Fix a segfault bug by asking for variable it doesn't find.
Since the convert_variable() didn't handle error code returned
from convert_variable_location(), it just passed an incomplete
variable field and then a segfault was occurred when formatting
the field.
This fixes that bug by handling success code correctly in
convert_variable(). Other callers of convert_variable_location()
are correctly checking the return code.
This bug was introduced by following commit. But another hidden
erroneous error handling has been there previously (-ENOMEM case).
commit 3d918a12a1
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20140529105232.28251.30447.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
The dwarf_getcfi() only checks .debug_frame section for CFI, but as
most binaries only have .eh_frame it'd return NULL and it makes
some variables inaccessible.
Using dwarf_getcfi_elf (along with dwarf_getelf()) allows to show and
add probe to more variables.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/1396854348-9296-1-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
As Namhyung reported(https://lkml.org/lkml/2014/4/1/89),
current perf-probe -L option doesn't handle errors in line-range
searching correctly. It causes a SEGV if an error occured in the
line-range searching.
----
$ perf probe -x ./perf -v -L map__load
Open Debuginfo file: /home/namhyung/project/linux/tools/perf/perf
fname: util/map.c, lineno:153
New line range: 153 to 2147483647
path: (null)
Segmentation fault (core dumped)
----
This is because line_range_inline_cb() ignores errors
from find_line_range_by_line() which means that lr->path is
already freed on the error path in find_line_range_by_line().
As a result, get_real_path() accesses the lr->path and it
causes a NULL pointer exception.
This fixes line_range_inline_cb() to handle the error correctly,
and report it to the caller.
Anyway, this just fixes a possible SEGV bug, Namhyung's patch
is also required.
Reported-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140402054831.19080.27006.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
The commit 5a62257a3d ("perf probe: Replace line_list with
intlist") replaced line_list to intlist but it has a problem that if a
same line was added again, it'd return -EEXIST rather than 1.
Since line_range_walk_cb() only checks the result being negative, it
resulted in failure or segfault sometimes.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/1396327677-3657-1-git-send-email-namhyung@kernel.org
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Support distro-style debuginfo supported by dso for setting uprobes.
Note that this tries to find a debuginfo file based on the real path of
the target binary. If the debuginfo is not correctly installed on the
system, this can not find it.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20140206053227.29635.54434.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Find the given address from offline dwarfs instead of online kernel
dwarfs.
On the KASLR enabled kernel, the kernel text section is loaded with
random offset, and the debuginfo__new_online_kernel can't handle it. So
let's move to the offline dwarf loader instead of using the online dwarf
loader.
As a result, since we don't need debuginfo__new_online_kernel any more,
this also removes the functions related to that.
Without this change;
# ./perf probe -l
probe:t_show (on _stext+901288 with m v)
probe:t_show_1 (on _stext+939624 with m v t)
probe:t_show_2 (on _stext+980296 with m v fmt)
probe:t_show_3 (on _stext+1014392 with m v file)
With this change;
# ./perf probe -l
probe:t_show (on t_show@linux-3/kernel/trace/ftrace.c with m v)
probe:t_show_1 (on t_show@linux-3/kernel/trace/trace.c with m v t)
probe:t_show_2 (on t_show@kernel/trace/trace_printk.c with m v fmt)
probe:t_show_3 (on t_show@kernel/trace/trace_events.c with m v file)
Changes from v2:
- Instead of retrying, directly opens offline dwarf.
- Remove debuginfo__new_online_kernel and related functions.
- Refer map->reloc to get the correct address of a symbol.
- Add a special case for handling ref_reloc_sym based address.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: "David A. Long" <dave.long@linaro.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20140206053218.29635.74821.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Several areas already used this technique, so do some audit to
consistently use it elsewhere.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-9sbere0kkplwe45ak6rk4a1f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
For the frequent idiom of:
free(ptr);
ptr = NULL;
Make it expect a pointer to the pointer being freed, so that it becomes
clear at first sight that the variable being freed is being modified.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-pfw02ezuab37kha18wlut7ir@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Its perfectly fine to call free(NULL), so no need to clutter the source
code with all those superfluous testing.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-uux5wpvevlerd42gqer13e7n@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Support basic dwarf(debuginfo) based operations for uprobe events. With
this change, perf probe can analyze debuginfo of user application binary
to set up new uprobe event.
This allows perf-probe --add(with local variables, line numbers) and
--line works with -x option. (Actually, --vars has already accepted -x
option)
For example, the following command shows the probe-able lines of a given
user space function. Something that so far was only available in the
'perf probe' tool for kernel space functions:
# ./perf probe -x perf --line map__load
<map__load@/home/fedora/ksrc/linux-2.6/tools/perf/util/map.c:0>
0 int map__load(struct map *map, symbol_filter_t filter)
1 {
2 const char *name = map->dso->long_name;
int nr;
5 if (dso__loaded(map->dso, map->type))
6 return 0;
8 nr = dso__load(map->dso, map, filter);
9 if (nr < 0) {
10 if (map->dso->has_build_id) {
And this shows the available variables at the given line of the
function.
# ./perf probe -x perf --vars map__load:8
Available variables at map__load:8
@<map__load+96>
char* name
struct map* map
symbol_filter_t filter
@<map__find_symbol+112>
char* name
symbol_filter_t filter
@<map__find_symbol_by_name+136>
char* name
symbol_filter_t filter
@<map_groups__find_symbol_by_name+176>
char* name
struct map* map
symbol_filter_t filter
And lastly, we can now define probe(s) with all available
variables on the given line:
# ./perf probe -x perf --add 'map__load:8 $vars'
Added new events:
probe_perf:map__load (on map__load:8 with $vars)
probe_perf:map__load_1 (on map__load:8 with $vars)
probe_perf:map__load_2 (on map__load:8 with $vars)
probe_perf:map__load_3 (on map__load:8 with $vars)
You can now use it in all perf tools, such as:
perf record -e probe_perf:map__load_3 -aR sleep 1
Changes from previous version:
- Add examples in the patch description.
- Use .text section start address and dwarf symbol address
for calculating the offset of given symbol, instead of
searching the symbol in symtab again.
With this change, we can safely handle multiple local
function instances (e.g. scnprintf in perf).
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: David A. Long <dave.long@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: systemtap@sourceware.org
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20131226054152.22364.47021.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
They convey no information, perhaps I was bitten by some snake at some
point, complete the detox by naming the last of those arguments more
sensibly.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-u1r0dnjoro08dgztiy2g3t2q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
At this point, --fentry (mcount function entry) option for gcc fuzzes
the debuginfo variable locations by skipping the mcount instruction
offset (on x86, this is a 5 byte call instruction).
This makes variable searching fail at the entry of functions which
are mcount'ed.
e.g.)
Available variables at vfs_read
@<vfs_read+0>
(No matched variables)
This patch adds additional location search at the function entry point
to solve this issue, which tries to find the earliest address for the
variable location.
Note that this only works with function parameters (formal parameters)
because any local variables should not exist on the function entry
address (those are not initialized yet).
With this patch, perf probe shows correct parameters if possible;
# perf probe --vars vfs_read
Available variables at vfs_read
@<vfs_read+0>
char* buf
loff_t* pos
size_t count
struct file* file
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20131011071025.15557.13275.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Support "$vars" meta argument syntax for tracing all local variables at
probe point.
Now you can trace all available local variables (including function
parameters) at the probe point by passing $vars.
# perf probe --add foo $vars
This automatically finds all local variables at foo() and adds it as
probe arguments.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20131011071023.15557.51770.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix perf probe --list to initialize fname local var always before
use it. This may cause a SEGV if there is a probe which is in
the function body but not in any inline function.
