The tools so far have been using the strerror_r() GNU variant, that
returns a string, be it the buffer passed or something else.
But that, besides being tricky in cases where we expect that the
function using strerror_r() returns the error formatted in a provided
buffer (we have to check if it returned something else and copy that
instead), breaks the build on systems not using glibc, like Alpine
Linux, where musl libc is used.
So, introduce yet another wrapper, str_error_r(), that has the GNU
interface, but uses the portable XSI variant of strerror_r(), so that
users rest asured that the provided buffer is used and it is what is
returned.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-d4t42fnf48ytlk8rjxs822tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Check the return value of strbuf APIs in perf-probe
related code, so that it can handle errors in strbuf.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160510054707.6158.69861.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We have addch() for chars, add() for fixed size data, and addstr() for
variable length strings, use them.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-0ap02fn2xtvpduj2j6b2o1j4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
'perf probe' through debuginfo__find_probes() in util/probe-finder.c
checks for the functions' frame descriptions in either .eh_frame section
of an ELF or the .debug_frame.
The check is based on whether either one of these sections is present.
Depending on distro, toolchain defaults, architetcutre, build flags,
etc., CFI might be found in either .eh_frame and/or .debug_frame.
Sometimes, it may happen that, .eh_frame, even if present, may not be
complete and may miss some descriptions.
Therefore, to be sure, to find the CFI covering an address we will
always have to investigate both if available.
For e.g., in powerpc, this may happen:
$ gcc -g bin.c -o bin
$ objdump --dwarf ./bin
<1><145>: Abbrev Number: 7 (DW_TAG_subprogram)
<146> DW_AT_external : 1
<146> DW_AT_name : (indirect string, offset: 0x9e): main
<14a> DW_AT_decl_file : 1
<14b> DW_AT_decl_line : 39
<14c> DW_AT_prototyped : 1
<14c> DW_AT_type : <0x57>
<150> DW_AT_low_pc : 0x100007b8
If the .eh_frame and .debug_frame are checked for the same binary, we
will find that, .eh_frame (although present) doesn't contain a
description for "main" function.
But, .debug_frame has a description:
000000d8 00000024 00000000 FDE cie=00000000 pc=100007b8..10000838
DW_CFA_advance_loc: 16 to 100007c8
DW_CFA_def_cfa_offset: 144
DW_CFA_offset_extended_sf: r65 at cfa+16
...
Due to this (since, perf checks whether .eh_frame is present and goes on
searching for that address inside that frame), perf is unable to process
the probes:
# perf probe -x ./bin main
Failed to get call frame on 0x100007b8
Error: Failed to add events.
To avoid this issue, we need to check both the sections (.eh_frame and
.debug_frame), which is done in this patch.
Note that, we can always force everything into both .eh_frame and
.debug_frame by:
$ gcc bin.c -fasynchronous-unwind-tables -fno-dwarf2-cfi-asm -g -o bin
Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Mark Wielaard <mjw@redhat.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/1454426806-13974-1-git-send-email-hemant@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The commit 05c8d802fa ("perf probe: Fix to free temporal Dwarf_Frame")
tried to fix the memory leak of Dwarf_Frame, but it released the frame
at wrong point. Since the dwarf_frame_cfa(frame, &pf->fb_ops, &nops) can
return an address inside the frame data structure to pf->fb_ops, we can
not release the frame before using pf->fb_ops.
This reverts the commit and releases the frame afterwards (right before
returning from call_probe_finder) correctly.
Reported-and-Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Reported-by: Michael Petlan <mpetlan@redhat.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 05c8d802fa ("perf probe: Fix to free temporal Dwarf_Frame")
LPU-Reference: 20151125103432.1473.31009.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since dwarf_cfi_addrframe returns malloc'd Dwarf_Frame object, it has to
be freed after it is used.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20151118064011.30709.65674.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When probing with a glob, errors in add_probe_trace_event() won't be
passed to debuginfo__find_trace_events() because it would be modified by
probe_point_search_cb(). It causes a segfault if perf fails to find an
argument for a probe point matched by the glob. For example:
# ./perf probe -v -n 'SyS_dup? oldfd'
probe-definition(0): SyS_dup? oldfd
symbol:SyS_dup? file:(null) line:0 offset:0 return:0 lazy:(null)
parsing arg: oldfd into oldfd
1 arguments
Looking at the vmlinux_path (7 entries long)
Using /lib/modules/4.3.0-rc4+/build/vmlinux for symbols
Open Debuginfo file: /lib/modules/4.3.0-rc4+/build/vmlinux
Try to find probe point from debuginfo.
Matched function: SyS_dup3
found inline addr: 0xffffffff812095c0
Probe point found: SyS_dup3+0
Searching 'oldfd' variable in context.
Converting variable oldfd into trace event.
oldfd type is long int.
found inline addr: 0xffffffff812096d4
Probe point found: SyS_dup2+36
Searching 'oldfd' variable in context.
Failed to find 'oldfd' in this function.
Matched function: SyS_dup3
Probe point found: SyS_dup3+0
Searching 'oldfd' variable in context.
Converting variable oldfd into trace event.
oldfd type is long int.
Matched function: SyS_dup2
Probe point found: SyS_dup2+0
Searching 'oldfd' variable in context.
Converting variable oldfd into trace event.
oldfd type is long int.
Found 4 probe_trace_events.
Opening /sys/kernel/debug/tracing//kprobe_events write=1
Writing event: p:probe/SyS_dup3 _text+2135488 oldfd=%di:s64
Segmentation fault (core dumped)
#
This patch ensures that add_probe_trace_event() doesn't touches
tf->ntevs and tf->tevs if those functions fail.
After the patch:
# perf probe 'SyS_dup? oldfd'
Failed to find 'oldfd' in this function.
Added new events:
probe:SyS_dup3 (on SyS_dup? with oldfd)
probe:SyS_dup3_1 (on SyS_dup? with oldfd)
probe:SyS_dup2 (on SyS_dup? with oldfd)
You can now use it in all perf tools, such as:
perf record -e probe:SyS_dup2 -aR sleep 1
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447417761-156094-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix memory leaking on the debuginfo__find_trace_events() failure path
which frees an array of probe_trace_events but doesn't clears all the
allocated sub-structures and strings.
So, before doing zfree(tevs), clear all the array elements which may
have allocated resources.
Reported-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447417761-156094-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf probe shows more precisely message when it finds given
%return target function is inlined.
Without this fix:
----
# ./perf probe -V getname_flags%return
Return probe must be on the head of a real function.
Debuginfo analysis failed.
Error: Failed to show vars.
----
With this fix:
----
# ./perf probe -V getname_flags%return
Failed to find "getname_flags%return",
because getname_flags is an inlined function and has no return point.
Debuginfo analysis failed.
Error: Failed to show vars.
----
Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20150930164137.3733.55055.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Perf probe always failed to find appropriate line numbers because of
failing to find .text start address offset from debuginfo.
e.g.
----
# ./perf probe -m pcspkr pcspkr_event:5
Added new events:
probe:pcspkr_event (on pcspkr_event:5 in pcspkr)
probe:pcspkr_event_1 (on pcspkr_event:5 in pcspkr)
You can now use it in all perf tools, such as:
perf record -e probe:pcspkr_event_1 -aR sleep 1
# ./perf probe -l
Failed to find debug information for address ffffffffa031f006
Failed to find debug information for address ffffffffa031f016
probe:pcspkr_event (on pcspkr_event+6 in pcspkr)
probe:pcspkr_event_1 (on pcspkr_event+22 in pcspkr)
----
This fixes the above issue as below.
1. Get the relative address of the symbol in .text by using
map->start.
2. Adjust the address by adding the offset of .text section
in the kernel module binary.
With this fix, perf probe -l shows lines correctly.
----
# ./perf probe -l
probe:pcspkr_event (on pcspkr_event:5@drivers/input/misc/pcspkr.c in pcspkr)
probe:pcspkr_event_1 (on pcspkr_event:5@drivers/input/misc/pcspkr.c in pcspkr)
----
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20150930164132.3733.24643.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix a trival bug about libdwfl usage of the report session, it should
explicitly begin and end a report session around dwfl_report_offline().
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20150930164128.3733.59876.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It should be useful to allow 'perf probe' probe at absolute offset of a
target. For example, when (u)probing at a instruction of a shared object
in a embedded system where debuginfo is not avaliable but we know the
offset of that instruction by manually digging.
This patch enables following perf probe command syntax:
# perf probe 0xffffffff811e6615
And
# perf probe /lib/x86_64-linux-gnu/libc-2.19.so 0xeb860
In the above example, we don't need a anchor symbol, so it is possible
to compute absolute addresses using other methods and then use 'perf
probe' to create the probing points.
v1 -> v2:
Drop the leading '+' in cmdline;
Allow uprobing at offset 0x0;
Improve 'perf probe -l' result when uprobe at area without debuginfo.
v2 -> v3:
Split bugfix to a separated patch.
Test result:
# perf probe 0xffffffff8119d175 %ax
# perf probe sys_write %ax
# perf probe /lib64/libc-2.18.so 0x0 %ax
# perf probe /lib64/libc-2.18.so 0x5 %ax
# perf probe /lib64/libc-2.18.so 0xd8e40 %ax
# perf probe /lib64/libc-2.18.so __write %ax
# perf probe /lib64/libc-2.18.so 0xd8e49 %ax
# cat /sys/kernel/debug/tracing/uprobe_events
p:probe_libc/abs_0 /lib64/libc-2.18.so:0x (null) arg1=%ax
p:probe_libc/abs_5 /lib64/libc-2.18.so:0x0000000000000005 arg1=%ax
p:probe_libc/abs_d8e40 /lib64/libc-2.18.so:0x00000000000d8e40 arg1=%ax
p:probe_libc/__write /lib64/libc-2.18.so:0x00000000000d8e40 arg1=%ax
p:probe_libc/abs_d8e49 /lib64/libc-2.18.so:0x00000000000d8e49 arg1=%ax
# cat /sys/kernel/debug/tracing/kprobe_events
p:probe/abs_ffffffff8119d175 0xffffffff8119d175 arg1=%ax
p:probe/sys_write _text+1692016 arg1=%ax
# perf probe -l
Failed to find debug information for address 5
probe:abs_ffffffff8119d175 (on sys_write+5 with arg1)
probe:sys_write (on sys_write with arg1)
probe_libc:__write (on @unix/syscall-template.S:81 in /lib64/libc-2.18.so with arg1)
probe_libc:abs_0 (on 0x0 in /lib64/libc-2.18.so with arg1)
probe_libc:abs_5 (on 0x5 in /lib64/libc-2.18.so with arg1)
probe_libc:abs_d8e40 (on @unix/syscall-template.S:81 in /lib64/libc-2.18.so with arg1)
probe_libc:abs_d8e49 (on __GI___libc_write+9 in /lib64/libc-2.18.so with arg1)
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1440586666-235233-7-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
So that we can pass more info to strlist__new() without having to change
its function signature, just adding entries to the strlist_config struct
with sensible defaults for when those fields are not specified.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-5uaaler4931i0s9sedxjquhq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This has a different model than the 'thread' and 'map' struct lifetimes:
there is not a definitive "don't use this DSO anymore" event, i.e. we may
get many 'struct map' holding references to the '/usr/lib64/libc-2.20.so'
DSO but then at some point some DSO may have no references but we still
don't want to straight away release its resources, because "soon" we may
get a new 'struct map' that needs it and we want to reuse its symtab or
other resources.
So we need some way to garbage collect it when crossing some memory
usage threshold, which is left for anoter patch, for now it is
sufficient to release it when calling dsos__exit(), i.e. when deleting
the whole list as part of deleting the 'struct machine' containing it,
which will leave only referenced objects being used.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/n/tip-majzgz07cm90t2tejrjy4clf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf probe currently errors out if there are any tail calls to probed
functions:
[root@rhel71be]# perf probe do_fork
Failed to find probe point in any functions.
Error: Failed to add events.
Fix this by teaching perf to ignore tail calls.
Without patch:
[root@rhel71be perf]# ./perf probe -v do_fork
probe-definition(0): do_fork symbol:do_fork file:(null) line:0 offset:0
return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (7 entries long)
symsrc__init: build id mismatch for /boot/vmlinux.
Using /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux for symbols
Open Debuginfo file:
/usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux
Try to find probe point from debuginfo.
found inline addr: 0xc0000000000bb9b0
Probe point found: do_fork+0
found inline addr: 0xc0000000000bbe20
Probe point found: kernel_thread+48
found inline addr: 0xc0000000000bbe5c
Probe point found: sys_fork+28
found inline addr: 0xc0000000000bbfac
Probe point found: sys_vfork+44
found inline addr: 0xc0000000000bc27c
Failed to find probe point in any functions.
An error occurred in debuginfo analysis (-2).
Error: Failed to add events. Reason: No such file or directory (Code: -2)
With patch:
[root@rhel71be perf]# ./perf probe -v do_fork
probe-definition(0): do_fork symbol:do_fork file:(null) line:0 offset:0
return:0 lazy:(null)
0 arguments
Looking at the vmlinux_path (7 entries long)
symsrc__init: build id mismatch for /boot/vmlinux.
Using /usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux for symbols
Open Debuginfo file:
/usr/lib/debug/lib/modules/3.10.0-201.el7.ppc64/vmlinux
Try to find probe point from debuginfo.
found inline addr: 0xc0000000000bb9b0
Probe point found: do_fork+0
found inline addr: 0xc0000000000bbe20
Probe point found: kernel_thread+48
found inline addr: 0xc0000000000bbe5c
Probe point found: sys_fork+28
found inline addr: 0xc0000000000bbfac
Probe point found: sys_vfork+44
found inline addr: 0xc0000000000bc27c
Ignoring tail call from SyS_clone
Found 4 probe_trace_events.
Opening /sys/kernel/debug/tracing/kprobe_events write=1
No kprobe blacklist support, ignored
Added new events:
Writing event: p:probe/do_fork _text+768432
Failed to write event: Invalid argument
Error: Failed to add events. Reason: Invalid argument (Code: -22)
[Ignore the error about failure to write event - this kernel is missing
a patch to resolve _text properly]
The reason to ignore tail calls is that the address does not belong to
any function frame. In the example above, the address in SyS_clone is
0xc0000000000bc27c, but looking at the debug-info:
<1><830081>: Abbrev Number: 133 (DW_TAG_subprogram)
<830083> DW_AT_external : 1
<830083> DW_AT_name : (indirect string, offset: 0x3cea3): SyS_clone
<830087> DW_AT_decl_file : 7
<830088> DW_AT_decl_line : 1689
<83008a> DW_AT_prototyped : 1
<83008a> DW_AT_type : <0x8110eb>
<83008e> DW_AT_low_pc : 0xc0000000000bc270
<830096> DW_AT_high_pc : 0xc
<83009e> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<8300a0> DW_AT_GNU_all_call_sites: 1
<8300a0> DW_AT_sibling : <0x830178>
<snip>
<3><830147>: Abbrev Number: 125 (DW_TAG_GNU_call_site)
<830148> DW_AT_low_pc : 0xc0000000000bc27c
<830150> DW_AT_GNU_tail_call: 1
<830150> DW_AT_abstract_origin: <0x82e7e1>
The frame ends at 0xc0000000000bc27c. I suppose this is why this
particular call is a "tail" call. FWIW, systemtap seems to ignore these
as well and requires users to explicitly place probes at these call
sites if necessary. I print out the caller so that users know.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/1430394151-15928-1-git-send-email-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Indicate to check variable location range in error message when we got
failed to find the variable.
Before this patch:
$ perf probe --add 'generic_perform_write+118 bytes'
Failed to find the location of bytes at this address.
Perhaps, it has been optimized out.
Error: Failed to add events.
After this patch:
$ perf probe --add 'generic_perform_write+118 bytes'
Failed to find the location of the 'bytes' variable at this address.
Perhaps it has been optimized out.
Use -V with the --range option to show 'bytes' location range.
Error: Failed to add events.
Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1431336304-16863-3-git-send-email-hekuang@huawei.com
[ Improve the error message based on lkml thread ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
It is not easy for users to get the accurate byte offset or the line
number where a local variable can be probed.
With '--range' option, local variables in the scope of the probe point
are showed with a byte offset range, and can be added according to this
range information.
For example, there are some variables in the function
generic_perform_write():
<generic_perform_write@mm/filemap.c:0>
0 ssize_t generic_perform_write(struct file *file,
1 struct iov_iter *i, loff_t pos)
2 {
3 struct address_space *mapping = file->f_mapping;
4 const struct address_space_operations *a_ops = mapping->a_ops;
...
42 status = a_ops->write_begin(file, mapping, pos, bytes, flags,
&page, &fsdata);
44 if (unlikely(status < 0))
But we fail when we try to probe the variable 'a_ops' at line 42 or 44.
$ perf probe --add 'generic_perform_write:42 a_ops'
Failed to find the location of a_ops at this address.
Perhaps, it has been optimized out.
This is because the source code do not match the assembly, so a variable
may not be available in the source code line where it appears.
After this patch, we can lookup the accurate byte offset range of a
variable, 'INV' indicates that this variable is not valid at the given
point, but available in the scope:
$ perf probe --vars 'generic_perform_write:42' --range
Available variables at generic_perform_write:42
@<generic_perform_write+141>
[INV] ssize_t written @<generic_perform_write+[324-331]>
[INV] struct address_space_operations* a_ops @<generic_perform_write+[55-61,170-176,223-246]>
[VAL] (unknown_type) fsdata @<generic_perform_write+[70-307,346-411]>
[VAL] loff_t pos @<generic_perform_write+[0-286,286-336,346-411]>
[VAL] long int status @<generic_perform_write+[83-342,346-411]>
[VAL] long unsigned int bytes @<generic_perform_write+[122-311,320-338,346-403,403-411]>
[VAL] struct address_space* mapping @<generic_perform_write+[35-344,346-411]>
[VAL] struct iov_iter* i @<generic_perform_write+[0-340,346-411]>
[VAL] struct page* page @<generic_perform_write+[70-307,346-411]>
Then it is more clear for us to add a probe with this variable:
$ perf probe --add 'generic_perform_write+170 a_ops'
Added new event:
probe:generic_perform_write (on generic_perform_write+170 with a_ops)
Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1431336304-16863-2-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use struct strbuf instead of bare char[] to remove the length limitation
of variables in variable_list, so they will not disappear due to
overlength, and make preparation for adding more description for
variables.
Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1431336304-16863-1-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Support glob wildcards for function name when adding new probes. This
will allow us to build caches of function-entry level information with
$params.
e.g.
----
# perf probe --no-inlines --add 'kmalloc* $params'
Added new events:
probe:kmalloc_slab (on kmalloc* with $params)
probe:kmalloc_large_node (on kmalloc* with $params)
probe:kmalloc_order_trace (on kmalloc* with $params)
You can now use it in all perf tools, such as:
perf record -e probe:kmalloc_order_trace -aR sleep 1
# perf probe --list
probe:kmalloc_large_node (on kmalloc_large_node@mm/slub.c with size flags node)
probe:kmalloc_order_trace (on kmalloc_order_trace@mm/slub.c with size flags order)
probe:kmalloc_slab (on kmalloc_slab@mm/slab_common.c with size flags)
----
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150508010335.24812.19972.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add --no-inlines(--inlines) option to avoid searching inline functions.
Searching all functions which matches glob pattern can take a long time
and find a lot of inline functions.
With this option perf-probe searches target on the non-inlined
functions.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150508010333.24812.86568.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Introduce probe_conf global configuration parameters for probe-event and
probe-finder, and removes related parameters from APIs.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150508010330.24812.21095.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf fixes from Ingo Molnar:
"Mostly tooling fixes, but also an uncore PMU driver fix and an uncore
PMU driver hardware-enablement addition"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf probe: Fix segfault if passed with ''.
perf report: Fix -T/--threads option to work again
perf bench numa: Fix immediate meeting of convergence condition
perf bench numa: Fixes of --quiet argument
perf bench futex: Fix hung wakeup tasks after requeueing
perf probe: Fix bug with global variables handling
perf top: Fix a segfault when kernel map is restricted.
tools lib traceevent: Fix build failure on 32-bit arch
perf kmem: Fix compiles on RHEL6/OL6
tools lib api: Undefine _FORTIFY_SOURCE before setting it
perf kmem: Consistently use PRIu64 for printing u64 values
perf trace: Disable events and drain events when forked workload ends
perf trace: Enable events when doing system wide tracing and starting a workload
perf/x86/intel/uncore: Move PCI IDs for IMC to uncore driver
perf/x86/intel/uncore: Add support for Intel Haswell ULT (lower power Mobile Processor) IMC uncore PMUs
perf/x86/intel: Add cpu_(prepare|starting|dying) for core_pmu
There are missing curly braces which causes find_variable() return wrong
value when probing with global variables.
