1. 02 Feb, 2023 19 commits
    • Namhyung Kim's avatar
      perf script: Add 'cgroup' field for output · 3fd7a168
      Namhyung Kim authored
      There's no field for the cgroup, let's add one.  To do that, users need to
      specify --all-cgroup option for perf record to capture the cgroup info.
      
        $ perf record --all-cgroups -- true
      
        $ perf script -F comm,pid,cgroup
                  true 337112  /user.slice/user-657345.slice/user@657345.service/...
                  true 337112  /user.slice/user-657345.slice/user@657345.service/...
                  true 337112  /user.slice/user-657345.slice/user@657345.service/...
                  true 337112  /user.slice/user-657345.slice/user@657345.service/...
      
      If it's recorded without the --all-cgroups, it'd complain.
      
        $ perf script -F comm,pid,cgroup
        Samples for 'cycles:u' event do not have CGROUP attribute set. Cannot print 'cgroup' field.
        Hint: run 'perf record --all-cgroups ...'
      Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Link: https://lore.kernel.org/r/20230126213610.3381147-1-namhyung@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      3fd7a168
    • Ross Zwisler's avatar
      perf tools docs: Use canonical ftrace path · 1df49ef9
      Ross Zwisler authored
      The canonical location for the tracefs filesystem is at /sys/kernel/tracing.
      
      But, from Documentation/trace/ftrace.rst:
      
        Before 4.1, all ftrace tracing control files were within the debugfs
        file system, which is typically located at /sys/kernel/debug/tracing.
        For backward compatibility, when mounting the debugfs file system,
        the tracefs file system will be automatically mounted at:
      
        /sys/kernel/debug/tracing
      
      A few spots in the perf docs still refer to this older debugfs path, so
      let's update them to avoid confusion.
      Signed-off-by: default avatarRoss Zwisler <zwisler@google.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
      Cc: linux-trace-kernel@vger.kernel.org
      Link: http://lore.kernel.org/lkml/20230130181915.1113313-5-zwisler@google.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      1df49ef9
    • Rob Herring's avatar
      perf arm-spe: Only warn once for each unsupported address packet · 28899594
      Rob Herring authored
      Unknown address packet indexes are not an error as the Arm architecture
      can (and has with SPEv1.2) define new ones and implementation defined
      ones are also allowed. The error message for every occurrence of the
      packet is needlessly noisy as well. Change the message to print just
      once for each unknown index.
      Reviewed-by: default avatarLeo Yan <leo.yan@linaro.org>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: James Clark <james.clark@arm.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Will Deacon <will@kernel.org>
      Link: https://lore.kernel.org/r/20230127205546.667740-1-robh@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      28899594
    • Krister Johansen's avatar
      perf symbols: Symbol lookup with kcore can fail if multiple segments match stext · 1c249565
      Krister Johansen authored
      This problem was encountered on an arm64 system with a lot of memory.
      Without kernel debug symbols installed, and with both kcore and kallsyms
      available, perf managed to get confused and returned "unknown" for all
      of the kernel symbols that it tried to look up.
      
      On this system, stext fell within the vmalloc segment.  The kcore symbol
      matching code tries to find the first segment that contains stext and
      uses that to replace the segment generated from just the kallsyms
      information.  In this case, however, there were two: a very large
      vmalloc segment, and the text segment.  This caused perf to get confused
      because multiple overlapping segments were inserted into the RB tree
      that holds the discovered segments.  However, that alone wasn't
      sufficient to cause the problem. Even when we could find the segment,
      the offsets were adjusted in such a way that the newly generated symbols
      didn't line up with the instruction addresses in the trace.  The most
      obvious solution would be to consult which segment type is text from
      kcore, but this information is not exposed to users.
      
      Instead, select the smallest matching segment that contains stext
      instead of the first matching segment.  This allows us to match the text
      segment instead of vmalloc, if one is contained within the other.
      Reviewed-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Signed-off-by: default avatarKrister Johansen <kjlx@templeofstupid.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: David Reaver <me@davidreaver.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Michael Petlan <mpetlan@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lore.kernel.org/lkml/20230125183418.GD1963@templeofstupid.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      1c249565
    • Athira Rajeev's avatar
      perf probe: Fix usage when libtraceevent is missing · 3980ee9a
      Athira Rajeev authored
      While parsing the tracepoint events in parse_events_add_tracepoint()
      function, code checks for HAVE_LIBTRACEEVENT support. This is needed
      since libtraceevent is necessary for tracepoint. But while adding probe
      points, check for LIBTRACEEVENT is not done in case of perf probe.
      Hence, in environment with missing libtraceevent-devel, it is observed
      that adding a probe point shows below message though it can't be used
      via perf record.
      
      Example:
      
      Adding probe point:
      	./perf probe 'vfs_getname=getname_flags:72 pathname=result->name:string'
      	Added new event:
      	  probe:vfs_getname    (on getname_flags:72 with pathname=result->name:string)
      
      	You can now use it in all perf tools, such as:
      
      		perf record -e probe:vfs_getname -aR sleep 1
      
      But trying perf record:
      	./perf  record -e probe:vfs_getname -aR sleep 1
      	event syntax error: 'probe:vfs_getname'
      				\___ unsupported tracepoint
      	libtraceevent is necessary for tracepoint support
      	Run 'perf list' for a list of valid events
      
      The builtin tool like perf record needs libtraceevent to
      parse tracefs. But still the probe can be used by enabling
      via tracefs. Patch fixes the probe usage message to the user
      based on presence of libtraceevent. With the fix,
      
       # ./perf probe 'pmu:myprobe=schedule'
       Added new event:
         pmu:myprobe          (on schedule)
      
       perf is not linked with libtraceevent, to use the new probe you can use tracefs:
      
      	cd /sys/kernel/tracing/
      	echo 1 > events/pmu/myprobe/enable
      	echo 1 > tracing_on
      	cat trace_pipe
      	Before removing the probe, echo 0 > events/pmu/myprobe/enable
      Signed-off-by: default avatarAthira Rajeev <atrajeev@linux.vnet.ibm.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Disha Goel <disgoel@linux.ibm.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: James Clark <james.clark@arm.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Kajol Jain <kjain@linux.ibm.com>
      Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: linuxppc-dev@lists.ozlabs.org
      Link: https://lore.kernel.org/r/20230131134748.54567-1-atrajeev@linux.vnet.ibm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      3980ee9a
    • Adrian Hunter's avatar
      perf symbols: Get symbols for .plt.got for x86-64 · ce4c8e79
      Adrian Hunter authored
      For x86_64, determine a symbol for .plt.got entries. That requires
      computing the target offset and finding that in .rela.dyn, which in
      turn means .rela.dyn needs to be sorted by offset.
      
      Example:
      
        In this example, the GNU C Library is using .plt.got for malloc and
        free.
      
        Before:
      
          $ gcc --version
          gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
          Copyright (C) 2021 Free Software Foundation, Inc.
          This is free software; see the source for copying conditions.  There is NO
          warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
          $ perf record -e intel_pt//u uname
          Linux
          [ perf record: Woken up 1 times to write data ]
          [ perf record: Captured and wrote 0.027 MB perf.data ]
          $ perf script --itrace=be --ns -F-event,+addr,-period,-comm,-tid,-cpu > /tmp/cmp1.txt
      
        After:
      
          $ perf script --itrace=be --ns -F-event,+addr,-period,-comm,-tid,-cpu > /tmp/cmp2.txt
          $ diff /tmp/cmp1.txt /tmp/cmp2.txt | head -12
          15509,15510c15509,15510
          < 27046.755390907:      7f0b2943e3ab _nl_normalize_codeset+0x5b (/usr/lib/x86_64-linux-gnu/libc.so.6) =>     7f0b29428380 offset_0x28380@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
          < 27046.755390907:      7f0b29428384 offset_0x28380@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) =>     7f0b294a5120 malloc+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
          ---
          > 27046.755390907:      7f0b2943e3ab _nl_normalize_codeset+0x5b (/usr/lib/x86_64-linux-gnu/libc.so.6) =>     7f0b29428380 malloc@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
          > 27046.755390907:      7f0b29428384 malloc@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) =>     7f0b294a5120 malloc+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
          15821,15822c15821,15822
          < 27046.755394865:      7f0b2943850c _nl_load_locale_from_archive+0x5bc (/usr/lib/x86_64-linux-gnu/libc.so.6) =>     7f0b29428370 offset_0x28370@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
          < 27046.755394865:      7f0b29428374 offset_0x28370@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) =>     7f0b294a5460 cfree@GLIBC_2.2.5+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
          ---
          > 27046.755394865:      7f0b2943850c _nl_load_locale_from_archive+0x5bc (/usr/lib/x86_64-linux-gnu/libc.so.6) =>     7f0b29428370 free@plt+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
          > 27046.755394865:      7f0b29428374 free@plt+0x4 (/usr/lib/x86_64-linux-gnu/libc.so.6) =>     7f0b294a5460 cfree@GLIBC_2.2.5+0x0 (/usr/lib/x86_64-linux-gnu/libc.so.6)
      Reviewed-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Link: https://lore.kernel.org/r/20230131131625.6964-10-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      ce4c8e79
    • Adrian Hunter's avatar
      perf symbols: Start adding support for .plt.got for x86 · 51a188ad
      Adrian Hunter authored
      For x86, .plt.got is used, for example, when the address is taken of a
      dynamically linked function. Start adding support by synthesizing a
      symbol for each entry. A subsequent patch will attempt to get a better
      name for the symbol.
      
      Example:
      
        Before:
      
          $ cat tstpltlib.c
          void fn1(void) {}
          void fn2(void) {}
          void fn3(void) {}
          void fn4(void) {}
          $ cat tstpltgot.c
          void fn1(void);
          void fn2(void);
          void fn3(void);
          void fn4(void);
      
          void callfn(void (*fn)(void))
          {
                  fn();
          }
      
          int main()
          {
                  fn4();
                  fn1();
                  callfn(fn3);
                  fn2();
                  fn3();
                  return 0;
          }
          $ gcc --version
          gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
          Copyright (C) 2021 Free Software Foundation, Inc.
          This is free software; see the source for copying conditions.  There is NO
          warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
          $ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
          $ gcc -Wall -Wextra -o tstpltgot tstpltgot.c -L . -ltstpltlib -Wl,-rpath="$(pwd)"
          $ readelf -SW tstpltgot | grep 'Name\|plt\|dyn'
            [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
            [ 6] .dynsym           DYNSYM          00000000000003d8 0003d8 0000f0 18   A  7   1  8
            [ 7] .dynstr           STRTAB          00000000000004c8 0004c8 0000c6 00   A  0   0  1
            [10] .rela.dyn         RELA            00000000000005d8 0005d8 0000d8 18   A  6   0  8
            [11] .rela.plt         RELA            00000000000006b0 0006b0 000048 18  AI  6  24  8
            [13] .plt              PROGBITS        0000000000001020 001020 000040 10  AX  0   0 16
            [14] .plt.got          PROGBITS        0000000000001060 001060 000020 10  AX  0   0 16
            [15] .plt.sec          PROGBITS        0000000000001080 001080 000030 10  AX  0   0 16
            [23] .dynamic          DYNAMIC         0000000000003d90 002d90 000210 10  WA  7   0  8
          $ perf record -e intel_pt//u --filter 'filter main @ ./tstpltgot , filter callfn @ ./tstpltgot' ./tstpltgot
          [ perf record: Woken up 1 times to write data ]
          [ perf record: Captured and wrote 0.011 MB perf.data ]
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          28393.810326915:   tr strt                               0 [unknown] =>     562350baa1b2 main+0x0
          28393.810326915:   tr end  call               562350baa1ba main+0x8 =>     562350baa090 fn4@plt+0x0
          28393.810326917:   tr strt                               0 [unknown] =>     562350baa1bf main+0xd
          28393.810326917:   tr end  call               562350baa1bf main+0xd =>     562350baa080 fn1@plt+0x0
          28393.810326917:   tr strt                               0 [unknown] =>     562350baa1c4 main+0x12
          28393.810326917:   call                       562350baa1ce main+0x1c =>     562350baa199 callfn+0x0
          28393.810326917:   tr end  call               562350baa1ad callfn+0x14 =>     7f607d36110f fn3+0x0
          28393.810326922:   tr strt                               0 [unknown] =>     562350baa1af callfn+0x16
          28393.810326922:   return                     562350baa1b1 callfn+0x18 =>     562350baa1d3 main+0x21
          28393.810326922:   tr end  call               562350baa1d3 main+0x21 =>     562350baa0a0 fn2@plt+0x0
          28393.810326924:   tr strt                               0 [unknown] =>     562350baa1d8 main+0x26
          28393.810326924:   tr end  call               562350baa1d8 main+0x26 =>     562350baa060 [unknown]  <- call to fn3 via .plt.got
          28393.810326925:   tr strt                               0 [unknown] =>     562350baa1dd main+0x2b
          28393.810326925:   tr end  return             562350baa1e3 main+0x31 =>     7f607d029d90 __libc_start_call_main+0x80
      
        After:
      
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          28393.810326915:   tr strt                               0 [unknown] =>     562350baa1b2 main+0x0
          28393.810326915:   tr end  call               562350baa1ba main+0x8 =>     562350baa090 fn4@plt+0x0
          28393.810326917:   tr strt                               0 [unknown] =>     562350baa1bf main+0xd
          28393.810326917:   tr end  call               562350baa1bf main+0xd =>     562350baa080 fn1@plt+0x0
          28393.810326917:   tr strt                               0 [unknown] =>     562350baa1c4 main+0x12
          28393.810326917:   call                       562350baa1ce main+0x1c =>     562350baa199 callfn+0x0
          28393.810326917:   tr end  call               562350baa1ad callfn+0x14 =>     7f607d36110f fn3+0x0
          28393.810326922:   tr strt                               0 [unknown] =>     562350baa1af callfn+0x16
          28393.810326922:   return                     562350baa1b1 callfn+0x18 =>     562350baa1d3 main+0x21
          28393.810326922:   tr end  call               562350baa1d3 main+0x21 =>     562350baa0a0 fn2@plt+0x0
          28393.810326924:   tr strt                               0 [unknown] =>     562350baa1d8 main+0x26
          28393.810326924:   tr end  call               562350baa1d8 main+0x26 =>     562350baa060 offset_0x1060@plt+0x0
          28393.810326925:   tr strt                               0 [unknown] =>     562350baa1dd main+0x2b
          28393.810326925:   tr end  return             562350baa1e3 main+0x31 =>     7f607d029d90 __libc_start_call_main+0x80
      Reviewed-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Link: https://lore.kernel.org/r/20230131131625.6964-9-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      51a188ad
    • Adrian Hunter's avatar
      perf symbols: Allow for static executables with .plt · a1ab1285
      Adrian Hunter authored
      A statically linked executable can have a .plt due to IFUNCs, in which
      case .symtab is used not .dynsym. Check the section header link to see
      if that is the case, and then use symtab instead.
      
      Example:
      
        Before:
      
          $ cat tstifunc.c
          #include <stdio.h>
      
          void thing1(void)
          {
                  printf("thing1\n");
          }
      
          void thing2(void)
          {
                  printf("thing2\n");
          }
      
          typedef void (*thing_fn_t)(void);
      
          thing_fn_t thing_ifunc(void)
          {
                  int x;
      
                  if (x & 1)
                          return thing2;
                  return thing1;
          }
      
          void thing(void) __attribute__ ((ifunc ("thing_ifunc")));
      
          int main()
          {
                  thing();
                  return 0;
          }
          $ gcc --version
          gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
          Copyright (C) 2021 Free Software Foundation, Inc.
          This is free software; see the source for copying conditions.  There is NO
          warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
          $ gcc -static -Wall -Wextra -Wno-uninitialized -o tstifuncstatic tstifunc.c
          $ readelf -SW tstifuncstatic | grep 'Name\|plt\|dyn'
            [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
            [ 4] .rela.plt         RELA            00000000004002e8 0002e8 000258 18  AI 29  20  8
            [ 6] .plt              PROGBITS        0000000000401020 001020 000190 00  AX  0   0 16
            [20] .got.plt          PROGBITS        00000000004c5000 0c4000 0000e0 08  WA  0   0  8
          $ perf record -e intel_pt//u --filter 'filter main @ ./tstifuncstatic' ./tstifuncstatic
          thing1
          [ perf record: Woken up 1 times to write data ]
          [ perf record: Captured and wrote 0.008 MB perf.data ]
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          15786.690189535:   tr strt                               0 [unknown] =>           4017cd main+0x0
          15786.690189535:   tr end  call                     4017d5 main+0x8 =>           401170 [unknown]
          15786.690197660:   tr strt                               0 [unknown] =>           4017da main+0xd
          15786.690197660:   tr end  return                   4017e0 main+0x13 =>           401c1a __libc_start_call_main+0x6a
      
        After:
      
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          15786.690189535:   tr strt                               0 [unknown] =>           4017cd main+0x0
          15786.690189535:   tr end  call                     4017d5 main+0x8 =>           401170 thing_ifunc@plt+0x0
          15786.690197660:   tr strt                               0 [unknown] =>           4017da main+0xd
          15786.690197660:   tr end  return                   4017e0 main+0x13 =>           401c1a __libc_start_call_main+0x6a
      Reviewed-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Link: https://lore.kernel.org/r/20230131131625.6964-8-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      a1ab1285
    • Adrian Hunter's avatar
      perf symbols: Allow for .plt without header · 60fbb3e4
      Adrian Hunter authored
      A static executable can have a .plt due to the presence of IFUNCs.  In
      that case the .plt does not have a header. Check for whether there is a
      header by comparing the number of entries to the number of relocation
      entries.
      Reviewed-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Link: https://lore.kernel.org/r/20230131131625.6964-7-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      60fbb3e4
    • Adrian Hunter's avatar
      perf symbols: Add support for IFUNC symbols for x86_64 · b7dbc0be
      Adrian Hunter authored
      For x86_64, the GNU linker is putting IFUNC information in the relocation
      addend, so use it to try to find a symbol for plt entries that refer to
      IFUNCs.
      
      Example:
      
        Before:
      
          $ cat tstpltlib.c
          void fn1(void) {}
          void fn2(void) {}
          void fn3(void) {}
          void fn4(void) {}
          $ cat tstpltifunc.c
          #include <stdio.h>
      
          void thing1(void)
          {
                  printf("thing1\n");
          }
      
          void thing2(void)
          {
                  printf("thing2\n");
          }
      
          typedef void (*thing_fn_t)(void);
      
          thing_fn_t thing_ifunc(void)
          {
                  int x;
      
                  if (x & 1)
                          return thing2;
                  return thing1;
          }
      
          void thing(void) __attribute__ ((ifunc ("thing_ifunc")));
      
          void fn1(void);
          void fn2(void);
          void fn3(void);
          void fn4(void);
      
          int main()
          {
                  fn4();
                  fn1();
                  thing();
                  fn2();
                  fn3();
                  return 0;
          }
          $ gcc --version
          gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
          Copyright (C) 2021 Free Software Foundation, Inc.
          This is free software; see the source for copying conditions.  There is NO
          warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
          $ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
          $ gcc -Wall -Wextra -Wno-uninitialized -o tstpltifunc tstpltifunc.c -L . -ltstpltlib -Wl,-rpath="$(pwd)"
          $ readelf -rW tstpltifunc | grep -A99 plt
          Relocation section '.rela.plt' at offset 0x738 contains 8 entries:
              Offset             Info             Type               Symbol's Value  Symbol's Name + Addend
          0000000000003f98  0000000300000007 R_X86_64_JUMP_SLOT     0000000000000000 puts@GLIBC_2.2.5 + 0
          0000000000003fa8  0000000400000007 R_X86_64_JUMP_SLOT     0000000000000000 __stack_chk_fail@GLIBC_2.4 + 0
          0000000000003fb0  0000000500000007 R_X86_64_JUMP_SLOT     0000000000000000 fn1 + 0
          0000000000003fb8  0000000600000007 R_X86_64_JUMP_SLOT     0000000000000000 fn3 + 0
          0000000000003fc0  0000000800000007 R_X86_64_JUMP_SLOT     0000000000000000 fn4 + 0
          0000000000003fc8  0000000900000007 R_X86_64_JUMP_SLOT     0000000000000000 fn2 + 0
          0000000000003fd0  0000000b00000007 R_X86_64_JUMP_SLOT     0000000000000000 getrandom@GLIBC_2.25 + 0
          0000000000003fa0  0000000000000025 R_X86_64_IRELATIVE                        125d
          $ perf record -e intel_pt//u --filter 'filter main @ ./tstpltifunc' ./tstpltifunc
          thing2
          [ perf record: Woken up 1 times to write data ]
          [ perf record: Captured and wrote 0.016 MB perf.data ]
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          21860.073683659:   tr strt                               0 [unknown] =>     561e212c42be main+0x0
          21860.073683659:   tr end  call               561e212c42c6 main+0x8 =>     561e212c4110 fn4@plt+0x0
          21860.073683661:   tr strt                               0 [unknown] =>     561e212c42cb main+0xd
          21860.073683661:   tr end  call               561e212c42cb main+0xd =>     561e212c40f0 fn1@plt+0x0
          21860.073683661:   tr strt                               0 [unknown] =>     561e212c42d0 main+0x12
          21860.073683661:   tr end  call               561e212c42d0 main+0x12 =>     561e212c40d0 offset_0x10d0@plt+0x0
          21860.073698451:   tr strt                               0 [unknown] =>     561e212c42d5 main+0x17
          21860.073698451:   tr end  call               561e212c42d5 main+0x17 =>     561e212c4120 fn2@plt+0x0
          21860.073698451:   tr strt                               0 [unknown] =>     561e212c42da main+0x1c
          21860.073698451:   tr end  call               561e212c42da main+0x1c =>     561e212c4100 fn3@plt+0x0
          21860.073698452:   tr strt                               0 [unknown] =>     561e212c42df main+0x21
          21860.073698452:   tr end  return             561e212c42e5 main+0x27 =>     7fb51cc29d90 __libc_start_call_main+0x80
      
        After:
      
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          21860.073683659:   tr strt                               0 [unknown] =>     561e212c42be main+0x0
          21860.073683659:   tr end  call               561e212c42c6 main+0x8 =>     561e212c4110 fn4@plt+0x0
          21860.073683661:   tr strt                               0 [unknown] =>     561e212c42cb main+0xd
          21860.073683661:   tr end  call               561e212c42cb main+0xd =>     561e212c40f0 fn1@plt+0x0
          21860.073683661:   tr strt                               0 [unknown] =>     561e212c42d0 main+0x12
          21860.073683661:   tr end  call               561e212c42d0 main+0x12 =>     561e212c40d0 thing_ifunc@plt+0x0
          21860.073698451:   tr strt                               0 [unknown] =>     561e212c42d5 main+0x17
          21860.073698451:   tr end  call               561e212c42d5 main+0x17 =>     561e212c4120 fn2@plt+0x0
          21860.073698451:   tr strt                               0 [unknown] =>     561e212c42da main+0x1c
          21860.073698451:   tr end  call               561e212c42da main+0x1c =>     561e212c4100 fn3@plt+0x0
          21860.073698452:   tr strt                               0 [unknown] =>     561e212c42df main+0x21
          21860.073698452:   tr end  return             561e212c42e5 main+0x27 =>     7fb51cc29d90 __libc_start_call_main+0x80
      Reviewed-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Link: https://lore.kernel.org/r/20230131131625.6964-6-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b7dbc0be
    • Adrian Hunter's avatar
      perf symbols: Record whether a symbol is an alias for an IFUNC symbol · 05963491
      Adrian Hunter authored
      To assist with synthesizing plt symbols for IFUNCs, record whether a
      symbol is an alias of an IFUNC symbol.
      Reviewed-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Link: https://lore.kernel.org/r/20230131131625.6964-5-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      05963491
    • Adrian Hunter's avatar
      perf symbols: Sort plt relocations for x86 · 78250284
      Adrian Hunter authored
      For x86, with the addition of IFUNCs, relocation information becomes
      disordered with respect to plt. Correct that by sorting the relocations by
      offset.
      
      Example:
      
        Before:
      
          $ cat tstpltlib.c
          void fn1(void) {}
          void fn2(void) {}
          void fn3(void) {}
          void fn4(void) {}
          $ cat tstpltifunc.c
          #include <stdio.h>
      
          void thing1(void)
          {
                  printf("thing1\n");
          }
      
          void thing2(void)
          {
                  printf("thing2\n");
          }
      
          typedef void (*thing_fn_t)(void);
      
          thing_fn_t thing_ifunc(void)
          {
                  int x;
      
                  if (x & 1)
                          return thing2;
                  return thing1;
          }
      
          void thing(void) __attribute__ ((ifunc ("thing_ifunc")));
      
          void fn1(void);
          void fn2(void);
          void fn3(void);
          void fn4(void);
      
          int main()
          {
                  fn4();
                  fn1();
                  thing();
                  fn2();
                  fn3();
                  return 0;
          }
          $ gcc --version
          gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
          Copyright (C) 2021 Free Software Foundation, Inc.
          This is free software; see the source for copying conditions.  There is NO
          warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
          $ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
          $ gcc -Wall -Wextra -Wno-uninitialized -o tstpltifunc tstpltifunc.c -L . -ltstpltlib -Wl,-rpath="$(pwd)"
          $ readelf -rW tstpltifunc | grep -A99 plt
          Relocation section '.rela.plt' at offset 0x738 contains 8 entries:
              Offset             Info             Type               Symbol's Value  Symbol's Name + Addend
          0000000000003f98  0000000300000007 R_X86_64_JUMP_SLOT     0000000000000000 puts@GLIBC_2.2.5 + 0
          0000000000003fa8  0000000400000007 R_X86_64_JUMP_SLOT     0000000000000000 __stack_chk_fail@GLIBC_2.4 + 0
          0000000000003fb0  0000000500000007 R_X86_64_JUMP_SLOT     0000000000000000 fn1 + 0
          0000000000003fb8  0000000600000007 R_X86_64_JUMP_SLOT     0000000000000000 fn3 + 0
          0000000000003fc0  0000000800000007 R_X86_64_JUMP_SLOT     0000000000000000 fn4 + 0
          0000000000003fc8  0000000900000007 R_X86_64_JUMP_SLOT     0000000000000000 fn2 + 0
          0000000000003fd0  0000000b00000007 R_X86_64_JUMP_SLOT     0000000000000000 getrandom@GLIBC_2.25 + 0
          0000000000003fa0  0000000000000025 R_X86_64_IRELATIVE                        125d
          $ perf record -e intel_pt//u --filter 'filter main @ ./tstpltifunc' ./tstpltifunc
          thing2
          [ perf record: Woken up 1 times to write data ]
          [ perf record: Captured and wrote 0.029 MB perf.data ]
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          20417.302513948:   tr strt                               0 [unknown] =>     5629a74892be main+0x0
          20417.302513948:   tr end  call               5629a74892c6 main+0x8 =>     5629a7489110 fn2@plt+0x0
          20417.302513949:   tr strt                               0 [unknown] =>     5629a74892cb main+0xd
          20417.302513949:   tr end  call               5629a74892cb main+0xd =>     5629a74890f0 fn3@plt+0x0
          20417.302513950:   tr strt                               0 [unknown] =>     5629a74892d0 main+0x12
          20417.302513950:   tr end  call               5629a74892d0 main+0x12 =>     5629a74890d0 __stack_chk_fail@plt+0x0
          20417.302528114:   tr strt                               0 [unknown] =>     5629a74892d5 main+0x17
          20417.302528114:   tr end  call               5629a74892d5 main+0x17 =>     5629a7489120 getrandom@plt+0x0
          20417.302528115:   tr strt                               0 [unknown] =>     5629a74892da main+0x1c
          20417.302528115:   tr end  call               5629a74892da main+0x1c =>     5629a7489100 fn4@plt+0x0
          20417.302528115:   tr strt                               0 [unknown] =>     5629a74892df main+0x21
          20417.302528115:   tr end  return             5629a74892e5 main+0x27 =>     7ff14da29d90 __libc_start_call_main+0x80
      
        After:
      
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          20417.302513948:   tr strt                               0 [unknown] =>     5629a74892be main+0x0
          20417.302513948:   tr end  call               5629a74892c6 main+0x8 =>     5629a7489110 fn4@plt+0x0
          20417.302513949:   tr strt                               0 [unknown] =>     5629a74892cb main+0xd
          20417.302513949:   tr end  call               5629a74892cb main+0xd =>     5629a74890f0 fn1@plt+0x0
          20417.302513950:   tr strt                               0 [unknown] =>     5629a74892d0 main+0x12
          20417.302513950:   tr end  call               5629a74892d0 main+0x12 =>     5629a74890d0 offset_0x10d0@plt+0x0
          20417.302528114:   tr strt                               0 [unknown] =>     5629a74892d5 main+0x17
          20417.302528114:   tr end  call               5629a74892d5 main+0x17 =>     5629a7489120 fn2@plt+0x0
          20417.302528115:   tr strt                               0 [unknown] =>     5629a74892da main+0x1c
          20417.302528115:   tr end  call               5629a74892da main+0x1c =>     5629a7489100 fn3@plt+0x0
          20417.302528115:   tr strt                               0 [unknown] =>     5629a74892df main+0x21
          20417.302528115:   tr end  return             5629a74892e5 main+0x27 =>     7ff14da29d90 __libc_start_call_main+0x80
      Reviewed-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Link: https://lore.kernel.org/r/20230131131625.6964-4-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      78250284
    • Adrian Hunter's avatar
      perf symbols: Add support for x86 .plt.sec · b2529f82
      Adrian Hunter authored
      The section .plt.sec was originally added for MPX and was first called
      .plt.bnd. While MPX has been deprecated, .plt.sec is now also used for
      IBT.  On x86_64, IBT may be enabled by default, but can be switched off
      using gcc option -fcf-protection=none, or switched on by -z ibt or -z
      ibtplt. On 32-bit, option -z ibt or -z ibtplt will enable IBT.
      
      With .plt.sec, calls are made into .plt.sec instead of .plt, so it makes
      more sense to put the symbols there instead of .plt. A notable
      difference is that .plt.sec does not have a header entry.
      
      For x86, when synthesizing symbols for plt, use offset and entry size of
      .plt.sec instead of .plt when there is a .plt.sec section.
      
      Example on Ubuntu 22.04 gcc 11.3:
      
        Before:
      
          $ cat tstpltlib.c
          void fn1(void) {}
          void fn2(void) {}
          void fn3(void) {}
          void fn4(void) {}
          $ cat tstplt.c
          void fn1(void);
          void fn2(void);
          void fn3(void);
          void fn4(void);
      
          int main()
          {
                  fn4();
                  fn1();
                  fn2();
                  fn3();
                  return 0;
          }
          $ gcc --version
          gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
          Copyright (C) 2021 Free Software Foundation, Inc.
          This is free software; see the source for copying conditions.  There is NO
          warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
          $ gcc -Wall -Wextra -shared -o libtstpltlib.so tstpltlib.c
          $ gcc -Wall -Wextra -z ibt -o tstplt tstplt.c -L . -ltstpltlib -Wl,-rpath=$(pwd)
          $ readelf -SW tstplt | grep 'plt\|Name'
            [Nr] Name              Type            Address          Off    Size   ES Flg Lk Inf Al
            [11] .rela.plt         RELA            0000000000000698 000698 000060 18  AI  6  24  8
            [13] .plt              PROGBITS        0000000000001020 001020 000050 10  AX  0   0 16
            [14] .plt.got          PROGBITS        0000000000001070 001070 000010 10  AX  0   0 16
            [15] .plt.sec          PROGBITS        0000000000001080 001080 000040 10  AX  0   0 16
          $ perf record -e intel_pt//u --filter 'filter main @ ./tstplt' ./tstplt
          [ perf record: Woken up 1 times to write data ]
          [ perf record: Captured and wrote 0.015 MB perf.data ]
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          38970.522546686:   tr strt                               0 [unknown] =>     55fc222a81a9 main+0x0
          38970.522546686:   tr end  call               55fc222a81b1 main+0x8 =>     55fc222a80a0 [unknown]
          38970.522546687:   tr strt                               0 [unknown] =>     55fc222a81b6 main+0xd
          38970.522546687:   tr end  call               55fc222a81b6 main+0xd =>     55fc222a8080 [unknown]
          38970.522546688:   tr strt                               0 [unknown] =>     55fc222a81bb main+0x12
          38970.522546688:   tr end  call               55fc222a81bb main+0x12 =>     55fc222a80b0 [unknown]
          38970.522546688:   tr strt                               0 [unknown] =>     55fc222a81c0 main+0x17
          38970.522546688:   tr end  call               55fc222a81c0 main+0x17 =>     55fc222a8090 [unknown]
          38970.522546689:   tr strt                               0 [unknown] =>     55fc222a81c5 main+0x1c
          38970.522546894:   tr end  return             55fc222a81cb main+0x22 =>     7f3a4dc29d90 __libc_start_call_main+0x80
      
        After:
      
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          38970.522546686:   tr strt                               0 [unknown] =>     55fc222a81a9 main+0x0
          38970.522546686:   tr end  call               55fc222a81b1 main+0x8 =>     55fc222a80a0 fn4@plt+0x0
          38970.522546687:   tr strt                               0 [unknown] =>     55fc222a81b6 main+0xd
          38970.522546687:   tr end  call               55fc222a81b6 main+0xd =>     55fc222a8080 fn1@plt+0x0
          38970.522546688:   tr strt                               0 [unknown] =>     55fc222a81bb main+0x12
          38970.522546688:   tr end  call               55fc222a81bb main+0x12 =>     55fc222a80b0 fn2@plt+0x0
          38970.522546688:   tr strt                               0 [unknown] =>     55fc222a81c0 main+0x17
          38970.522546688:   tr end  call               55fc222a81c0 main+0x17 =>     55fc222a8090 fn3@plt+0x0
          38970.522546689:   tr strt                               0 [unknown] =>     55fc222a81c5 main+0x1c
          38970.522546894:   tr end  return             55fc222a81cb main+0x22 =>     7f3a4dc29d90 __libc_start_call_main+0x80
      Reviewed-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Link: https://lore.kernel.org/r/20230131131625.6964-3-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b2529f82
    • Adrian Hunter's avatar
      perf symbols: Correct plt entry sizes for x86 · 66fe2d53
      Adrian Hunter authored
      In 32-bit executables the .plt entry size can be set to 4 when it is really
      16. In fact the only sizes used for x86 (32 or 64 bit) are 8 or 16, so
      check for those and, if not, use the alignment to choose which it is.
      
      Example on Ubuntu 22.04 gcc 11.3:
      
        Before:
      
          $ cat tstpltlib.c
          void fn1(void) {}
          void fn2(void) {}
          void fn3(void) {}
          void fn4(void) {}
          $ cat tstplt.c
          void fn1(void);
          void fn2(void);
          void fn3(void);
          void fn4(void);
      
          int main()
          {
                  fn4();
                  fn1();
                  fn2();
                  fn3();
                  return 0;
          }
          $ gcc --version
          gcc (Ubuntu 11.3.0-1ubuntu1~22.04) 11.3.0
          Copyright (C) 2021 Free Software Foundation, Inc.
          This is free software; see the source for copying conditions.  There is NO
          warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
          $ gcc -m32 -Wall -Wextra -shared -o libtstpltlib32.so tstpltlib.c
          $ gcc -m32 -Wall -Wextra -o tstplt32 tstplt.c -L . -ltstpltlib32 -Wl,-rpath=$(pwd)
          $ perf record -e intel_pt//u --filter 'filter main @ ./tstplt32' ./tstplt32
          [ perf record: Woken up 1 times to write data ]
          [ perf record: Captured and wrote 0.011 MB perf.data ]
          $ readelf -SW tstplt32 | grep 'plt\|Name'
            [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
            [10] .rel.plt          REL             0000041c 00041c 000028 08  AI  5  22  4
            [12] .plt              PROGBITS        00001030 001030 000060 04  AX  0   0 16   <- ES is 0x04, should be 0x10
            [13] .plt.got          PROGBITS        00001090 001090 000008 08  AX  0   0  8
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          17894.383903029:   tr strt                               0 [unknown] =>         565b81cd main+0x0
          17894.383903029:   tr end  call                   565b81d4 main+0x7 =>         565b80d0 __x86.get_pc_thunk.bx+0x0
          17894.383903031:   tr strt                               0 [unknown] =>         565b81d9 main+0xc
          17894.383903031:   tr end  call                   565b81df main+0x12 =>         565b8070 [unknown]
          17894.383903032:   tr strt                               0 [unknown] =>         565b81e4 main+0x17
          17894.383903032:   tr end  call                   565b81e4 main+0x17 =>         565b8050 [unknown]
          17894.383903033:   tr strt                               0 [unknown] =>         565b81e9 main+0x1c
          17894.383903033:   tr end  call                   565b81e9 main+0x1c =>         565b8080 [unknown]
          17894.383903033:   tr strt                               0 [unknown] =>         565b81ee main+0x21
          17894.383903033:   tr end  call                   565b81ee main+0x21 =>         565b8060 [unknown]
          17894.383903237:   tr strt                               0 [unknown] =>         565b81f3 main+0x26
          17894.383903237:   tr end  return                 565b81fc main+0x2f =>         f7c21519 [unknown]
      
        After:
      
          $ perf script --itrace=be --ns -F+flags,-event,+addr,-period,-comm,-tid,-cpu,-dso
          17894.383903029:   tr strt                               0 [unknown] =>         565b81cd main+0x0
          17894.383903029:   tr end  call                   565b81d4 main+0x7 =>         565b80d0 __x86.get_pc_thunk.bx+0x0
          17894.383903031:   tr strt                               0 [unknown] =>         565b81d9 main+0xc
          17894.383903031:   tr end  call                   565b81df main+0x12 =>         565b8070 fn4@plt+0x0
          17894.383903032:   tr strt                               0 [unknown] =>         565b81e4 main+0x17
          17894.383903032:   tr end  call                   565b81e4 main+0x17 =>         565b8050 fn1@plt+0x0
          17894.383903033:   tr strt                               0 [unknown] =>         565b81e9 main+0x1c
          17894.383903033:   tr end  call                   565b81e9 main+0x1c =>         565b8080 fn2@plt+0x0
          17894.383903033:   tr strt                               0 [unknown] =>         565b81ee main+0x21
          17894.383903033:   tr end  call                   565b81ee main+0x21 =>         565b8060 fn3@plt+0x0
          17894.383903237:   tr strt                               0 [unknown] =>         565b81f3 main+0x26
          17894.383903237:   tr end  return                 565b81fc main+0x2f =>         f7c21519 [unknown]
      Reviewed-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Link: https://lore.kernel.org/r/20230131131625.6964-2-adrian.hunter@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      66fe2d53
    • Athira Rajeev's avatar
      perf tests shell: Fix check for libtracevent support · 766b0bee
      Athira Rajeev authored
      Test “Use vfs_getname probe to get syscall args filenames” fails in
      environment with missing libtraceevent support as below:
      
        82: Use vfs_getname probe to get syscall args filenames             :
        --- start ---
        test child forked, pid 304726
        Recording open file:
        event syntax error: 'probe:vfs_getname*'
                             \___ unsupported tracepoint
      
        libtraceevent is necessary for tracepoint support
        Run 'perf list' for a list of valid events
      
         Usage: perf record [<options>] [<command>]
            or: perf record [<options>] -- <command> [<options>]
      
            -e, --event <event>   event selector. use 'perf list' to list available events
        test child finished with -1
        ---- end ----
        Use vfs_getname probe to get syscall args filenames: FAILED!
      
      The environment has debuginfo but is missing the libtraceevent devel.
      
      Hence perf is compiled without libtraceevent support.  The test tries to
      add probe “probe:vfs_getname” and then uses it with “perf record”.  This
      fails at function “parse_events_add_tracepoint" due to missing
      libtraceevent.
      
      Similarly "probe libc's inet_pton & backtrace it with ping" test slso
      fails with same reason.
      
      Add a function in 'perf test shell' library to check if perf record with
      —dry-run reports any error on missing support for libtraceevent. Update
      both the tests to use this new function “skip_no_probe_record_support”
      before proceeding With using probe point via perf builtin record.
      
      With the change,
      
        82: Use vfs_getname probe to get syscall args filenames             :
        --- start ---
        test child forked, pid 305014
        Recording open file:
        libtraceevent is necessary for tracepoint support
        test child finished with -2
        ---- end ----
        Use vfs_getname probe to get syscall args filenames: Skip
      
         81: probe libc's inet_pton & backtrace it with ping                 :
        --- start ---
        test child forked, pid 305036
        libtraceevent is necessary for tracepoint support
        test child finished with -2
        ---- end ----
        probe libc's inet_pton & backtrace it with ping: Skip
      Signed-off-by: default avatarAthira Rajeev <atrajeev@linux.vnet.ibm.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Disha Goel <disgoel@linux.ibm.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: James Clark <james.clark@arm.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: kjain@linux.ibm.com,
      Cc: linuxppc-dev@lists.ozlabs.org
      Link: http://lore.kernel.org/r/20230201180421.59640-2-atrajeev@linux.vnet.ibm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      766b0bee
    • Athira Rajeev's avatar
      perf tests shell: Add check for perf data file in record+probe_libc_inet_pton test · 84cce3d6
      Athira Rajeev authored
      The "probe libc's inet_pton & backtrace it with ping" test installs a
      uprobe and uses perf record/script to check the backtrace. Currently
      even if the "perf record" fails, the test reports success. Logs below:
      
        # ./perf test -v "probe libc's inet_pton & backtrace it with ping"
        81: probe libc's inet_pton & backtrace it with ping                 :
        --- start ---
        test child forked, pid 304211
        failed to open /tmp/perf.data.Btf: No such file or directory
        test child finished with 0
        ---- end ----
        probe libc's inet_pton & backtrace it with ping: Ok
      
      Fix this by adding check for presence of perf.data file
      before proceeding with "perf script".
      
      With the patch changes, test reports fail correctly.
      
       # ./perf test -v "probe libc's inet_pton & backtrace it with ping"
       81: probe libc's inet_pton & backtrace it with ping                 :
        --- start ---
        test child forked, pid 304358
        FAIL: perf record failed to create "/tmp/perf.data.Uoi"
        test child finished with -1
        ---- end ----
        probe libc's inet_pton & backtrace it with ping: FAILED!
      Signed-off-by: default avatarAthira Rajeev <atrajeev@linux.vnet.ibm.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Disha Goel <disgoel@linux.ibm.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: James Clark <james.clark@arm.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Kajol Jain <kjain@linux.ibm.com>
      Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: linuxppc-dev@lists.ozlabs.org
      Link: http://lore.kernel.org/r/20230201180421.59640-1-atrajeev@linux.vnet.ibm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      84cce3d6
    • Namhyung Kim's avatar
      perf test: Add pipe mode test to the Intel PT test suite · e072b097
      Namhyung Kim authored
      The test_pipe() function will check perf report and perf inject with
      pipe input.
      Reviewed-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: James Clark <james.clark@arm.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Leo Yan <leo.yan@linaro.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Link: https://lore.kernel.org/r/20230131023350.1903992-5-namhyung@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      e072b097
    • Namhyung Kim's avatar
      perf session: Avoid calling lseek(2) for pipe · 14bf4784
      Namhyung Kim authored
      We should not call lseek(2) for pipes as it won't work.  And we already
      in the proper place to read the data for AUXTRACE.  Add the comment like
      in the PERF_RECORD_HEADER_TRACING_DATA.
      Reviewed-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Reviewed-by: default avatarJames Clark <james.clark@arm.com>
      Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Leo Yan <leo.yan@linaro.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Link: https://lore.kernel.org/r/20230131023350.1903992-4-namhyung@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      14bf4784
    • Namhyung Kim's avatar
      perf intel-pt: Do not try to queue auxtrace data on pipe · aeb802f8
      Namhyung Kim authored
      When it processes AUXTRACE_INFO, it calls to auxtrace_queue_data() to
      collect AUXTRACE data first.  That won't work with pipe since it needs
      lseek() to read the scattered aux data.
      
        $ perf record -o- -e intel_pt// true | perf report -i- --itrace=i100
        # To display the perf.data header info, please use --header/--header-only options.
        #
        0x4118 [0xa0]: failed to process type: 70
        Error:
        failed to process sample
      
      For the pipe mode, it can handle the aux data as it gets.  But there's
      no guarantee it can get the aux data in time.  So the following warning
      will be shown at the beginning:
      
        WARNING: Intel PT with pipe mode is not recommended.
                 The output cannot relied upon.  In particular,
                 time stamps and the order of events may be incorrect.
      
      Fixes: dbd13432 ("perf intel-pt: Add support for decoding AUX area samples")
      Reviewed-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
      Reviewed-by: default avatarJames Clark <james.clark@arm.com>
      Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Ian Rogers <irogers@google.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Leo Yan <leo.yan@linaro.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Stephane Eranian <eranian@google.com>
      Link: https://lore.kernel.org/r/20230131023350.1903992-3-namhyung@kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      aeb802f8
  2. 01 Feb, 2023 1 commit
  3. 30 Jan, 2023 2 commits
    • Mike Leach's avatar
      perf cs-etm: Update decoder code for OpenCSD version 1.4 · c6535b6b
      Mike Leach authored
      OpenCSD version 1.4 is released with support for FEAT_ITE.
      
      This adds a new packet type, with associated output element ID in the
      packet type enum - OCSD_GEN_TRC_ELEM_INSTRUMENTATION.
      
      As we just ignore this packet in perf, add to the switch statement to
      avoid the "enum not handled in switch error", but conditionally so as
      not to break the perf build for older OpenCSD installations.
      Reviewed-by: default avatarJames Clark <james.clark@arm.com>
      Signed-off-by: default avatarMike Leach <mike.leach@linaro.org>
      Acked-by: default avatarIan Rogers <irogers@google.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Leo Yan <leo.yan@linaro.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
      Cc: coresight@lists.linaro.org
      Cc: linux-arm-kernel@lists.infradead.org
      Link: https://lore.kernel.org/r/20230120153706.20388-1-mike.leach@linaro.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      c6535b6b
    • Naveen N. Rao's avatar
      perf test: Fix DWARF unwind test by adding non-inline to expected function in a backtrace · dfadf8b3
      Naveen N. Rao authored
      'DWARF unwind' 'perf test' can sometimes fail:
      
        $ perf test -v 74
        Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
         74: Test dwarf unwind                                               :
        --- start ---
        test child forked, pid 3785254
        Problems creating module maps, continuing anyway...
        Problems creating module maps, continuing anyway...
        unwind: test__arch_unwind_sample:ip = 0x102d0ad4c (0x36ad4c)
        unwind: access_mem addr 0x7fffc33128c8, val 1031c3228, offset 120
        unwind: access_mem addr 0x7fffc33128d0, val 12427cc70, offset 128
        <snip>
        unwind: test_dwarf_unwind__krava_3:ip = 0x102b8768b (0x1e768b)
        unwind: access_mem addr 0x7fffc3313048, val 7fffc3313050, offset 2040
        unwind: access_mem addr 0x7fffc3313060, val 102b8777c, offset 2064
        unwind: test_dwarf_unwind__krava_2:ip = 0x102b8770b (0x1e770b)
        unwind: access_mem addr 0x7fffc3313088, val 7fffc3313090, offset 2104
        unwind: access_mem addr 0x7fffc33130a0, val 102b87890, offset 2128
        unwind: test_dwarf_unwind__krava_1:ip = 0x102b8777b (0x1e777b)
        unwind: access_mem addr 0x7fffc3313108, val 10323a274, offset 2232
        unwind: access_mem addr 0x7fffc3313110, val ffffffffffffffff, offset 2240
        unwind: access_mem addr 0x7fffc3313118, val 102c08ed0, offset 2248
        unwind: access_mem addr 0x7fffc3313120, val 1031db000, offset 2256
        unwind: access_mem addr 0x7fffc3313128, val 7fffc3313130, offset 2264
        unwind: access_mem addr 0x7fffc3313140, val 102b45ee8, offset 2288
        unwind: '':ip = 0x102b8788f (0x1e788f)
        failed: got unresolved address 0x102b8788f
        unwind: failed with 'no error'
        got wrong number of stack entries 0 != 8
        test child finished with -1
        ---- end ----
        Test dwarf unwind: FAILED!
      
      We expect to resolve test__dwarf_unwind as the last symbol, but that
      function can be optimized away:
      
        $ objdump -tT /usr/bin/perf | grep dwarf_unwind
        000000000083b018 g    DO .data	0000000000000040  Base        tests__dwarf_unwind
        00000000001e7750 g    DF .text	0000000000000068  Base        0x60 test_dwarf_unwind__krava_1
        00000000001e76e0 g    DF .text	0000000000000068  Base        0x60 test_dwarf_unwind__krava_2
        00000000001e7620 g    DF .text	00000000000000b4  Base        0x60 test_dwarf_unwind__krava_3
        00000000001e74f0 g    DF .text	0000000000000128  Base        0x60 test_dwarf_unwind__compare
        00000000001e7350 g    DF .text	000000000000019c  Base        0x60 test_dwarf_unwind__thread
        000000000083b000 g    DO .data	0000000000000018  Base        suite__dwarf_unwind
      
      Fix this similar to commit fdf7c49c ("perf tests: Fix dwarf
      unwind for stripped binaries") by marking the function as a global and
      adding the 'noinline' attribute to it.
      
      With this patch:
      
        $ objdump -tT perf | grep dwarf_unwind
        000000000083b018 g    DO .data	0000000000000040  Base        tests__dwarf_unwind
        00000000001e80f0 g    DF .text	0000000000000068  Base        0x60 test_dwarf_unwind__krava_1
        00000000001e8080 g    DF .text	0000000000000068  Base        0x60 test_dwarf_unwind__krava_2
        00000000001e7fc0 g    DF .text	00000000000000b4  Base        0x60 test_dwarf_unwind__krava_3
        00000000001e7e90 g    DF .text	0000000000000128  Base        0x60 test_dwarf_unwind__compare
        00000000001e7cf0 g    DF .text	000000000000019c  Base        0x60 test_dwarf_unwind__thread
        00000000001e8160 g    DF .text	0000000000000248  Base        0x60 test__dwarf_unwind
        000000000083b000 g    DO .data	0000000000000018  Base        suite__dwarf_unwind
        $ ./perf test 74
         74: Test dwarf unwind                                               : Ok
      Reported-by: default avatarDisha Goel <disgoel@linux.vnet.ibm.com>
      Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
      Link: http://lore.kernel.org/lkml/20230125123442.107156-1-naveen.n.rao@linux.vnet.ibm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      dfadf8b3
  4. 27 Jan, 2023 4 commits
  5. 23 Jan, 2023 4 commits
    • Athira Rajeev's avatar
      perf test buildid: Fix shell string substitutions · f1942108
      Athira Rajeev authored
      The perf test named “build id cache operations” skips with below error
      on some distros:
      
        <<>>
         78: build id cache operations                                       :
        test child forked, pid 111101
        WARNING: wine not found. PE binaries will not be run.
        test binaries: /tmp/perf.ex.SHA1.PKz /tmp/perf.ex.MD5.Gt3 ./tests/shell/../pe-file.exe
        DEBUGINFOD_URLS=
        Adding 4abd406f041feb4f10ecde3fc30fd0639e1a91cb /tmp/perf.ex.SHA1.PKz: Ok
        build id: 4abd406f041feb4f10ecde3fc30fd0639e1a91cb
        ./tests/shell/buildid.sh: 69: ./tests/shell/buildid.sh: Bad substitution
        test child finished with -2
        build id cache operations: Skip
        <<>>
      
      The test script "tests/shell/buildid.sh" uses some of the string
      substitution ways which are supported in bash, but not in "sh" or other
      shells. Above error on line number 69 that reports "Bad substitution"
      is:
      
        <<>>
        link=${build_id_dir}/.build-id/${id:0:2}/${id:2}
        <<>>
      
      Here the way of getting first two characters from id ie, ${id:0:2} and
      similarly expressions like ${id:2} is not recognised in "sh". So the
      line errors and instead of hitting failure, the test gets skipped as
      shown in logs.  So the syntax issue causes test not to be executed in
      such cases. Similarly usage : "${@: -1}" [ to pick last argument passed
      to a function] in “test_record” doesn’t work in all distros.
      
      Fix this by using alternative way with shell substitution to pick
      required characters from the string. Also fix the usage of “${@: -1}” to
      work in all cases.
      
      Another usage in “test_record” is:
      
        <<>>
        ${perf} record --buildid-all -o ${data} $@ &> ${log}
        <<>>
      
      This causes the 'perf record' to start in background and Results in the
      data file not being created by the time "check" function is invoked.
      Below log shows 'perf record' result getting displayed after the call to
      "check" function.
      
        <<>>
        running: perf record /tmp/perf.ex.SHA1.EAU
        build id: 4abd406f041feb4f10ecde3fc30fd0639e1a91cb
        link: /tmp/perf.debug.mLT/.build-id/4a/bd406f041feb4f10ecde3fc30fd0639e1a91cb
        failed: link /tmp/perf.debug.mLT/.build-id/4a/bd406f041feb4f10ecde3fc30fd0639e1a91cb does not exist
        test child finished with -1
        build id cache operations: FAILED!
        root@machine:~/athira/linux/tools/perf# Couldn't synthesize bpf events.
        [ perf record: Woken up 1 times to write data ]
        [ perf record: Captured and wrote 0.010 MB /tmp/perf.data.bFF ]
        <<>>
      
      Fix this by redirecting output instead of using “&” which starts the
      command in background.
      Reviewed-by: default avatarDavid Laight <David.Laight@ACULAB.COM>
      Signed-off-by: default avatarAthira Jajeev <atrajeev@linux.vnet.ibm.com>
      Tested-by: default avatarDisha Goel <disgoel@linux.ibm.com>
      Acked-by: default avatarIan Rogers <irogers@google.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: James Clark <james.clark@arm.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Kajol Jain <kjain@linux.ibm.com>
      Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: linuxppc-dev@lists.ozlabs.org
      Link: https://lore.kernel.org/r/20230119142719.32628-1-atrajeev@linux.vnet.ibm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      f1942108
    • Diederik de Haas's avatar
      perf: Various spelling fixes · fc5d836c
      Diederik de Haas authored
      Fix various spelling errors as reported by Debian's lintian tool.
      
      "amount of times" -> "number of times"
      ocurrence -> occurrence
      upto -> up to
      Signed-off-by: default avatarDiederik de Haas <didi.debian@cknow.org>
      Acked-by: default avatarIan Rogers <irogers@google.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: https://lore.kernel.org/r/20230122122034.48020-1-didi.debian@cknow.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      fc5d836c
    • Naveen N. Rao's avatar
      perf test: Switch basic bpf filtering test to use syscall tracepoint · 7158005b
      Naveen N. Rao authored
      BPF filtering tests can sometime fail. Running the test in verbose mode
      shows the following:
      
        $ sudo perf test 42
        42: BPF filter                                                      :
        42.1: Basic BPF filtering                                           : FAILED!
        42.2: BPF pinning                                                   : Skip
        42.3: BPF prologue generation                                       : Skip
        $ perf --version
        perf version 4.18.0-425.3.1.el8.ppc64le
        $ sudo perf test -v 42
        42: BPF filter                                                      :
        42.1: Basic BPF filtering                                           :
        --- start ---
        test child forked, pid 711060
        ...
        bpf: config 'func=do_epoll_wait' is ok
        Looking at the vmlinux_path (8 entries long)
        Using /usr/lib/debug/lib/modules/4.18.0-425.3.1.el8.ppc64le/vmlinux for symbols
        Open Debuginfo file: /usr/lib/debug/.build-id/81/56f5a07f92ccb62c5600ba0e4aacfb5f3a7534.debug
        Try to find probe point from debuginfo.
        Matched function: do_epoll_wait [4ef8cb0]
        found inline addr: 0xc00000000061dbe4
        Probe point found: __se_compat_sys_epoll_pwait+196
        found inline addr: 0xc00000000061d9f4
        Probe point found: __se_sys_epoll_pwait+196
        found inline addr: 0xc00000000061d824
        Probe point found: __se_sys_epoll_wait+36
        Found 3 probe_trace_events.
        Opening /sys/kernel/tracing//kprobe_events write=1
        ...
        BPF filter result incorrect, expected 56, got 56 samples
        test child finished with -1
        ---- end ----
        BPF filter subtest 1: FAILED!
      
      The statement above about the result being incorrect looks weird, and it
      is due to that particular perf build missing commit 3e11300c
      ("perf test: Fix bpf test sample mismatch reporting"). In reality, due
      to commit 4b04e0de ("perf test: Fix basic bpf filtering test"),
      perf expects there to be 56*3 samples.
      
      However, the number of samples we receive is going to be dependent on
      where the probes are installed, which is dependent on where
      do_epoll_wait gets inlined. On s390x, it looks like probes at all the
      inlined locations are hit. But, that is not the case on ppc64le.
      
      Fix this by switching the test to instead use the syscall tracepoint.
      This ensures that we will only ever install a single event enabling us
      to reliably determine the sample count.
      Reported-by: default avatarDisha Goel <disgoel@linux.vnet.ibm.com>
      Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
      Cc: Kajol Jain <kjain@linux.ibm.com>
      Cc: bpf@vger.kernel.org
      Link: http://lore.kernel.org/lkml/20230123083224.276404-1-naveen.n.rao@linux.vnet.ibm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      7158005b
    • Arnaldo Carvalho de Melo's avatar
      Merge remote-tracking branch 'torvalds/master' into perf/core · 91f67b9a
      Arnaldo Carvalho de Melo authored
      To pick fixes that went via perf/urgent.
      Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      91f67b9a
  6. 22 Jan, 2023 10 commits