linux.git/tools/perf, branch v5.15-rc2

perf bpf: Ignore deprecation warning when using libbpf's btf__get_from_id()

2021-09-18T20:47:02+00:00

Perf code re-implements libbpf's btf__load_from_kernel_by_id() API as
a weak function, presumably to dynamically link against old version of
libbpf shared library. Unfortunately this causes compilation warning
when perf is compiled against libbpf v0.6+.

For now, just ignore deprecation warning, but there might be a better
solution, depending on perf's needs.

Signed-off-by: Andrii Nakryiko 
Cc: Alexei Starovoitov 
Cc: Daniel Borkmann 
Cc: kernel-team@fb.com
LPU-Reference: 20210914170004.4185659-1-andrii@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Initialize srcline string member in add_location struct

2021-09-18T20:43:05+00:00

It's later supposed to be either a correct address or NULL. Without the
initialization, it may contain an undefined value which results in the
following segmentation fault:

  # perf top --sort comm -g --ignore-callees=do_idle

terminates with:

  #0  0x00007ffff56b7685 in __strlen_avx2 () from /lib64/libc.so.6
  #1  0x00007ffff55e3802 in strdup () from /lib64/libc.so.6
  #2  0x00005555558cb139 in hist_entry__init (callchain_size=, sample_self=true, template=0x7fffde7fb110, he=0x7fffd801c250) at util/hist.c:489
  #3  hist_entry__new (template=template@entry=0x7fffde7fb110, sample_self=sample_self@entry=true) at util/hist.c:564
  #4  0x00005555558cb4ba in hists__findnew_entry (hists=hists@entry=0x5555561d9e38, entry=entry@entry=0x7fffde7fb110, al=al@entry=0x7fffde7fb420,
      sample_self=sample_self@entry=true) at util/hist.c:657
  #5  0x00005555558cba1b in __hists__add_entry (hists=hists@entry=0x5555561d9e38, al=0x7fffde7fb420, sym_parent=, bi=bi@entry=0x0, mi=mi@entry=0x0,
      sample=sample@entry=0x7fffde7fb4b0, sample_self=true, ops=0x0, block_info=0x0) at util/hist.c:288
  #6  0x00005555558cbb70 in hists__add_entry (sample_self=true, sample=0x7fffde7fb4b0, mi=0x0, bi=0x0, sym_parent=, al=, hists=0x5555561d9e38)
      at util/hist.c:1056
  #7  iter_add_single_cumulative_entry (iter=0x7fffde7fb460, al=) at util/hist.c:1056
  #8  0x00005555558cc8a4 in hist_entry_iter__add (iter=iter@entry=0x7fffde7fb460, al=al@entry=0x7fffde7fb420, max_stack_depth=, arg=arg@entry=0x7fffffff7db0)
      at util/hist.c:1231
  #9  0x00005555557cdc9a in perf_event__process_sample (machine=, sample=0x7fffde7fb4b0, evsel=, event=, tool=0x7fffffff7db0)
      at builtin-top.c:842
  #10 deliver_event (qe=, qevent=) at builtin-top.c:1202
  #11 0x00005555558a9318 in do_flush (show_progress=false, oe=0x7fffffff80e0) at util/ordered-events.c:244
  #12 __ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP, timestamp=timestamp@entry=0) at util/ordered-events.c:323
  #13 0x00005555558a9789 in __ordered_events__flush (timestamp=, how=, oe=) at util/ordered-events.c:339
  #14 ordered_events__flush (how=OE_FLUSH__TOP, oe=0x7fffffff80e0) at util/ordered-events.c:341
  #15 ordered_events__flush (oe=oe@entry=0x7fffffff80e0, how=how@entry=OE_FLUSH__TOP) at util/ordered-events.c:339
  #16 0x00005555557cd631 in process_thread (arg=0x7fffffff7db0) at builtin-top.c:1114
  #17 0x00007ffff7bb817a in start_thread () from /lib64/libpthread.so.0
  #18 0x00007ffff5656dc3 in clone () from /lib64/libc.so.6

If you look at the frame #2, the code is:

488	 if (he->srcline) {
489          he->srcline = strdup(he->srcline);
490          if (he->srcline == NULL)
491              goto err_rawdata;
492	 }

If he->srcline is not NULL (it is not NULL if it is uninitialized rubbish),
it gets strdupped and strdupping a rubbish random string causes the problem.

Also, if you look at the commit 1fb7d06a509e, it adds the srcline property
into the struct, but not initializing it everywhere needed.

