kprobes up to par with the latest changes to ftrace (multi buffering
and the new function probes).
He also discovered and fixed some bugs in doing so. When pulling in his
patches, I also found a few minor bugs as well and fixed them.
This also includes a compile fix for some archs that select the ring buffer
but not tracing.
I based this off of the last patch you took from me that fixed the merge
conflict error, as that was the commit that had all the changes I needed
for this set of changes.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
iQEcBAABAgAGBQJRjYnJAAoJEOdOSU1xswtMg9EH/iFs438FgrNMk2ZdQftmqcqA
cqcactHo1mmoHjAoLZT/oDBjEThhVUuqzMXrFRutSYcTh4PsQEC3arX0mpsC+T12
UEEV/tZS3TXH+GXEyrOit/O3kzntQcDHwJDV4+0n80IrJmw4IDZbnV3R8DWjS6wp
so+dq0A1pwehcG/upgpw1oTKsGv1G/p6vyf968B6W44icHEClLiph4JE2kzE6D3r
fzSpOLaQoBEvwIRf6xRKxi240VqIItXwfG7pwNpPpSC37gRLzm74zGr+Sj93/k1y
pARbZ/5XO7/pcVYQYupErRAoV5in+QMZ67k5G1vQIvyOS9r039catbQf/7PkzcI=
=EZCE
-----END PGP SIGNATURE-----
Merge tag 'trace-fixes-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing/kprobes update from Steven Rostedt:
"The majority of these changes are from Masami Hiramatsu bringing
kprobes up to par with the latest changes to ftrace (multi buffering
and the new function probes).
He also discovered and fixed some bugs in doing so. When pulling in
his patches, I also found a few minor bugs as well and fixed them.
This also includes a compile fix for some archs that select the ring
buffer but not tracing.
I based this off of the last patch you took from me that fixed the
merge conflict error, as that was the commit that had all the changes
I needed for this set of changes."
* tag 'trace-fixes-v3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/kprobes: Support soft-mode disabling
tracing/kprobes: Support ftrace_event_file base multibuffer
tracing/kprobes: Pass trace_probe directly from dispatcher
tracing/kprobes: Increment probe hit-count even if it is used by perf
tracing/kprobes: Use bool for retprobe checker
ftrace: Fix function probe when more than one probe is added
ftrace: Fix the output of enabled_functions debug file
ftrace: Fix locking in register_ftrace_function_probe()
tracing: Add helper function trace_create_new_event() to remove duplicate code
tracing: Modify soft-mode only if there's no other referrer
tracing: Indicate enabled soft-mode in enable file
tracing/kprobes: Fix to increment return event probe hit-count
ftrace: Cleanup regex_lock and ftrace_lock around hash updating
ftrace, kprobes: Fix a deadlock on ftrace_regex_lock
ftrace: Have ftrace_regex_write() return either read or error
tracing: Return error if register_ftrace_function_probe() fails for event_enable_func()
tracing: Don't succeed if event_enable_func did not register anything
ring-buffer: Select IRQ_WORK
Support soft-mode disabling on kprobe-based dynamic events.
Soft-disabling is just ignoring recording if the soft disabled
flag is set.
Link: http://lkml.kernel.org/r/20130509054454.30398.7237.stgit@mhiramat-M0-7522
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Increment probe hit-count for profiling even if it is used
by perf tool. Same thing has already done in trace_uprobe.
Link: http://lkml.kernel.org/r/20130509054436.30398.21133.stgit@mhiramat-M0-7522
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The enabled_functions debugfs file was created to be able to see
what functions have been modified from nops to calling a tracer.
The current method uses the counter in the function record.
As when a ftrace_ops is registered to a function, its count
increases. But that doesn't mean that the function is actively
being traced. /proc/sys/kernel/ftrace_enabled can be set to zero
which would disable it, as well as something can go wrong and
we can think its enabled when only the counter is set.
The record's FTRACE_FL_ENABLED flag is set or cleared when its
function is modified. That is a much more accurate way of knowing
what function is enabled or not.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The iteration of the ftrace function list and the call to
ftrace_match_record() need to be protected by the ftrace_lock.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Both __trace_add_new_event() and __trace_early_add_new_event() do
basically the same thing, except that __trace_add_new_event() does
a little more.