Problem introduced in:
commit e08cfd4bda
Author: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Date: Mon Sep 30 18:21:44 2013 +0900
perf probe: Fix to find line information for probe list
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20131011122317.9662.29736.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix to find the correct (as much as possible) line information for
listing probes. Without this fix, perf probe --list action will show
incorrect line information as below;
probe:getname_flags (on getname_flags@ksrc/linux-3/fs/namei.c)
probe:getname_flags_1 (on getname:-89@x86/include/asm/current.h)
probe:getname_flags_2 (on user_path_at_empty:-2054@x86/include/asm/current.h)
The minus line number is obviously wrong, and current.h is not related
to the probe point. Deeper investigation discovered that there were 2
issues related to this bug, and minor typos too.
The 1st issue is the rack of considering about nested inlined functions,
which causes the wrong (relative) line number.
The 2nd issue is that the dwarf line info is not correct at those
points. It points 14th line of current.h.
Since it seems that the line info includes somewhat unreliable
information, this fixes perf to try to find correct line information
from both of debuginfo and line info as below.
1) Probe address is the entry of a function instance
In this case, the line is set as the function declared line.
2) Probe address is the entry of an expanded inline function block
In this case, the line is set as the function call-site line.
This means that the line number is relative from the entry line
of caller function (which can be an inlined function if nested)
3) Probe address is inside a function instance or an expanded
inline function block
In this case, perf probe queries the line number from lineinfo
and verify the function declared file is same as the file name
queried from lineinfo.
If the file name is different, it is a failure case. The probe
address is shown as symbol+offset.
4) Probe address is not in the any function instance
This is a failure case, the probe address is shown as
symbol+offset.
With this fix, perf probe -l shows correct probe lines as below;
probe:getname_flags (on getname_flags@ksrc/linux-3/fs/namei.c)
probe:getname_flags_1 (on getname:2@ksrc/linux-3/fs/namei.c)
probe:getname_flags_2 (on user_path_at_empty:4@ksrc/linux-3/fs/namei.c)
Changes at v2:
- Fix typos in the function comments. (Thanks to Namhyung Kim)
- Use die_find_top_inlinefunc instead of die_find_inlinefunc_next.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130930092144.1693.11058.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix perf probe to probe on some symbols which have some optimzation
suffixes, e.g. ".part", ".isra", and ".constprop".
To fix this issue, instead of using the DIE name, perf probe uses the
symbol name found by dwfl_module_addrsym().
This also involves a perf probe --vars operation update which now shows
the symbol name instead of the DIE name.
Without this patch, putting a probe on an inlined function which was
compiled with a suffixed symbol will fail like this:
$ perf probe -v getname_flags
probe-definition(0): getname_flags
symbol:getname_flags file:(null) line:0 offset:0 return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (6 entries long)
Using /lib/modules/3.11.0+/build/vmlinux for symbols
found inline addr: 0xffffffff8119bb70
Probe point found: getname_flags+0
found inline addr: 0xffffffff8119bcb6
Probe point found: getname+6
found inline addr: 0xffffffff811a06a6
Probe point found: user_path_at_empty+6
find 3 probe_trace_events.
Opening /sys/kernel/debug//tracing/kprobe_events write=1
Added new events:
Writing event: p:probe/getname_flags getname_flags+0
Failed to write event: No such file or directory
Error: Failed to add events. (-1)
Because the debuginfo knows only the original (non suffix) symbol name,
it uses the original symbol for probe address but the kernel (kallsyms)
knows only suffixed symbol. Then, the kernel rejects that original
symbol.
This patch uses dwfl_module_addrsym() to get the correct (suffixed)
symbol from symtab when a probe point is found.
Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130925131616.31632.46658.stgit@udc4-manage.rcp.hitachi.co.jp
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The commit ba28c59bc9 fixed a declaration
entry bug in probe_point_search_cb(). There are same bugs in line
finder and call_probe_finder(). This introduces a new dwarf utility
function to determine given DIE is a function definition, not
declaration.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20120423032435.8737.80064.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Before casting a type of a variable to string, convert_variable_type()
confirms that the type is a pointer or an array. then if it is a pointer
to char, it is casted to string. but in case of an array of char, it
isn't
Signed-off-by: H.C. Lee <hyc.lee@gmail.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/CANFS6bb75e8a_UtyAD9yF73hfXDy0N8tSjDz=a+Vna=Y8ORMHg@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Union members can be accessed with '.' or '->' like data structure
member access
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/CANFS6baeuSBxPGQ8SUZWZErJ2bWs-Nojg+FSo138E1QK8bJJig@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf defines both __used and __unused variables to use for marking
unused variables. The variable __used is defined to
__attribute__((__unused__)), which contradicts the kernel definition to
__attribute__((__used__)) for new gcc versions. On Android, __used is
also defined in system headers and this leads to warnings like: warning:
'__used__' attribute ignored
__unused is not defined in the kernel and is not a standard definition.
If __unused is included everywhere instead of __used, this leads to
conflicts with glibc headers, since glibc has a variables with this name
in its headers.
The best approach is to use __maybe_unused, the definition used in the
kernel for __attribute__((unused)). In this way there is only one
definition in perf sources (instead of 2 definitions that point to the
same thing: __used and __unused) and it works on both Linux and Android.
This patch simply replaces all instances of __used and __unused with
__maybe_unused.
Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1347315303-29906-7-git-send-email-irina.tirdea@intel.com
[ committer note: fixed up conflict with a116e05 in builtin-sched.c ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If DIE entries corresponding to declarations appear before definition
entry, probe finder returns error instead of continuing to look further
for a definition entry.
This patch ensures we reach to the DIE entry corresponding to the
definition and get the function address.
V2: A simpler solution based on Masami's suggestion.
Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/4F703FB9.9020407@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The perf probe command allows kprobe to be inserted at any offset from a
function start, which results in adding kprobes to unintended location.
Example: perf probe do_fork+10000 is allowed even though size of do_fork
is ~904.
This patch will ensure probe addition fails when the offset specified is
greater than size of the function.
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/4F473F33.4060409@linux.vnet.ibm.com
Signed-off-by: Prashanth Nageshappa <prashanth@linux.vnet.ibm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There are unnecessary #include <ctype.h> out there, and they might cause
a nasty build failure in some environment. As we already have most of
ctype macros in util.h, just get rid of them.
A few of exceptions are util/symbol.c which needs isupper() macro util.h
doesn't provide and perl scripting support code which includes ctype.h
internally.
Suggested-by: Ingo Molnar <mingo@elte.hu>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1327827356-8786-4-git-send-email-namhyung@gmail.com
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix to call convert_variable() if previous call does not fail.
To call convert_variable, it ensures "ret" is 0. However, since
"ret" has the return value of synthesize_perf_probe_arg() which
always returns positive value if it succeeded, perf probe doesn't
call convert_variable(). This will cause a SEGV when we add an
event with arguments.
This has to be fixed as it ensures "ret" is greater than 0
(or not negative).
This regression has been introduced by my previous patch, f182e3e1.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110820053922.3286.65805.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
gcc 4.6 generates a concrete out-of-line instance when there is a
function which is implicitly inlined somewhere but also has its own
instance. The concrete out-of-line instance means that it has an
abstract origin of the function which is referred by not only
inlined-subroutines but also a concrete subprogram.
Since current dwarf_func_inline_instances() can find only instances of
inlined-subroutines, this introduces new die_walk_instances() to find
both of subprogram and inlined-subroutines.
e.g. without this,
Available variables at sched_group_rt_period
@<cpu_rt_period_read_uint+9>
struct task_group* tg
perf probe failed to find actual subprogram instance of
sched_group_rt_period().
With this,
Available variables at sched_group_rt_period
@<cpu_rt_period_read_uint+9>
struct task_group* tg
@<sched_group_rt_period+0>
struct task_group* tg
Now it found the sched_group_rt_period() itself.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110311.19900.63997.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix variable searching logic to search one in inner than local scope or
global(CU) scope. In the other words, skip searching in intermediate
scopes.
e.g., in the following code,
int var1;
void inline infunc(int i)
{
i++; <--- [A]
}
void func(void)
{
int var1, var2;
infunc(var2);
}
At [A], "var1" should point the global variable "var1", however, if user
mis-typed as "var2", variable search should be failed. However, current
logic searches variable infunc() scope, global scope, and then func()
scope. Thus, it can find "var2" variable in func() scope. This may not
be what user expects.
