linux-toradex.git/kernel/trace/trace_kprobe.c, branch T20_LinuxImageV2.0Beta1_20121218

ftrace/kprobes: Fix not to delete probes if in use

2011-11-11T17:43:13+00:00

commit 02ca1521ad404cf566e0075848f80d064c0a0503 upstream.

Fix kprobe-tracer not to delete a probe if the probe is in use.
In that case, delete operation will return -EBUSY.

This bug can cause a kernel panic if enabled probes are deleted
during perf record.

(Add some probes on functions)
sh-4.2# perf probe --del probe:\*
sh-4.2# exit
(kernel panic)

This is originally reported on the fedora bugzilla:

 https://bugzilla.redhat.com/show_bug.cgi?id=742383

I've also checked that this problem doesn't happen on
tracepoints when module removing because perf event
locks target module.

$ sudo ./perf record -e xfs:\* -aR sh
sh-4.2# rmmod xfs
ERROR: Module xfs is in use
sh-4.2# exit
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.203 MB perf.data (~8862 samples) ]

Signed-off-by: Masami Hiramatsu 
Cc: Arnaldo Carvalho de Melo 
Cc: Ingo Molnar 
Cc: Frederic Weisbecker 
Cc: Frank Ch. Eigler 
Link: http://lkml.kernel.org/r/20111004104438.14591.6553.stgit@fedora15
Signed-off-by: Steven Rostedt 
Signed-off-by: Greg Kroah-Hartman

tracing/kprobe: Update symbol reference when loading module

2011-07-15T19:45:32+00:00

Since the address of a module-local variable can only be
solved after the target module is loaded, the symbol
fetch-argument should be updated when loading target
module.

Signed-off-by: Masami Hiramatsu 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Frederic Weisbecker 
Cc: Arnaldo Carvalho de Melo 
Link: http://lkml.kernel.org/r/20110627072703.6528.75042.stgit@fedora15
Signed-off-by: Steven Rostedt

tracing/kprobes: Support module init function probing

2011-07-15T19:17:14+00:00

To support probing module init functions, kprobe-tracer allows
user to define a probe on non-existed function when it is given
with a module name. This also enables user to set a probe on
a function on a specific module, even if a same name (but different)
function is locally defined in another module.

The module name must be in the front of function name and separated
by a ':'. e.g. btrfs:btrfs_init_sysfs

Signed-off-by: Masami Hiramatsu 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Frederic Weisbecker 
Cc: Arnaldo Carvalho de Melo 
Link: http://lkml.kernel.org/r/20110627072656.6528.89970.stgit@fedora15
Signed-off-by: Steven Rostedt

tracing/kprobes: Merge trace probe enable/disable functions

2011-07-15T19:10:58+00:00

Merge redundant enable/disable functions into enable_trace_probe()
and disable_trace_probe().

Signed-off-by: Masami Hiramatsu 
Cc: Arnaldo Carvalho de Melo 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Link: http://lkml.kernel.org/r/20110627072644.6528.26910.stgit@fedora15

[ converted kprobe selftest to use  enable_trace_probe ]

Signed-off-by: Steven Rostedt

tracing/kprobes: Rename probe_* to trace_probe_*

2011-07-14T21:44:43+00:00

Rename probe_* to trace_probe_* for avoiding namespace
confliction. This also fixes improper names of find_probe_event()
and cleanup_all_probes() to find_trace_probe() and
release_all_trace_probes() respectively.

Signed-off-by: Masami Hiramatsu 
Cc: Arnaldo Carvalho de Melo 
Cc: Ingo Molnar 
Cc: Peter Zijlstra 
Cc: Frederic Weisbecker 
Link: http://lkml.kernel.org/r/20110627072636.6528.60374.stgit@fedora15
Signed-off-by: Steven Rostedt

Merge branch 'tip/perf/core-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core

2011-07-05T09:55:43+00:00

tracing/kprobes: Fix kprobe-tracer to support stack trace

2011-06-15T02:48:53+00:00

Fix to support kernel stack trace correctly on kprobe-tracer.
Since the execution path of kprobe-based dynamic events is different
from other tracepoint-based events, normal ftrace_trace_stack() doesn't
work correctly. To fix that, this introduces ftrace_trace_stack_regs()
which traces stack via pt_regs instead of current stack register.

e.g.

 # echo p schedule+4 > /sys/kernel/debug/tracing/kprobe_events
 # echo 1 > /sys/kernel/debug/tracing/options/stacktrace
 # echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable
 # head -n 20 /sys/kernel/debug/tracing/trace
            bash-2968  [000] 10297.050245: p_schedule_4: (schedule+0x4/0x4ca)
            bash-2968  [000] 10297.050247: 
 => schedule_timeout
 => n_tty_read
 => tty_read
 => vfs_read
 => sys_read
 => system_call_fastpath
     kworker/0:1-2940  [000] 10297.050265: p_schedule_4: (schedule+0x4/0x4ca)
     kworker/0:1-2940  [000] 10297.050266: 
 => worker_thread
 => kthread
 => kernel_thread_helper
            sshd-1132  [000] 10297.050365: p_schedule_4: (schedule+0x4/0x4ca)
            sshd-1132  [000] 10297.050365: 
 => sysret_careful

Note: Even with this fix, the first entry will be skipped
if the probe is put on the function entry area before
the frame pointer is set up (usually, that is 4 bytes
 (push %bp; mov %sp %bp) on x86), because stack unwinder
depends on the frame pointer.

Signed-off-by: Masami Hiramatsu 
Cc: Frederic Weisbecker 
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Peter Zijlstra 
Cc: Namhyung Kim 
Link: http://lkml.kernel.org/r/20110608070934.17777.17116.stgit@fedora15
Signed-off-by: Steven Rostedt

kprobes/trace: Fix kprobe selftest for gcc 4.6

2011-06-07T18:47:36+00:00

With gcc 4.6, the self test kprobe function:

 kprobe_trace_selftest_target()

is optimized such that kallsyms does not list it. The kprobes
test uses this function to insert a probe and test it. But
it will fail the test if the function is not listed in kallsyms.

Adding a __used annotation keeps the symbol in the kallsyms table.

Suggested-by: David Daney 
Cc: Masami Hiramatsu 
Signed-off-by: Steven Rostedt

sched: Get rid of lock_depth

2011-04-24T11:18:38+00:00

Neil Brown pointed out that lock_depth somehow escaped the BKL
removal work.  Let's get rid of it now.

Note that the perf scripting utilities still have a bunch of
code for dealing with common_lock_depth in tracepoints; I have
left that in place in case anybody wants to use that code with
older kernels.

Suggested-by: Neil Brown 
Signed-off-by: Jonathan Corbet 
Cc: Arnd Bergmann 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Linus Torvalds 
Cc: Andrew Morton 
Link: http://lkml.kernel.org/r/20110422111910.456c0e84@bike.lwn.net
Signed-off-by: Ingo Molnar

Fix common misspellings

2011-03-31T14:26:23+00:00

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi