linux-toradex.git/arch/ia64/kernel/kprobes.c, branch v3.0.26

kprobes: Disable booster when CONFIG_PREEMPT=y

2010-02-04T08:36:18+00:00

Disable kprobe booster when CONFIG_PREEMPT=y at this time,
because it can't ensure that all kernel threads preempted on
kprobe's boosted slot run out from the slot even using
freeze_processes().

The booster on preemptive kernel will be resumed if
synchronize_tasks() or something like that is introduced.

Signed-off-by: Masami Hiramatsu 
Cc: systemtap 
Cc: DLE 
Cc: Ananth N Mavinakayanahalli 
Cc: Frederic Weisbecker 
Cc: Jim Keniston 
Cc: Mathieu Desnoyers 
Cc: Steven Rostedt 
LKML-Reference: <20100202214904.4694.24330.stgit@dhcp-100-2-132.bos.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

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial

2009-01-07T19:31:52+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits)
  trivial: chack -> check typo fix in main Makefile
  trivial: Add a space (and a comma) to a printk in 8250 driver
  trivial: Fix misspelling of "firmware" in docs for ncr53c8xx/sym53c8xx
  trivial: Fix misspelling of "firmware" in powerpc Makefile
  trivial: Fix misspelling of "firmware" in usb.c
  trivial: Fix misspelling of "firmware" in qla1280.c
  trivial: Fix misspelling of "firmware" in a100u2w.c
  trivial: Fix misspelling of "firmware" in megaraid.c
  trivial: Fix misspelling of "firmware" in ql4_mbx.c
  trivial: Fix misspelling of "firmware" in acpi_memhotplug.c
  trivial: Fix misspelling of "firmware" in ipw2100.c
  trivial: Fix misspelling of "firmware" in atmel.c
  trivial: Fix misspelled firmware in Kconfig
  trivial: fix an -> a typos in documentation and comments
  trivial: fix then -> than typos in comments and documentation
  trivial: update Jesper Juhl CREDITS entry with new email
  trivial: fix singal -> signal typo
  trivial: Fix incorrect use of "loose" in event.c
  trivial: printk: fix indentation of new_text_line declaration
  trivial: rtc-stk17ta8: fix sparse warning
  ...

kprobes: add kprobe_insn_mutex and cleanup arch_remove_kprobe()

2009-01-06T23:59:20+00:00

Add kprobe_insn_mutex for protecting kprobe_insn_pages hlist, and remove
kprobe_mutex from architecture dependent code.

This allows us to call arch_remove_kprobe() (and free_insn_slot) while
holding kprobe_mutex.

Signed-off-by: Masami Hiramatsu 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Cc: Russell King 
Cc: "Luck, Tony" 
Cc: Paul Mackerras 
Cc: Benjamin Herrenschmidt 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

trivial: fix then -> than typos in comments and documentation

2009-01-06T10:28:06+00:00

- (better, more, bigger ...) then -> (...) than

Signed-off-by: Frederik Schwarzer 
Signed-off-by: Jiri Kosina

kprobes: improve kretprobe scalability with hashed locking

2008-07-25T17:53:30+00:00

Currently list of kretprobe instances are stored in kretprobe object (as
used_instances,free_instances) and in kretprobe hash table.  We have one
global kretprobe lock to serialise the access to these lists.  This causes
only one kretprobe handler to execute at a time.  Hence affects system
performance, particularly on SMP systems and when return probe is set on
lot of functions (like on all systemcalls).

Solution proposed here gives fine-grain locks that performs better on SMP
system compared to present kretprobe implementation.

Solution:

 1) Instead of having one global lock to protect kretprobe instances
    present in kretprobe object and kretprobe hash table.  We will have
    two locks, one lock for protecting kretprobe hash table and another
    lock for kretporbe object.

 2) We hold lock present in kretprobe object while we modify kretprobe
    instance in kretprobe object and we hold per-hash-list lock while
    modifying kretprobe instances present in that hash list.  To prevent
    deadlock, we never grab a per-hash-list lock while holding a kretprobe
    lock.

 3) We can remove used_instances from struct kretprobe, as we can
    track used instances of kretprobe instances using kretprobe hash
    table.

Time duration for kernel compilation ("make -j 8") on a 8-way ppc64 system
with return probes set on all systemcalls looks like this.

cacheline              non-cacheline             Un-patched kernel
aligned patch 	       aligned patch
===============================================================================
real    9m46.784s       9m54.412s                  10m2.450s
user    40m5.715s       40m7.142s                  40m4.273s
sys     2m57.754s       2m58.583s                  3m17.430s
===========================================================

Time duration for kernel compilation ("make -j 8) on the same system, when
kernel is not probed.
=========================
real    9m26.389s
user    40m8.775s
sys     2m7.283s
=========================

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

[IA64] kprobes: kprobe-booster for ia64

2008-04-09T17:36:43+00:00

Add kprobe-booster support on ia64.

Kprobe-booster improves the performance of kprobes by eliminating single-step,
where possible.  Currently, kprobe-booster is implemented on x86 and x86-64.
This is an ia64 port.

On ia64, kprobe-booster executes a copied bundle directly, instead of single
stepping.  Bundles which have B or X unit and which may cause an exception
(including break) are not executed directly.  And also, to prevent hitting
break exceptions on the copied bundle, only the hindmost kprobe is executed
directly if several kprobes share a bundle and are placed in different slots.
Note: set_brl_inst() is used for preparing an instruction buffer(it does not
modify any active code), so it does not need any atomic operation.

Signed-off-by: Masami Hiramatsu 
Cc: Anil S Keshavamurthy 
Cc: Ananth N Mavinakayanahalli 
Cc: bibo,mao 
Cc: Rusty Lynch 
Cc: Prasanna S Panchamukhi 
Cc: Jim Keniston 
Cc: Shaohua Li 
Signed-off-by: Andrew Morton 
Signed-off-by: Tony Luck

[IA64] kprobes arch consolidation build fix

2008-03-06T17:49:01+00:00

ia64 named their handler kprobes_fault_handler while all other
arches used kprobe_fault_handler.  Change the function definition
and header declaration.

Signed-off-by: Harvey Harrison 
Signed-off-by: Tony Luck

[IA64] fix ia64 kprobes compilation

2008-03-04T22:35:42+00:00

This patch fixes the following compile error with a recent gcc:
  CC      kernel/kprobes.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/kernel/kprobes.c:1066: error: __ksymtab_jprobe_return causes a section type conflict

Signed-off-by: Adrian Bunk 
Signed-off-by: Tony Luck

[IA64] Fix the order of atomic operations in restore_previous_kprobes on ia64

2008-02-04T23:09:39+00:00

Fix the order of atomic operations to prevent overwriting prev_kprobe[0].
To pop values from stack, we must decrement stack index right AFTER
reading values.

Signed-off-by: Masami Hiramatsu 
Signed-off-by: Tony Luck