Filter out instances except for inlined_subroutine and subprogram DIE in
die_walk_instances() and die_is_func_instance().
This fixes an issue that perf probe sets some probes on calling address
instead of a target function itself.
When perf probe walks on instances of an abstruct origin (a kind of
function prototype of inlined function), die_walk_instances() can also
pass a GNU_call_site (a GNU extension for call site) to callback. Since
it is not an inlined instance of target function, we have to filter out
when searching a probe point.
Without this patch, perf probe sets probes on call site address too.This
can happen on some function which is marked "inlined", but has actual
symbol. (I'm not sure why GCC mark it "inlined"):
# perf probe -D vfs_read
p:probe/vfs_read _text+2500017
p:probe/vfs_read_1 _text+2499468
p:probe/vfs_read_2 _text+2499563
p:probe/vfs_read_3 _text+2498876
p:probe/vfs_read_4 _text+2498512
p:probe/vfs_read_5 _text+2498627
With this patch:
Slightly different results, similar tho:
# perf probe -D vfs_read
p:probe/vfs_read _text+2498512
Committer testing:
# uname -a
Linux quaco 5.3.8-200.fc30.x86_64 #1 SMP Tue Oct 29 14:46:22 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
Before:
# perf probe -D vfs_read
p:probe/vfs_read _text+3131557
p:probe/vfs_read_1 _text+3130975
p:probe/vfs_read_2 _text+3131047
p:probe/vfs_read_3 _text+3130380
p:probe/vfs_read_4 _text+3130000
# uname -a
Linux quaco 5.3.8-200.fc30.x86_64 #1 SMP Tue Oct 29 14:46:22 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
#
After:
# perf probe -D vfs_read
p:probe/vfs_read _text+3130000
#
Fixes: db0d2c6420 ("perf probe: Search concrete out-of-line instances")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157241937063.32002.11024544873990816590.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Skip end-of-sequence and non-statement lines while walking through lines
list.
The "end-of-sequence" line information means:
"the current address is that of the first byte after the
end of a sequence of target machine instructions."
(DWARF version 4 spec 6.2.2)
This actually means out of scope and we can not probe on it.
On the other hand, the statement lines (is_stmt) means:
"the current instruction is a recommended breakpoint location.
A recommended breakpoint location is intended to “represent”
a line, a statement and/or a semantically distinct subpart
of a statement."
(DWARF version 4 spec 6.2.2)
So, non-statement line info also should be skipped.
These can reduce unneeded probe points and also avoid an error.
E.g. without this patch:
# perf probe -a "clear_tasks_mm_cpumask:1"
Added new events:
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask:1)
probe:clear_tasks_mm_cpumask_1 (on clear_tasks_mm_cpumask:1)
probe:clear_tasks_mm_cpumask_2 (on clear_tasks_mm_cpumask:1)
probe:clear_tasks_mm_cpumask_3 (on clear_tasks_mm_cpumask:1)
probe:clear_tasks_mm_cpumask_4 (on clear_tasks_mm_cpumask:1)
You can now use it in all perf tools, such as:
perf record -e probe:clear_tasks_mm_cpumask_4 -aR sleep 1
#
This puts 5 probes on one line, but acutally it's not inlined function.
This is because there are many non statement instructions at the
function prologue.
With this patch:
# perf probe -a "clear_tasks_mm_cpumask:1"
Added new event:
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask:1)
You can now use it in all perf tools, such as:
perf record -e probe:clear_tasks_mm_cpumask -aR sleep 1
#
Now perf-probe skips unneeded addresses.
Committer testing:
Slightly different results, but similar:
Before:
# uname -a
Linux quaco 5.3.8-200.fc30.x86_64 #1 SMP Tue Oct 29 14:46:22 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
#
# perf probe -a "clear_tasks_mm_cpumask:1"
Added new events:
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask:1)
probe:clear_tasks_mm_cpumask_1 (on clear_tasks_mm_cpumask:1)
probe:clear_tasks_mm_cpumask_2 (on clear_tasks_mm_cpumask:1)
You can now use it in all perf tools, such as:
perf record -e probe:clear_tasks_mm_cpumask_2 -aR sleep 1
#
After:
# perf probe -a "clear_tasks_mm_cpumask:1"
Added new event:
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask:1)
You can now use it in all perf tools, such as:
perf record -e probe:clear_tasks_mm_cpumask -aR sleep 1
# perf probe -l
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask@kernel/cpu.c)
#
Fixes: 4cc9cec636 ("perf probe: Introduce lines walker interface")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157241936090.32002.12156347518596111660.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Make find_best_scope() returns innermost DIE at given address if there
is no best matched scope DIE. Since Gcc sometimes generates intuitively
strange line info which is out of inlined function address range, we
need this fixup.
Without this, sometimes perf probe failed to probe on a line inside an
inlined function:
# perf probe -D ksys_open:3
Failed to find scope of probe point.
Error: Failed to add events.
With this fix, 'perf probe' can probe it:
# perf probe -D ksys_open:3
p:probe/ksys_open _text+25707308
p:probe/ksys_open_1 _text+25710596
p:probe/ksys_open_2 _text+25711114
p:probe/ksys_open_3 _text+25711343
p:probe/ksys_open_4 _text+25714058
p:probe/ksys_open_5 _text+2819653
p:probe/ksys_open_6 _text+2819701
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Link: http://lore.kernel.org/lkml/157291300887.19771.14936015360963292236.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Currently when cross compiling perf tool for ARM64 on my x86 machine I
get this error:
arch/arm64/util/sym-handling.c:9:10: fatal error: gelf.h: No such file or directory
#include <gelf.h>
For the build, libelf is reported off:
Auto-detecting system features:
...
... libelf: [ OFF ]
Indeed, test-libelf is not built successfully:
more ./build/feature/test-libelf.make.output
test-libelf.c:2:10: fatal error: libelf.h: No such file or directory
#include <libelf.h>
^~~~~~~~~~
compilation terminated.
I have no such problems natively compiling on ARM64, and I did not
previously have this issue for cross compiling. Fix by relocating the
gelf.h include.
Signed-off-by: John Garry <john.garry@huawei.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lore.kernel.org/lkml/1573045254-39833-1-git-send-email-john.garry@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix to show ranges of variables (--range and --vars option) in functions
which DIE has only ranges but no entry_pc attribute.
Without this fix:
# perf probe --range -V clear_tasks_mm_cpumask
Available variables at clear_tasks_mm_cpumask
@<clear_tasks_mm_cpumask+0>
(No matched variables)
With this fix:
# perf probe --range -V clear_tasks_mm_cpumask
Available variables at clear_tasks_mm_cpumask
@<clear_tasks_mm_cpumask+0>
[VAL] int cpu @<clear_tasks_mm_cpumask+[0-35,317-317,2052-2059]>
Committer testing:
Before:
[root@quaco ~]# perf probe --range -V clear_tasks_mm_cpumask
Available variables at clear_tasks_mm_cpumask
@<clear_tasks_mm_cpumask+0>
(No matched variables)
[root@quaco ~]#
After:
[root@quaco ~]# perf probe --range -V clear_tasks_mm_cpumask
Available variables at clear_tasks_mm_cpumask
@<clear_tasks_mm_cpumask+0>
[VAL] int cpu @<clear_tasks_mm_cpumask+[0-23,23-105,105-106,106-106,1843-1850,1850-1862]>
[root@quaco ~]#
Using it:
[root@quaco ~]# perf probe clear_tasks_mm_cpumask cpu
Added new event:
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask with cpu)
You can now use it in all perf tools, such as:
perf record -e probe:clear_tasks_mm_cpumask -aR sleep 1
[root@quaco ~]# perf probe -l
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask@kernel/cpu.c with cpu)
[root@quaco ~]#
[root@quaco ~]# perf trace -e probe:*cpumask
^C[root@quaco ~]#
Fixes: 349e8d2611 ("perf probe: Add --range option to show a variable's location range")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157199323018.8075.8179744380479673672.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since debuginfo__find_probe_point() uses dwarf_entrypc() for finding the
entry address of the function on which a probe is, it will fail when the
function DIE has only ranges attribute.
To fix this issue, use die_entrypc() instead of dwarf_entrypc().
Without this fix, perf probe -l shows incorrect offset:
# perf probe -l
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask+18446744071579263632@work/linux/linux/kernel/cpu.c)
probe:clear_tasks_mm_cpumask_1 (on clear_tasks_mm_cpumask+18446744071579263752@work/linux/linux/kernel/cpu.c)
With this:
# perf probe -l
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask@work/linux/linux/kernel/cpu.c)
probe:clear_tasks_mm_cpumask_1 (on clear_tasks_mm_cpumask:21@work/linux/linux/kernel/cpu.c)
Committer testing:
Before:
[root@quaco ~]# perf probe -l
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask+18446744071579765152@kernel/cpu.c)
[root@quaco ~]#
After:
[root@quaco ~]# perf probe -l
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask@kernel/cpu.c)
[root@quaco ~]#
Fixes: 1d46ea2a6a ("perf probe: Fix listing incorrect line number with inline function")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157199321227.8075.14655572419136993015.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix perf probe to probe an inlne function which has no entry pc
or low pc but only has ranges attribute.
This seems very rare case, but I could find a few examples, as
same as probe_point_search_cb(), use die_entrypc() to get the
entry address in probe_point_inline_cb() too.
Without this patch:
# perf probe -D __amd_put_nb_event_constraints
Failed to get entry address of __amd_put_nb_event_constraints.
Probe point '__amd_put_nb_event_constraints' not found.
Error: Failed to add events.
With this patch:
# perf probe -D __amd_put_nb_event_constraints
p:probe/__amd_put_nb_event_constraints amd_put_event_constraints+43
Committer testing:
Before:
[root@quaco ~]# perf probe -D __amd_put_nb_event_constraints
Failed to get entry address of __amd_put_nb_event_constraints.
Probe point '__amd_put_nb_event_constraints' not found.
Error: Failed to add events.
[root@quaco ~]#
After:
[root@quaco ~]# perf probe -D __amd_put_nb_event_constraints
p:probe/__amd_put_nb_event_constraints _text+33789
[root@quaco ~]#
Fixes: 4ea42b1814 ("perf: Add perf probe subcommand, a kprobe-event setup helper")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157199320336.8075.16189530425277588587.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix 'perf probe' to probe a function which has no entry pc or low pc but
only has ranges attribute.
probe_point_search_cb() uses dwarf_entrypc() to get the probe address,
but that doesn't work for the function DIE which has only ranges
attribute. Use die_entrypc() instead.
Without this fix:
# perf probe -k ../build-x86_64/vmlinux -D clear_tasks_mm_cpumask:0
Probe point 'clear_tasks_mm_cpumask' not found.
Error: Failed to add events.
With this:
# perf probe -k ../build-x86_64/vmlinux -D clear_tasks_mm_cpumask:0
p:probe/clear_tasks_mm_cpumask clear_tasks_mm_cpumask+0
Committer testing:
Before:
[root@quaco ~]# perf probe clear_tasks_mm_cpumask:0
Probe point 'clear_tasks_mm_cpumask' not found.
Error: Failed to add events.
[root@quaco ~]#
After:
[root@quaco ~]# perf probe clear_tasks_mm_cpumask:0
Added new event:
probe:clear_tasks_mm_cpumask (on clear_tasks_mm_cpumask)
You can now use it in all perf tools, such as:
perf record -e probe:clear_tasks_mm_cpumask -aR sleep 1
[root@quaco ~]#
Using it with 'perf trace':
[root@quaco ~]# perf trace -e probe:clear_tasks_mm_cpumask
Doesn't seem to be used in x86_64:
$ find . -name "*.c" | xargs grep clear_tasks_mm_cpumask
./kernel/cpu.c: * clear_tasks_mm_cpumask - Safely clear tasks' mm_cpumask for a CPU
./kernel/cpu.c:void clear_tasks_mm_cpumask(int cpu)
./arch/xtensa/kernel/smp.c: clear_tasks_mm_cpumask(cpu);
./arch/csky/kernel/smp.c: clear_tasks_mm_cpumask(cpu);
./arch/sh/kernel/smp.c: clear_tasks_mm_cpumask(cpu);
./arch/arm/kernel/smp.c: clear_tasks_mm_cpumask(cpu);
./arch/powerpc/mm/nohash/mmu_context.c: clear_tasks_mm_cpumask(cpu);
$ find . -name "*.h" | xargs grep clear_tasks_mm_cpumask
./include/linux/cpu.h:void clear_tasks_mm_cpumask(int cpu);
$ find . -name "*.S" | xargs grep clear_tasks_mm_cpumask
$
Fixes: e1ecbbc3fa ("perf probe: Fix to handle optimized not-inlined functions")
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157199319438.8075.4695576954550638618.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since there are some DIE which has only ranges instead of the
combination of entrypc/highpc, address verification must use
dwarf_haspc() instead of dwarf_entrypc/dwarf_highpc.
Also, the ranges only DIE will have a partial code in different section
(e.g. unlikely code will be in text.unlikely as "FUNC.cold" symbol). In
that case, we can not use dwarf_entrypc() or die_entrypc(), because the
offset from original DIE can be a minus value.
Instead, this simply gets the symbol and offset from symtab.
Without this patch;
# perf probe -D clear_tasks_mm_cpumask:1
Failed to get entry address of clear_tasks_mm_cpumask
Error: Failed to add events.
And with this patch:
# perf probe -D clear_tasks_mm_cpumask:1
p:probe/clear_tasks_mm_cpumask clear_tasks_mm_cpumask+0
p:probe/clear_tasks_mm_cpumask_1 clear_tasks_mm_cpumask+5
p:probe/clear_tasks_mm_cpumask_2 clear_tasks_mm_cpumask+8
p:probe/clear_tasks_mm_cpumask_3 clear_tasks_mm_cpumask+16
p:probe/clear_tasks_mm_cpumask_4 clear_tasks_mm_cpumask+82
Committer testing:
I managed to reproduce the above:
[root@quaco ~]# perf probe -D clear_tasks_mm_cpumask:1
p:probe/clear_tasks_mm_cpumask _text+919968
p:probe/clear_tasks_mm_cpumask_1 _text+919973
p:probe/clear_tasks_mm_cpumask_2 _text+919976
[root@quaco ~]#
But then when trying to actually put the probe in place, it fails if I
use :0 as the offset:
[root@quaco ~]# perf probe -L clear_tasks_mm_cpumask | head -5
<clear_tasks_mm_cpumask@/usr/src/debug/kernel-5.2.fc30/linux-5.2.18-200.fc30.x86_64/kernel/cpu.c:0>
0 void clear_tasks_mm_cpumask(int cpu)
1 {
2 struct task_struct *p;
[root@quaco ~]# perf probe clear_tasks_mm_cpumask:0
Probe point 'clear_tasks_mm_cpumask' not found.
Error: Failed to add events.
[root@quaco
The next patch is needed to fix this case.
Fixes: 576b523721 ("perf probe: Fix probing symbols with optimization suffix")
Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157199318513.8075.10463906803299647907.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix die_walk_lines() to list the function entry line correctly. Since
the dwarf_entrypc() does not return the entry pc if the DIE has only
range attribute, __die_walk_funclines() fails to list the declaration
line (entry line) in that case.
To solve this issue, this introduces die_entrypc() which correctly
returns the entry PC (the first address range) even if the DIE has only
range attribute. With this fix die_walk_lines() shows the function entry
line is able to probe correctly.
Fixes: 4cc9cec636 ("perf probe: Introduce lines walker interface")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157190837419.1859.4619125803596816752.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Since some inlined functions are in lexical blocks of given function, we
have to recursively walk through the DIE tree. Without this fix,
perf-probe -L can miss the inlined functions which is in a lexical block
(like if (..) { func() } case.)
However, even though, to walk the lines in a given function, we don't
need to follow the children DIE of inlined functions because those do
not have any lines in the specified function.
We need to walk though whole trees only if we walk all lines in a given
file, because an inlined function can include another inlined function
in the same file.
Fixes: b0e9cb2802 ("perf probe: Fix to search nested inlined functions in CU")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157190836514.1859.15996864849678136353.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Fix die_is_func_instance() to find range-only function instance.
In some case, a function instance can be made without any low PC or
entry PC, but only with address ranges by optimization. (e.g. cold text
partially in "text.unlikely" section) To find such function instance, we
have to check the range attribute too.
Fixes: e1ecbbc3fa ("perf probe: Fix to handle optimized not-inlined functions")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/157190835669.1859.8368628035930950596.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Support directory output that contains a regular perf.data file, named
"data". By default the directory is named perf.data i.e.
perf.data
└── data
Most of the infrastructure to support a directory is already there. This
patch makes the changes needed to support the format above.
Presently there is no 'perf record' option to output a directory.
This is preparation for adding support for putting a copy of /proc/kcore in
the directory.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lore.kernel.org/lkml/20191004083121.12182-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