Committer notes:

Now I see, when using --ignore-callees=do_idle we end up here at line
2189 in add_callchain_ip():

2181         if (al.sym != NULL) {
2182                 if (perf_hpp_list.parent && !*parent &&
2183                     symbol__match_regex(al.sym, &parent_regex))
2184                         *parent = al.sym;
2185                 else if (have_ignore_callees && root_al &&
2186                   symbol__match_regex(al.sym, &ignore_callees_regex)) {
2187                         /* Treat this symbol as the root,
2188                            forgetting its callees. */
2189                         *root_al = al;
2190                         callchain_cursor_reset(cursor);
2191                 }
2192         }

And the al that doesn't have the ->srcline field initialized will be
copied to the root_al, so then, back to:

1211 int hist_entry_iter__add(struct hist_entry_iter *iter, struct addr_location *al,
1212                          int max_stack_depth, void *arg)
1213 {
1214         int err, err2;
1215         struct map *alm = NULL;
1216
1217         if (al)
1218                 alm = map__get(al->map);
1219
1220         err = sample__resolve_callchain(iter->sample, &callchain_cursor, &iter->parent,
1221                                         iter->evsel, al, max_stack_depth);
1222         if (err) {
1223                 map__put(alm);
1224                 return err;
1225         }
1226
1227         err = iter->ops->prepare_entry(iter, al);
1228         if (err)
1229                 goto out;
1230
1231         err = iter->ops->add_single_entry(iter, al);
1232         if (err)
1233                 goto out;
1234

That al at line 1221 is what hist_entry_iter__add() (called from
sample__resolve_callchain()) saw as 'root_al', and then:

        iter->ops->add_single_entry(iter, al);

will go on with al->srcline with a bogus value, I'll add the above
sequence to the cset and apply, thanks!

Signed-off-by: Michael Petlan 
CC: Milian Wolff 
Cc: Jiri Olsa 
Fixes: 1fb7d06a509e ("perf report Use srcline from callchain for hist entries")
Link: https //lore.kernel.org/r/20210719145332.29747-1-mpetlan@redhat.com
Reported-by: Juri Lelli 
Signed-off-by: Arnaldo Carvalho de Melo

perf script: Fix ip display when type != attr->type

2021-09-18T20:43:05+00:00

set_print_ip_opts() was not being called when type != attr->type
because there is not a one-to-one relationship between output types
and attr->type. That resulted in ip not printing.

The attr_type() function is removed, and the match of attr->type to
output type is corrected.

Example on ADL using taskset to select an atom cpu:

 # perf record -e cpu_atom/cpu-cycles/ taskset 0x1000 uname
 Linux
 [ perf record: Woken up 1 times to write data ]
 [ perf record: Captured and wrote 0.003 MB perf.data (7 samples) ]

 Before:

  # perf script | head
         taskset   428 [-01] 10394.179041:          1 cpu_atom/cpu-cycles/:
         taskset   428 [-01] 10394.179043:          1 cpu_atom/cpu-cycles/:
         taskset   428 [-01] 10394.179044:         11 cpu_atom/cpu-cycles/:
         taskset   428 [-01] 10394.179045:        407 cpu_atom/cpu-cycles/:
         taskset   428 [-01] 10394.179046:      16789 cpu_atom/cpu-cycles/:
         taskset   428 [-01] 10394.179052:     676300 cpu_atom/cpu-cycles/:
           uname   428 [-01] 10394.179278:    4079859 cpu_atom/cpu-cycles/:

 After:

  # perf script | head
         taskset   428 10394.179041:          1 cpu_atom/cpu-cycles/:  ffffffff95a0bb97 __intel_pmu_enable_all.constprop.48+0x47 ([kernel.kallsyms])
         taskset   428 10394.179043:          1 cpu_atom/cpu-cycles/:  ffffffff95a0bb97 __intel_pmu_enable_all.constprop.48+0x47 ([kernel.kallsyms])
         taskset   428 10394.179044:         11 cpu_atom/cpu-cycles/:  ffffffff95a0bb97 __intel_pmu_enable_all.constprop.48+0x47 ([kernel.kallsyms])
         taskset   428 10394.179045:        407 cpu_atom/cpu-cycles/:  ffffffff95a0bb97 __intel_pmu_enable_all.constprop.48+0x47 ([kernel.kallsyms])
         taskset   428 10394.179046:      16789 cpu_atom/cpu-cycles/:  ffffffff95a0bb97 __intel_pmu_enable_all.constprop.48+0x47 ([kernel.kallsyms])
         taskset   428 10394.179052:     676300 cpu_atom/cpu-cycles/:      7f829ef73800 cfree+0x0 (/lib/libc-2.32.so)
           uname   428 10394.179278:    4079859 cpu_atom/cpu-cycles/:  ffffffff95bae912 vma_interval_tree_remove+0x1f2 ([kernel.kallsyms])

Signed-off-by: Adrian Hunter 
Reviewed-by: Kan Liang 
Cc: Jin Yao 
Cc: Jiri Olsa 
Link: http://lore.kernel.org/lkml/20210911133053.15682-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf annotate: Fix fused instr logic for assembly functions

2021-09-18T20:43:05+00:00

Some x86 microarchitectures fuse a subset of cmp/test/ALU instructions
with branch instructions, and thus perf annotate highlight such valid
pairs as fused.

When annotated with source, perf uses struct disasm_line to contain
either source or instruction line from objdump output. Usually, a C
statement generates multiple instructions which include such
cmp/test/ALU + branch instruction pairs. But in case of assembly
function, each individual assembly source line generate one
instruction.

The 'perf annotate' instruction fusion logic assumes the previous
disasm_line as the previous instruction line, which is wrong because,
for assembly function, previous disasm_line contains source line.  And
thus perf fails to highlight valid fused instruction pairs for assembly
functions.

Fix it by searching backward until we find an instruction line and
consider that disasm_line as fused with current branch instruction.

Before:
         │    cmpq    %rcx, RIP+8(%rsp)
    0.00 │      cmp    %rcx,0x88(%rsp)
         │    je      .Lerror_bad_iret      <--- Source line
    0.14 │   ┌──je     b4                   <--- Instruction line
         │   │movl    %ecx, %eax

After:
         │    cmpq    %rcx, RIP+8(%rsp)
    0.00 │   ┌──cmp    %rcx,0x88(%rsp)
         │   │je      .Lerror_bad_iret
    0.14 │   ├──je     b4
         │   │movl    %ecx, %eax

Reviewed-by: Jin Yao 
Signed-off-by: Ravi Bangoria 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Kim Phillips 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Link: https //lore.kernel.org/r/20210911043854.8373-1-ravi.bangoria@amd.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add an option to build without libbfd

2021-09-11T19:06:52+00:00

Some distributions, like debian, don't link perf with libbfd. Add a
build flag to make this configuration buildable and testable.

This was inspired by:

  https://lore.kernel.org/linux-perf-users/20210910102307.2055484-1-tonyg@leastfixedpoint.com/T/#u

Signed-off-by: Ian Rogers 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: tony garnock-jones 
Link: http://lore.kernel.org/lkml/20210910225756.729087-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Allow build-id with trailing zeros

2021-09-11T19:04:47+00:00

Currently perf saves a build-id with size but old versions assumes the
size of 20.  In case the build-id is less than 20 (like for MD5), it'd
fill the rest with 0s.

I saw a problem when old version of perf record saved a binary in the
build-id cache and new version of perf reads the data.  The symbols
should be read from the build-id cache (as the path no longer has the
same binary) but it failed due to mismatch in the build-id.

  symsrc__init: build id mismatch for /home/namhyung/.debug/.build-id/53/e4c2f42a4c61a2d632d92a72afa08f00000000/elf.

The build-id event in the data has 20 byte build-ids, but it saw a
different size (16) when it reads the build-id of the elf file in the
build-id cache.

  $ readelf -n ~/.debug/.build-id/53/e4c2f42a4c61a2d632d92a72afa08f00000000/elf

  Displaying notes found in: .note.gnu.build-id
    Owner                Data size 	Description
    GNU                  0x00000010	NT_GNU_BUILD_ID (unique build ID bitstring)
      Build ID: 53e4c2f42a4c61a2d632d92a72afa08f

Let's fix this by allowing trailing zeros if the size is different.

Fixes: 39be8d0115b321ed ("perf tools: Pass build_id object to dso__build_id_equal()")
Signed-off-by: Namhyung Kim 
Acked-by: Jiri Olsa 
Cc: Andi Kleen 
Cc: Ian Rogers 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20210910224630.1084877-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix hybrid config terms list corruption

2021-09-11T19:00:34+00:00

A config terms list was spliced twice, resulting in a never-ending loop
when the list was traversed. Fix by using list_splice_init() and copying
and freeing the lists as necessary.

This patch also depends on patch "perf tools: Factor out
copy_config_terms() and free_config_terms()"

Example on ADL:

 Before:

  # perf record -e '{intel_pt//,cycles/aux-sample-size=4096/pp}' uname &
  # jobs
  [1]+  Running                    perf record -e "{intel_pt//,cycles/aux-sample-size=4096/pp}" uname
  # perf top -E 10
    PerfTop:    4071 irqs/sec  kernel: 6.9%  exact: 100.0% lost: 0/0 drop: 0/0 [4000Hz cycles],  (all, 24 CPUs)
  ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

    97.60%  perf           [.] __evsel__get_config_term
     0.25%  [kernel]       [k] kallsyms_expand_symbol.constprop.13
     0.24%  perf           [.] kallsyms__parse
     0.15%  [kernel]       [k] _raw_spin_lock
     0.14%  [kernel]       [k] number
     0.13%  [kernel]       [k] advance_transaction
     0.08%  [kernel]       [k] format_decode
     0.08%  perf           [.] map__process_kallsym_symbol
     0.08%  perf           [.] rb_insert_color
     0.08%  [kernel]       [k] vsnprintf
  exiting.
  # kill %1

After:

  # perf record -e '{intel_pt//,cycles/aux-sample-size=4096/pp}' uname &
  Linux
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.060 MB perf.data ]
  # perf script | head
       perf-exec   604 [001]  1827.312293:                            psb:  psb offs: 0                       ffffffffb8415e87 pt_config_start+0x37 ([kernel.kallsyms])
       perf-exec   604  1827.312293:          1                       branches:  ffffffffb856a3bd event_sched_in.isra.133+0xfd ([kernel.kallsyms]) => ffffffffb856a9a0 perf_pmu_nop_void+0x0 ([kernel.kallsyms])
       perf-exec   604  1827.312293:          1                       branches:  ffffffffb856b10e merge_sched_in+0x26e ([kernel.kallsyms]) => ffffffffb856a2c0 event_sched_in.isra.133+0x0 ([kernel.kallsyms])
       perf-exec   604  1827.312293:          1                       branches:  ffffffffb856a45d event_sched_in.isra.133+0x19d ([kernel.kallsyms]) => ffffffffb8568b80 perf_event_set_state.part.61+0x0 ([kernel.kallsyms])
       perf-exec   604  1827.312293:          1                       branches:  ffffffffb8568b86 perf_event_set_state.part.61+0x6 ([kernel.kallsyms]) => ffffffffb85662a0 perf_event_update_time+0x0 ([kernel.kallsyms])
       perf-exec   604  1827.312293:          1                       branches:  ffffffffb856a35c event_sched_in.isra.133+0x9c ([kernel.kallsyms]) => ffffffffb8567610 perf_log_itrace_start+0x0 ([kernel.kallsyms])
       perf-exec   604  1827.312293:          1                       branches:  ffffffffb856a377 event_sched_in.isra.133+0xb7 ([kernel.kallsyms]) => ffffffffb8403b40 x86_pmu_add+0x0 ([kernel.kallsyms])
       perf-exec   604  1827.312293:          1                       branches:  ffffffffb8403b86 x86_pmu_add+0x46 ([kernel.kallsyms]) => ffffffffb8403940 collect_events+0x0 ([kernel.kallsyms])
       perf-exec   604  1827.312293:          1                       branches:  ffffffffb8403a7b collect_events+0x13b ([kernel.kallsyms]) => ffffffffb8402cd0 collect_event+0x0 ([kernel.kallsyms])

Fixes: 30def61f64bac5 ("perf parse-events Create two hybrid cache events")
Fixes: 94da591b1c7913 ("perf parse-events Create two hybrid raw events")
Fixes: 9cbfa2f64c04d9 ("perf parse-events Create two hybrid hardware events")
Signed-off-by: Adrian Hunter 
Acked-by: Jiri Olsa 
Cc: Jin Yao 
Cc: Kan Liang 
Link: https //lore.kernel.org/r/20210909125508.28693-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Factor out copy_config_terms() and free_config_terms()

2021-09-11T19:00:13+00:00

Factor out copy_config_terms() and free_config_terms() so that they can
be reused.

Signed-off-by: Adrian Hunter 
Acked-by: Jiri Olsa 
Cc: Jin Yao 
Cc: Kan Liang 
Link: https //lore.kernel.org/r/20210909125508.28693-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix perf_event_attr__fprintf() missing/dupl. fields

2021-09-11T18:58:36+00:00

Some fields are missing and text_poke is duplicated. Fix that up.

Signed-off-by: Adrian Hunter 
Cc: Jiri Olsa 
Link: http://lore.kernel.org/lkml/20210911120550.12203-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Ignore Documentation dependency file

2021-09-11T18:36:16+00:00

When building directly on the checked out repository the build process
produces a file that should be ignored, so add it to .gitignore.

Fixes: a81df63a5df3e195 ("perf doc: Fix doc.dep")
Reported-by: Linus Torvalds 
Signed-off-by: Ian Rogers 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20210910232249.739661-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo