linux.git/tools/perf/util/machine.c, branch v5.10

perf tools: Fix crash with non-jited bpf progs

2020-11-03T11:30:34+00:00

The addr in PERF_RECORD_KSYMBOL events for non-jited bpf progs points to
the bpf interpreter, ie. within kernel text section. When processing the
unregister event, this causes unexpected removal of vmlinux_map,
crashing perf later in cleanup:

  # perf record -- timeout --signal=INT 2s /usr/share/bcc/tools/execsnoop
  PCOMM            PID    PPID   RET ARGS
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.208 MB perf.data (5155 samples) ]
  perf: tools/include/linux/refcount.h:131: refcount_sub_and_test: Assertion `!(new > val)' failed.
  Aborted (core dumped)

  # perf script -D|grep KSYM
  0 0xa40 [0x48]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b530 len 0 type 1 flags 0x0 name bpf_prog_f958f6eb72ef5af6
  0 0xab0 [0x48]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b530 len 0 type 1 flags 0x0 name bpf_prog_8c42dee26e8cd4c2
  0 0xb20 [0x48]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b530 len 0 type 1 flags 0x0 name bpf_prog_f958f6eb72ef5af6
  108563691893 0x33d98 [0x58]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b3b0 len 0 type 1 flags 0x0 name bpf_prog_bc5697a410556fc2_syscall__execve
  108568518458 0x34098 [0x58]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b3f0 len 0 type 1 flags 0x0 name bpf_prog_45e2203c2928704d_do_ret_sys_execve
  109301967895 0x34830 [0x58]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b3b0 len 0 type 1 flags 0x1 name bpf_prog_bc5697a410556fc2_syscall__execve
  109302007356 0x348b0 [0x58]: PERF_RECORD_KSYMBOL addr ffffffffa9b6b3f0 len 0 type 1 flags 0x1 name bpf_prog_45e2203c2928704d_do_ret_sys_execve
  perf: tools/include/linux/refcount.h:131: refcount_sub_and_test: Assertion `!(new > val)' failed.

Here the addresses match the bpf interpreter:

  # grep -e ffffffffa9b6b530 -e ffffffffa9b6b3b0 -e ffffffffa9b6b3f0 /proc/kallsyms
  ffffffffa9b6b3b0 t __bpf_prog_run224
  ffffffffa9b6b3f0 t __bpf_prog_run192
  ffffffffa9b6b530 t __bpf_prog_run32

Fix by not allowing vmlinux_map to be removed by PERF_RECORD_KSYMBOL
unregister event.

Signed-off-by: Tommi Rantala 
Acked-by: Jiri Olsa 
Tested-by: Jiri Olsa 
Link: https://lore.kernel.org/r/20201016114718.54332-1-tommi.t.rantala@nokia.com
Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Add machine__for_each_dso() function

2020-09-17T18:47:12+00:00

Add the machine__for_each_dso() to iterate over all dso objects defined
for the within a machine object. It will be used in the MMAP3 patch
series.

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexey Budankov 
Cc: Andi Kleen 
Cc: Frank Ch. Eigler 
Cc: Ian Rogers 
Cc: Mark Rutland 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Stephane Eranian 
Link: http://lore.kernel.org/lkml/20200913210313.1985612-22-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add bpf image check to mapis_kmodule

2020-09-03T19:04:46+00:00

When validating kcore modules the do_validate_kcore_modules function
checks on every kernel module dso against modules record. The
__map__is_kmodule check is used to get only kernel module dso objects
through.

Currently the bpf images are slipping through the check and making the
validation to fail, so report falls back from kcore usage to kallsyms.

Adding __map__is_bpf_image check for bpf image and adding it to
__map__is_kmodule check.

Fixes: 3c29d4483e85 ("perf annotate: Add basic support for bpf_image")
Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Ian Rogers 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: http://lore.kernel.org/lkml/20200826213017.818788-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Rename 'enum dso_kernel_type' to 'enum dso_space_type'

2020-08-13T12:53:21+00:00

Rename enum dso_kernel_type to enum dso_space_type, which seems like
better fit.

Committer notes:

This is used with 'struct dso'->kernel, which once was a boolean, so
DSO_SPACE__USER is zero, !zero means some sort of kernel space, be it
the host kernel space or a guest kernel space.

Signed-off-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Signed-off-by: Arnaldo Carvalho de Melo

perf script: Show text poke address symbol

2020-07-10T11:39:14+00:00

It is generally more useful to show the symbol with an address. In this
case, the print function requires the 'machine' which means changing
callers to provide it as a parameter. It is optional because most events
do not need it and the callers that matter can provide it.

Committer notes:

Made 'union perf_event' continue to be the first parameter to the
perf_event__fprintf() and perf_event__fprintf_text_poke() events.

Signed-off-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Jiri Olsa 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Mathieu Poirier 
Cc: Peter Zijlstra 
Cc: Steven Rostedt (VMware) 
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20200512121922.8997-16-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add support for PERF_RECORD_KSYMBOL_TYPE_OOL

2020-07-10T11:30:25+00:00

PERF_RECORD_KSYMBOL_TYPE_OOL marks an executable page. Create a map
backed only by memory, which will be populated as necessary by text poke
events.

Committer notes:

From the patch:

OOL stands for "Out of line" code such as kprobe-replaced instructions
or optimized kprobes or ftrace trampolines.

Signed-off-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Jiri Olsa 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Mathieu Poirier 
Cc: Peter Zijlstra 
Cc: Steven Rostedt (VMware) 
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20200512121922.8997-13-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Add support for PERF_RECORD_TEXT_POKE

2020-07-10T11:20:01+00:00

Add processing for PERF_RECORD_TEXT_POKE events. When a text poke event
is processed, then the kernel dso data cache is updated with the poked
bytes.

Signed-off-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Borislav Petkov 
Cc: H. Peter Anvin 
Cc: Jiri Olsa 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Mathieu Poirier 
Cc: Peter Zijlstra 
Cc: Steven Rostedt (VMware) 
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20200512121922.8997-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix is_bpf_image function logic

2020-05-28T13:03:26+00:00

Adrian reported that is_bpf_image is not working the way it was intended
- passing on trampolines and dispatcher names. Instead it returned true
for all the bpf names.

The reason even this logic worked properly is that all bpf objects, even
trampolines and dispatcher, were assigned DSO_BINARY_TYPE__BPF_IMAGE
binary_type.

The later for bpf_prog objects, the binary_type was fixed in bpf load
event processing, which is executed after the ksymbol code.

Fixing the is_bpf_image logic, so it properly recognizes trampoline and
dispatcher objects.

Fixes: 3c29d4483e85 ("perf annotate: Add basic support for bpf_image")
Reported-by: Adrian Hunter 
Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20200512122310.3154754-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Rename perf_evselenv() to evselenv()

2020-05-05T19:35:31+00:00

As it is a 'struct evsel' method, not part of tools/lib/perf/, aka
libperf, to whom the perf_ prefix belongs.

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Rename perf_evselhas() to evselhas()