linux-stable.git/kernel/kprobes.c, branch linux-2.6.30.y

kprobes: fix to use text_mutex around arm/disarm kprobe

2009-05-08T23:23:48+00:00

Fix kprobes to lock text_mutex around some arch_arm/disarm_kprobe() which
are newly added by commit de5bd88d5a5cce3cacea904d3503e5ebdb3852a2.

Signed-off-by: Masami Hiramatsu 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Mathieu Desnoyers 
Cc: Jim Keniston 
Cc: Ingo Molnar 
Signed-off-by: Linus Torvalds

kprobes: support per-kprobe disabling

2009-04-07T15:31:08+00:00

Add disable_kprobe() and enable_kprobe() to disable/enable kprobes
temporarily.

disable_kprobe() asynchronously disables probe handlers of specified
kprobe.  So, after calling it, some handlers can be called at a while.
enable_kprobe() enables specified kprobe.

aggr_pre_handler and aggr_post_handler check disabled probes.  On the
other hand aggr_break_handler and aggr_fault_handler don't check it
because these handlers will be called while executing pre or post handlers
and usually those help error handling.

Signed-off-by: Masami Hiramatsu 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: David S. Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes: rename kprobe_enabled to kprobes_all_disarmed

2009-04-07T15:31:08+00:00

Rename kprobe_enabled to kprobes_all_disarmed and invert logic due to
avoiding naming confusion from per-probe disabling.

Signed-off-by: Masami Hiramatsu 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: David S. Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes: move EXPORT_SYMBOL_GPL just after function definitions

2009-04-07T15:31:08+00:00

Clean up positions of EXPORT_SYMBOL_GPL in kernel/kprobes.c according to
checkpatch.pl.

Signed-off-by: Masami Hiramatsu 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: David S. Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes: cleanup aggr_kprobe related code

2009-04-07T15:31:07+00:00

Currently, kprobes can disable all probes at once, but can't disable it
individually (not unregister, just disable an kprobe, because
unregistering needs to wait for scheduler synchronization).  These patches
introduce APIs for on-the-fly per-probe disabling and re-enabling by
dis-arming/re-arming its breakpoint instruction.

This patch:

Change old_p to ap in add_new_kprobe() for readability, copy flags member
in add_aggr_kprobe(), and simplify the code flow of
register_aggr_kprobe().

Signed-off-by: Masami Hiramatsu 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: David S. Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes: Fix locking imbalance in kretprobes

2009-03-18T11:51:16+00:00

Fix locking imbalance in kretprobes:

=====================================
[ BUG: bad unlock balance detected! ]
-------------------------------------
kthreadd/2 is trying to release lock (&rp->lock) at:
[] pre_handler_kretprobe+0xea/0xf4
but there are no more locks to release!

other info that might help us debug this:
1 lock held by kthreadd/2:
 #0:  (rcu_read_lock){..--}, at: [] __atomic_notifier_call_chain+0x0/0x5a

stack backtrace:
Pid: 2, comm: kthreadd Not tainted 2.6.29-rc8 #1
Call Trace:
 [] ? printk+0xf/0x17
 [] ? pre_handler_kretprobe+0xea/0xf4
 [] print_unlock_inbalance_bug+0xc3/0xce
 [] ? clocksource_read+0x7/0xa
 [] ? getnstimeofday+0x5f/0xf6
 [] ? register_lock_class+0x17/0x293
 [] ? mark_lock+0x1e/0x30b
 [] ? tick_dev_program_event+0x4a/0xbc
 [] ? __slab_alloc+0xa5/0x415
 [] ? pre_handler_kretprobe+0x28/0xf4
 [] ? pre_handler_kretprobe+0xea/0xf4
 [] lock_release_non_nested+0xa4/0x1a5
 [] ? pre_handler_kretprobe+0xea/0xf4
 [] lock_release+0x141/0x166
 [] _spin_unlock_irqrestore+0x19/0x50
 [] pre_handler_kretprobe+0xea/0xf4
 [] kprobe_exceptions_notify+0x1c9/0x43e
 [] notifier_call_chain+0x26/0x48
 [] __atomic_notifier_call_chain+0x37/0x5a
 [] ? __atomic_notifier_call_chain+0x0/0x5a
 [] atomic_notifier_call_chain+0xc/0xe
 [] notify_die+0x2d/0x2f
 [] do_int3+0x1f/0x71
 [] int3+0x2c/0x34
 [] ? do_fork+0x1/0x288
 [] ? kernel_thread+0x71/0x79
 [] ? kthread+0x0/0x60
 [] ? kthread+0x0/0x60
 [] ? kernel_thread_helper+0x0/0x10
 [] kthreadd+0xac/0x148
 [] ? kthreadd+0x0/0x148
 [] kernel_thread_helper+0x7/0x10

Signed-off-by: Ananth N Mavinakayanahalli 
Tested-by: Bharata B Rao 
Cc: Masami Hiramatsu 
Cc: Jim Keniston 
Cc: Linus Torvalds 
Cc: Andrew Morton 
Cc:  [2.6.29.x, 2.6.28.x, 2.6.27.x]
LKML-Reference: <20090318113621.GB4129@in.ibm.com>
Signed-off-by: Ingo Molnar

tracing, Text Edit Lock - kprobes architecture independent support

2009-03-06T15:49:00+00:00

Use the mutual exclusion provided by the text edit lock in the kprobes code. It
allows coherent manipulation of the kernel code by other subsystems.

Changelog:

Move the kernel_text_lock/unlock out of the for loops.
Use text_mutex directly instead of a function.
Remove whitespace modifications.

(note : kprobes_mutex is always taken outside of text_mutex)

Signed-off-by: Mathieu Desnoyers 
Acked-by: Ananth N Mavinakayanahalli 
Acked-by: Masami Hiramatsu 
LKML-Reference: <49B14306.2080202@redhat.com>
Signed-off-by: Ingo Molnar

kprobes: check CONFIG_FREEZER instead of CONFIG_PM

2009-01-16T19:32:17+00:00

Check CONFIG_FREEZER instead of CONFIG_PM because kprobe booster
depends on freeze_processes() and thaw_processes() when CONFIG_PREEMPT=y.

This fixes a linkage error which occurs when CONFIG_PREEMPT=y, CONFIG_PM=y
and CONFIG_FREEZER=n.

Reported-by: Cheng Renquan 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Rafael J. Wysocki 
Acked-by: Ingo Molnar 
Signed-off-by: Len Brown

kprobes: support probing module __init function

2009-01-06T23:59:21+00:00

Allow kprobes to probe module __init routines.  When __init functions are
freed, kprobes which probe those functions are set to "Gone" flag.  These
"Gone" probes are disarmed from the code and never be enabled.

Signed-off-by: Masami Hiramatsu 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes: remove called_from argument

2009-01-06T23:59:21+00:00

Remove called_from argument from kprobes which had been used for
preventing self-refering of kernel module.  However, since we don't keep
module's refcount after registering kprobe any more, there is no reason to
check that.

This patch also simplifies registering/unregistering functions because we
don't need to use __builtin_return_address(0) which was passed to
called_from.

[ananth@in.ibm.com: build fix]
Signed-off-by: Masami Hiramatsu 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Signed-off-by: Ananth N Mavinakayanahalli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds