arch supports OPTPROBE).

Changes in v9:
 - Fix a bug to optimize probe when enabling.
 - Check nearby probes can be optimize/unoptimize when disarming/arming
   kprobes, instead of registering/unregistering. This will help
   kprobe-tracer because most of probes on it are usually disabled.

Changes in v6:
 - Cleanup coding style for readability.
 - Add comments around get/put_online_cpus().

Changes in v5:
 - Use get_online_cpus()/put_online_cpus() for avoiding text_mutex
   deadlock.

Signed-off-by: Masami Hiramatsu 
Cc: systemtap 
Cc: DLE 
Cc: Ananth N Mavinakayanahalli 
Cc: Jim Keniston 
Cc: Srikar Dronamraju 
Cc: Christoph Hellwig 
Cc: Steven Rostedt 
Cc: Frederic Weisbecker 
Cc: Anders Kaseorg 
Cc: Tim Abbott 
Cc: Andi Kleen 
Cc: Jason Baron 
Cc: Mathieu Desnoyers 
Cc: Frederic Weisbecker 
Cc: Ananth N Mavinakayanahalli 
LKML-Reference: <20100225133407.6725.81992.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar