linux-toradex.git/kernel/kprobes.c, branch v3.0.58

kprobes: adjust "fix a memory leak in function pre_handler_kretprobe()"

2012-03-12T17:32:57+00:00

3.0.21's 603b63484725a6e88e4ae5da58716efd88154b1e directly used
the upstream patch, yet kprobes locking in 3.0.x uses spin_lock...()
rather than raw_spin_lock...().

Signed-off-by: Jan Beulich 
Signed-off-by: Greg Kroah-Hartman

kprobes: fix a memory leak in function pre_handler_kretprobe()

2012-02-13T19:06:06+00:00

commit 55ca6140e9bb307efc97a9301a4f501de02a6fd6 upstream.

In function pre_handler_kretprobe(), the allocated kretprobe_instance
object will get leaked if the entry_handler callback returns non-zero.
This may cause all the preallocated kretprobe_instance objects exhausted.

This issue can be reproduced by changing
samples/kprobes/kretprobe_example.c to probe "mutex_unlock".  And the fix
is straightforward: just put the allocated kretprobe_instance object back
onto the free_instances list.

[akpm@linux-foundation.org: use raw_spin_lock/unlock]
Signed-off-by: Jiang Liu 
Acked-by: Jim Keniston 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Masami Hiramatsu 
Cc: Anil S Keshavamurthy 
Cc: "David S. Miller" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

kprobes: initialize before using a hlist

2012-01-26T01:25:04+00:00

commit d496aab567e7e52b3e974c9192a5de6e77dce32c upstream.

Commit ef53d9c5e ("kprobes: improve kretprobe scalability with hashed
locking") introduced a bug where we can potentially leak
kretprobe_instances since we initialize a hlist head after having used
it.

Initialize the hlist head before using it.

Reported by: Jim Keniston 
Acked-by: Jim Keniston 
Signed-off-by: Ananth N Mavinakayanahalli 
Acked-by: Masami Hiramatsu 
Cc: Srinivasa D S 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

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