This problem can be reproduced as following:
$ perf probe -v --add='generic_perform_write global_variable_for_test'
...
Try to find probe point from debuginfo.
Probe point found: generic_perform_write+0
Searching 'global_variable_for_test' variable in context.
An error occurred in debuginfo analysis (-2).
Error: Failed to add events. Reason: No such file or directory (Code: -2)
After this patch:
$ perf probe -v --add='generic_perform_write global_variable_for_test'
...
Converting variable global_variable_for_test into trace event.
global_variable_for_test type is int.
Found 1 probe_trace_events.
Opening /sys/kernel/debug/tracing/kprobe_events write=1
Added new event:
Writing event: p:probe/generic_perform_write _stext+1237464
global_variable_for_test=@global_variable_for_test+0:s32
probe:generic_perform_write (on generic_perform_write with
global_variable_for_test)
You can now use it in all perf tools, such as:
perf record -e probe:generic_perform_write -aR sleep 1
Signed-off-by: He Kuang <hekuang@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1429949338-18678-1-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf updates from Ingo Molnar:
"This update has mostly fixes, but also other bits:
- perf tooling fixes
- PMU driver fixes
- Intel Broadwell PMU driver HW-enablement for LBR callstacks
- a late coming 'perf kmem' tool update that enables it to also
analyze page allocation data. Note, this comes with MM tracepoint
changes that we believe to not break anything: because it changes
the formerly opaque 'struct page *' field that uniquely identifies
pages to 'pfn' which identifies pages uniquely too, but isn't as
opaque and can be used for other purposes as well"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/pt: Fix and clean up error handling in pt_event_add()
perf/x86/intel: Add Broadwell support for the LBR callstack
perf/x86/intel/rapl: Fix energy counter measurements but supporing per domain energy units
perf/x86/intel: Fix Core2,Atom,NHM,WSM cycles:pp events
perf/x86: Fix hw_perf_event::flags collision
perf probe: Fix segfault when probe with lazy_line to file
perf probe: Find compilation directory path for lazy matching
perf probe: Set retprobe flag when probe in address-based alternative mode
perf kmem: Analyze page allocator events also
tracing, mm: Record pfn instead of pointer to struct page
Pull perf changes from Ingo Molnar:
"Core kernel changes:
- One of the more interesting features in this cycle is the ability
to attach eBPF programs (user-defined, sandboxed bytecode executed
by the kernel) to kprobes.
This allows user-defined instrumentation on a live kernel image
that can never crash, hang or interfere with the kernel negatively.
(Right now it's limited to root-only, but in the future we might
allow unprivileged use as well.)
(Alexei Starovoitov)
- Another non-trivial feature is per event clockid support: this
allows, amongst other things, the selection of different clock
sources for event timestamps traced via perf.
This feature is sought by people who'd like to merge perf generated
events with external events that were measured with different
clocks:
- cluster wide profiling
- for system wide tracing with user-space events,
- JIT profiling events
etc. Matching perf tooling support is added as well, available via
the -k, --clockid <clockid> parameter to perf record et al.
(Peter Zijlstra)
Hardware enablement kernel changes:
- x86 Intel Processor Trace (PT) support: which is a hardware tracer
on steroids, available on Broadwell CPUs.
The hardware trace stream is directly output into the user-space
ring-buffer, using the 'AUX' data format extension that was added
to the perf core to support hardware constraints such as the
necessity to have the tracing buffer physically contiguous.
This patch-set was developed for two years and this is the result.
A simple way to make use of this is to use BTS tracing, the PT
driver emulates BTS output - available via the 'intel_bts' PMU.
More explicit PT specific tooling support is in the works as well -
will probably be ready by 4.2.
(Alexander Shishkin, Peter Zijlstra)
- x86 Intel Cache QoS Monitoring (CQM) support: this is a hardware
feature of Intel Xeon CPUs that allows the measurement and
allocation/partitioning of caches to individual workloads.
These kernel changes expose the measurement side as a new PMU
driver, which exposes various QoS related PMU events. (The
partitioning change is work in progress and is planned to be merged
as a cgroup extension.)
(Matt Fleming, Peter Zijlstra; CPU feature detection by Peter P
Waskiewicz Jr)
- x86 Intel Haswell LBR call stack support: this is a new Haswell
feature that allows the hardware recording of call chains, plus
tooling support. To activate this feature you have to enable it
via the new 'lbr' call-graph recording option:
perf record --call-graph lbr
perf report
or:
perf top --call-graph lbr
This hardware feature is a lot faster than stack walk or dwarf
based unwinding, but has some limitations:
- It reuses the current LBR facility, so LBR call stack and
branch record can not be enabled at the same time.
- It is only available for user-space callchains.
(Yan, Zheng)
- x86 Intel Broadwell CPU support and various event constraints and
event table fixes for earlier models.
