Support vmlinux on current working direcotry by default and
also update file-open messages.
Now perf probe searches ./vmlinux too.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
LKML-Reference: <20091208220309.10142.33040.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove event suffix number _0 if it is the first.
The first event has no suffix, and from the second,
each event has suffix number counted from _1. This
reduces typing cost :-).
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
LKML-Reference: <20091208220301.10142.50031.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix add-probe command syntax without --add option.
perf-probe supports add-probe command without --add
option. But it treats each argument as an event definition.
e.g.

perf probe func arg1 arg2

 is interpreted as

perf probe --add func --add arg1 --add arg2

But it may be useless in many cases.

This patch fixes this syntax to fold those arguments into
one event definition if there is no --add option. With this
change, above command is interpreted as below;

perf probe --add "func arg1 arg2"
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
LKML-Reference: <20091208220254.10142.73767.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Change probe-added message more user-friendly expression and
show usage of new events.

Before:
Added new event: p:probe/schedule_0 schedule+10 prev=%ax cpu=%bx

After:
Added new event:
  probe:schedule_1                         (on schedule+1 with prev cpu)

You can now use it on all perf tools, such as:

        perf record -e probe:schedule_1 -a sleep 1
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
LKML-Reference: <20091208220247.10142.91642.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Change event list format for user readability. perf probe --list
shows event list in "[GROUP:EVENT] EVENT-DEFINITION" format, but
this format is different from the output of perf-list, and
EVENT-DEFINITION is a bit blunt. This patch changes the format to
more user friendly one.

Before:
[probe:schedule_0]	schedule+10 prev cpu

After:
  probe:schedule_0                         (on schedule+10 with prev cpu)
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
LKML-Reference: <20091208220240.10142.42916.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Today's linux-next build failed with:

  kernel/hw_breakpoint.c:86: error: 'task_bp_pinned' redeclared as different kind of symbol
  ...

Caused by commit dd17c8f7 ("percpu:
remove per_cpu__ prefix") from the percpu tree interacting with
commit 56053170 ("hw-breakpoints:
Fix task-bound breakpoint slot allocation") from the tip tree.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20091208182515.bb6dda4a.sfr@canb.auug.org.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

asm/hw_breakpoint.h is evidently a kernel internal file and
should not be included globally, not even under an #ifdef.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
LKML-Reference: <200912071712.58650.arnd@arndb.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Use pr_debug() for "missing vmlinux" debugging message.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091207170059.19230.51459.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Check e_snprintf() format string by gcc, and fix a bug of
e_snprintf() caller.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091207170053.19230.7690.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix event namelist to duplicate string. Without duplicating, adding
multiple probes causes stack overwrite bug, because it reuses a
buffer on stack while the buffer is already added in the namelist.
String duplication solves this bug because only contents of the
buffer is copied to the namelist.
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091207170046.19230.55557.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix strtailcmp() to compare s1[0] and s2[0]. strtailcmp() returns 0
if "a" and "b" or "a" and "ab", it's a wrong behavior. This patch
fixes it.
Signed-off-by: N"Juha Leppanen" <juha_motorsportcom@luukku.com>
Acked-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Juha Leppanen <juha_motorsportcom@luukku.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091207170040.19230.37464.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Delete empty or incomplete inat-tables.c if gen-insn-attr-x86.awk
failed, because it causes a build error if user tries to build
kernel next time.
Reported-by: NArkadiusz Miskiewicz <arekm@maven.pl>
Signed-off-by: NMasami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091207170033.19230.37688.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

At least, insn.c and inat.c is needed for kprobe for now. So,
this compile those only if KPROBES is enabled.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
LKML-Reference: <878wdg8icq.fsf@devron.myhome.or.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Uses of strcat are almost always signs that someone is too lazy
to think about the code a bit more carefully.  One always has to
know about the lengths of the strings involved to avoid buffer
overflows.

This is one case where the size of the object code for me is
reduced by 38 bytes.  The code should also be faster, especially
if flags is non-NULL.
Signed-off-by: NUlrich Drepper <drepper@redhat.com>
Cc: a.p.zijlstra@chello.nl
Cc: fweisbec@gmail.com
Cc: jaswinderrajput@gmail.com
Cc: paulus@samba.org
LKML-Reference: <200912061825.nB6IPUa1023306@hs20-bc2-1.build.redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The 'scripting unsupported' message should only be displayed
when the -s or -g options are used, and not when they aren't, as
the current code does.
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Cc: rostedt@goodmis.org
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1260163919-6679-3-git-send-email-tzanussi@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Merge branch 'perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into perf/urgent

Whatever the context nature of a breakpoint, we always perform the
following constraint checks before allocating it a slot:

- Check the number of pinned breakpoint bound the concerned cpus
- Check the max number of task-bound breakpoints that are belonging
  to a task.
- Add both and see if we have a reamining slot for the new breakpoint

This is the right thing to do when we are about to register a cpu-only
bound breakpoint. But not if we are dealing with a task bound
breakpoint. What we want in this case is:

- Check the number of pinned breakpoint bound the concerned cpus
- Check the number of breakpoints that already belong to the task
  in which the breakpoint to register is bound to.
- Add both

This fixes a regression that makes the "firefox -g" command fail to
register breakpoints once we deal with a secondary thread.
Reported-by: NWalt <w41ter@gmail.com>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>

The perf attrs used to set up breakpoint parameters are often allocated
in the stack and not zeroed out before calling hw_breakpoint_init().
Handle it from this helper to avoid random attributes set by the stack.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Prasad <prasad@linux.vnet.ibm.com>

When I added the xs callbacks into perf, I forgot to re-check
the no-libperl case. This patch fixes the undefined reference
error for that.
Reported-by: NArnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: NTom Zanussi <tzanussi@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1260153712.6564.4.camel@tropicana>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

raw->size is not used, this patch just cleans it up.
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B1C8CC4.4050007@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The remain buff size is 'len - pos->long_name_len - 1', not
'len - pos->long_name_len + 1'

This bug was introduced by commit 7691b1ec ("perf tools: Misc small
fixes").
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Acked-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B1C7F73.80707@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

We use 'data.raw_data' parameter to call process_raw_event(),
but data.raw_data buffer not include data size. it can make perf
tool crash.

This bug was introduced by commit 180f95e2 ("perf: Make common
SAMPLE_EVENT parser").
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B1C7F45.5080105@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

If we use 'perf sched trace', it will call symbol__init() again,
and can lead to a perf tool crash:

 [root@localhost perf]# ./perf sched trace
 *** glibc detected *** ./perf: free(): invalid next size (normal): 0x094c1898 ***
 ======= Backtrace: =========
 /lib/libc.so.6[0xb7602404]
 /lib/libc.so.6(cfree+0x96)[0xb76043b6]
 ./perf[0x80730fe]
 ./perf[0x8074c97]
 ./perf[0x805eb59]
 ./perf[0x80536fd]
 ./perf[0x804b618]
 ./perf[0x804bdc3]
 /lib/libc.so.6(__libc_start_main+0xe5)[0xb75a9735]
 ./perf[0x804af81]
 ======= Memory map: ========
 08048000-08158000 r-xp 00000000 fe:00 556831     /home/eric/....
 08158000-08168000 rw-p 0010f000 fe:00 556831     /home/eric/...
 08168000-085fe000 rw-p 00000000 00:00 0
 094ab000-094cc000 rw-p 00000000 00:00 0          [heap]
Signed-off-by: NXiao Guangrong <xiaoguangrong@cn.fujitsu.com>
LKML-Reference: <4B1C7EE1.8030906@cn.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1260129790-11520-1-git-send-email-acme@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

- util/header.c
	"len" is aligned to 64. So, it tries to write the out of
	long_name buffer.

	So, this use "zero_buf" to write aligned area.

- util/trace-event-read.c
	"size" is not including nul byte. So, this allocates it, and set '\0'.

- util/trace-event-parse.c
	It needs parens to calc correct size.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <87d42s8iiu.fsf_-_@devron.myhome.or.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Currently, sample event data is parsed for each commands, and it
is assuming that the data is not including other data. (E.g.
timechart, trace, etc. can't parse the event if it has
PERF_SAMPLE_CALLCHAIN)

So, even if we record the superset data for multiple commands at
a time, commands can't parse. etc.

To fix it, this makes common sample event parser, and use it to
parse sample event correctly. (PERF_SAMPLE_READ is unsupported
for now though, it seems to be not using.)
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <87hbs48imv.fsf@devron.myhome.or.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Update "struct trace_entry" to match with current one. And
remove "size" field from it.

If it has "size", it become cause of alignment mismatch of
structure with kernel.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Acked-by: NArjan van de Ven <arjan@infradead.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <87ljhg8ioe.fsf@devron.myhome.or.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Fix the following warning:

 arch/x86/tools/test_get_len.c: In function "main":
 arch/x86/tools/test_get_len.c:116: warning: unused variable "c"
Signed-off-by: NJean Delvare <khali@linux-fr.org>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

The size argument to zalloc should be the size of desired
structure, not the pointer to it.

The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@expression@
expression *x;
@@

x =
 <+...
-sizeof(x)
+sizeof(*x)
...+>// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <Pine.LNX.4.64.0912061016120.20858@ask.diku.dk>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

When we enter in irq, two things can happen to preserve the link
to the previous frame pointer:

- If we were in an irq already, we don't switch to the irq stack
  as we are inside. We just need to save the previous frame
  pointer and to link the new one to the previous.

- Otherwise we need another level of indirection. We enter the irq with
  the previous stack. We save the previous bp inside and make bp
  pointing to its saved address. Then we switch to the irq stack and
  push bp another time but to the new stack. This makes two levels to
  dereference instead of one.

In the second case, the current stacktrace code omits the second level
and loses the frame pointer accuracy. The stack that follows will then
be considered as unreliable.

Handling that makes the perf callchain happier.
Before:

43.94%  [k] _raw_read_lock
            |
            --- _read_lock
               |
               |--60.53%-- send_sigio
               |          __kill_fasync
               |          kill_fasync
               |          evdev_pass_event
               |          evdev_event
               |          input_pass_event
               |          input_handle_event
               |          input_event
               |          synaptics_process_byte
               |          psmouse_handle_byte
               |          psmouse_interrupt
               |          serio_interrupt
               |          i8042_interrupt
               |          handle_IRQ_event
               |          handle_edge_irq
               |          handle_irq
               |          __irqentry_text_start
               |          ret_from_intr
               |          |
               |          |--30.43%-- __select
               |          |
               |          |--17.39%-- 0x454f15
               |          |
               |          |--13.04%-- __read
               |          |
               |          |--13.04%-- vread_hpet
               |          |
               |          |--13.04%-- _xcb_lock_io
               |          |
               |           --13.04%-- 0x7f630878ce8

After:

    50.00%  [k] _raw_read_lock
            |
            --- _read_lock
               |
               |--98.97%-- send_sigio
               |          __kill_fasync
               |          kill_fasync
               |          evdev_pass_event
               |          evdev_event
               |          input_pass_event
               |          input_handle_event
               |          input_event
               |          |
               |          |--96.88%-- synaptics_process_byte
               |          |          psmouse_handle_byte
               |          |          psmouse_interrupt
               |          |          serio_interrupt
               |          |          i8042_interrupt
               |          |          handle_IRQ_event
               |          |          handle_edge_irq
               |          |          handle_irq
               |          |          __irqentry_text_start
               |          |          ret_from_intr
               |          |          |
               |          |          |--39.78%-- __const_udelay
               |          |          |          |
               |          |          |          |--91.89%-- ath5k_hw_register_timeout
               |          |          |          |          ath5k_hw_noise_floor_calibration
               |          |          |          |          ath5k_hw_reset
               |          |          |          |          ath5k_reset
               |          |          |          |          ath5k_config
               |          |          |          |          ieee80211_hw_config
               |          |          |          |          |
               |          |          |          |          |--88.24%-- ieee80211_scan_work
               |          |          |          |          |          worker_thread
               |          |          |          |          |          kthread
               |          |          |          |          |          child_rip
               |          |          |          |          |
               |          |          |          |           --11.76%-- ieee80211_scan_completed
               |          |          |          |                     ieee80211_scan_work
               |          |          |          |                     worker_thread
               |          |          |          |                     kthread
               |          |          |          |                     child_rip
               |          |          |          |
               |          |          |           --8.11%-- ath5k_hw_noise_floor_calibration
               |          |          |                     ath5k_hw_reset
               |          |          |                     ath5k_reset
               |          |          |                     ath5k_config

Note: This does not only affect perf events but also x86-64
stacktraces. They were considered as unreliable once we quit
the irq stack frame.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>

While dumping a stacktrace, the end of the exception stack won't link
the frame pointer to the previous stack.

The interrupted stack will then be considered as unreliable and ignored
by perf, as the frame pointer is unreliable itself.

This happens because we overwrite the frame pointer that links to the
interrupted frame with the address of the exception stack. This is
done in order to reserve space inside.
But rbp has been chosen here only because it is not a scratch register,
so that the address of the exception stack remains in rbp after calling
do_debug(), we can then release the exception stack space without the
need to retrieve its address again.

But we can pick another non-scratch register to do that, so that we
preserve the link to the interrupted stack frame in the stacktraces.

Just randomly choose r12. Every registers are saved just before and
restored just after calling do_debug(). And r12 is not used in the
middle, which makes it a perfect candidate.

Example: perf record -g -a -c 1 -f -e mem:$(tasklist_lock_addr):rw

Before:
    44.18%  [k] _raw_read_lock
            |
            |
            ---  |--6.31%-- waitid
                 |
                 |--4.26%-- writev
                 |
                 |--3.63%-- __select
                 |
                 |--3.15%-- __waitpid
                 |          |
                 |          |--28.57%-- 0x8b52e00000139f
                 |          |
                 |          |--28.57%-- 0x8b52e0000013c6
                 |          |
                 |          |--14.29%-- 0x7fde786dc000
                 |          |
                 |          |--14.29%-- 0x62696c2f7273752f
                 |          |
                 |           --14.29%-- 0x1ea9df800000000
                 |
                 |--3.00%-- __poll

After:

    43.94%  [k] _raw_read_lock
            |
            --- _read_lock
               |
               |--60.53%-- send_sigio
               |          __kill_fasync
               |          kill_fasync
               |          evdev_pass_event
               |          evdev_event
               |          input_pass_event
               |          input_handle_event
               |          input_event
               |          synaptics_process_byte
               |          psmouse_handle_byte
               |          psmouse_interrupt
               |          serio_interrupt
               |          i8042_interrupt
               |          handle_IRQ_event
               |          handle_edge_irq
               |          handle_irq
               |          __irqentry_text_start
               |          ret_from_intr
               |          |
               |          |--30.43%-- __select
               |          |
               |          |--17.39%-- 0x454f15
               |          |
               |          |--13.04%-- __read
               |          |
               |          |--13.04%-- vread_hpet
               |          |
               |          |--13.04%-- _xcb_lock_io
               |          |
               |           --13.04%-- 0x7f630878ce87

Note: it does not only affect perf events but also other stacktraces in
x86-64. They were considered as unreliable once we quit the debug
stack frame.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>

Dumping the callchains from breakpoint events with perf gives strange
results:

3.75%             perf  [kernel]           [k] _raw_read_unlock
                       |
                       --- _raw_read_unlock
                           perf_callchain
                           perf_prepare_sample
                           __perf_event_overflow
                           perf_swevent_overflow
                           perf_swevent_add
                           perf_bp_event
                           hw_breakpoint_exceptions_notify
                           notifier_call_chain
                           __atomic_notifier_call_chain
                           atomic_notifier_call_chain
                           notify_die
                           do_debug
                           debug
                           munmap

We are infected with all the debug stack. Like the nmi stack, the debug
stack is undesired as it is part of the profiling path, not helpful for
the user.

Ignore it.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>

As it is not used anymore and has been superseded by overflow_handler.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>

struct perf_event::event callback was called when a breakpoint
triggers. But this is a rather opaque callback, pretty
tied-only to the breakpoint API and not really integrated into perf
as it triggers even when we don't overflow.

We prefer to use overflow_handler() as it fits into the perf events
rules, being called only when we overflow.
Reported-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>

Drop the callback and task parameters from modify_user_hw_breakpoint().
For now we have no user that need to modify a breakpoint to the point
of changing its handler or its task context.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>

This field might result from an older manual rebasing mistake.
We don't use it.
Reported-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>

It stands to anonymize a structure, but structures can already
anonymize by themselves.
Reported-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>

Add two reserved fields for future extensions in the hardware
breakpoints interface. Further needs may arise.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>

Merge reason: add these fixes to 'perf probe'.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Merge reason: It's ready for v2.6.33.
Signed-off-by: NIngo Molnar <mingo@elte.hu>