So, it would better not search outer scopes except outermost (compile
unit) scope which contains only global variables, when it failed to find
given variable in local scope.
E.g.
Without this:
$ perf probe -V pre_schedule --externs > without.vars
With this:
$ perf probe -V pre_schedule --externs > with.vars
Check the diff:
$ diff without.vars with.vars
88d87
< int cpu
133d131
< long unsigned int* switch_count
These vars are actually in the scope of schedule(), the caller of
pre_schedule().
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110305.19900.94374.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix perf probe to search local variables in appropriate local inlined
function scope. For example, pre_schedule() has only 2 local variables,
as below;
$ perf probe -L pre_schedule
<pre_schedule@/home/mhiramat/ksrc/linux-2.6/kernel/sched.c:0>
0 static inline void pre_schedule(struct rq *rq, struct task_struct *prev)
{
2 if (prev->sched_class->pre_schedule)
3 prev->sched_class->pre_schedule(rq, prev);
}
However, current perf probe shows 4 local variables on pre_schedule(),
because it searches variables in the caller(schedule()) scope.
$ perf probe -V pre_schedule
Available variables at pre_schedule
@<schedule+445>
int cpu
long unsigned int* switch_count
struct rq* rq
struct task_struct* prev
This patch fixes this issue by searching variables in the local scope of
the instance of inlined function. Here is the result.
$ perf probe -V pre_schedule
Available variables at pre_schedule
@<schedule+445>
struct rq* rq
struct task_struct* prev
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110259.19900.85664.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix line-range collector to walk all instances of inlined function,
because some execution paths can be optimized out depending on the
function argument of instances.
E.g.)
inline_func (arg) {
if (arg)
do_something;
else
do_another;
}
func_A() {
inline_func(1)
}
func_B() {
inline_func(0)
}
In this case, func_A may have only do_something code and func_B may have
only do_another.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110247.19900.93702.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix a memory leak for scopes array when it finds a variable in the
global scope.
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20110811110229.19900.63019.stgit@fedora15
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Introduce debuginfo to encapsulate dwarf information.
This new object allows us to reuse and expand debuginfo easily.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072739.6528.12438.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Move dwarf library related routines to dwarf-aux.{c,h}.
This includes several minor changes.
- Add simple documents for each API.
- Rename die_find_real_subprogram() to die_find_realfunc()
- Rename line_walk_handler_t to line_walk_callback_t.
- Minor cleanups.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072727.6528.57647.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Since there are dwarf_bitsize, dwarf_bitoffset and dwarf_bytesize
defined in libdw, we don't need die_get_bit_size, die_get_bit_offset
and die_get_byte_size anymore.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072721.6528.2747.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Since strtailcmp() is enough generic, it should be defined in string.c.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20110627072715.6528.10677.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Since die_find/walk* callbacks use DIE_FIND_CB_FOUND for
both of failed and found cases, it should be "END"
instead "FOUND" for avoiding confusion.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Link: http://lkml.kernel.org/r/20110627072709.6528.45706.stgit@fedora15
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
pubname_callback_param::found should be initialized to 0 in
fastpath lookup, the structure is on the stack and
uninitialized otherwise.
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Link: http://lkml.kernel.org/r/1304066518-30420-2-git-send-email-ming.m.lin@intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix a bug showing incorrect line number when a probe is put on the head of an
inline function. This patch updates find_perf_probe_point() and introduces new
rules to get correct line number.
- If debuginfo doesn't have a correct file name, we shouldn't return line
number too, because, without file name, line number is meaningless.
- If the address is in a function, it stores the function name and the offset
from the function entry.
- If the address is on a line, it tries to get the relative line number from
the function entry line, except for the address is same as the entry
address of the function (in this case, the relative line number should
be 0).
- If the address is in an inline function entry (call-site), it uses the
inline function call line number as the line on which the address is.
- If the address is in an inline function body, it stores the inline
function name and offset from the inline function call site instead of the
(non-inlined) function.
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110330092605.2132.11629.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>
Fix die_find_inlinefunc() to return correct innermost inlined function
at given address. Without this fix, it returns the outermost inlined
function.
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110330092559.2132.78634.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>
Since dwfl_end() closes given fd with dwfl, caller doesn't need to close its fd
when finishing process.
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110330092547.2132.93728.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>
Fix to ensure function declared file matches given file name. This fixes
a potential bug.
As I've commented on Lin Ming's fastpath enhancement, decl_file should
be checked on each probe point if user gives a probe point as func@file.
Cc: 2nddept-manager@sdl.hitachi.co.jp
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20110330092541.2132.3584.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>
v3 -> v2:
- Make pubname_search_cb more generic
- Add fastpath to find_probes also
v2 -> v1:
- Don't compare file names with cu_find_realpath(...), instead, compare
them with the name returned by dwarf_decl_file(sp_die)
The vmlinux file may have thousands of CUs.
We can lookup function name from .debug_pubnames section
to avoid the slow loop on CUs.
1. Improvement data for find_line_range
./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \
-s /home/mlin/linux-2.6 \
--line csum_partial_copy_to_user > tmp.log
before patch applied
=====================
847,988,276 cycles
0.355075856 seconds time elapsed
after patch applied
=====================
206,102,622 cycles
0.086883555 seconds time elapsed
2. Improvement data for find_probes
./perf stat -e cycles -r 10 -- ./perf probe -k /home/mlin/vmlinux \
-s /home/mlin/linux-2.6 \
--vars csum_partial_copy_to_user > tmp.log
before patch applied
=====================
848,490,844 cycles
0.355307901 seconds time elapsed
after patch applied
=====================
205,684,469 cycles
0.086694010 seconds time elapsed
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: linux-kernel <linux-kernel@vger.kernel.org>
LKML-Reference: <1301041668.14111.52.camel@minggr.sh.intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Newer compilers (gcc 4.6) complains about:
return ret < 0 ?: 0;
For the following reason:
util/probe-finder.c: In function ‘probe_point_lazy_walker’:
util/probe-finder.c:1331:18: error: the omitted middle operand in ?: will always be ‘true’, suggest explicit middle operand [-Werror=parentheses]
And indeed the return value is a somewhat obscure (but correct) value
of 'true', so return 'ret' instead - this is cleaner and unconfuses
GCC as well.
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
While fixing an error propagating problem in f809b25 I added two
redundant checks.
I did that because I didn't expect the checks to be on the while and for
loop condition expression, where they are tested before we run the loop,
where the 'ret' variable is set.
So remove it from there and leave it just after it is actually set,
eliminating unneded tests.
Reported-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There are two hunks in this patch that stops probe processing as soon as one
error is found, breaking out of loops, the other fix an error propagation that
should return a negative error number but instead was returning the result of
"ret < 0", which is 1 and thus made several error checks fail because they test
agains < 0.
The problem could be triggered by asking for a variable that was optimized out,
fact that should stop the whole probe processing but instead was segfaulting
while installing broken probes:
[root@emilia ~]# probe perf_mmap:55 user_lock_limit
Failed to find the location of user_lock_limit at this address.
Perhaps, it has been optimized out.
Failed to find 'user_lock_limit' in this function.
Add new events:
probe:perf_mmap (on perf_mmap:55 with user_lock_limit)
probe:perf_mmap_1 (on perf_mmap:55 with user_lock_limit)
Segmentation fault (core dumped)
[root@emilia ~]# perf probe -l
probe:perf_mmap (on perf_mmap:55@git/linux/kernel/perf_event.c with user_lock_limit)
probe:perf_mmap_1 (on perf_mmap:55@git/linux/kernel/perf_event.c with user_lock_limit)
[root@emilia ~]#
After the fix:
[root@emilia ~]# probe perf_mmap:55 user_lock_limit
Failed to find the location of user_lock_limit at this address.
Perhaps, it has been optimized out.
Failed to find 'user_lock_limit' in this function.
Error: Failed to add events. (-2)
[root@emilia ~]#
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
