linux-stable.git/tools/perf/util/machine.c, branch linux-4.19.y

perf machine: Initialize srcline string member in add_location struct

2021-09-22T09:48:11+00:00

commit 57f0ff059e3daa4e70a811cb1d31a49968262d20 upstream.

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 
Signed-off-by: Greg Kroah-Hartman

perf map: No need to adjust the long name of modules

2020-01-27T13:49:53+00:00

commit f068435d9bb2d825d59e3c101bc579f09315ee01 upstream.

At some point in the past we needed to make sure we would get the long
name of modules and not just what we get from /proc/modules, but that
need, as described in the cset that introduced the adjustment function:

Fixes: c03d5184f0e9 ("perf machine: Adjust dso->long_name for offline module")

Without using the buildid-cache:

  # lsmod | grep trusted
  # insmod trusted.ko
  # lsmod | grep trusted
  trusted                24576  0
  # strace -e open,openat perf probe -m ./trusted.ko key_seal |& grep trusted
  openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 4
  openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 7
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/.debug/root/trusted.ko/dd3d355d567394d540f527e093e0f64b95879584/probes", O_RDWR|O_CREAT, 0644) = 3
  openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/.debug/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, ".debug/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 4
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
    probe:key_seal       (on key_seal in trusted)
  # perf probe -l
    probe:key_seal       (on key_seal in trusted)
  #

No attempt at opening '[trusted]'.

Now using the build-id cache:

  # rmmod trusted
  # perf buildid-cache --add ./trusted.ko
  # insmod trusted.ko
  # strace -e open,openat perf probe -m ./trusted.ko key_seal |& grep trusted
  openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 4
  openat(AT_FDCWD, "/sys/module/trusted/notes/.note.gnu.build-id", O_RDONLY) = 7
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/.debug/root/trusted.ko/dd3d355d567394d540f527e093e0f64b95879584/probes", O_RDWR|O_CREAT, 0644) = 3
  openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/usr/lib/debug/root/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/.debug/trusted.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, ".debug/trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "trusted.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 4
  openat(AT_FDCWD, "/root/trusted.ko", O_RDONLY) = 3
  #

Again, no attempt at reading '[trusted]'.

Finally, adding a probe to that function and then using:

[root@quaco ~]# perf trace -e probe_perf:*/max-stack=16/ --max-events=2
     0.000 perf/13456 probe_perf:dso__adjust_kmod_long_name(__probe_ip: 5492263)
                                       dso__adjust_kmod_long_name (/home/acme/bin/perf)
                                       machine__process_kernel_mmap_event (/home/acme/bin/perf)
                                       machine__process_mmap_event (/home/acme/bin/perf)
                                       perf_event__process_mmap (/home/acme/bin/perf)
                                       machines__deliver_event (/home/acme/bin/perf)
                                       perf_session__deliver_event (/home/acme/bin/perf)
                                       perf_session__process_event (/home/acme/bin/perf)
                                       process_simple (/home/acme/bin/perf)
                                       reader__process_events (/home/acme/bin/perf)
                                       __perf_session__process_events (/home/acme/bin/perf)
                                       perf_session__process_events (/home/acme/bin/perf)
                                       process_buildids (/home/acme/bin/perf)
                                       record__finish_output (/home/acme/bin/perf)
                                       __cmd_record (/home/acme/bin/perf)
                                       cmd_record (/home/acme/bin/perf)
                                       run_builtin (/home/acme/bin/perf)
     0.055 perf/13456 probe_perf:dso__adjust_kmod_long_name(__probe_ip: 5492263)
                                       dso__adjust_kmod_long_name (/home/acme/bin/perf)
                                       machine__process_kernel_mmap_event (/home/acme/bin/perf)
                                       machine__process_mmap_event (/home/acme/bin/perf)
                                       perf_event__process_mmap (/home/acme/bin/perf)
                                       machines__deliver_event (/home/acme/bin/perf)
                                       perf_session__deliver_event (/home/acme/bin/perf)
                                       perf_session__process_event (/home/acme/bin/perf)
                                       process_simple (/home/acme/bin/perf)
                                       reader__process_events (/home/acme/bin/perf)
                                       __perf_session__process_events (/home/acme/bin/perf)
                                       perf_session__process_events (/home/acme/bin/perf)
                                       process_buildids (/home/acme/bin/perf)
                                       record__finish_output (/home/acme/bin/perf)
                                       __cmd_record (/home/acme/bin/perf)
                                       cmd_record (/home/acme/bin/perf)
                                       run_builtin (/home/acme/bin/perf)
  #

This was the only path I could find using the perf tools that reach at this
function, then as of november/2019, if we put a probe in the line where the
actuall setting of the dso->long_name is done:

  # perf trace -e probe_perf:*
  ^C[root@quaco ~]
  # perf stat -e probe_perf:*  -I 2000
       2.000404265                  0      probe_perf:dso__adjust_kmod_long_name
       4.001142200                  0      probe_perf:dso__adjust_kmod_long_name
       6.001704120                  0      probe_perf:dso__adjust_kmod_long_name
       8.002398316                  0      probe_perf:dso__adjust_kmod_long_name
      10.002984010                  0      probe_perf:dso__adjust_kmod_long_name
      12.003597851                  0      probe_perf:dso__adjust_kmod_long_name
      14.004113303                  0      probe_perf:dso__adjust_kmod_long_name
      16.004582773                  0      probe_perf:dso__adjust_kmod_long_name
      18.005176373                  0      probe_perf:dso__adjust_kmod_long_name
      20.005801605                  0      probe_perf:dso__adjust_kmod_long_name
      22.006467540                  0      probe_perf:dso__adjust_kmod_long_name
  ^C    23.683261941                  0      probe_perf:dso__adjust_kmod_long_name

  #

Its not being used at all.

To further test this I used kvm.ko as the offline module, i.e. removed
if from the buildid-cache by nuking it completely (rm -rf ~/.debug) and
moved it from the normal kernel distro path, removed the modules, stoped
the kvm guest, and then installed it manually, etc.

  # rmmod kvm-intel
  # rmmod kvm
  # lsmod | grep kvm
  # modprobe kvm-intel
  modprobe: ERROR: ctx=0x55d3b1722260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory
  modprobe: ERROR: ctx=0x55d3b1722260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory
  modprobe: ERROR: could not insert 'kvm_intel': Unknown symbol in module, or unknown parameter (see dmesg)
  # insmod ./kvm.ko
  # modprobe kvm-intel
  modprobe: ERROR: ctx=0x562f34026260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory
  modprobe: ERROR: ctx=0x562f34026260 path=/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm/kvm.ko.xz error=No such file or directory
  # lsmod | grep kvm
  kvm_intel             299008  0
  kvm                   765952  1 kvm_intel
  irqbypass              16384  1 kvm
  #
  # perf probe -x ~/bin/perf machine__findnew_module_map:12 mname=m.name:string filename=filename:string 'dso_long_name=map->dso->long_name:string' 'dso_name=map->dso->name:string'
  # perf probe -l
    probe_perf:machine__findnew_module_map (on machine__findnew_module_map:12@util/machine.c in /home/acme/bin/perf with mname filename dso_long_name dso_name)
  # perf record
  ^C[ perf record: Woken up 2 times to write data ]
  [ perf record: Captured and wrote 3.416 MB perf.data (33956 samples) ]
  # perf trace -e probe_perf:machine*
  
       6.322 perf/23099 probe_perf:machine__findnew_module_map(__probe_ip: 5492493, mname: "[salsa20_generic]", filename: "/lib/modules/5.3.8-200.fc30.x86_64/kernel/crypto/salsa20_generic.ko.xz", dso_long_name: "/lib/modules/5.3.8-200.fc30.x86_64/kernel/crypto/salsa20_generic.ko.xz", dso_name: "[salsa20_generic]")
       6.375 perf/23099 probe_perf:machine__findnew_module_map(__probe_ip: 5492493, mname: "[kvm]", filename: "[kvm]", dso_long_name: "[kvm]", dso_name: "[kvm]")
  

The filename doesn't come with the path, no point in trying to set the dso->long_name.

  [root@quaco ~]# strace -e open,openat perf probe -m ./kvm.ko kvm_apic_local_deliver |& egrep 'open.*kvm'
  openat(AT_FDCWD, "/sys/module/kvm_intel/notes/.note.gnu.build-id", O_RDONLY) = 4
  openat(AT_FDCWD, "/sys/module/kvm/notes/.note.gnu.build-id", O_RDONLY) = 4
  openat(AT_FDCWD, "/lib/modules/5.3.8-200.fc30.x86_64/kernel/arch/x86/kvm", O_RDONLY|O_NONBLOCK|O_CLOEXEC|O_DIRECTORY) = 7
  openat(AT_FDCWD, "/sys/module/kvm_intel/notes/.note.gnu.build-id", O_RDONLY) = 8
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/.debug/root/kvm.ko/5955f426cb93f03f30f3e876814be2db80ab0b55/probes", O_RDWR|O_CREAT, 0644) = 3
  openat(AT_FDCWD, "/usr/lib/debug/root/kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/usr/lib/debug/root/kvm.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/.debug/kvm.ko", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, ".debug/kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "kvm.ko.debug", O_RDONLY) = -1 ENOENT (No such file or directory)
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 4
  openat(AT_FDCWD, "/root/kvm.ko", O_RDONLY) = 3
  [root@quaco ~]#

Cc: Adrian Hunter 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-jlfew3lyb24d58egrp0o72o2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf callchain: Fix segfault in thread__resolve_callchain_sample()

2019-12-17T19:35:51+00:00

[ Upstream commit aceb98261ea7d9fe38f9c140c5531f0b13623832 ]

Do not dereference 'chain' when it is NULL.

  $ perf record -e intel_pt//u -e branch-misses:u uname
  $ perf report --itrace=l --branch-history
  perf: Segmentation fault

Fixes: e9024d519d89 ("perf callchain: Honour the ordering of PERF_CONTEXT_{USER,KERNEL,etc}")
Signed-off-by: Adrian Hunter 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Link: http://lore.kernel.org/lkml/20191114142538.4097-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf record: Fix module size on s390

2019-08-16T08:12:41+00:00

commit 12a6d2940b5f02b4b9f71ce098e3bb02bc24a9ea upstream.

On s390 the modules loaded in memory have the text segment located after
the GOT and Relocation table. This can be seen with this output:

  [root@m35lp76 perf]# fgrep qeth /proc/modules
  qeth 151552 1 qeth_l2, Live 0x000003ff800b2000
  ...
  [root@m35lp76 perf]# cat /sys/module/qeth/sections/.text
  0x000003ff800b3990
  [root@m35lp76 perf]#

There is an offset of 0x1990 bytes. The size of the qeth module is
151552 bytes (0x25000 in hex).

The location of the GOT/relocation table at the beginning of a module is
unique to s390.

commit 203d8a4aa6ed ("perf s390: Fix 'start' address of module's map")
adjusts the start address of a module in the map structures, but does
not adjust the size of the modules. This leads to overlapping of module
maps as this example shows:

[root@m35lp76 perf] # ./perf report -D
     0 0 0xfb0 [0xa0]: PERF_RECORD_MMAP -1/0: [0x3ff800b3990(0x25000)
          @ 0]:  x /lib/modules/.../qeth.ko.xz
     0 0 0x1050 [0xb0]: PERF_RECORD_MMAP -1/0: [0x3ff800d85a0(0x8000)
          @ 0]:  x /lib/modules/.../ip6_tables.ko.xz

The module qeth.ko has an adjusted start address modified to b3990, but
its size is unchanged and the module ends at 0x3ff800d8990.  This end
address overlaps with the next modules start address of 0x3ff800d85a0.

