Add basic module probe support on perf probe. This introduces "--module
<MODNAME>" option to perf probe for putting probes and showing lines and
variables in the given module.
Currently, this supports only probing on running modules. Supporting off-line
module probing is the next step.
e.g.)
[show lines]
# ./perf probe --module drm -L drm_vblank_info
<drm_vblank_info:0>
0 int drm_vblank_info(struct seq_file *m, void *data)
1 {
struct drm_info_node *node = (struct drm_info_node *) m->private
3 struct drm_device *dev = node->minor->dev;
...
[show vars]
# ./perf probe --module drm -V drm_vblank_info:3
Available variables at drm_vblank_info:3
@<drm_vblank_info+20>
(unknown_type) data
struct drm_info_node* node
struct seq_file* m
[put a probe]
# ./perf probe --module drm drm_vblank_info:3 node m
Add new event:
probe:drm_vblank_info (on drm_vblank_info:3 with node m)
You can now use it on all perf tools, such as:
perf record -e probe:drm_vblank_info -aR sleep 1
[list probes]
# ./perf probe -l
probe:drm_vblank_info (on drm_vblank_info:3@drivers/gpu/drm/drm_info.c with ...
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101021101341.3542.71638.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add -V (--vars) option for listing accessible local variables at given probe
point. This will help finding which local variables are available for event
arguments.
e.g.)
# perf probe -V call_timer_fn:23
Available variables at call_timer_fn:23
@<run_timer_softirq+345>
function_type* fn
int preempt_count
long unsigned int data
struct list_head work_list
struct list_head* head
struct timer_list* timer
struct tvec_base* base
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20101021101323.3542.40282.stgit@ltc236.sdl.hitachi.co.jp>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Gcc generates DW_AT_comp_dir and stores relative source path if building kernel
without O= option. In that case, perf probe --line sometimes doesn't work
without --source option, because it tries to access relative source path.
This adds DW_AT_comp_dir support to perf probe for finding an absolute source
path when no --source option.
LKML-Reference: <4C36EBE7.3060802@hitachi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Those functions operated on members now grouped in 'struct machine', so
move those methods to this new class.
The changes made to 'perf probe' shows that using this abstraction
inserting probes on guests almost got supported for free.
Cc: Avi Kivity <avi@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When we run into dry run mode, we want to make
write_kprobe_trace_event to succeed on writing the event. Let's
initialize it to 0.
Fixes the following build error:
util/probe-event.c:1266: attention : «ret» may be used uninitialized in this function
util/probe-event.c:1266: note: «ret» was declared here
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <1271808065-25290-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since line_finder.lno_s/e are signed int but line_range.start/end
are unsigned int, it is possible to be overflow when converting
line_range->start/end to line_finder->lno_s/e.
This changes line_range.start/end and line_list.line to signed int
and adds overflow checks when setting line_finder.lno_s/e.
LKML-Reference: <20100414223942.14630.72730.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Set the last field name to the argument name when the argument
is refering a data-structure member.
e.g.
./perf probe --add 'vfs_read file->f_mode'
Add new event:
probe:vfs_read (on vfs_read with f_mode=file->f_mode)
This probe records file->f_mode, but the argument name becomes "f_mode".
This enables perf-trace command to parse trace event format correctly.
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20100412171700.3790.72961.stgit@localhost6.localdomain6>
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
gcc 4.2.1 produces:
util/probe-event.c: In function 'add_perf_probe_events':
util/probe-event.c:883: warning: 'tev' may be used uninitialized in this function
make: *** [util/probe-event.o] Error 1
Newer GCCs get this right.
To work it around, initialize the variable to NULL so that older GCCs see
it as initialized too.
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100316220612.32050.33806.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix the !drawf build.
This uses the existing NO_DWARF_SUPPORT mechanism we use for that,
but it's really fragile and needs a cleanup. (in a separate patch)
1) Such uses:
#ifndef NO_DWARF_SUPPORT
are double inverted logic a'la 'not not'. Instead the flag should
be called DWARF_SUPPORT.
2) Furthermore, assymetric #ifdef polluted code flow like:
if (need_dwarf)
#ifdef NO_DWARF_SUPPORT
die("Debuginfo-analysis is not supported");
#else /* !NO_DWARF_SUPPORT */
pr_debug("Some probes require debuginfo.\n");
fd = open_vmlinux();
is very fragile and not acceptable. Instead of that helper functions
should be created and the dwarf/no-dwarf logic should be separated more
cleanly.
3) Local variable #ifdefs like this:
#ifndef NO_DWARF_SUPPORT
int fd;
#endif
Are fragile as well and should be eliminated. Helper functions achieve
that too.
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20100316220612.32050.33806.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'perf-probes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: Issue at least one memory barrier in stop_machine_text_poke()
perf probe: Correct probe syntax on command line help
perf probe: Add lazy line matching support
perf probe: Show more lines after last line
perf probe: Check function address range strictly in line finder
perf probe: Use libdw callback routines
perf probe: Use elfutils-libdw for analyzing debuginfo
perf probe: Rename probe finder functions
perf probe: Fix bugs in line range finder
perf probe: Update perf probe document
perf probe: Do not show --line option without dwarf support
kprobes: Add documents of jump optimization
kprobes/x86: Support kprobes jump optimization on x86
x86: Add text_poke_smp for SMP cross modifying code
kprobes/x86: Cleanup save/restore registers
kprobes/x86: Boost probes when reentering
kprobes: Jump optimization sysctl interface
kprobes: Introduce kprobes jump optimization
kprobes: Introduce generic insn_slot framework
kprobes/x86: Cleanup RELATIVEJUMP_INSTRUCTION to RELATIVEJUMP_OPCODE
Add lazy line matching support for specifying new probes.
This also changes the syntax of perf probe a bit. Now
perf probe accepts one of below probe event definitions.
1) Define event based on function name
[EVENT=]FUNC[@SRC][:RLN|+OFF|%return|;PTN] [ARG ...]
2) Define event based on source file with line number
[EVENT=]SRC:ALN [ARG ...]
3) Define event based on source file with lazy pattern
[EVENT=]SRC;PTN [ARG ...]
- New lazy matching pattern(PTN) follows ';' (semicolon). And it
must be put the end of the definition.
- So, @SRC is no longer the part which must be put at the end
of the definition.
Note that ';' (semicolon) can be interpreted as the end of
a command by the shell. This means that you need to quote it.
(anyway you will need to quote the lazy pattern itself too,
because it may contains other sensitive characters, like
'[',']' etc.).
Lazy matching
-------------
The lazy line matching is similar to glob matching except
ignoring spaces in both of pattern and target.
e.g.
'a=*' can matches 'a=b', 'a = b', 'a == b' and so on.
This provides some sort of flexibility and robustness to
probe point definitions against minor code changes.
(for example, actual 10th line of schedule() can be changed
easily by modifying schedule(), but the same line matching
'rq=cpu_rq*' may still exist.)
Changes in v3:
- Cast Dwarf_Addr to uintmax_t for printf-formats.
Changes in v2:
- Cast Dwarf_Addr to unsigned long long for printf-formats.
Signed-off-by: Masami 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: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20100225133611.6725.45078.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Add --line option to support showing probable source-code lines.
perf probe --line SRC:LN[-LN|+NUM]
or
perf probe --line FUNC[:LN[-LN|+NUM]]
This option shows source-code with line number if the line can
be probed. Lines without line number (and blue color) means that
the line can not be probed, because debuginfo doesn't have the
information of those lines.
The argument specifies the range of lines, "source.c:100-120"
shows lines between 100th to l20th in source.c file. And
"func:10+20" shows 20 lines from 10th line of func function.
e.g.
# ./perf probe --line kernel/sched.c:1080
<kernel/sched.c:1080>
*
* called with rq->lock held and irqs disabled
*/
static void hrtick_start(struct rq *rq, u64 delay)
{
struct hrtimer *timer = &rq->hrtick_timer;
1086 ktime_t time = ktime_add_ns(timer->base->get_time(), delay);
hrtimer_set_expires(timer, time);
1090 if (rq == this_rq()) {
1091 hrtimer_restart(timer);
1092 } else if (!rq->hrtick_csd_pending) {
1093 __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd,
1094 rq->hrtick_csd_pending = 1;
If you specifying function name, this shows function-relative
line number.
# ./perf probe --line schedule
<schedule:0>
asmlinkage void __sched schedule(void)
1 {
struct task_struct *prev, *next;
unsigned long *switch_count;
struct rq *rq;
int cpu;
need_resched:
preempt_disable();
9 cpu = smp_processor_id();
10 rq = cpu_rq(cpu);
11 rcu_sched_qs(cpu);
12 prev = rq->curr;
13 switch_count = &prev->nivcsw;
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
LKML-Reference: <20100106144534.27218.77939.stgit@dhcp-100-2-132.bos.redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