Instead of having duplicate code between the two functions, add
a helper function trace_create_new_event() that both can use.
This will help against having bugs fixed in one function but not
the other.
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Modify soft-mode flag only if no other soft-mode referrer
(currently only the ftrace triggers) by using a reference
counter in each ftrace_event_file.
Without this fix, adding and removing several different
enable/disable_event triggers on the same event clear
soft-mode bit from the ftrace_event_file. This also
happens with a typo of glob on setting triggers.
e.g.
# echo vfs_symlink:enable_event:net:netif_rx > set_ftrace_filter
# cat events/net/netif_rx/enable
0*
# echo typo_func:enable_event:net:netif_rx > set_ftrace_filter
# cat events/net/netif_rx/enable
0
# cat set_ftrace_filter
#### all functions enabled ####
vfs_symlink:enable_event:net:netif_rx:unlimited
As above, we still have a trigger, but soft-mode is gone.
Link: http://lkml.kernel.org/r/20130509054429.30398.7464.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: David Sharp <dhsharp@google.com>
Cc: Hiraku Toyooka <hiraku.toyooka.gu@hitachi.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Indicate enabled soft-mode event as "1*" in "enable" file
for each event, because it can be soft-disabled when disable_event
trigger is hit.
Link: http://lkml.kernel.org/r/20130509054426.30398.28202.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cleanup regex_lock and ftrace_lock locking points around
ftrace_ops hash update code.
The new rule is that regex_lock protects ops->*_hash
read-update-write code for each ftrace_ops. Usually,
hash update is done by following sequence.
1. allocate a new local hash and copy the original hash.
2. update the local hash.
3. move(actually, copy) back the local hash to ftrace_ops.
4. update ftrace entries if needed.
5. release the local hash.
This makes regex_lock protect #1-#4, and ftrace_lock
to protect #3, #4 and adding and removing ftrace_ops from the
ftrace_ops_list. The ftrace_lock protects #3 as well because
the move functions update the entries too.
Link: http://lkml.kernel.org/r/20130509054421.30398.83411.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Fix a deadlock on ftrace_regex_lock which happens when setting
an enable_event trigger on dynamic kprobe event as below.
----
sh-2.05b# echo p vfs_symlink > kprobe_events
sh-2.05b# echo vfs_symlink:enable_event:kprobes:p_vfs_symlink_0 > set_ftrace_filter
=============================================
[ INFO: possible recursive locking detected ]
3.9.0+ #35 Not tainted
---------------------------------------------
sh/72 is trying to acquire lock:
(ftrace_regex_lock){+.+.+.}, at: [<ffffffff810ba6c1>] ftrace_set_hash+0x81/0x1f0
but task is already holding lock:
(ftrace_regex_lock){+.+.+.}, at: [<ffffffff810b7cbd>] ftrace_regex_write.isra.29.part.30+0x3d/0x220
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(ftrace_regex_lock);
lock(ftrace_regex_lock);
*** DEADLOCK ***
----
To fix that, this introduces a finer regex_lock for each ftrace_ops.
ftrace_regex_lock is too big of a lock which protects all
filter/notrace_hash operations, but it doesn't need to be a global
lock after supporting multiple ftrace_ops because each ftrace_ops
has its own filter/notrace_hash.
Link: http://lkml.kernel.org/r/20130509054417.30398.84254.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ Added initialization flag and automate mutex initialization for
non ftrace.c ftrace_probes. ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As ftrace_regex_write() reads the result of ftrace_process_regex()
which can sometimes return a positive number, only consider a
failure if the return is negative. Otherwise, it will skip possible
other registered probes and by returning a positive number that
wasn't read, it will confuse the user processes doing the writing.
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
register_ftrace_function_probe() returns the number of functions
it registered, which can be zero, it can also return a negative number
if something went wrong. But event_enable_func() only checks for
the case that it didn't register anything, it needs to also check
for the case that something went wrong and return that error code
as well.
Added some comments about the code as well, to make it more
understandable.
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Return 0 instead of the number of activated ftrace function probes if
event_enable_func succeeded and return an error code if it failed or
did not register any functions. But it currently returns the number
of registered functions and if it didn't register anything, it returns 0,
but that is considered success.
This also fixes the return value. As if it succeeds, it returns the
number of functions that were enabled, which is returned back to
the user in ftrace_regex_write (the write() return code). If only
one function is enabled, then the return code of the write is one,
and this can confuse the user program in thinking it only wrote 1
byte.
Link: http://lkml.kernel.org/r/20130509054413.30398.55650.stgit@mhiramat-M0-7522
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Tom Zanussi <tom.zanussi@intel.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
[ Rewrote change log to reflect that this fixes two bugs - SR ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull block driver updates from Jens Axboe:
"It might look big in volume, but when categorized, not a lot of
drivers are touched. The pull request contains:
- mtip32xx fixes from Micron.
- A slew of drbd updates, this time in a nicer series.
- bcache, a flash/ssd caching framework from Kent.
- Fixes for cciss"
* 'for-3.10/drivers' of git://git.kernel.dk/linux-block: (66 commits)
bcache: Use bd_link_disk_holder()
bcache: Allocator cleanup/fixes
cciss: bug fix to prevent cciss from loading in kdump crash kernel
cciss: add cciss_allow_hpsa module parameter
drivers/block/mg_disk.c: add CONFIG_PM_SLEEP to suspend/resume functions
mtip32xx: Workaround for unaligned writes
bcache: Make sure blocksize isn't smaller than device blocksize
bcache: Fix merge_bvec_fn usage for when it modifies the bvm
bcache: Correctly check against BIO_MAX_PAGES
bcache: Hack around stuff that clones up to bi_max_vecs
bcache: Set ra_pages based on backing device's ra_pages
bcache: Take data offset from the bdev superblock.
mtip32xx: mtip32xx: Disable TRIM support
mtip32xx: fix a smatch warning
bcache: Disable broken btree fuzz tester
bcache: Fix a format string overflow
bcache: Fix a minor memory leak on device teardown
bcache: Documentation updates
bcache: Use WARN_ONCE() instead of __WARN()
bcache: Add missing #include <linux/prefetch.h>
...
As the wake up logic for waiters on the buffer has been moved
from the tracing code to the ring buffer, it requires also adding
IRQ_WORK as the wake up code is performed via irq_work.
This fixes compile breakage when a user of the ring buffer is selected
but tracing and irq_work are not.
Link http://lkml.kernel.org/r/20130503115332.GT8356@rric.localhost
Cc: Arnd Bergmann <arnd@arndb.de>
Reported-by: Robert Richter <rric@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Pull perf updates from Ingo Molnar:
"Features:
- Add "uretprobes" - an optimization to uprobes, like kretprobes are
an optimization to kprobes. "perf probe -x file sym%return" now
works like kretprobes. By Oleg Nesterov.
- Introduce per core aggregation in 'perf stat', from Stephane
Eranian.
- Add memory profiling via PEBS, from Stephane Eranian.
- Event group view for 'annotate' in --stdio, --tui and --gtk, from
Namhyung Kim.
- Add support for AMD NB and L2I "uncore" counters, by Jacob Shin.
- Add Ivy Bridge-EP uncore support, by Zheng Yan
- IBM zEnterprise EC12 oprofile support patchlet from Robert Richter.
- Add perf test entries for checking breakpoint overflow signal
handler issues, from Jiri Olsa.
- Add perf test entry for for checking number of EXIT events, from
Namhyung Kim.
- Add perf test entries for checking --cpu in record and stat, from
Jiri Olsa.
- Introduce perf stat --repeat forever, from Frederik Deweerdt.
- Add --no-demangle to report/top, from Namhyung Kim.
- PowerPC fixes plus a couple of cleanups/optimizations in uprobes
and trace_uprobes, by Oleg Nesterov.
Various fixes and refactorings:
- Fix dependency of the python binding wrt libtraceevent, from
Naohiro Aota.
- Simplify some perf_evlist methods and to allow 'stat' to share code
with 'record' and 'trace', by Arnaldo Carvalho de Melo.
- Remove dead code in related to libtraceevent integration, from
Namhyung Kim.
- Revert "perf sched: Handle PERF_RECORD_EXIT events" to get 'perf
sched lat' back working, by Arnaldo Carvalho de Melo
- We don't use Newt anymore, just plain libslang, by Arnaldo Carvalho
de Melo.
- Kill a bunch of die() calls, from Namhyung Kim.
- Fix build on non-glibc systems due to libio.h absence, from Cody P
Schafer.
- Remove some perf_session and tracing dead code, from David Ahern.
- Honor parallel jobs, fix from Borislav Petkov
- Introduce tools/lib/lk library, initially just removing duplication
among tools/perf and tools/vm. from Borislav Petkov
... and many more I missed to list, see the shortlog and git log for
more details."
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (136 commits)
perf/x86/intel/P4: Robistify P4 PMU types
perf/x86/amd: Fix AMD NB and L2I "uncore" support
perf/x86/amd: Remove old-style NB counter support from perf_event_amd.c
perf/x86: Check all MSRs before passing hw check
perf/x86/amd: Add support for AMD NB and L2I "uncore" counters
perf/x86/intel: Add Ivy Bridge-EP uncore support
perf/x86/intel: Fix SNB-EP CBO and PCU uncore PMU filter management
perf/x86: Avoid kfree() in CPU_{STARTING,DYING}
uprobes/perf: Avoid perf_trace_buf_prepare/submit if ->perf_events is empty
uprobes/tracing: Don't pass addr=ip to perf_trace_buf_submit()
uprobes/tracing: Change create_trace_uprobe() to support uretprobes
uprobes/tracing: Make seq_printf() code uretprobe-friendly
uprobes/tracing: Make register_uprobe_event() paths uretprobe-friendly
uprobes/tracing: Make uprobe_{trace,perf}_print() uretprobe-friendly
uprobes/tracing: Introduce is_ret_probe() and uretprobe_dispatcher()
uprobes/tracing: Introduce uprobe_{trace,perf}_print() helpers
uprobes/tracing: Generalize struct uprobe_trace_entry_head
uprobes/tracing: Kill the pointless local_save_flags/preempt_count calls
uprobes/tracing: Kill the pointless seq_print_ip_sym() call
uprobes/tracing: Kill the pointless task_pt_regs() calls
...
During the 3.10 merge, a conflict happened and the resolution was
almost, but not quite, correct. An if statement was reversed.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
[ Duh. That was just silly of me - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Along with the usual minor fixes and clean ups there are a few major
changes with this pull request.
1) Multiple buffers for the ftrace facility
This feature has been requested by many people over the last few years.
I even heard that Google was about to implement it themselves. I finally
had time and cleaned up the code such that you can now create multiple
instances of the ftrace buffer and have different events go to different
buffers. This way, a low frequency event will not be lost in the noise
of a high frequency event.
Note, currently only events can go to different buffers, the tracers
(ie. function, function_graph and the latency tracers) still can only
be written to the main buffer.
2) The function tracer triggers have now been extended.
The function tracer had two triggers. One to enable tracing when a
function is hit, and one to disable tracing. Now you can record a
stack trace on a single (or many) function(s), take a snapshot of the
buffer (copy it to the snapshot buffer), and you can enable or disable
an event to be traced when a function is hit.
3) A perf clock has been added.
A "perf" clock can be chosen to be used when tracing. This will cause
ftrace to use the same clock as perf uses, and hopefully this will make
it easier to interleave the perf and ftrace data for analysis.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
iQEcBAABAgAGBQJRfnTPAAoJEOdOSU1xswtMqYYH/1WIdrwXmxHflErnYkCIr3sU
QtYae2K5A1HcgiqOvRJrdWMOt016iMx5CaQQyBFM1vvMiPY0sTWRmwNxDfZzz9LN
10jRvWEzZSLtzl+a9mkFWLEpr5nR/QODOxkWFCnRWscp46sp04LSTxGDYsOnPQZB
sam/AQ1h4xA+DqDBChm9BDEUEPorGleTlN54LBaCGgSFGvrbF+eAg2s4vHNAQAvQ
8d5xjSE9zC7J+FqbVxvJTbKI3+EqKL6hMsJKsKfi0SI+FuxBaFMSltXck5zKyTI4
HpNJzXCmw+v90Tju7oMkPHh6RTbESPCHoGU+wqE52fM6m7oScVeuI/kfc6USwU4=
=W1n+
-----END PGP SIGNATURE-----
Merge tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"Along with the usual minor fixes and clean ups there are a few major
changes with this pull request.
1) Multiple buffers for the ftrace facility
This feature has been requested by many people over the last few
years. I even heard that Google was about to implement it themselves.
I finally had time and cleaned up the code such that you can now
create multiple instances of the ftrace buffer and have different
events go to different buffers. This way, a low frequency event will
not be lost in the noise of a high frequency event.
Note, currently only events can go to different buffers, the tracers
(ie function, function_graph and the latency tracers) still can only
be written to the main buffer.
2) The function tracer triggers have now been extended.
The function tracer had two triggers. One to enable tracing when a
function is hit, and one to disable tracing. Now you can record a
stack trace on a single (or many) function(s), take a snapshot of the
buffer (copy it to the snapshot buffer), and you can enable or disable
an event to be traced when a function is hit.
3) A perf clock has been added.
A "perf" clock can be chosen to be used when tracing. This will cause
ftrace to use the same clock as perf uses, and hopefully this will
make it easier to interleave the perf and ftrace data for analysis."
* tag 'trace-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (82 commits)
tracepoints: Prevent null probe from being added
tracing: Compare to 1 instead of zero for is_signed_type()
tracing: Remove obsolete macro guard _TRACE_PROFILE_INIT
ftrace: Get rid of ftrace_profile_bits
tracing: Check return value of tracing_init_dentry()
tracing: Get rid of unneeded key calculation in ftrace_hash_move()
tracing: Reset ftrace_graph_filter_enabled if count is zero
tracing: Fix off-by-one on allocating stat->pages
kernel: tracing: Use strlcpy instead of strncpy
tracing: Update debugfs README file
tracing: Fix ftrace_dump()
tracing: Rename trace_event_mutex to trace_event_sem
tracing: Fix comment about prefix in arch_syscall_match_sym_name()
tracing: Convert trace_destroy_fields() to static
tracing: Move find_event_field() into trace_events.c
tracing: Use TRACE_MAX_PRINT instead of constant
tracing: Use pr_warn_once instead of open coded implementation
ring-buffer: Add ring buffer startup selftest
tracing: Bring Documentation/trace/ftrace.txt up to date
tracing: Add "perf" trace_clock
...
Conflicts:
kernel/trace/ftrace.c
kernel/trace/trace.c
Conflicts:
arch/x86/kernel/cpu/perf_event_intel.c
Merge in the latest fixes before applying new patches, resolve the conflict.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This reverts commit 3a366e614d.
Wanlong Gao reports that it causes a kernel panic on his machine several
minutes after boot. Reverting it removes the panic.
Jens says:
"It's not quite clear why that is yet, so I think we should just revert
the commit for 3.9 final (which I'm assuming is pretty close).
The wifi is crap at the LSF hotel, so sending this email instead of
queueing up a revert and pull request."
Reported-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Requested-by: Jens Axboe <axboe@kernel.dk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
perf_trace_buf_prepare() + perf_trace_buf_submit() make no sense
if this task/CPU has no active counters. Change uprobe_perf_print()
to return if hlist_empty(call->perf_events).
Note: this is not uprobe-specific, we can change other users too.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
uprobe_perf_print() passes addr=ip to perf_trace_buf_submit() for
no reason. This sets perf_sample_data->addr for PERF_SAMPLE_ADDR,
we already have perf_sample_data->ip initialized if PERF_SAMPLE_IP.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Finally change create_trace_uprobe() to check if argv[0][0] == 'r'
and pass the correct "is_ret" to alloc_trace_uprobe().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
Change probes_seq_show() and print_uprobe_event() to check
is_ret_probe() and print the correct data.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
Change uprobe_event_define_fields(), and __set_print_fmt() to check
is_ret_probe() and use the appropriate format/fields.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
Change uprobe_trace_print() and uprobe_perf_print() to check
is_ret_probe() and fill ring_buffer_event accordingly.
Also change uprobe_trace_func() and uprobe_perf_func() to not
_print() if is_ret_probe() is true. Note that we keep ->handler()
nontrivial even for uretprobe, we need this for filtering and for
other potential extensions.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
Create the new functions we need to support uretprobes, and change
alloc_trace_uprobe() to initialize consumer.ret_handler if the new
"is_ret" argument is true. Curently this argument is always false,
so the new code is never called and is_ret_probe(tu) is false too.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
Extract the output code from uprobe_trace_func() and uprobe_perf_func()
into the new helpers, they will be used by ->ret_handler() too. We also
add the unused "unsigned long func" argument in advance, to simplify the
next changes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
struct uprobe_trace_entry_head has a single member for reporting,
"unsigned long ip". If we want to support uretprobes we need to
create another struct which has "func" and "ret_ip" and duplicate
a lot of functions, like trace_kprobe.c does.
To avoid this copy-and-paste horror we turn ->ip into ->vaddr[]
and add couple of trivial helpers to calculate sizeof/data. This
uglifies the code a bit, but this allows us to avoid a lot more
complications later, when we add the support for ret-probes.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
uprobe_trace_func() is never called with irqs or preemption
disabled, no need to ask preempt_count() or local_save_flags().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Anton Arapov <anton@redhat.com>
seq_print_ip_sym(ip) in print_uprobe_event() is pointless,
kallsyms_lookup(ip) can not resolve a user-space address.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
uprobe_trace_func() and uprobe_perf_func() do not need task_pt_regs(),
we already have "struct pt_regs *regs".
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Tested-by: Anton Arapov <anton@redhat.com>
It seems that function profiler's hash size is fixed at 1024. Add and
use FTRACE_PROFILE_HASH_BITS instead and update hash size macro.
Link: http://lkml.kernel.org/r/1365551750-4504-1-git-send-email-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ftrace_graph_count can be decreased with a "!" pattern, so that
the enabled flag should be updated too.
Link: http://lkml.kernel.org/r/1365663698-2413-1-git-send-email-namhyung@kernel.org
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: stable@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
As ftrace_filter_lseek is now used with ftrace_pid_fops, it needs to
be moved out of the #ifdef CONFIG_DYNAMIC_FTRACE section as the
ftrace_pid_fops is defined when DYNAMIC_FTRACE is not.
Cc: stable@vger.kernel.org
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently set_ftrace_pid and set_graph_function files use seq_lseek
for their fops. However seq_open() is called only for FMODE_READ in
the fops->open() so that if an user tries to seek one of those file
when she open it for writing, it sees NULL seq_file and then panic.
It can be easily reproduced with following command:
$ cd /sys/kernel/debug/tracing
$ echo 1234 | sudo tee -a set_ftrace_pid
In this example, GNU coreutils' tee opens the file with fopen(, "a")
and then the fopen() internally calls lseek().
Link: http://lkml.kernel.org/r/1365663302-2170-1-git-send-email-namhyung@kernel.org
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: stable@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
On the failure path, stat->start and stat->pages will refer same page.
So it'll attempt to free the same page again and get kernel panic.
Link: http://lkml.kernel.org/r/1364820385-32027-1-git-send-email-namhyung@kernel.org
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: stable@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Use strlcpy() instead of strncpy() as it will always add a '\0'
to the end of the string even if the buffer is smaller than what
is being copied.
Link: http://lkml.kernel.org/r/51624254.30301@asianux.com
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The function tracing control loop used by perf spits out a warning
if the called function is not a control function. This is because
the control function references a per cpu allocated data structure
on struct ftrace_ops that is not allocated for other types of
functions.
commit 0a016409e4 "ftrace: Optimize the function tracer list loop"
Had an optimization done to all function tracing loops to optimize
for a single registered ops. Unfortunately, this allows for a slight
race when tracing starts or ends, where the stub function might be
called after the current registered ops is removed. In this case we
get the following dump:
root# perf stat -e ftrace:function sleep 1
[ 74.339105] WARNING: at include/linux/ftrace.h:209 ftrace_ops_control_func+0xde/0xf0()
[ 74.349522] Hardware name: PRIMERGY RX200 S6
[ 74.357149] Modules linked in: sg igb iTCO_wdt ptp pps_core iTCO_vendor_support i7core_edac dca lpc_ich i2c_i801 coretemp edac_core crc32c_intel mfd_core ghash_clmulni_intel dm_multipath acpi_power_meter pcspk
r microcode vhost_net tun macvtap macvlan nfsd kvm_intel kvm auth_rpcgss nfs_acl lockd sunrpc uinput xfs libcrc32c sd_mod crc_t10dif sr_mod cdrom mgag200 i2c_algo_bit drm_kms_helper ttm qla2xxx mptsas ahci drm li
bahci scsi_transport_sas mptscsih libata scsi_transport_fc i2c_core mptbase scsi_tgt dm_mirror dm_region_hash dm_log dm_mod
[ 74.446233] Pid: 1377, comm: perf Tainted: G W 3.9.0-rc1 #1
[ 74.453458] Call Trace:
[ 74.456233] [<ffffffff81062e3f>] warn_slowpath_common+0x7f/0xc0
[ 74.462997] [<ffffffff810fbc60>] ? rcu_note_context_switch+0xa0/0xa0
[ 74.470272] [<ffffffff811041a2>] ? __unregister_ftrace_function+0xa2/0x1a0
[ 74.478117] [<ffffffff81062e9a>] warn_slowpath_null+0x1a/0x20
[ 74.484681] [<ffffffff81102ede>] ftrace_ops_control_func+0xde/0xf0
[ 74.491760] [<ffffffff8162f400>] ftrace_call+0x5/0x2f
[ 74.497511] [<ffffffff8162f400>] ? ftrace_call+0x5/0x2f
[ 74.503486] [<ffffffff8162f400>] ? ftrace_call+0x5/0x2f
[ 74.509500] [<ffffffff810fbc65>] ? synchronize_sched+0x5/0x50
[ 74.516088] [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[ 74.522268] [<ffffffff810fbc65>] ? synchronize_sched+0x5/0x50
[ 74.528837] [<ffffffff811041a2>] ? __unregister_ftrace_function+0xa2/0x1a0
[ 74.536696] [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[ 74.542878] [<ffffffff8162402d>] ? mutex_lock+0x1d/0x50
[ 74.548869] [<ffffffff81105c67>] unregister_ftrace_function+0x27/0x50
[ 74.556243] [<ffffffff8111eadf>] perf_ftrace_event_register+0x9f/0x140
[ 74.563709] [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[ 74.569887] [<ffffffff8162402d>] ? mutex_lock+0x1d/0x50
[ 74.575898] [<ffffffff8111e94e>] perf_trace_destroy+0x2e/0x50
[ 74.582505] [<ffffffff81127ba9>] tp_perf_event_destroy+0x9/0x10
[ 74.589298] [<ffffffff811295d0>] free_event+0x70/0x1a0
[ 74.595208] [<ffffffff8112a579>] perf_event_release_kernel+0x69/0xa0
[ 74.602460] [<ffffffff816254d5>] ? _cond_resched+0x5/0x40
[ 74.608667] [<ffffffff8112a640>] put_event+0x90/0xc0
[ 74.614373] [<ffffffff8112a740>] perf_release+0x10/0x20
[ 74.620367] [<ffffffff811a3044>] __fput+0xf4/0x280
[ 74.625894] [<ffffffff811a31de>] ____fput+0xe/0x10
[ 74.631387] [<ffffffff81083697>] task_work_run+0xa7/0xe0
[ 74.637452] [<ffffffff81014981>] do_notify_resume+0x71/0xb0
[ 74.643843] [<ffffffff8162fa92>] int_signal+0x12/0x17
To fix this a new ftrace_ops flag is added that denotes the ftrace_list_end
ftrace_ops stub as just that, a stub. This flag is now checked in the
control loop and the function is not called if the flag is set.
Thanks to Jovi for not just reporting the bug, but also pointing out
where the bug was in the code.
Link: http://lkml.kernel.org/r/514A8855.7090402@redhat.com
Link: http://lkml.kernel.org/r/1364377499-1900-15-git-send-email-jovi.zhangwei@huawei.com
Tested-by: WANG Chao <chaowang@redhat.com>
Reported-by: WANG Chao <chaowang@redhat.com>
Reported-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
If we reenable ftrace via syctl, we currently set ftrace_trace_function
based on the previous simplistic algorithm. This is inconsistent with
what update_ftrace_function does. So better call that helper instead.
Link: http://lkml.kernel.org/r/5151D26F.1070702@siemens.com
Cc: stable@vger.kernel.org
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The commit 34600f0e9 "tracing: Fix race with max_tr and changing tracers"
fixed the updating of the main buffers with the race of changing
tracers, but left out the fix to the updating of just a per cpu buffer.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Linus Torvalds