(Andi Kleen)
- x86 Intel HT CPUs event scheduling workarounds. This is a complex
CPU bug affecting the SNB,IVB,HSW families that results in counter
value corruption. The mitigation code is automatically enabled and
is transparent.
(Maria Dimakopoulou, Stephane Eranian)
The perf tooling side had a ton of changes in this cycle as well, so
I'm only able to list the user visible changes here, in addition to
the tooling changes outlined above:
User visible changes affecting all tools:
- Improve support of compressed kernel modules (Jiri Olsa)
- Save DSO loading errno to better report errors (Arnaldo Carvalho de Melo)
- Bash completion for subcommands (Yunlong Song)
- Add 'I' event modifier for perf_event_attr.exclude_idle bit (Jiri Olsa)
- Support missing -f to override perf.data file ownership. (Yunlong Song)
- Show the first event with an invalid filter (David Ahern, Arnaldo Carvalho de Melo)
User visible changes in individual tools:
'perf data':
New tool for converting perf.data to other formats, initially
for the CTF (Common Trace Format) from LTTng (Jiri Olsa,
Sebastian Siewior)
'perf diff':
Add --kallsyms option (David Ahern)
'perf list':
Allow listing events with 'tracepoint' prefix (Yunlong Song)
Sort the output of the command (Yunlong Song)
'perf kmem':
Respect -i option (Jiri Olsa)
Print big numbers using thousands' group (Namhyung Kim)
Allow -v option (Namhyung Kim)
Fix alignment of slab result table (Namhyung Kim)
'perf probe':
Support multiple probes on different binaries on the same command line (Masami Hiramatsu)
Support unnamed union/structure members data collection. (Masami Hiramatsu)
Check kprobes blacklist when adding new events. (Masami Hiramatsu)
'perf record':
Teach 'perf record' about perf_event_attr.clockid (Peter Zijlstra)
Support recording running/enabled time (Andi Kleen)
'perf sched':
Improve the performance of 'perf sched replay' on high CPU core count machines (Yunlong Song)
'perf report' and 'perf top':
Allow annotating entries in callchains in the hists browser (Arnaldo Carvalho de Melo)
Indicate which callchain entries are annotated in the
TUI hists browser (Arnaldo Carvalho de Melo)
Add pid/tid filtering to 'report' and 'script' commands (David Ahern)
Consider PERF_RECORD_ events with cpumode == 0 in 'perf top', removing one
cause of long term memory usage buildup, i.e. not processing PERF_RECORD_EXIT
events (Arnaldo Carvalho de Melo)
'perf stat':
Report unsupported events properly (Suzuki K. Poulose)
Output running time and run/enabled ratio in CSV mode (Andi Kleen)
'perf trace':
Handle legacy syscalls tracepoints (David Ahern, Arnaldo Carvalho de Melo)
Only insert blank duration bracket when tracing syscalls (Arnaldo Carvalho de Melo)
Filter out the trace pid when no threads are specified (Arnaldo Carvalho de Melo)
Dump stack on segfaults (Arnaldo Carvalho de Melo)
No need to explicitely enable evsels for workload started from perf, let it
be enabled via perf_event_attr.enable_on_exec, removing some events that take
place in the 'perf trace' before a workload is really started by it.
(Arnaldo Carvalho de Melo)
Allow mixing with tracepoints and suppressing plain syscalls. (Arnaldo Carvalho de Melo)
There's also been a ton of infrastructure work done, such as the
split-out of perf's build system into tools/build/ and other changes -
see the shortlog and changelog for details"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (358 commits)
perf/x86/intel/pt: Clean up the control flow in pt_pmu_hw_init()
perf evlist: Fix type for references to data_head/tail
perf probe: Check the orphaned -x option
perf probe: Support multiple probes on different binaries
perf buildid-list: Fix segfault when show DSOs with hits
perf tools: Fix cross-endian analysis
perf tools: Fix error path to do closedir() when synthesizing threads
perf tools: Fix synthesizing fork_event.ppid for non-main thread
perf tools: Add 'I' event modifier for exclude_idle bit
perf report: Don't call map__kmap if map is NULL.
perf tests: Fix attr tests
perf probe: Fix ARM 32 building error
perf tools: Merge all perf_event_attr print functions
perf record: Add clockid parameter
perf sched replay: Use replay_repeat to calculate the runavg of cpu usage instead of the default value 10
perf sched replay: Support using -f to override perf.data file ownership
perf sched replay: Fix the EMFILE error caused by the limitation of the maximum open files
perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task
perf sched replay: Fix the segmentation fault problem caused by pr_err in threads
perf sched replay: Realloc the memory of pid_to_task stepwise to adapt to the different pid_max configurations
...
Pull trivial tree from Jiri Kosina:
"Usual trivial tree updates. Nothing outstanding -- mostly printk()
and comment fixes and unused identifier removals"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
goldfish: goldfish_tty_probe() is not using 'i' any more
powerpc: Fix comment in smu.h
qla2xxx: Fix printks in ql_log message
lib: correct link to the original source for div64_u64
si2168, tda10071, m88ds3103: Fix firmware wording
usb: storage: Fix printk in isd200_log_config()
qla2xxx: Fix printk in qla25xx_setup_mode
init/main: fix reset_device comment
ipwireless: missing assignment
goldfish: remove unreachable line of code
coredump: Fix do_coredump() comment
stacktrace.h: remove duplicate declaration task_struct
smpboot.h: Remove unused function prototype
treewide: Fix typo in printk messages
treewide: Fix typo in printk messages
mod_devicetable: fix comment for match_flags
The first argument passed to find_probe_point_lazy() should be CU die,
which will be passed to die_walk_lines() when lazy_line matches.
Currently, when we probe with lazy_line pattern to file without function
name, NULL pointer is passed and causes a segment fault.
Can be reproduced as following:
$ perf probe -k vmlinux --add='fs/super.c;s->s_count=1;'
[ 1958.984658] perf[1020]: segfault at 10 ip 00007fc6e10d8c71 sp
00007ffcbfaaf900 error 4 in libdw-0.161.so[7fc6e10ce000+34000]
Segmentation fault
After this patch:
$ perf probe -k vmlinux --add='fs/super.c;s->s_count=1;'
Added new event:
probe:_stext (on @fs/super.c)
You can now use it in all perf tools, such as:
perf record -e probe:_stext -aR sleep 1
Signed-off-by: He Kuang <hekuang@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1428925290-5623-3-git-send-email-hekuang@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If we use lazy matching, it failed to open a souce file if perf command
is invoked outside of compilation directory:
$ perf probe -a '__schedule;clear_*'
Failed to open kernel/sched/core.c: No such file or directory
Error: Failed to add events. (-2)
OTOH, other commands like "probe -L" can solve the souce directory by
themselves. Let's make it possible for lazy matching too!
Signed-off-by: Naohiro Aota <naota@elisp.net>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
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/1426223923-1493-1-git-send-email-naota@elisp.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix 'perf probe' to track down unnamed union/structure members.
perf probe did not track down the tree of unnamed union/structure
members, since it just failed to find given "name" in a parent
structure/union. To solve this issue, I've introduced 2 changes.
- Fix die_find_member() to track down the type-DIE if it is
unnamed, and if it contains the specified member, returns the
unnamed member.
(note that we don't return found member, since unnamed member
has the offset in the parent structure)
- Fix convert_variable_fields() to track down the unnamed union/
structure (one-by-one).
With this patch, perf probe can access unnamed fields:
-----
#./perf probe -nfx ./perf lock__delete ops 'locked_ops=ops->locked.ops'
Added new event:
probe_perf:lock__delete (on lock__delete in /home/mhiramat/ksrc/linux-3/tools/perf/perf with ops locked_ops=ops->locked.ops)
You can now use it in all perf tools, such as:
perf record -e probe_perf:lock__delete -aR sleep 1
-----
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Report-Link: https://lkml.org/lkml/2015/3/5/431
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150402073312.14482.37942.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Remove bias offset to find probe point by address.
Without this patch, probe points on kernel and executables are shown
correctly, but do not work with libraries:
# ./perf probe -l
probe:do_fork (on do_fork@kernel/fork.c)
probe_libc:malloc (on malloc in /usr/lib64/libc-2.17.so)
probe_perf:strlist__new (on strlist__new@util/strlist.c in /home/mhiramat/ksrc/linux-3/tools/perf/perf)
Removing bias allows it to show it as real place:
# ./perf probe -l
probe:do_fork (on do_fork@kernel/fork.c)
probe_libc:malloc (on __libc_malloc@malloc/malloc.c in /usr/lib64/libc-2.17.so)
probe_perf:strlist__new (on strlist__new@util/strlist.c in /home/mhiramat/ksrc/linux-3/tools/perf/perf)
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naohiro Aota <naota@elisp.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150302124946.9191.64085.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix to handle optimized no-inline functions which have only function
definition but no actual instance at that point.
To fix this problem, we need to find actual instance of the function.
Without this patch:
----
# perf probe -a __up
Failed to get entry address of __up.
Error: Failed to add events.
# perf probe -L __up
Specified source line is not found.
Error: Failed to show lines.
----
With this patch:
----
# perf probe -a __up
Added new event:
probe:__up (on __up)
You can now use it in all perf tools, such as:
perf record -e probe:__up -aR sleep 1
# perf probe -L __up
<__up@/home/fedora/ksrc/linux-3/kernel/locking/semaphore.c:0>
0 static noinline void __sched __up(struct semaphore *sem)
{
struct semaphore_waiter *waiter = list_first_entry(&sem->wait_
struct semaphore_waite
4 list_del(&waiter->list);
5 waiter->up = true;
6 wake_up_process(waiter->task);
7 }
----
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150130093744.30575.43290.stgit@localhost.localdomain
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
David reported that perf can segfault when adding an uprobe event like
this:
$ perf probe -x /lib64/libc-2.14.90.so -a 'malloc size=%di'
(gdb) bt
#0 parse_eh_frame_hdr (hdr=0x0, hdr_size=2596, hdr_vaddr=71788,
ehdr=0x7fffffffd390, eh_frame_vaddr=
0x7fffffffd378, table_entries=0x8808d8, table_encoding=0x8808e0 "") at
dwarf_getcfi_elf.c:79
#1 0x000000385f81615a in getcfi_scn_eh_frame (hdr_vaddr=71788,
hdr_scn=0x8839b0, shdr=0x7fffffffd2f0, scn=<optimized out>,
ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:231
#2 getcfi_shdr (ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:283
#3 dwarf_getcfi_elf (elf=0x882b30) at dwarf_getcfi_elf.c:309
#4 0x00000000004d5bac in debuginfo__find_probes (pf=0x7fffffffd4f0,
dbg=Unhandled dwarf expression opcode 0xfa) at util/probe-finder.c:993
#5 0x00000000004d634a in debuginfo__find_trace_events (dbg=0x880840,
pev=<optimized out>, tevs=0x880f88, max_tevs=<optimized out>) at
util/probe-finder.c:1200
#6 0x00000000004aed6b in try_to_find_probe_trace_events (target=0x881b20
"/lib64/libpthread-2.14.90.so",
max_tevs=128, tevs=0x880f88, pev=0x859b30) at util/probe-event.c:482
#7 convert_to_probe_trace_events (target=0x881b20
"/lib64/libpthread-2.14.90.so", max_tevs=128, tevs=0x880f88,
pev=0x859b30) at util/probe-event.c:2356
#8 add_perf_probe_events (pevs=<optimized out>, npevs=1, max_tevs=128,
target=0x881b20 "/lib64/libpthread-2.14.90.so", force_add=false) at
util/probe-event.c:2391
#9 0x000000000044014f in __cmd_probe (argc=<optimized out>,
argv=0x7fffffffe2f0, prefix=Unhandled dwarf expression opcode 0xfa) at
at builtin-probe.c:488
#10 0x0000000000440313 in cmd_probe (argc=5, argv=0x7fffffffe2f0,
prefix=<optimized out>) at builtin-probe.c:506
#11 0x000000000041d133 in run_builtin (p=0x805680, argc=5,
argv=0x7fffffffe2f0) at perf.c:341
#12 0x000000000041c8b2 in handle_internal_command (argv=<optimized out>,
argc=<optimized out>) at perf.c:400
#13 run_argv (argv=<optimized out>, argcp=<optimized out>) at perf.c:444
#14 main (argc=5, argv=0x7fffffffe2f0) at perf.c:559
And I found a related commit (5704c8c4fa71 "getcfi_scn_eh_frame: Don't
crash and burn when .eh_frame bits aren't there.") in elfutils that can
lead to a unexpected crash like this. To safely use the function, it
needs to check the .eh_frame section is a PROGBITS type.
Reported-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Mark Wielaard <mjw@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20141230090533.GH6081@sejong
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Do not use dwfl_module_addrsym if dwarf_diename can find the symbol
name, since dwfl_module_addrsym can be failed on shared libraries.
Without this patch
----
$ perf probe -x ../lib/traceevent/libtraceevent.so -V create_arg_op
Failed to find symbol at 0x11df1
Failed to find the address of create_arg_op
Error: Failed to show vars.
----
With this patch
----
$ perf probe -x ../lib/traceevent/libtraceevent.so -V create_arg_op
Available variables at create_arg_op
@<create_arg_op+0>
enum filter_op_type btype
struct filter_arg* arg
----
This bug was reported on linux-perf-users@vger.kernel.org.
Reported-by: david lerner <dlernerdroid@gmail.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: david lerner <dlernerdroid@gmail.com>
Cc: linux-perf-user@vger.kernel.org
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://permalink.gmane.org/gmane.linux.kernel.perf.user/1691
Link: http://lkml.kernel.org/r/20140917084101.3722.25299.stgit@kbuild-f20.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To make error messages thread-safe, this replaces strerror with
strerror_r for warnings, and just shows the return value instead of
using strerror for debug messages.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naohiro Aota <naota@elisp.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20140814022234.3545.22199.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix an error message when failed to find given address in --vars
mode.
Without this fix, perf probe -V doesn't show the final "Error"
message if it fails to find given source line. Moreover, it
tells it fails to find "variables" instead of the source line.
-----
# perf probe -V foo@bar
Failed to find variables at foo@bar (0)
-----
The result also shows mysterious error code. Actually the error
returns 0 or -ENOENT means that it just fails to find the address
of given source line. (0 means there is no matching address,
and -ENOENT means there is an entry(DIE) but it has no instance,
e.g. an empty inlined function)
This fixes it to show what happened and the final error message
as below.
-----
# perf probe -V foo@bar
Failed to find the address of foo@bar
Error: Failed to show vars.
-----
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@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/20140606071359.6788.84716.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Improve the error message if we can not find given member in the given
structure. Currently perf probe shows a wrong error message as below.
-----
# perf probe getname_flags:65 "result->BOGUS"
result(type:filename) has no member BOGUS.
Failed to find 'result' in this function.
Error: Failed to add events. (-22)
-----
The first message is correct, but the second one is not, since we didn't
fail to find a variable but fails to find the member of given variable.
-----
# perf probe getname_flags:65 "result->BOGUS"
result(type:filename) has no member BOGUS.
Error: Failed to add events. (-22)
-----
With this patch, the error message shows only the first one. And if we
really failed to find given variable, it tells us so.
-----
# perf probe getname_flags:65 "BOGUS"
Failed to find 'BOGUS' in this function.
Error: Failed to add events. (-2)
-----
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@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/20140606071345.6788.23744.stgit@kbuild-fedora.novalocal
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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>
