linux-stable.git/tools/perf/util, branch linux-5.5.y

perf map: Fix off by one in strncpy() size argument

2020-04-02T13:09:53+00:00

commit db2c549407d4a76563c579e4768f7d6d32afefba upstream.

This patch fixes an off-by-one error in strncpy size argument in
tools/perf/util/map.c. The issue is that in:

        strncmp(filename, "/system/lib/", 11)

the passed string literal: "/system/lib/" has 12 bytes (without the NULL
byte) and the passed size argument is 11. As a result, the logic won't
match the ending "/" byte and will pass filepaths that are stored in
other directories e.g. "/system/libmalicious/bin" or just
"/system/libmalicious".

This functionality seems to be present only on Android. I assume the
/system/ directory is only writable by the root user, so I don't think
this bug has much (or any) security impact.

Fixes: eca818369996 ("perf tools: Add automatic remapping of Android libraries")
Signed-off-by: disconnect3d 
Cc: Alexander Shishkin 
Cc: Changbin Du 
Cc: Jiri Olsa 
Cc: John Keeping 
Cc: Mark Rutland 
Cc: Michael Lentine 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Stephane Eranian 
Link: http://lore.kernel.org/lkml/20200309104855.3775-1-dominik.b.czarnota@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf probe: Do not depend on dwfl_module_addrsym()

2020-04-01T09:00:09+00:00

commit 1efde2754275dbd9d11c6e0132a4f09facf297ab upstream.

Do not depend on dwfl_module_addrsym() because it can fail on user-space
shared libraries.

Actually, same bug was fixed by commit 664fee3dc379 ("perf probe: Do not
use dwfl_module_addrsym if dwarf_diename finds symbol name"), but commit
07d369857808 ("perf probe: Fix wrong address verification) reverted to
get actual symbol address from symtab.

This fixes it again by getting symbol address from DIE, and only if the
DIE has only address range, it uses dwfl_module_addrsym().

Fixes: 07d369857808 ("perf probe: Fix wrong address verification)
Reported-by: Alexandre Ghiti 
Signed-off-by: Masami Hiramatsu 
Tested-by: Alexandre Ghiti 
Cc: Alexander Shishkin 
Cc: Greg Kroah-Hartman 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Sasha Levin 
Link: http://lore.kernel.org/lkml/158281812176.476.14164573830975116234.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf probe: Fix to delete multiple probe event

2020-04-01T09:00:09+00:00

commit 6b8d68f1ce9266b05a55e93c62923ff51daae4c1 upstream.

When we put an event with multiple probes, perf-probe fails to delete
with filters. This comes from a failure to list up the event name
because of overwrapping its name.

To fix this issue, skip to list up the event which has same name.

Without this patch:

  # perf probe -l \*
    probe_perf:map__map_ip (on perf_sample__fprintf_brstackoff:21@
    probe_perf:map__map_ip (on perf_sample__fprintf_brstackoff:25@
    probe_perf:map__map_ip (on append_inlines:12@util/machine.c in
    probe_perf:map__map_ip (on unwind_entry:19@util/machine.c in /
    probe_perf:map__map_ip (on map__map_ip@util/map.h in /home/mhi
    probe_perf:map__map_ip (on map__map_ip@util/map.h in /home/mhi
  # perf probe -d \*
  "*" does not hit any event.
    Error: Failed to delete events. Reason: No such file or directory (Code: -2)

With it:

  # perf probe -d \*
  Removed event: probe_perf:map__map_ip
  #

Fixes: 72363540c009 ("perf probe: Support multiprobe event")
Reported-by: Arnaldo Carvalho de Melo 
Reported-by: He Zhe 
Signed-off-by: Masami Hiramatsu 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/158287666197.16697.7514373548551863562.stgit@devnote2
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf maps: Add missing unlock to maps__insert() error case

2020-03-05T15:45:23+00:00

commit 85fc95d75970ee7dd8e01904e7fb1197c275ba6b upstream.

`tools/perf/util/map.c` has a function named `maps__insert` that
acquires a write lock if its in multithread context.

Even though this lock is released when function successfully completes,
there's a branch that is executed when `maps_by_name == NULL` that
returns from this function without releasing the write lock.

Added an `up_write` to release the lock when this happens.

Fixes: a7c2b572e217 ("perf map_groups: Auto sort maps by name, if needed")
Signed-off-by: Cengiz Can 
Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: http://lore.kernel.org/lkml/20200120141553.23934-1-cengiz@kernel.wtf
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf stat: Don't report a null stalled cycles per insn metric

2020-02-19T18:54:12+00:00

commit 80cc7bb6c104d733bff60ddda09f19139c61507c upstream.

For data collected on machines with front end stalled cycles supported,
such as found on modern AMD CPU families, commit 146540fb545b ("perf
stat: Always separate stalled cycles per insn") introduces a new line in
CSV output with a leading comma that upsets some automated scripts.
Scripts have to use "-e ex_ret_instr" to work around this issue, after
upgrading to a version of perf with that commit.

We could add "if (have_frontend_stalled && !config->csv_sep)" to the not
(total && avg) else clause, to emphasize that CSV users are usually
scripts, and are written to do only what is needed, i.e., they wouldn't
typically invoke "perf stat" without specifying an explicit event list.

But - let alone CSV output - why should users now tolerate a constant
0-reporting extra line in regular terminal output?:

BEFORE:

$ sudo perf stat --all-cpus -einstructions,cycles -- sleep 1

 Performance counter stats for 'system wide':

       181,110,981      instructions              #    0.58  insn per cycle
                                                  #    0.00  stalled cycles per insn
       309,876,469      cycles

       1.002202582 seconds time elapsed

The user would not like to see the now permanent:

  "0.00  stalled cycles per insn"

line fixture, as it gives no useful information.

So this patch removes the printing of the zeroed stalled cycles line
altogether, almost reverting the very original commit fb4605ba47e7
("perf stat: Check for frontend stalled for metrics"), which seems like
it was written to normalize --metric-only column output of common Intel
machines at the time: modern Intel machines have ceased to support the
genericised frontend stalled metrics AFAICT.

AFTER:

$ sudo perf stat --all-cpus -einstructions,cycles -- sleep 1

 Performance counter stats for 'system wide':

       244,071,432      instructions              #    0.69  insn per cycle
       355,353,490      cycles

       1.001862516 seconds time elapsed

Output behaviour when stalled cycles is indeed measured is not affected
(BEFORE == AFTER):

$ sudo perf stat --all-cpus -einstructions,cycles,stalled-cycles-frontend -- sleep 1

 Performance counter stats for 'system wide':

       247,227,799      instructions              #    0.63  insn per cycle
                                                  #    0.26  stalled cycles per insn
       394,745,636      cycles
        63,194,485      stalled-cycles-frontend   #   16.01% frontend cycles idle

       1.002079770 seconds time elapsed

Fixes: 146540fb545b ("perf stat: Always separate stalled cycles per insn")
Signed-off-by: Kim Phillips 
Acked-by: Andi Kleen 
Acked-by: Jiri Olsa 
Acked-by: Song Liu 
Cc: Alexander Shishkin 
Cc: Cong Wang 
Cc: Davidlohr Bueso 
Cc: Jin Yao 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20200207230613.26709-1-kim.phillips@amd.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf hists: Fix variable name's inconsistency in hists__for_each() macro

2019-12-20T21:58:13+00:00

Variable names are inconsistent in hists__for_each macro().

Due to this inconsistency, the macro replaces its second argument with
"fmt" regardless of its original name.

So far it works because only "fmt" is passed to the second argument.
However, this behavior is not expected and should be fixed.

Fixes: f0786af536bb ("perf hists: Introduce hists__for_each_format macro")
Fixes: aa6f50af822a ("perf hists: Introduce hists__for_each_sort_list macro")
Signed-off-by: Yuya Fujita 
Acked-by: Jiri Olsa 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/OSAPR01MB1588E1C47AC22043175DE1B2E8520@OSAPR01MB1588.jpnprd01.prod.outlook.com
Signed-off-by: Arnaldo Carvalho de Melo

perf map: Set kmap->kmaps backpointer for main kernel map chunks

2019-12-20T21:55:40+00:00

When a map is create to represent the main kernel area (vmlinux) with
map__new2() we allocate an extra area to store a pointer to the 'struct
maps' for the kernel maps, so that we can access that struct when
loading ELF files or kallsyms, as we will need to split it in multiple
maps, one per kernel module or ELF section (such as ".init.text").

So when map->dso->kernel is non-zero, it is expected that
map__kmap(map)->kmaps to be set to the tree of kernel maps (modules,
chunks of the main kernel, bpf progs put in place via
PERF_RECORD_KSYMBOL, the main kernel).

This was not the case when we were splitting the main kernel into chunks
for its ELF sections, which ended up making 'perf report --children'
processing a perf.data file with callchains to trip on
__map__is_kernel(), when we press ENTER to see the popup menu for main
histogram entries that starts at a symbol in the ".init.text" ELF
section, e.g.:

-    8.83%     0.00%  swapper     [kernel.vmlinux].init.text  [k] start_kernel
     start_kernel
     cpu_startup_entry
     do_idle
     cpuidle_enter
     cpuidle_enter_state
     intel_idle

Fix it.

Reviewed-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/lkml/20191218190120.GB13282@kernel.org/
Signed-off-by: Arnaldo Carvalho de Melo

perf header: Fix false warning when there are no duplicate cache entries

2019-12-11T15:28:14+00:00

Before this patch, perf expected that there might be NPROC*4 unique
cache entries at max, however, it also expected that some of them would
be shared and/or of the same size, thus the final number of entries
would be reduced to be lower than NPROC*4. In case the number of entries
hadn't been reduced (was NPROC*4), the warning was printed.

However, some systems might have unusual cache topology, such as the
following two-processor KVM guest:

	cpu  level  shared_cpu_list  size
	  0     1         0           32K
	  0     1         0           64K
	  0     2         0           512K
	  0     3         0           8192K
	  1     1         1           32K
	  1     1         1           64K
	  1     2         1           512K
	  1     3         1           8192K

This KVM guest has 8 (NPROC*4) unique cache entries, which used to make
perf printing the message, although there actually aren't "way too many
cpu caches".

v2: Removing unused argument.

v3: Unifying the way we obtain number of cpus.

v4: Removed '& UINT_MAX' construct which is redundant.

Signed-off-by: Michael Petlan 
Acked-by: Jiri Olsa 
LPU-Reference: 20191208162056.20772-1-mpetlan@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo

perf metricgroup: Fix printing event names of metric group with multiple events

2019-12-11T15:28:14+00:00

Commit f01642e4912b ("perf metricgroup: Support multiple events for
metricgroup") introduced support for multiple events in a metric group.
But with the current upstream, metric events names are not printed
properly

In power9 platform:

command:# ./perf stat --metric-only -M translation -C 0 -I 1000 sleep 2
     1.000208486
     2.000368863
     2.001400558

Similarly in skylake platform:

command:./perf stat --metric-only -M Power -I 1000
     1.000579994
     2.002189493

With current upstream version, issue is with event name comparison logic
in find_evsel_group(). Current logic is to compare events belonging to a
metric group to the events in perf_evlist.  Since the break statement is
missing in the loop used for comparison between metric group and
perf_evlist events, the loop continues to execute even after getting a
pattern match, and end up in discarding the matches.

Incase of single metric event belongs to metric group, its working fine,
because in case of single event once it compare all events it reaches to
end of perf_evlist.

Example for single metric event in power9 platform:

command:# ./perf stat --metric-only  -M branches_per_inst -I 1000 sleep 1
     1.000094653                  0.2
     1.001337059                  0.0

This patch fixes the issue by making sure once we found all events
belongs to that metric event matched in find_evsel_group(), we
successfully break from that loop by adding corresponding condition.

With this patch:
In power9 platform:

command:# ./perf stat --metric-only -M translation -C 0 -I 1000 sleep 2
result:#
            time  derat_4k_miss_rate_percent  derat_4k_miss_ratio derat_miss_ratio derat_64k_miss_rate_percent  derat_64k_miss_ratio dslb_miss_rate_percent islb_miss_rate_percent
     1.000135672                         0.0                  0.3              1.0                         0.0                   0.2                    0.0                    0.0
     2.000380617                         0.0                  0.0              0.0                         0.0                   0.0                    0.0                    0.0

command:# ./perf stat --metric-only -M Power -I 1000

Similarly in skylake platform:
result:#
            time    Turbo_Utilization    C3_Core_Residency  C6_Core_Residency  C7_Core_Residency    C2_Pkg_Residency  C3_Pkg_Residency     C6_Pkg_Residency   C7_Pkg_Residency
     1.000563580                  0.3                  0.0                2.6               44.2                21.9               0.0                  0.0               0.0
     2.002235027                  0.4                  0.0                2.7               43.0                20.7               0.0                  0.0               0.0

Committer testing:

  Before:

  [root@seventh ~]# perf stat --metric-only -M Power -I 1000
  #           time
       1.000383223
       2.001168182
       3.001968545
       4.002741200
       5.003442022
  ^C     5.777687244

  [root@seventh ~]#

  After the patch:

  [root@seventh ~]# perf stat --metric-only -M Power -I 1000
  #           time    Turbo_Utilization    C3_Core_Residency    C6_Core_Residency    C7_Core_Residency     C2_Pkg_Residency     C3_Pkg_Residency     C6_Pkg_Residency     C7_Pkg_Residency
       1.000406577                  0.4                  0.1                  1.4                 97.0                  0.0                  0.0                  0.0                  0.0
       2.001481572                  0.3                  0.0                  0.6                 97.9                  0.0                  0.0                  0.0                  0.0
       3.002332585                  0.2                  0.0                  1.0                 97.5                  0.0                  0.0                  0.0                  0.0
       4.003196624                  0.2                  0.0                  0.3                 98.6                  0.0                  0.0                  0.0                  0.0
       5.004063851                  0.3                  0.0                  0.7                 97.7                  0.0                  0.0                  0.0                  0.0
  ^C     5.471260276                  0.2                  0.0                  0.5                 49.3                  0.0                  0.0                  0.0                  0.0

  [root@seventh ~]#
  [root@seventh ~]# dmesg | grep -i skylake
  [    0.187807] Performance Events: PEBS fmt3+, Skylake events, 32-deep LBR, full-width counters, Intel PMU driver.
  [root@seventh ~]#

Fixes: f01642e4912b ("perf metricgroup: Support multiple events for metricgroup")
Signed-off-by: Kajol Jain 
Reviewed-by: Ravi Bangoria 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Anju T Sudhakar 
Cc: Jin Yao 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Madhavan Srinivasan 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20191120084059.24458-1-kjain@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf arch: Make the default get_cpuid() return compatible error

2019-12-11T15:25:14+00:00

Some of the functions calling get_cpuid() propagate back the error it
returns, and all are using errno (positive) values, make the weak
default get_cpuid() function return ENOSYS to be consistent and to allow
checking if this is an arch not providing this function or if a provided
one is having trouble getting the cpuid, to decide if the warning should
be provided to the user or just a debug message should be emitted.

Reviewed-by: Mark Rutland 
Tested-by: Mark Rutland 
Tested-by: John Garry  # arm64
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Namhyung Kim 
Cc: Will Deacon 
Link: https://lkml.kernel.org/n/tip-lxwjr0cd2eggzx04a780ffrv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo