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

perf probe: Correct demangled symbols in C++ program

2024-12-05T09:59:35+00:00

[ Upstream commit 314909f13cc12d47c468602c37dace512d225eeb ]

An issue can be observed when probe C++ demangled symbol with steps:

  # nm test_cpp_mangle | grep print_data
    0000000000000c94 t _GLOBAL__sub_I__Z10print_datai
    0000000000000afc T _Z10print_datai
    0000000000000b38 T _Z10print_dataR5Point

  # perf probe -x /home/niayan01/test_cpp_mangle -F --demangle
    ...
    print_data(Point&)
    print_data(int)
    ...

  # perf --debug verbose=3 probe -x test_cpp_mangle --add "test=print_data(int)"
    probe-definition(0): test=print_data(int)
    symbol:print_data(int) file:(null) line:0 offset:0 return:0 lazy:(null)
    0 arguments
    Open Debuginfo file: /home/niayan01/test_cpp_mangle
    Try to find probe point from debuginfo.
    Symbol print_data(int) address found : afc
    Matched function: print_data [2ccf]
    Probe point found: print_data+0
    Found 1 probe_trace_events.
    Opening /sys/kernel/tracing//uprobe_events write=1
    Opening /sys/kernel/tracing//README write=0
    Writing event: p:probe_test_cpp_mangle/test /home/niayan01/test_cpp_mangle:0xb38
    ...

When tried to probe symbol "print_data(int)", the log shows:

    Symbol print_data(int) address found : afc

The found address is 0xafc - which is right with verifying the output
result from nm. Afterwards when write event, the command uses offset
0xb38 in the last log, which is a wrong address.

The dwarf_diename() gets a common function name, in above case, it
returns string "print_data". As a result, the tool parses the offset
based on the common name. This leads to probe at the wrong symbol
"print_data(Point&)".

To fix the issue, use the die_get_linkage_name() function to retrieve
the distinct linkage name - this is the mangled name for the C++ case.
Based on this unique name, the tool can get a correct offset for
probing. Based on DWARF doc, it is possible the linkage name is missed
in the DIE, it rolls back to use dwarf_diename().

After:

  # perf --debug verbose=3 probe -x test_cpp_mangle --add "test=print_data(int)"
    probe-definition(0): test=print_data(int)
    symbol:print_data(int) file:(null) line:0 offset:0 return:0 lazy:(null)
    0 arguments
    Open Debuginfo file: /home/niayan01/test_cpp_mangle
    Try to find probe point from debuginfo.
    Symbol print_data(int) address found : afc
    Matched function: print_data [2d06]
    Probe point found: print_data+0
    Found 1 probe_trace_events.
    Opening /sys/kernel/tracing//uprobe_events write=1
    Opening /sys/kernel/tracing//README write=0
    Writing event: p:probe_test_cpp_mangle/test /home/niayan01/test_cpp_mangle:0xafc
    Added new event:
      probe_test_cpp_mangle:test (on print_data(int) in /home/niayan01/test_cpp_mangle)

    You can now use it in all perf tools, such as:

            perf record -e probe_test_cpp_mangle:test -aR sleep 1

  # perf --debug verbose=3 probe -x test_cpp_mangle --add "test2=print_data(Point&)"
    probe-definition(0): test2=print_data(Point&)
    symbol:print_data(Point&) file:(null) line:0 offset:0 return:0 lazy:(null)
    0 arguments
    Open Debuginfo file: /home/niayan01/test_cpp_mangle
    Try to find probe point from debuginfo.
    Symbol print_data(Point&) address found : b38
    Matched function: print_data [2ccf]
    Probe point found: print_data+0
    Found 1 probe_trace_events.
    Opening /sys/kernel/tracing//uprobe_events write=1
    Parsing probe_events: p:probe_test_cpp_mangle/test /home/niayan01/test_cpp_mangle:0x0000000000000afc
    Group:probe_test_cpp_mangle Event:test probe:p
    Opening /sys/kernel/tracing//README write=0
    Writing event: p:probe_test_cpp_mangle/test2 /home/niayan01/test_cpp_mangle:0xb38
    Added new event:
      probe_test_cpp_mangle:test2 (on print_data(Point&) in /home/niayan01/test_cpp_mangle)

    You can now use it in all perf tools, such as:

            perf record -e probe_test_cpp_mangle:test2 -aR sleep 1

Fixes: fb1587d869a3 ("perf probe: List probes with line number and file name")
Signed-off-by: Leo Yan 
Acked-by: Masami Hiramatsu (Google) 
Link: https://lore.kernel.org/r/20241012141432.877894-1-leo.yan@arm.com
Signed-off-by: Namhyung Kim 
Signed-off-by: Sasha Levin

perf time-utils: Fix 32-bit nsec parsing

2024-11-08T15:19:07+00:00

[ Upstream commit 38e2648a81204c9fc5b4c87a8ffce93a6ed91b65 ]

The "time utils" test fails in 32-bit builds:
  ...
  parse_nsec_time("18446744073.709551615")
  Failed. ptime 4294967295709551615 expected 18446744073709551615
  ...

Switch strtoul to strtoull as an unsigned long in 32-bit build isn't
64-bits.

Fixes: c284d669a20d408b ("perf tools: Move parse_nsec_time to time-utils.c")
Signed-off-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Athira Rajeev 
Cc: Chaitanya S Prakash 
Cc: Colin Ian King 
Cc: David Ahern 
Cc: Dominique Martinet 
Cc: Ingo Molnar 
Cc: James Clark 
Cc: Jiri Olsa 
Cc: John Garry 
Cc: Junhao He 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Masami Hiramatsu 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Yang Jihong 
Link: https://lore.kernel.org/r/20240831070415.506194-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf report: Fix condition in sort__sym_cmp()

2024-08-19T03:31:59+00:00

[ Upstream commit cb39d05e67dc24985ff9f5150e71040fa4d60ab8 ]

It's expected that both hist entries are in the same hists when
comparing two.  But the current code in the function checks one without
dso sort key and other with the key.  This would make the condition true
in any case.

I guess the intention of the original commit was to add '!' for the
right side too.  But as it should be the same, let's just remove it.

Fixes: 69849fc5d2119 ("perf hists: Move sort__has_dso into struct perf_hpp_list")
Reviewed-by: Kan Liang 
Signed-off-by: Namhyung Kim 
Link: https://lore.kernel.org/r/20240621170528.608772-2-namhyung@kernel.org
Signed-off-by: Sasha Levin

perf thread_map: Free strlist on normal path in thread_map__new_by_tid_str()

2024-03-26T22:22:39+00:00

[ Upstream commit 1eb3d924e3c0b8c27388b0583a989d757866efb6 ]

slist needs to be freed in both error path and normal path in
thread_map__new_by_tid_str().

Fixes: b52956c961be3a04 ("perf tools: Allow multiple threads or processes in record, stat, top")
Reviewed-by: Arnaldo Carvalho de Melo 
Signed-off-by: Yang Jihong 
Signed-off-by: Namhyung Kim 
Link: https://lore.kernel.org/r/20240206083228.172607-6-yangjihong1@huawei.com
Signed-off-by: Sasha Levin

perf evsel: Fix duplicate initialization of data->id in evsel__parse_sample()

2024-03-26T22:22:38+00:00

[ Upstream commit 4962aec0d684c8edb14574ccd0da53e4926ff834 ]

data->id has been initialized at line 2362, remove duplicate initialization.

Fixes: 3ad31d8a0df2 ("perf evsel: Centralize perf_sample initialization")
Signed-off-by: Yang Jihong 
Reviewed-by: Arnaldo Carvalho de Melo 
Reviewed-by: Ian Rogers 
Signed-off-by: Namhyung Kim 
Link: https://lore.kernel.org/r/20240127025756.4041808-1-yangjihong1@huawei.com
Signed-off-by: Sasha Levin

perf genelf: Set ELF program header addresses properly

2024-01-25T22:33:38+00:00

[ Upstream commit 1af478903fc48c1409a8dd6b698383b62387adf1 ]

The text section starts after the ELF headers so PHDR.p_vaddr and
others should have the correct addresses.

Fixes: babd04386b1df8c3 ("perf jit: Include program header in ELF files")
Reviewed-by: Ian Rogers 
Signed-off-by: Namhyung Kim 
Cc: Adrian Hunter 
Cc: Fangrui Song 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Lieven Hey 
Cc: Milian Wolff 
Cc: Pablo Galindo 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20231212070547.612536-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf intel-pt: Fix CYC timestamps after standalone CBR

2023-08-11T09:45:20+00:00

commit 430635a0ef1ce958b7b4311f172694ece2c692b8 upstream.

After a standalone CBR (not associated with TSC), update the cycles
reference timestamp and reset the cycle count, so that CYC timestamps
are calculated relative to that point with the new frequency.

Fixes: cc33618619cefc6d ("perf tools: Add Intel PT support for decoding CYC packets")
Signed-off-by: Adrian Hunter 
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230403154831.8651-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Adrian Hunter 
Signed-off-by: Greg Kroah-Hartman

perf dwarf-aux: Fix off-by-one in die_get_varname()

2023-08-11T09:45:09+00:00

[ Upstream commit 3abfcfd847717d232e36963f31a361747c388fe7 ]

The die_get_varname() returns "(unknown_type)" string if it failed to
find a type for the variable.  But it had a space before the opening
parenthesis and it made the closing parenthesis cut off due to the
off-by-one in the string length (14).

Signed-off-by: Namhyung Kim 
Fixes: 88fd633cdfa19060 ("perf probe: No need to use formatting strbuf method")
Cc: Adrian Hunter 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Masami Hiramatsu 
Cc: Peter Zijlstra 
Link: https://lore.kernel.org/r/20230612234102.3909116-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf symbols: Fix return incorrect build_id size in elf_read_build_id()

2023-05-17T09:13:25+00:00

[ Upstream commit 1511e4696acb715a4fe48be89e1e691daec91c0e ]

In elf_read_build_id(), if gnu build_id is found, should return the size of
the actually copied data. If descsz is greater thanBuild_ID_SIZE,
write_buildid data access may occur.

Fixes: be96ea8ffa788dcc ("perf symbols: Fix issue with binaries using 16-bytes buildids (v2)")
Reported-by: Will Ochowicz 
Signed-off-by: Yang Jihong 
Tested-by: Will Ochowicz 
Acked-by: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Ian Rogers 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Leo Yan 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Link: https://lore.kernel.org/lkml/CWLP265MB49702F7BA3D6D8F13E4B1A719C649@CWLP265MB4970.GBRP265.PROD.OUTLOOK.COM/T/
Link: https://lore.kernel.org/r/20230427012841.231729-1-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf map: Delete two variable initialisations before null pointer checks in sort__sym_from_cmp()

2023-05-17T09:13:25+00:00

[ Upstream commit c160118a90d4acf335993d8d59b02ae2147a524e ]

Addresses of two data structure members were determined before
corresponding null pointer checks in the implementation of the function
“sort__sym_from_cmp”.

Thus avoid the risk for undefined behaviour by removing extra
initialisations for the local variables “from_l” and “from_r” (also
because they were already reassigned with the same value behind this
pointer check).

This issue was detected by using the Coccinelle software.

Fixes: 1b9e97a2a95e4941 ("perf tools: Fix report -F symbol_from for data without branch info")
Signed-off-by: 
Acked-by: Ian Rogers 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: German Gomez 
Cc: Ingo Molnar 
Cc: Jiri Olsa 
Cc: Kan Liang 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Link: https://lore.kernel.org/cocci/54a21fea-64e3-de67-82ef-d61b90ffad05@web.de/
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin