linux-toradex.git/include/linux/kprobes.h, branch tegra-9.12.15

tracing: remove notrace from __kprobes annotation

2009-09-16T03:51:31+00:00

When ftrace had issues with NMIs, it was needed to annotate all
the areas that kprobes had issues with notrace. Now that ftrace is
NMI safe, the functions that limit ftrace from tracing are just a
small few.

Kprobes is too big of a set for ftrace not to trace. Remove the
coupling.

Signed-off-by: Steven Rostedt

kprobes: support kretprobe and jprobe per-probe disabling

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

Add disable/enable_kretprobe() and disable/enable_jprobe().

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: 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: cleanup comment style in kprobes.h

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

Fix comment style in kprobes.h.

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

x86, mm, kprobes: fault.c, simplify notify_page_fault()

2009-02-20T23:09:42+00:00

Impact: cleanup

Remove an #ifdef from notify_page_fault(). The function still
compiles to nothing in the !CONFIG_KPROBES case.

Introduce kprobes_built_in() and kprobe_fault_handler() helpers
to allow this - they returns 0 if !CONFIG_KPROBES.

No code changed:

   text	   data	    bss	    dec	    hex	filename
   4618	     32	     24	   4674	   1242	fault.o.before
   4618	     32	     24	   4674	   1242	fault.o.after

Cc: Masami Hiramatsu 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Signed-off-by: Ingo Molnar

kprobes: fix module compilation error with CONFIG_KPROBES=n

2009-01-30T02:04:43+00:00

Define kprobes related data structures even if CONFIG_KPROBES is not set.
This fixes compilation errors which occur if CONFIG_KPROBES is not set, in
kprobe using modules.

[akpm@linux-foundation.org: fix build for non-kprobes-supporting architectures]
Reviewed-by: Ananth N Mavinakayanahalli 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kprobes: support probing module __exit function

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

Allows kprobes to probe __exit routine.  This adds flags member to struct
kprobe.  When module is freed(kprobes hooks module_notifier to get this
event), kprobes which probe the functions in that module are set to "Gone"
flag to the flags member.  These "Gone" probes are never be enabled.
Users can check the GONE flag through debugfs.

This also removes mod_refcounted, because we couldn't free a module if
kprobe incremented the refcount of that module.

[akpm@linux-foundation.org: document some locking]
[mhiramat@redhat.com: bugfix: pass aggr_kprobe to arch_remove_kprobe]
[mhiramat@redhat.com: bugfix: release old_p's insn_slot before error return]
Signed-off-by: Masami Hiramatsu 
Acked-by: Ananth N Mavinakayanahalli 
Cc: Anil S Keshavamurthy 
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

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

ftrace: ignore functions that cannot be kprobe-ed

2008-10-14T08:34:22+00:00

kprobes already has an extensive list of annotations for functions
that should not be instrumented. Add notrace annotations to these
functions as well.

This is particularly useful for functions called by the NMI path.

Signed-off-by: Ingo Molnar

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