When the size of the leading GOT/Relocation table stored in the
beginning of the text segment (0x1990 bytes) is subtracted from module
qeth end address, there are no overlaps anymore:

   0x3ff800d8990 - 0x1990 = 0x0x3ff800d7000

which is the same as

   0x3ff800b2000 + 0x25000 = 0x0x3ff800d7000.

To fix this issue, also adjust the modules size in function
arch__fix_module_text_start(). Add another function parameter named size
and reduce the size of the module when the text segment start address is
changed.

Output after:
     0 0 0xfb0 [0xa0]: PERF_RECORD_MMAP -1/0: [0x3ff800b3990(0x23670)
          @ 0]:  x /lib/modules/.../qeth.ko.xz
     0 0 0x1050 [0xb0]: PERF_RECORD_MMAP -1/0: [0x3ff800d85a0(0x7a60)
          @ 0]:  x /lib/modules/.../ip6_tables.ko.xz

Reported-by: Stefan Liebler 
Signed-off-by: Thomas Richter 
Acked-by: Heiko Carstens 
Cc: Hendrik Brueckner 
Cc: Vasily Gorbik 
Cc: stable@vger.kernel.org
Fixes: 203d8a4aa6ed ("perf s390: Fix 'start' address of module's map")
Link: http://lkml.kernel.org/r/20190724122703.3996-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf machine: Update kernel map address and re-order properly

2019-05-04T07:20:22+00:00

[ Upstream commit 977c7a6d1e263ff1d755f28595b99e4bc0c48a9f ]

Since commit 1fb87b8e9599 ("perf machine: Don't search for active kernel
start in __machine__create_kernel_maps"), the __machine__create_kernel_maps()
just create a map what start and end are both zero. Though the address will be
updated later, the order of map in the rbtree may be incorrect.

The commit ee05d21791db ("perf machine: Set main kernel end address properly")
fixed the logic in machine__create_kernel_maps(), but it's still wrong in
function machine__process_kernel_mmap_event().

To reproduce this issue, we need an environment which the module address
is before the kernel text segment. I tested it on an aarch64 machine with
kernel 4.19.25:

  [root@localhost hulk]# grep _stext /proc/kallsyms
  ffff000008081000 T _stext
  [root@localhost hulk]# grep _etext /proc/kallsyms
  ffff000009780000 R _etext
  [root@localhost hulk]# tail /proc/modules
  hisi_sas_v2_hw 77824 0 - Live 0xffff00000191d000
  nvme_core 126976 7 nvme, Live 0xffff0000018b6000
  mdio 20480 1 ixgbe, Live 0xffff0000018ab000
  hisi_sas_main 106496 1 hisi_sas_v2_hw, Live 0xffff000001861000
  hns_mdio 20480 2 - Live 0xffff000001822000
  hnae 28672 3 hns_dsaf,hns_enet_drv, Live 0xffff000001815000
  dm_mirror 40960 0 - Live 0xffff000001804000
  dm_region_hash 32768 1 dm_mirror, Live 0xffff0000017f5000
  dm_log 32768 2 dm_mirror,dm_region_hash, Live 0xffff0000017e7000
  dm_mod 315392 17 dm_mirror,dm_log, Live 0xffff000001780000
  [root@localhost hulk]#

Before fix:

  [root@localhost bin]# perf record sleep 3
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.011 MB perf.data (9 samples) ]
  [root@localhost bin]# perf buildid-list -i perf.data
  4c4e46c971ca935f781e603a09b52a92e8bdfee8 [vdso]
  [root@localhost bin]# perf buildid-list -i perf.data -H
  0000000000000000000000000000000000000000 /proc/kcore
  [root@localhost bin]#

After fix:

  [root@localhost tools]# ./perf/perf record sleep 3
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.011 MB perf.data (9 samples) ]
  [root@localhost tools]# ./perf/perf buildid-list -i perf.data
  28a6c690262896dbd1b5e1011ed81623e6db0610 [kernel.kallsyms]
  106c14ce6e4acea3453e484dc604d66666f08a2f [vdso]
  [root@localhost tools]# ./perf/perf buildid-list -i perf.data -H
  28a6c690262896dbd1b5e1011ed81623e6db0610 /proc/kcore

Signed-off-by: Wei Li 
Acked-by: Jiri Olsa 
Acked-by: Namhyung Kim 
Cc: Alexander Shishkin 
Cc: David Ahern 
Cc: Hanjun Guo 
Cc: Kim Phillips 
Cc: Li Bin 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20190228092003.34071-1-liwei391@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin (Microsoft)

perf report: Fix wrong iteration count in --branch-history

2019-02-20T09:25:39+00:00

[ Upstream commit a3366db06bb656cef2e03f30f780d93059bcc594 ]

By calculating the removed loops, we can get the iteration count.

But the iteration count could be reported incorrectly, reporting
impossibly high counts.

That's because previous code uses the number of removed LBR entries for
the iteration count. That's not good. Fix this by increasing the
iteration count when a loop is detected.

When matching the chain, the iteration count would be added up, finally we need
to compute the average value when printing out.

For example,

  $ perf report --branch-history --stdio --no-children

Before:

  ---f2 +0
     |
     |--33.62%--f1 +9 (cycles:1)
     |          f1 +0
     |          main +22 (cycles:1)
     |          main +17
     |          main +38 (cycles:1)
     |          main +27
     |          f1 +26 (cycles:1)
     |          f1 +24
     |          f2 +27 (cycles:7)
     |          f2 +0
     |          f1 +19 (cycles:1)
     |          f1 +14
     |          f2 +27 (cycles:11)
     |          f2 +0
     |          f1 +9 (cycles:1 iter:2968 avg_cycles:3)
     |          f1 +0
     |          main +22 (cycles:1 iter:2968 avg_cycles:3)
     |          main +17
     |          main +38 (cycles:1 iter:2968 avg_cycles:3)

2968 is an impossible high iteration count and avg_cycles is too small.

After:

  ---f2 +0
     |
     |--33.62%--f1 +9 (cycles:1)
     |          f1 +0
     |          main +22 (cycles:1)
     |          main +17
     |          main +38 (cycles:1)
     |          main +27
     |          f1 +26 (cycles:1)
     |          f1 +24
     |          f2 +27 (cycles:7)
     |          f2 +0
     |          f1 +19 (cycles:1)
     |          f1 +14
     |          f2 +27 (cycles:11)
     |          f2 +0
     |          f1 +9 (cycles:1 iter:1 avg_cycles:23)
     |          f1 +0
     |          main +22 (cycles:1 iter:1 avg_cycles:23)
     |          main +17
     |          main +38 (cycles:1 iter:1 avg_cycles:23)

avg_cycles:23 is the average cycles of this iteration.

Fixes: c4ee06251d42 ("perf report: Calculate the average cycles of iterations")

Signed-off-by: Jin Yao 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1546582230-17507-1-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf thread: Add fallback functions for cases where cpumode is insufficient

2019-01-09T16:38:42+00:00

commit 8e80ad9983caeee09c3a0a1a37e05bff93becce4 upstream.

For branch stacks or branch samples, the sample cpumode might not be
correct because it applies only to the sample 'ip' and not necessary to
'addr' or branch stack addresses. Add fallback functions that can be
used to deal with those cases

Signed-off-by: Adrian Hunter 
Cc: Andi Kleen 
Cc: David S. Miller 
Cc: Jiri Olsa 
Cc: Leo Yan 
Cc: Mathieu Poirier 
Cc: stable@vger.kernel.org # 4.19
Link: http://lkml.kernel.org/r/20181106210712.12098-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf callchain: Honour the ordering of PERF_CONTEXT_{USER,KERNEL,etc}

2018-11-21T08:19:19+00:00

commit e9024d519d892b38176cafd46f68a7cdddd77412 upstream.

When processing using 'perf report -g caller', which is the default, we
ended up reverting the callchain entries received from the kernel, but
simply reverting throws away the information that tells that from a
point onwards the addresses are for userspace, kernel, guest kernel,
guest user, hypervisor.

The idea is that if we are walking backwards, for each cluster of
non-cpumode entries we have to first scan backwards for the next one and
use that for the cluster.

This seems silly and more expensive than it needs to be but it is enough
for a initial fix.

The code here is really complicated because it is intimately intertwined
with the lbr and branch handling, as well as this callchain order,
further fixes will be needed to properly take into account the cpumode
in those cases.

Another problem with ORDER_CALLER is that the NULL "0" IP that is at the
end of most callchains shows up at the top of the histogram because
every callchain contains it and with ORDER_CALLER it is the first entry.

Signed-off-by: David S. Miller 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Souvik Banerjee 
Cc: Wang Nan 
Cc: stable@vger.kernel.org # 4.19
Link: https://lkml.kernel.org/n/tip-2wt3ayp6j2y2f2xowixa8y6y@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf record: Use unmapped IP for inline callchain cursors

2018-10-05T14:18:09+00:00

Only use the mapped IP to find inline frames, but keep using the
unmapped IP for the callchain cursor. This ensures we properly show the
unmapped IP when displaying a frame we received via the
dso__parse_addr_inlines API for a module which does not contain
sufficient debug symbols to show the srcline.

This is another follow-up to commit 19610184693c ("perf script: Show
virtual addresses instead of offsets").

Signed-off-by: Milian Wolff 
Acked-by: Jiri Olsa 
Tested-by: Ravi Bangoria 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Jin Yao 
Cc: Namhyung Kim 
Cc: Sandipan Das 
Fixes: 19610184693c ("perf script: Show virtual addresses instead of offsets")
Link: http://lkml.kernel.org/r/20180926135207.30263-2-milian.wolff@kdab.com
Link: http://lkml.kernel.org/r/20181002073949.3297-1-milian.wolff@kdab.com
[ Squashed a fix from Milian for a problem reported by Ravi, fixed up space damage ]
Signed-off-by: Arnaldo Carvalho de Melo

perf report: Don't try to map ip to invalid map

2018-09-27T19:05:43+00:00

Fixes a crash when the report encounters an address that could not be
associated with an mmaped region:

  #0  0x00005555557bdc4a in callchain_srcline (ip=, sym=0x0, map=0x0) at util/machine.c:2329
  #1  unwind_entry (entry=entry@entry=0x7fffffff9180, arg=arg@entry=0x7ffff5642498) at util/machine.c:2329
  #2  0x00005555558370af in entry (arg=0x7ffff5642498, cb=0x5555557bdb50 , thread=, ip=18446744073709551615) at util/unwind-libunwind-local.c:586
  #3  get_entries (ui=ui@entry=0x7fffffff9620, cb=0x5555557bdb50 , arg=0x7ffff5642498, max_stack=) at util/unwind-libunwind-local.c:703
  #4  0x0000555555837192 in _unwind__get_entries (cb=, arg=, thread=, data=, max_stack=) at util/unwind-libunwind-local.c:725
  #5  0x00005555557c310f in thread__resolve_callchain_unwind (max_stack=127, sample=0x7fffffff9830, evsel=0x555555c7b3b0, cursor=0x7ffff5642498, thread=0x555555c7f6f0) at util/machine.c:2351
  #6  thread__resolve_callchain (thread=0x555555c7f6f0, cursor=0x7ffff5642498, evsel=0x555555c7b3b0, sample=0x7fffffff9830, parent=0x7fffffff97b8, root_al=0x7fffffff9750, max_stack=127) at util/machine.c:2378
  #7  0x00005555557ba4ee in sample__resolve_callchain (sample=, cursor=, parent=parent@entry=0x7fffffff97b8, evsel=, al=al@entry=0x7fffffff9750,
      max_stack=) at util/callchain.c:1085

Signed-off-by: Milian Wolff 
Tested-by: Sandipan Das 
Acked-by: Jiri Olsa 
Cc: Jin Yao 
Cc: Namhyung Kim 
Fixes: 2a9d5050dc84 ("perf script: Show correct offsets for DWARF-based unwinding")
Link: http://lkml.kernel.org/r/20180926135207.30263-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo