Commit Graph

2572 Commits

Author SHA1 Message Date
Sergei Trofimovich 32fa058398 libbpf: Add pr_warn() for EINVAL cases in linker_sanity_check_elf
Before the change on `i686-linux` `systemd` build failed as:

    $ bpftool gen object src/core/bpf/socket_bind/socket-bind.bpf.o src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o
    Error: failed to link 'src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o': Invalid argument (22)

After the change it fails as:

    $ bpftool gen object src/core/bpf/socket_bind/socket-bind.bpf.o src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o
    libbpf: ELF section #9 has inconsistent alignment addr=8 != d=4 in src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o
    Error: failed to link 'src/core/bpf/socket_bind/socket-bind.bpf.unstripped.o': Invalid argument (22)

Now it's slightly easier to figure out what is wrong with an ELF file.

Signed-off-by: Sergei Trofimovich <slyich@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20231208215100.435876-1-slyich@gmail.com
2023-12-08 17:11:18 -08:00
David Vernet 8b7b0e5fe4 bpf: Load vmlinux btf for any struct_ops map
In libbpf, when determining whether we need to load vmlinux btf, we're
currently (among other things) checking whether there is any struct_ops
program present in the object. This works for most realistic struct_ops
maps, as a struct_ops map is of course typically composed of one or more
struct_ops programs. However, that technically need not be the case. A
struct_ops interface could be defined which allows a map to be specified
which one or more non-prog fields, and which provides default behavior
if no struct_ops progs is actually provided otherwise. For sched_ext,
for example, you technically only need to specify the name of the
scheduler in the struct_ops map, with the core scheduler logic providing
default behavior if no prog is actually specified.

If we were to define and try to load such a struct_ops map, we would
crash in libbpf when initializing it as obj->btf_vmlinux will be NULL:

Reading symbols from minimal...
(gdb) r
Starting program: minimal_example
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".

Program received signal SIGSEGV, Segmentation fault.
0x000055555558308c in btf__type_cnt (btf=0x0) at btf.c:612
612             return btf->start_id + btf->nr_types;
(gdb) bt
    type_name=0x5555555d99e3 "sched_ext_ops", kind=4) at btf.c:914
    kind=4) at btf.c:942
    type=0x7fffffffe558, type_id=0x7fffffffe548, ...
    data_member=0x7fffffffe568) at libbpf.c:948
    kern_btf=0x0) at libbpf.c:1017
    at libbpf.c:8059

So as to account for such bare-bones struct_ops maps, let's update
obj_needs_vmlinux_btf() to also iterate over an obj's maps and check
whether any of them are struct_ops maps.

Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20231208061704.400463-1-void@manifault.com
2023-12-08 09:38:59 -08:00
Andrii Nakryiko 1571740a9b libbpf: add BPF token support to bpf_prog_load() API
Wire through token_fd into bpf_prog_load().

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-16-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:03:00 -08:00
Andrii Nakryiko 1a8df7fa00 libbpf: add BPF token support to bpf_btf_load() API
Allow user to specify token_fd for bpf_btf_load() API that wraps
kernel's BPF_BTF_LOAD command. This allows loading BTF from unprivileged
process as long as it has BPF token allowing BPF_BTF_LOAD command, which
can be created and delegated by privileged process.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-15-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:03:00 -08:00
Andrii Nakryiko 37891cea66 libbpf: add BPF token support to bpf_map_create() API
Add ability to provide token_fd for BPF_MAP_CREATE command through
bpf_map_create() API.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-14-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:03:00 -08:00
Andrii Nakryiko ecd435143e libbpf: add bpf_token_create() API
Add low-level wrapper API for BPF_TOKEN_CREATE command in bpf() syscall.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-13-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-06 10:03:00 -08:00
Jiri Olsa 48f0dfd8d3 libbpf: Add st_type argument to elf_resolve_syms_offsets function
We need to get offsets for static variables in following changes,
so making elf_resolve_syms_offsets to take st_type value as argument
and passing it to elf_sym_iter_new.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20231125193130.834322-2-jolsa@kernel.org
2023-11-28 21:50:09 -08:00
Eduard Zingerman b8d78cb2e2 libbpf: Start v1.4 development cycle
Bump libbpf.map to v1.4.0 to start a new libbpf version cycle.

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231123000439.12025-1-eddyz87@gmail.com
2023-11-23 22:49:41 +01:00
Yonghong Song 7f7c43693c libbpf: Fix potential uninitialized tail padding with LIBBPF_OPTS_RESET
Martin reported that there is a libbpf complaining of non-zero-value tail
padding with LIBBPF_OPTS_RESET macro if struct bpf_netkit_opts is modified
to have a 4-byte tail padding. This only happens to clang compiler.
The commend line is: ./test_progs -t tc_netkit_multi_links
Martin and I did some investigation and found this indeed the case and
the following are the investigation details.

Clang:
  clang version 18.0.0
  <I tried clang15/16/17 and they all have similar results>

tools/lib/bpf/libbpf_common.h:
  #define LIBBPF_OPTS_RESET(NAME, ...)                                      \
        do {                                                                \
                memset(&NAME, 0, sizeof(NAME));                             \
                NAME = (typeof(NAME)) {                                     \
                        .sz = sizeof(NAME),                                 \
                        __VA_ARGS__                                         \
                };                                                          \
        } while (0)

  #endif

tools/lib/bpf/libbpf.h:
  struct bpf_netkit_opts {
        /* size of this struct, for forward/backward compatibility */
        size_t sz;
        __u32 flags;
        __u32 relative_fd;
        __u32 relative_id;
        __u64 expected_revision;
        size_t :0;
  };
  #define bpf_netkit_opts__last_field expected_revision
In the above struct bpf_netkit_opts, there is no tail padding.

prog_tests/tc_netkit.c:
  static void serial_test_tc_netkit_multi_links_target(int mode, int target)
  {
        ...
        LIBBPF_OPTS(bpf_netkit_opts, optl);
        ...
        LIBBPF_OPTS_RESET(optl,
                .flags = BPF_F_BEFORE,
                .relative_fd = bpf_program__fd(skel->progs.tc1),
        );
        ...
  }

Let us make the following source change, note that we have a 4-byte
tailing padding now.
  diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
  index 6cd9c501624f..0dd83910ae9a 100644
  --- a/tools/lib/bpf/libbpf.h
  +++ b/tools/lib/bpf/libbpf.h
  @@ -803,13 +803,13 @@ bpf_program__attach_tcx(const struct bpf_program *prog, int ifindex,
   struct bpf_netkit_opts {
        /* size of this struct, for forward/backward compatibility */
        size_t sz;
  -       __u32 flags;
        __u32 relative_fd;
        __u32 relative_id;
        __u64 expected_revision;
  +       __u32 flags;
        size_t :0;
   };
  -#define bpf_netkit_opts__last_field expected_revision
  +#define bpf_netkit_opts__last_field flags

The clang 18 generated asm code looks like below:
    ;       LIBBPF_OPTS_RESET(optl,
    55e3: 48 8d 7d 98                   leaq    -0x68(%rbp), %rdi
    55e7: 31 f6                         xorl    %esi, %esi
    55e9: ba 20 00 00 00                movl    $0x20, %edx
    55ee: e8 00 00 00 00                callq   0x55f3 <serial_test_tc_netkit_multi_links_target+0x18d3>
    55f3: 48 c7 85 10 fd ff ff 20 00 00 00      movq    $0x20, -0x2f0(%rbp)
    55fe: 48 8b 85 68 ff ff ff          movq    -0x98(%rbp), %rax
    5605: 48 8b 78 18                   movq    0x18(%rax), %rdi
    5609: e8 00 00 00 00                callq   0x560e <serial_test_tc_netkit_multi_links_target+0x18ee>
    560e: 89 85 18 fd ff ff             movl    %eax, -0x2e8(%rbp)
    5614: c7 85 1c fd ff ff 00 00 00 00 movl    $0x0, -0x2e4(%rbp)
    561e: 48 c7 85 20 fd ff ff 00 00 00 00      movq    $0x0, -0x2e0(%rbp)
    5629: c7 85 28 fd ff ff 08 00 00 00 movl    $0x8, -0x2d8(%rbp)
    5633: 48 8b 85 10 fd ff ff          movq    -0x2f0(%rbp), %rax
    563a: 48 89 45 98                   movq    %rax, -0x68(%rbp)
    563e: 48 8b 85 18 fd ff ff          movq    -0x2e8(%rbp), %rax
    5645: 48 89 45 a0                   movq    %rax, -0x60(%rbp)
    5649: 48 8b 85 20 fd ff ff          movq    -0x2e0(%rbp), %rax
    5650: 48 89 45 a8                   movq    %rax, -0x58(%rbp)
    5654: 48 8b 85 28 fd ff ff          movq    -0x2d8(%rbp), %rax
    565b: 48 89 45 b0                   movq    %rax, -0x50(%rbp)
    ;       link = bpf_program__attach_netkit(skel->progs.tc2, ifindex, &optl);

At -O0 level, the clang compiler creates an intermediate copy.
We have below to store 'flags' with 4-byte store and leave another 4 byte
in the same 8-byte-aligned storage undefined,
    5629: c7 85 28 fd ff ff 08 00 00 00 movl    $0x8, -0x2d8(%rbp)
and later we store 8-byte to the original zero'ed buffer
    5654: 48 8b 85 28 fd ff ff          movq    -0x2d8(%rbp), %rax
    565b: 48 89 45 b0                   movq    %rax, -0x50(%rbp)

This caused a problem as the 4-byte value at [%rbp-0x2dc, %rbp-0x2e0)
may be garbage.

gcc (gcc 11.4) does not have this issue as it does zeroing struct first before
doing assignments:
  ;       LIBBPF_OPTS_RESET(optl,
    50fd: 48 8d 85 40 fc ff ff          leaq    -0x3c0(%rbp), %rax
    5104: ba 20 00 00 00                movl    $0x20, %edx
    5109: be 00 00 00 00                movl    $0x0, %esi
    510e: 48 89 c7                      movq    %rax, %rdi
    5111: e8 00 00 00 00                callq   0x5116 <serial_test_tc_netkit_multi_links_target+0x1522>
    5116: 48 8b 45 f0                   movq    -0x10(%rbp), %rax
    511a: 48 8b 40 18                   movq    0x18(%rax), %rax
    511e: 48 89 c7                      movq    %rax, %rdi
    5121: e8 00 00 00 00                callq   0x5126 <serial_test_tc_netkit_multi_links_target+0x1532>
    5126: 48 c7 85 40 fc ff ff 00 00 00 00      movq    $0x0, -0x3c0(%rbp)
    5131: 48 c7 85 48 fc ff ff 00 00 00 00      movq    $0x0, -0x3b8(%rbp)
    513c: 48 c7 85 50 fc ff ff 00 00 00 00      movq    $0x0, -0x3b0(%rbp)
    5147: 48 c7 85 58 fc ff ff 00 00 00 00      movq    $0x0, -0x3a8(%rbp)
    5152: 48 c7 85 40 fc ff ff 20 00 00 00      movq    $0x20, -0x3c0(%rbp)
    515d: 89 85 48 fc ff ff             movl    %eax, -0x3b8(%rbp)
    5163: c7 85 58 fc ff ff 08 00 00 00 movl    $0x8, -0x3a8(%rbp)
  ;       link = bpf_program__attach_netkit(skel->progs.tc2, ifindex, &optl);

It is not clear how to resolve the compiler code generation as the compiler
generates correct code w.r.t. how to handle unnamed padding in C standard.
So this patch changed LIBBPF_OPTS_RESET macro to avoid uninitialized tail
padding. We already knows LIBBPF_OPTS macro works on both gcc and clang,
even with tail padding. So LIBBPF_OPTS_RESET is changed to be a
LIBBPF_OPTS followed by a memcpy(), thus avoiding uninitialized tail padding.

The below is asm code generated with this patch and with clang compiler:
    ;       LIBBPF_OPTS_RESET(optl,
    55e3: 48 8d bd 10 fd ff ff          leaq    -0x2f0(%rbp), %rdi
    55ea: 31 f6                         xorl    %esi, %esi
    55ec: ba 20 00 00 00                movl    $0x20, %edx
    55f1: e8 00 00 00 00                callq   0x55f6 <serial_test_tc_netkit_multi_links_target+0x18d6>
    55f6: 48 c7 85 10 fd ff ff 20 00 00 00      movq    $0x20, -0x2f0(%rbp)
    5601: 48 8b 85 68 ff ff ff          movq    -0x98(%rbp), %rax
    5608: 48 8b 78 18                   movq    0x18(%rax), %rdi
    560c: e8 00 00 00 00                callq   0x5611 <serial_test_tc_netkit_multi_links_target+0x18f1>
    5611: 89 85 18 fd ff ff             movl    %eax, -0x2e8(%rbp)
    5617: c7 85 1c fd ff ff 00 00 00 00 movl    $0x0, -0x2e4(%rbp)
    5621: 48 c7 85 20 fd ff ff 00 00 00 00      movq    $0x0, -0x2e0(%rbp)
    562c: c7 85 28 fd ff ff 08 00 00 00 movl    $0x8, -0x2d8(%rbp)
    5636: 48 8b 85 10 fd ff ff          movq    -0x2f0(%rbp), %rax
    563d: 48 89 45 98                   movq    %rax, -0x68(%rbp)
    5641: 48 8b 85 18 fd ff ff          movq    -0x2e8(%rbp), %rax
    5648: 48 89 45 a0                   movq    %rax, -0x60(%rbp)
    564c: 48 8b 85 20 fd ff ff          movq    -0x2e0(%rbp), %rax
    5653: 48 89 45 a8                   movq    %rax, -0x58(%rbp)
    5657: 48 8b 85 28 fd ff ff          movq    -0x2d8(%rbp), %rax
    565e: 48 89 45 b0                   movq    %rax, -0x50(%rbp)
    ;       link = bpf_program__attach_netkit(skel->progs.tc2, ifindex, &optl);

In the above code, a temporary buffer is zeroed and then has proper value assigned.
Finally, values in temporary buffer are copied to the original variable buffer,
hence tail padding is guaranteed to be 0.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/bpf/20231107201511.2548645-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-11-09 19:07:51 -08:00
Linus Torvalds 7ab89417ed perf tools changes for v6.7
Build
 -----
 * Compile BPF programs by default if clang (>= 12.0.1) is available to
   enable more features like kernel lock contention, off-cpu profiling,
   kwork, sample filtering and so on.  It can be disabled by passing
   BUILD_BPF_SKEL=0 to make.
 
 * Produce better error messages for bison on debug build (make DEBUG=1)
   by defining YYDEBUG symbol internally.
 
 perf record
 -----------
 * Track sideband events (like FORK/MMAP) from all CPUs even if perf record
   targets a subset of CPUs only (using -C option).  Otherwise it may lose
   some information happened on a CPU out of the target list.
 
 * Fix checking raw sched_switch tracepoint argument using system BTF.
   This affects off-cpu profiling which attaches a BPF program to the raw
   tracepoint.
 
 perf lock contention
 --------------------
 * Add --lock-cgroup option to see contention by cgroups.  This should be
   used with BPF only (using -b option).
 
     $ sudo perf lock con -ab --lock-cgroup -- sleep 1
      contended   total wait     max wait     avg wait   cgroup
 
            835     14.06 ms     41.19 us     16.83 us   /system.slice/led.service
             25    122.38 us     13.77 us      4.89 us   /
             44     23.73 us      3.87 us       539 ns   /user.slice/user-657345.slice/session-c4.scope
              1       491 ns       491 ns       491 ns   /system.slice/connectd.service
 
 * Add -G/--cgroup-filter option to see contention only for given cgroups.
   This can be useful when you identified a cgroup in the above command and
   want to investigate more on it.  It also works with other output options
   like -t/--threads and -l/--lock-addr.
 
     $ sudo perf lock con -ab -G /user.slice/user-657345.slice/session-c4.scope -- sleep 1
      contended   total wait     max wait     avg wait         type   caller
 
              8     77.11 us     17.98 us      9.64 us     spinlock   futex_wake+0xc8
              2     24.56 us     14.66 us     12.28 us     spinlock   tick_do_update_jiffies64+0x25
              1      4.97 us      4.97 us      4.97 us     spinlock   futex_q_lock+0x2a
 
 * Use per-cpu array for better spinlock tracking.  This is to improve
   performance of the BPF program and to avoid nested contention on a lock
   in the BPF hash map.
 
 * Update callstack check for PowerPC.  To find a representative caller of a
   lock, it needs to look up the call stacks.  It ends the lookup when it sees
   0 in the call stack buffer.  However, PowerPC call stacks can have 0 values
   in the beginning so skip them when it expects valid call stacks after.
 
 perf kwork
 ----------
 * Support 'sched' class (for -k option) so that it can see task scheduling
   event (using sched_switch tracepoint) as well as irq and workqueue items.
 
 * Add perf kwork top subcommand to show more accurate cpu utilization with
   sched class above.  It works both with a recorded data (using perf kwork
   record command) and BPF (using -b option).  Unlike perf top command, it
   does not support interactive mode (yet).
 
     $ sudo perf kwork top -b -k sched
     Starting trace, Hit <Ctrl+C> to stop and report
     ^C
     Total  : 160702.425 ms, 8 cpus
     %Cpu(s):  36.00% id,   0.00% hi,   0.00% si
     %Cpu0   [||||||||||||||||||              61.66%]
     %Cpu1   [||||||||||||||||||              61.27%]
     %Cpu2   [|||||||||||||||||||             66.40%]
     %Cpu3   [||||||||||||||||||              61.28%]
     %Cpu4   [||||||||||||||||||              61.82%]
     %Cpu5   [|||||||||||||||||||||||         77.41%]
     %Cpu6   [||||||||||||||||||              61.73%]
     %Cpu7   [||||||||||||||||||              63.25%]
 
           PID     SPID    %CPU           RUNTIME  COMMMAND
       -------------------------------------------------------------
             0        0   38.72       8089.463 ms  [swapper/1]
             0        0   38.71       8084.547 ms  [swapper/3]
             0        0   38.33       8007.532 ms  [swapper/0]
             0        0   38.26       7992.985 ms  [swapper/6]
             0        0   38.17       7971.865 ms  [swapper/4]
             0        0   36.74       7447.765 ms  [swapper/7]
             0        0   33.59       6486.942 ms  [swapper/2]
             0        0   22.58       3771.268 ms  [swapper/5]
          9545     9351    2.48        447.136 ms  sched-messaging
          9574     9351    2.09        418.583 ms  sched-messaging
          9724     9351    2.05        372.407 ms  sched-messaging
          9531     9351    2.01        368.804 ms  sched-messaging
          9512     9351    2.00        362.250 ms  sched-messaging
          9514     9351    1.95        357.767 ms  sched-messaging
          9538     9351    1.86        384.476 ms  sched-messaging
          9712     9351    1.84        386.490 ms  sched-messaging
          9723     9351    1.83        380.021 ms  sched-messaging
          9722     9351    1.82        382.738 ms  sched-messaging
          9517     9351    1.81        354.794 ms  sched-messaging
          9559     9351    1.79        344.305 ms  sched-messaging
          9725     9351    1.77        365.315 ms  sched-messaging
     <SNIP>
 
 * Add hard/soft-irq statistics to perf kwork top.  This will show the
   total CPU utilization with IRQ stats like below:
 
     $ sudo perf kwork top -b -k sched,irq,softirq
     Starting trace, Hit <Ctrl+C> to stop and report
     ^C
     Total  :  12554.889 ms, 8 cpus
     %Cpu(s):  96.23% id,   0.10% hi,   0.19% si      <---- here
     %Cpu0   [|                                4.60%]
     %Cpu1   [|                                4.59%]
     %Cpu2   [                                 2.73%]
     %Cpu3   [|                                3.81%]
     <SNIP>
 
 perf bench
 ----------
 * Add -G/--cgroups option to perf bench sched pipe.  The pipe bench is
   good to measure context switch overhead.  With this option, it puts
   the reader and writer tasks in separate cgroups to enforce context
   switch between two different cgroups.
 
   Also it needs to set CPU affinity of the tasks in a CPU to accurately
   measure the impact of cgroup context switches.
 
     $ sudo perf stat -e context-switches,cgroup-switches -- \
     > taskset -c 0 perf bench sched pipe -l 100000
     # Running 'sched/pipe' benchmark:
     # Executed 100000 pipe operations between two processes
 
          Total time: 0.307 [sec]
 
            3.078180 usecs/op
              324867 ops/sec
 
      Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 100000':
 
                200,026      context-switches
                     63      cgroup-switches
 
            0.321637922 seconds time elapsed
 
   You can see small number of cgroup-switches because both write and read
   tasks are in the same cgroup.
 
     $ sudo mkdir /sys/fs/cgroup/{AAA,BBB}
 
     $ sudo perf stat -e context-switches,cgroup-switches -- \
     > taskset -c 0 perf bench sched pipe -l 100000 -G AAA,BBB
     # Running 'sched/pipe' benchmark:
     # Executed 100000 pipe operations between two processes
 
          Total time: 0.351 [sec]
 
            3.512990 usecs/op
              284657 ops/sec
 
      Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 100000 -G AAA,BBB':
 
                200,020      context-switches
                200,019      cgroup-switches
 
            0.365034567 seconds time elapsed
 
   Now context-switches and cgroup-switches are almost same.  And you can
   see the pipe operation took little more.
 
 * Kill child processes when perf bench sched messaging exited abnormally.
   Otherwise it'd leave the child doing unnecessary work.
 
 perf test
 ---------
 * Fix various shellcheck issues on the tests written in shell script.
 
 * Skip tests when condition is not satisfied:
   - object code reading test for non-text section addresses.
   - CoreSight test if cs_etm// event is not available.
   - lock contention test if not enough CPUs.
 
 Event parsing
 -------------
 * Make PMU alias name loading lazy to reduce the startup time in the
   event parsing code for perf record, stat and others in the general
   case.
 
 * Lazily compute PMU default config.  In the same sense, delay PMU
   initialization until it's really needed to reduce the startup cost.
 
 * Fix event term values that are raw events.  The event specification
   can have several terms including event name.  But sometimes it clashes
   with raw event encoding which starts with 'r' and has hex-digits.
 
   For example, an event named 'read' should be processed as a normal
   event but it was mis-treated as a raw encoding and caused a failure.
 
     $ perf stat -e 'uncore_imc_free_running/event=read/' -a sleep 1
     event syntax error: '..nning/event=read/'
                                       \___ parser error
     Run 'perf list' for a list of valid events
 
      Usage: perf stat [<options>] [<command>]
 
         -e, --event <event> event selector. use 'perf list' to list available events
 
 Event metrics
 -------------
 * Add "Compat" regex to match event with multiple identifiers.
 
 * Usual updates for Intel, Power10, Arm telemetry/CMN and AmpereOne.
 
 Misc
 ----
 * Assorted memory leak fixes and footprint reduction.
 
 * Add "bpf_skeletons" to perf version --build-options so that users can
   check whether their perf tools have BPF support easily.
 
 * Fix unaligned access in Intel-PT packet decoder found by undefined-behavior
   sanitizer.
 
 * Avoid frequency mode for the dummy event.  Surprisingly it'd impact
   kernel timer tick handler performance by force iterating all PMU events.
 
 * Update bash shell completion for events and metrics.
 
 Signed-off-by: Namhyung Kim <namhyung@kernel.org>
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Merge tag 'perf-tools-for-v6.7-1-2023-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Namhyung Kim:
 "Build:

   - Compile BPF programs by default if clang (>= 12.0.1) is available
     to enable more features like kernel lock contention, off-cpu
     profiling, kwork, sample filtering and so on.

     This can be disabled by passing BUILD_BPF_SKEL=0 to make.

   - Produce better error messages for bison on debug build (make
     DEBUG=1) by defining YYDEBUG symbol internally.

  perf record:

   - Track sideband events (like FORK/MMAP) from all CPUs even if perf
     record targets a subset of CPUs only (using -C option). Otherwise
     it may lose some information happened on a CPU out of the target
     list.

   - Fix checking raw sched_switch tracepoint argument using system BTF.
     This affects off-cpu profiling which attaches a BPF program to the
     raw tracepoint.

  perf lock contention:

   - Add --lock-cgroup option to see contention by cgroups. This should
     be used with BPF only (using -b option).

       $ sudo perf lock con -ab --lock-cgroup -- sleep 1
        contended   total wait     max wait     avg wait   cgroup

              835     14.06 ms     41.19 us     16.83 us   /system.slice/led.service
               25    122.38 us     13.77 us      4.89 us   /
               44     23.73 us      3.87 us       539 ns   /user.slice/user-657345.slice/session-c4.scope
                1       491 ns       491 ns       491 ns   /system.slice/connectd.service

   - Add -G/--cgroup-filter option to see contention only for given
     cgroups.

     This can be useful when you identified a cgroup in the above
     command and want to investigate more on it. It also works with
     other output options like -t/--threads and -l/--lock-addr.

       $ sudo perf lock con -ab -G /user.slice/user-657345.slice/session-c4.scope -- sleep 1
        contended   total wait     max wait     avg wait         type   caller

                8     77.11 us     17.98 us      9.64 us     spinlock   futex_wake+0xc8
                2     24.56 us     14.66 us     12.28 us     spinlock   tick_do_update_jiffies64+0x25
                1      4.97 us      4.97 us      4.97 us     spinlock   futex_q_lock+0x2a

   - Use per-cpu array for better spinlock tracking. This is to improve
     performance of the BPF program and to avoid nested contention on a
     lock in the BPF hash map.

   - Update callstack check for PowerPC. To find a representative caller
     of a lock, it needs to look up the call stacks. It ends the lookup
     when it sees 0 in the call stack buffer. However, PowerPC call
     stacks can have 0 values in the beginning so skip them when it
     expects valid call stacks after.

  perf kwork:

   - Support 'sched' class (for -k option) so that it can see task
     scheduling event (using sched_switch tracepoint) as well as irq and
     workqueue items.

   - Add perf kwork top subcommand to show more accurate cpu utilization
     with sched class above. It works both with a recorded data (using
     perf kwork record command) and BPF (using -b option). Unlike perf
     top command, it does not support interactive mode (yet).

       $ sudo perf kwork top -b -k sched
       Starting trace, Hit <Ctrl+C> to stop and report
       ^C
       Total  : 160702.425 ms, 8 cpus
       %Cpu(s):  36.00% id,   0.00% hi,   0.00% si
       %Cpu0   [||||||||||||||||||              61.66%]
       %Cpu1   [||||||||||||||||||              61.27%]
       %Cpu2   [|||||||||||||||||||             66.40%]
       %Cpu3   [||||||||||||||||||              61.28%]
       %Cpu4   [||||||||||||||||||              61.82%]
       %Cpu5   [|||||||||||||||||||||||         77.41%]
       %Cpu6   [||||||||||||||||||              61.73%]
       %Cpu7   [||||||||||||||||||              63.25%]

             PID     SPID    %CPU           RUNTIME  COMMMAND
         -------------------------------------------------------------
               0        0   38.72       8089.463 ms  [swapper/1]
               0        0   38.71       8084.547 ms  [swapper/3]
               0        0   38.33       8007.532 ms  [swapper/0]
               0        0   38.26       7992.985 ms  [swapper/6]
               0        0   38.17       7971.865 ms  [swapper/4]
               0        0   36.74       7447.765 ms  [swapper/7]
               0        0   33.59       6486.942 ms  [swapper/2]
               0        0   22.58       3771.268 ms  [swapper/5]
            9545     9351    2.48        447.136 ms  sched-messaging
            9574     9351    2.09        418.583 ms  sched-messaging
            9724     9351    2.05        372.407 ms  sched-messaging
            9531     9351    2.01        368.804 ms  sched-messaging
            9512     9351    2.00        362.250 ms  sched-messaging
            9514     9351    1.95        357.767 ms  sched-messaging
            9538     9351    1.86        384.476 ms  sched-messaging
            9712     9351    1.84        386.490 ms  sched-messaging
            9723     9351    1.83        380.021 ms  sched-messaging
            9722     9351    1.82        382.738 ms  sched-messaging
            9517     9351    1.81        354.794 ms  sched-messaging
            9559     9351    1.79        344.305 ms  sched-messaging
            9725     9351    1.77        365.315 ms  sched-messaging
       <SNIP>

   - Add hard/soft-irq statistics to perf kwork top. This will show the
     total CPU utilization with IRQ stats like below:

       $ sudo perf kwork top -b -k sched,irq,softirq
       Starting trace, Hit <Ctrl+C> to stop and report
       ^C
       Total  :  12554.889 ms, 8 cpus
       %Cpu(s):  96.23% id,   0.10% hi,   0.19% si      <---- here
       %Cpu0   [|                                4.60%]
       %Cpu1   [|                                4.59%]
       %Cpu2   [                                 2.73%]
       %Cpu3   [|                                3.81%]
       <SNIP>

  perf bench:

   - Add -G/--cgroups option to perf bench sched pipe. The pipe bench is
     good to measure context switch overhead. With this option, it puts
     the reader and writer tasks in separate cgroups to enforce context
     switch between two different cgroups.

     Also it needs to set CPU affinity of the tasks in a CPU to
     accurately measure the impact of cgroup context switches.

       $ sudo perf stat -e context-switches,cgroup-switches -- \
       > taskset -c 0 perf bench sched pipe -l 100000
       # Running 'sched/pipe' benchmark:
       # Executed 100000 pipe operations between two processes

            Total time: 0.307 [sec]

              3.078180 usecs/op
                324867 ops/sec

        Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 100000':

                  200,026      context-switches
                       63      cgroup-switches

              0.321637922 seconds time elapsed

     You can see small number of cgroup-switches because both write and
     read tasks are in the same cgroup.

       $ sudo mkdir /sys/fs/cgroup/{AAA,BBB}

       $ sudo perf stat -e context-switches,cgroup-switches -- \
       > taskset -c 0 perf bench sched pipe -l 100000 -G AAA,BBB
       # Running 'sched/pipe' benchmark:
       # Executed 100000 pipe operations between two processes

            Total time: 0.351 [sec]

              3.512990 usecs/op
                284657 ops/sec

        Performance counter stats for 'taskset -c 0 perf bench sched pipe -l 100000 -G AAA,BBB':

                  200,020      context-switches
                  200,019      cgroup-switches

              0.365034567 seconds time elapsed

     Now context-switches and cgroup-switches are almost same. And you
     can see the pipe operation took little more.

   - Kill child processes when perf bench sched messaging exited
     abnormally. Otherwise it'd leave the child doing unnecessary work.

  perf test:

   - Fix various shellcheck issues on the tests written in shell script.

   - Skip tests when condition is not satisfied:
      - object code reading test for non-text section addresses.
      - CoreSight test if cs_etm// event is not available.
      - lock contention test if not enough CPUs.

  Event parsing:

   - Make PMU alias name loading lazy to reduce the startup time in the
     event parsing code for perf record, stat and others in the general
     case.

   - Lazily compute PMU default config. In the same sense, delay PMU
     initialization until it's really needed to reduce the startup cost.

   - Fix event term values that are raw events. The event specification
     can have several terms including event name. But sometimes it
     clashes with raw event encoding which starts with 'r' and has
     hex-digits.

     For example, an event named 'read' should be processed as a normal
     event but it was mis-treated as a raw encoding and caused a
     failure.

       $ perf stat -e 'uncore_imc_free_running/event=read/' -a sleep 1
       event syntax error: '..nning/event=read/'
                                         \___ parser error
       Run 'perf list' for a list of valid events

        Usage: perf stat [<options>] [<command>]

           -e, --event <event> event selector. use 'perf list' to list available events

  Event metrics:

   - Add "Compat" regex to match event with multiple identifiers.

   - Usual updates for Intel, Power10, Arm telemetry/CMN and AmpereOne.

  Misc:

   - Assorted memory leak fixes and footprint reduction.

   - Add "bpf_skeletons" to perf version --build-options so that users
     can check whether their perf tools have BPF support easily.

   - Fix unaligned access in Intel-PT packet decoder found by
     undefined-behavior sanitizer.

   - Avoid frequency mode for the dummy event. Surprisingly it'd impact
     kernel timer tick handler performance by force iterating all PMU
     events.

   - Update bash shell completion for events and metrics"

* tag 'perf-tools-for-v6.7-1-2023-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (187 commits)
  perf vendor events intel: Update tsx_cycles_per_elision metrics
  perf vendor events intel: Update bonnell version number to v5
  perf vendor events intel: Update westmereex events to v4
  perf vendor events intel: Update meteorlake events to v1.06
  perf vendor events intel: Update knightslanding events to v16
  perf vendor events intel: Add typo fix for ivybridge FP
  perf vendor events intel: Update a spelling in haswell/haswellx
  perf vendor events intel: Update emeraldrapids to v1.01
  perf vendor events intel: Update alderlake/alderlake events to v1.23
  perf build: Disable BPF skeletons if clang version is < 12.0.1
  perf callchain: Fix spelling mistake "statisitcs" -> "statistics"
  perf report: Fix spelling mistake "heirachy" -> "hierarchy"
  perf python: Fix binding linkage due to rename and move of evsel__increase_rlimit()
  perf tests: test_arm_coresight: Simplify source iteration
  perf vendor events intel: Add tigerlake two metrics
  perf vendor events intel: Add broadwellde two metrics
  perf vendor events intel: Fix broadwellde tma_info_system_dram_bw_use metric
  perf mem_info: Add and use map_symbol__exit and addr_map_symbol__exit
  perf callchain: Minor layout changes to callchain_list
  perf callchain: Make brtype_stat in callchain_list optional
  ...
2023-11-03 08:17:38 -10:00
Ian Rogers 78c32f4cb1 libperf rc_check: Add RC_CHK_EQUAL
Comparing pointers with reference count checking is tricky to avoid a
SEGV. Add a convenience macro to simplify and use.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: James Clark <james.clark@arm.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: liuwenyu <liuwenyu7@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20231024222353.3024098-5-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2023-10-25 13:37:22 -07:00
Ian Rogers 75265320d2 libperf rc_check: Make implicit enabling work for GCC
Make the implicit REFCOUNT_CHECKING robust to when building with GCC.

Fixes: 9be6ab181b ("libperf rc_check: Enable implicitly with sanitizers")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: German Gomez <german.gomez@arm.com>
Cc: James Clark <james.clark@arm.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: liuwenyu <liuwenyu7@huawei.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Yanteng Si <siyanteng@loongson.cn>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lore.kernel.org/r/20231024222353.3024098-4-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2023-10-25 13:36:50 -07:00
Daniel Borkmann 05c31b4ab2 libbpf: Add link-based API for netkit
This adds bpf_program__attach_netkit() API to libbpf. Overall it is very
similar to tcx. The API looks as following:

  LIBBPF_API struct bpf_link *
  bpf_program__attach_netkit(const struct bpf_program *prog, int ifindex,
                             const struct bpf_netkit_opts *opts);

The struct bpf_netkit_opts is done in similar way as struct bpf_tcx_opts
for supporting bpf_mprog control parameters. The attach location for the
primary and peer device is derived from the program section "netkit/primary"
and "netkit/peer", respectively.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20231024214904.29825-4-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-10-24 16:06:58 -07:00
Andrii Nakryiko 137df1189d libbpf: Don't assume SHT_GNU_verdef presence for SHT_GNU_versym section
Fix too eager assumption that SHT_GNU_verdef ELF section is going to be
present whenever binary has SHT_GNU_versym section. It seems like either
SHT_GNU_verdef or SHT_GNU_verneed can be used, so failing on missing
SHT_GNU_verdef actually breaks use cases in production.

One specific reported issue, which was used to manually test this fix,
was trying to attach to `readline` function in BASH binary.

Fixes: bb7fa09399 ("libbpf: Support symbol versioning for uprobe")
Reported-by: Liam Wisehart <liamwisehart@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Manu Bretelle <chantr4@gmail.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Acked-by: Hengqi Chen <hengqi.chen@gmail.com>
Link: https://lore.kernel.org/bpf/20231016182840.4033346-1-andrii@kernel.org
2023-10-17 11:43:20 +02:00
Ian Rogers c4b5140c6e tools api: Avoid potential double free
io__getline will free the line on error but it doesn't clear the out
argument. This may lead to the line being freed twice, like in
tools/perf/util/srcline.c as detected by clang-tidy.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Yang Jihong <yangjihong1@huawei.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: llvm@lists.linux.dev
Cc: Ming Wang <wangming01@loongson.cn>
Cc: Tom Rix <trix@redhat.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20231009183920.200859-17-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
2023-10-12 10:01:57 -07:00
Daan De Meyer bf90438c78 libbpf: Add support for cgroup unix socket address hooks
Add the necessary plumbing to hook up the new cgroup unix sockaddr
hooks into libbpf.

Signed-off-by: Daan De Meyer <daan.j.demeyer@gmail.com>
Link: https://lore.kernel.org/r/20231011185113.140426-6-daan.j.demeyer@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-10-11 17:27:55 -07:00
Alexandre Ghiti 8a412c5c1c libbpf: Fix syscall access arguments on riscv
Since commit 08d0ce30e0 ("riscv: Implement syscall wrappers"), riscv
selects ARCH_HAS_SYSCALL_WRAPPER so let's use the generic implementation
of PT_REGS_SYSCALL_REGS().

Fixes: 08d0ce30e0 ("riscv: Implement syscall wrappers")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/bpf/20231004110905.49024-2-bjorn@kernel.org
2023-10-04 13:19:13 -07:00
Hengqi Chen 2147c8d07e libbpf: Allow Golang symbols in uprobe secdef
Golang symbols in ELF files are different from C/C++
which contains special characters like '*', '(' and ')'.
With generics, things get more complicated, there are
symbols like:

  github.com/cilium/ebpf/internal.(*Deque[go.shape.interface { Format(fmt.State, int32); TypeName() string;github.com/cilium/ebpf/btf.copy() github.com/cilium/ebpf/btf.Type}]).Grow

Matching such symbols using `%m[^\n]` in sscanf, this
excludes newline which typically does not appear in ELF
symbols. This should work in most use-cases and also
work for unicode letters in identifiers. If newline do
show up in ELF symbols, users can still attach to such
symbol by specifying bpf_uprobe_opts::func_name.

A working example can be found at this repo ([0]).

  [0]: https://github.com/chenhengqi/libbpf-go-symbols

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230929155954.92448-1-hengqi.chen@gmail.com
2023-09-29 14:32:20 -07:00
Martin Kelly 16058ff28b libbpf: Add ring__consume
Add ring__consume to consume a single ringbuffer, analogous to
ring_buffer__consume.

Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230925215045.2375758-14-martin.kelly@crowdstrike.com
2023-09-25 16:22:43 -07:00
Martin Kelly ae76939037 libbpf: Add ring__map_fd
Add ring__map_fd to get the file descriptor underlying a given
ringbuffer.

Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230925215045.2375758-12-martin.kelly@crowdstrike.com
2023-09-25 16:22:43 -07:00
Martin Kelly e79abf717f libbpf: Add ring__size
Add ring__size to get the total size of a given ringbuffer.

Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230925215045.2375758-10-martin.kelly@crowdstrike.com
2023-09-25 16:22:43 -07:00
Martin Kelly 3b34d29726 libbpf: Add ring__avail_data_size
Add ring__avail_data_size for querying the currently available data in
the ringbuffer, similar to the BPF_RB_AVAIL_DATA flag in
bpf_ringbuf_query. This is racy during ongoing operations but is still
useful for overall information on how a ringbuffer is behaving.

Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230925215045.2375758-8-martin.kelly@crowdstrike.com
2023-09-25 16:22:42 -07:00
Martin Kelly 059a8c0c5a libbpf: Add ring__producer_pos, ring__consumer_pos
Add APIs to get the producer and consumer position for a given
ringbuffer.

Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230925215045.2375758-6-martin.kelly@crowdstrike.com
2023-09-25 16:22:42 -07:00
Martin Kelly 1c97f6afd7 libbpf: Add ring_buffer__ring
Add a new function ring_buffer__ring, which exposes struct ring * to the
user, representing a single ringbuffer.

Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230925215045.2375758-4-martin.kelly@crowdstrike.com
2023-09-25 16:22:42 -07:00
Martin Kelly ef3b82003e libbpf: Switch rings to array of pointers
Switch rb->rings to be an array of pointers instead of a contiguous
block. This allows for each ring pointer to be stable after
ring_buffer__add is called, which allows us to expose struct ring * to
the user without gotchas. Without this change, the realloc in
ring_buffer__add could invalidate a struct ring *, making it unsafe to
give to the user.

Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230925215045.2375758-3-martin.kelly@crowdstrike.com
2023-09-25 16:22:42 -07:00
Martin Kelly 4448f64c54 libbpf: Refactor cleanup in ring_buffer__add
Refactor the cleanup code in ring_buffer__add to use a unified err_out
label. This reduces code duplication, as well as plugging a potential
leak if mmap_sz != (__u64)(size_t)mmap_sz (currently this would miss
unmapping tmp because ringbuf_unmap_ring isn't called).

Signed-off-by: Martin Kelly <martin.kelly@crowdstrike.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230925215045.2375758-2-martin.kelly@crowdstrike.com
2023-09-25 16:22:42 -07:00
Hengqi Chen bb7fa09399 libbpf: Support symbol versioning for uprobe
In current implementation, we assume that symbol found in .dynsym section
would have a version suffix and use it to compare with symbol user supplied.
According to the spec ([0]), this assumption is incorrect, the version info
of dynamic symbols are stored in .gnu.version and .gnu.version_d sections
of ELF objects. For example:

    $ nm -D /lib/x86_64-linux-gnu/libc.so.6 | grep rwlock_wrlock
    000000000009b1a0 T __pthread_rwlock_wrlock@GLIBC_2.2.5
    000000000009b1a0 T pthread_rwlock_wrlock@@GLIBC_2.34
    000000000009b1a0 T pthread_rwlock_wrlock@GLIBC_2.2.5

    $ readelf -W --dyn-syms /lib/x86_64-linux-gnu/libc.so.6 | grep rwlock_wrlock
      706: 000000000009b1a0   878 FUNC    GLOBAL DEFAULT   15 __pthread_rwlock_wrlock@GLIBC_2.2.5
      2568: 000000000009b1a0   878 FUNC    GLOBAL DEFAULT   15 pthread_rwlock_wrlock@@GLIBC_2.34
      2571: 000000000009b1a0   878 FUNC    GLOBAL DEFAULT   15 pthread_rwlock_wrlock@GLIBC_2.2.5

In this case, specify pthread_rwlock_wrlock@@GLIBC_2.34 or
pthread_rwlock_wrlock@GLIBC_2.2.5 in bpf_uprobe_opts::func_name won't work.
Because the qualified name does NOT match `pthread_rwlock_wrlock` (without
version suffix) in .dynsym sections.

This commit implements the symbol versioning for dynsym and allows user to
specify symbol in the following forms:
  - func
  - func@LIB_VERSION
  - func@@LIB_VERSION

In case of symbol conflicts, error out and users should resolve it by
specifying a qualified name.

  [0]: https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/symversion.html

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230918024813.237475-3-hengqi.chen@gmail.com
2023-09-22 14:27:36 -07:00
Hengqi Chen 7257cee652 libbpf: Resolve symbol conflicts at the same offset for uprobe
Dynamic symbols in shared library may have the same name, for example:

    $ nm -D /lib/x86_64-linux-gnu/libc.so.6 | grep rwlock_wrlock
    000000000009b1a0 T __pthread_rwlock_wrlock@GLIBC_2.2.5
    000000000009b1a0 T pthread_rwlock_wrlock@@GLIBC_2.34
    000000000009b1a0 T pthread_rwlock_wrlock@GLIBC_2.2.5

    $ readelf -W --dyn-syms /lib/x86_64-linux-gnu/libc.so.6 | grep rwlock_wrlock
     706: 000000000009b1a0   878 FUNC    GLOBAL DEFAULT   15 __pthread_rwlock_wrlock@GLIBC_2.2.5
    2568: 000000000009b1a0   878 FUNC    GLOBAL DEFAULT   15 pthread_rwlock_wrlock@@GLIBC_2.34
    2571: 000000000009b1a0   878 FUNC    GLOBAL DEFAULT   15 pthread_rwlock_wrlock@GLIBC_2.2.5

Currently, users can't attach a uprobe to pthread_rwlock_wrlock because
there are two symbols named pthread_rwlock_wrlock and both are global
bind. And libbpf considers it as a conflict.

Since both of them are at the same offset we could accept one of them
harmlessly. Note that we already does this in elf_resolve_syms_offsets.

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230918024813.237475-2-hengqi.chen@gmail.com
2023-09-22 14:18:55 -07:00
David S. Miller 685c6d5b2c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
The following pull-request contains BPF updates for your *net-next* tree.

We've added 73 non-merge commits during the last 9 day(s) which contain
a total of 79 files changed, 5275 insertions(+), 600 deletions(-).

The main changes are:

1) Basic BTF validation in libbpf, from Andrii Nakryiko.

2) bpf_assert(), bpf_throw(), exceptions in bpf progs, from Kumar Kartikeya Dwivedi.

3) next_thread cleanups, from Oleg Nesterov.

4) Add mcpu=v4 support to arm32, from Puranjay Mohan.

5) Add support for __percpu pointers in bpf progs, from Yonghong Song.

6) Fix bpf tailcall interaction with bpf trampoline, from Leon Hwang.

7) Raise irq_work in bpf_mem_alloc while irqs are disabled to improve refill probabablity, from Hou Tao.

Please consider pulling these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git

Thanks a lot!

Also thanks to reporters, reviewers and testers of commits in this pull-request:

Alan Maguire, Andrey Konovalov, Dave Marchevsky, "Eric W. Biederman",
Jiri Olsa, Maciej Fijalkowski, Quentin Monnet, Russell King (Oracle),
Song Liu, Stanislav Fomichev, Yonghong Song
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-17 15:12:06 +01:00
Kumar Kartikeya Dwivedi 7e2925f672 libbpf: Add support for custom exception callbacks
Add support to libbpf to append exception callbacks when loading a
program. The exception callback is found by discovering the declaration
tag 'exception_callback:<value>' and finding the callback in the value
of the tag.

The process is done in two steps. First, for each main program, the
bpf_object__sanitize_and_load_btf function finds and marks its
corresponding exception callback as defined by the declaration tag on
it. Second, bpf_object__reloc_code is modified to append the indicated
exception callback at the end of the instruction iteration (since
exception callback will never be appended in that loop, as it is not
directly referenced).

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-16-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:36:43 -07:00
Kumar Kartikeya Dwivedi 6c918709bd libbpf: Refactor bpf_object__reloc_code
Refactor bpf_object__append_subprog_code out of bpf_object__reloc_code
to be able to reuse it to append subprog related code for the exception
callback to the main program.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-15-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:36:43 -07:00
Yang Jihong f6ff1c7604 perf evlist: Add perf_evlist__go_system_wide() helper
For dummy events that keep tracking, we may need to modify its cpu_maps.

For example, change the cpu_maps to record sideband events for all CPUS.

Add perf_evlist__go_system_wide() helper to support this scenario.

Signed-off-by: Yang Jihong <yangjihong1@huawei.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: https://lore.kernel.org/r/20230904023340.12707-2-yangjihong1@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-09-12 17:31:22 -03:00
Linus Torvalds 535a265d7f perf tools changes for v6.6:
perf tools maintainership:
 
 - Add git information for perf-tools and perf-tools-next trees/branches to the
   MAINTAINERS file. That is where development now takes place and myself and
   Namhyung Kim have write access, more people to come as we emulate other
   maintainer groups.
 
 perf record:
 
 - Record kernel data maps when 'perf record --data' is used, so that global variables can
   be resolved and used in tools that do data profiling.
 
 perf trace:
 
 - Remove the old, experimental support for BPF events in which a .c file was passed as
   an event: "perf trace -e hello.c" to then get compiled and loaded.
 
   The only known usage for that, that shipped with the kernel as an example for such events,
   augmented the raw_syscalls tracepoints and was converted to a libbpf skeleton, reusing all
   the user space components and the BPF code connected to the syscalls.
 
   In the end just the way to glue the BPF part and the user space type beautifiers changed,
   now being performed by libbpf skeletons.
 
   The next step is to use BTF to do pretty printing of all syscall types, as discussed with
   Alan Maguire and others.
 
   Now, on a perf built with BUILD_BPF_SKEL=1 we get most if not all path/filenames/strings,
   some of the networking data structures, perf_event_attr, etc, i.e. systemwide tracing of
   nanosleep calls and perf_event_open syscalls while 'perf stat' runs 'sleep' for 5 seconds:
 
   # perf trace -a -e *nanosleep,perf* perf stat -e cycles,instructions sleep 5
      0.000 (   9.034 ms): perf/327641 perf_event_open(attr_uptr: { type: 0 (PERF_TYPE_HARDWARE), size: 136, config: 0 (PERF_COUNT_HW_CPU_CYCLES), sample_type: IDENTIFIER, read_format: TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING, disabled: 1, inherit: 1, enable_on_exec: 1, exclude_guest: 1 }, pid: 327642 (perf), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 3
      9.039 (   0.006 ms): perf/327641 perf_event_open(attr_uptr: { type: 0 (PERF_TYPE_HARDWARE), size: 136, config: 0x1 (PERF_COUNT_HW_INSTRUCTIONS), sample_type: IDENTIFIER, read_format: TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING, disabled: 1, inherit: 1, enable_on_exec: 1, exclude_guest: 1 }, pid: 327642 (perf-exec), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
          ? (           ): gpm/991  ... [continued]: clock_nanosleep())               = 0
     10.133 (           ): sleep/327642 clock_nanosleep(rqtp: { .tv_sec: 5, .tv_nsec: 0 }, rmtp: 0x7ffd36f83ed0) ...
          ? (           ): pool-gsd-smart/3051  ... [continued]: clock_nanosleep())   = 0
     30.276 (           ): gpm/991 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffcc6f73710) ...
    223.215 (1000.430 ms): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) = 0
     30.276 (2000.394 ms): gpm/991  ... [continued]: clock_nanosleep())               = 0
   1230.814 (           ): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) ...
   1230.814 (1000.404 ms): pool-gsd-smart/3051  ... [continued]: clock_nanosleep())   = 0
   2030.886 (           ): gpm/991 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffcc6f73710) ...
   2237.709 (1000.153 ms): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) = 0
          ? (           ): crond/1172  ... [continued]: clock_nanosleep())            = 0
   3242.699 (           ): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) ...
   2030.886 (2000.385 ms): gpm/991  ... [continued]: clock_nanosleep())               = 0
   3728.078 (           ): crond/1172 clock_nanosleep(rqtp: { .tv_sec: 60, .tv_nsec: 0 }, rmtp: 0x7ffe0971dcf0) ...
   3242.699 (1000.158 ms): pool-gsd-smart/3051  ... [continued]: clock_nanosleep())   = 0
   4031.409 (           ): gpm/991 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffcc6f73710) ...
     10.133 (5000.375 ms): sleep/327642  ... [continued]: clock_nanosleep())          = 0
 
  Performance counter stats for 'sleep 5':
 
          2,617,347      cycles
          1,855,997      instructions                     #    0.71  insn per cycle
 
        5.002282128 seconds time elapsed
 
        0.000855000 seconds user
        0.000852000 seconds sys
   #
 
 perf annotate:
 
 - Building with binutils' libopcode now is opt-in (BUILD_NONDISTRO=1) for
   licensing reasons, and we missed a build test on tools/perf/tests makefile.
 
   Since we now default to NDEBUG=1, we ended up segfaulting when building with
   BUILD_NONDISTRO=1 because a needed initialization routine was being "error
   checked" via an assert.
 
   Fix it by explicitly checking the result and aborting instead if it fails.
 
   We better back propagate the error, but at least 'perf annotate' on samples
   collected for a BPF program is back working when perf is built with
   BUILD_NONDISTRO=1.
 
 perf report/top:
 
 - Add back TUI hierarchy mode header, that is seen when using 'perf report/top --hierarchy'.
 
 - Fix the number of entries for 'e' key in the TUI that was preventing navigation of
   lines when expanding an entry.
 
 perf report/script:
 
 - Support cross platform register handling, allowing a perf.data file collected
   on one architecture to have registers sampled correctly displayed when
   analysis tools such as 'perf report' and 'perf script' are used on a different
   architecture.
 
 - Fix handling of event attributes in pipe mode, i.e. when one uses:
 
 	perf record -o - | perf report -i -
 
   When no perf.data files are used.
 
 - Handle files generated via pipe mode with a version of perf and then read
   also via pipe mode with a different version of perf, where the event attr
   record may have changed, use the record size field to properly support this
   version mismatch.
 
 perf probe:
 
 - Accessing global variables from uprobes isn't supported, make the error
   message state that instead of stating that some minimal kernel version is
   needed to have that feature. This seems just a tool limitation, the kernel
   probably has all that is needed.
 
 perf tests:
 
 - Fix a reference count related leak in the dlfilter v0 API where the result
   of a thread__find_symbol_fb() is not matched with an addr_location__exit()
   to drop the reference counts of the resolved components (machine, thread, map,
   symbol, etc). Add a dlfilter test to make sure that doesn't regresses.
 
 - Lots of fixes for the 'perf test' written in shell script related to problems
   found with the shellcheck utility.
 
 - Fixes for 'perf test' shell scripts testing features enabled when perf is
   built with BUILD_BPF_SKEL=1, such as 'perf stat' bpf counters.
 
 - Add perf record sample filtering test, things like the following example, that gets
   implemented as a BPF filter attached to the event:
 
    # perf record -e task-clock -c 10000 --filter 'ip < 0xffffffff00000000'
 
 - Improve the way the task_analyzer test checks if libtraceevent is linked,
   using 'perf version --build-options' instead of the more expensinve
   'perf record -e "sched:sched_switch"'.
 
 - Add support for riscv in the mmap-basic test. (This went as well via the RiscV tree, same contents).
 
 libperf:
 
 - Implement riscv mmap support (This went as well via the RiscV tree, same contents).
 
 perf script:
 
 - New tool that converts perf.data files to the firefox profiler format so that one can use
   the visualizer at https://profiler.firefox.com/. Done by Anup Sharma as part of this year's
   Google Summer of Code.
 
   One can generate the output and upload it to the web interface but Anup also automated
   everything:
 
      perf script gecko -F 99 -a sleep 60
 
 - Support syscall name parsing on arm64.
 
 - Print "cgroup" field on the same line as "comm".
 
 perf bench:
 
 - Add new 'uprobe' benchmark to measure the overhead of uprobes with/without
   BPF programs attached to it.
 
 - breakpoints are not available on power9, skip that test.
 
 perf stat:
 
 - Add #num_cpus_online literal to be used in 'perf stat' metrics, and add this extra
   'perf test' check that exemplifies its purpose:
 
 	TEST_ASSERT_VAL("#num_cpus_online",
                        expr__parse(&num_cpus_online, ctx, "#num_cpus_online") == 0);
 	TEST_ASSERT_VAL("#num_cpus", expr__parse(&num_cpus, ctx, "#num_cpus") == 0);
 	TEST_ASSERT_VAL("#num_cpus >= #num_cpus_online", num_cpus >= num_cpus_online);
 
 Miscellaneous:
 
 - Improve tool startup time by lazily reading PMU, JSON, sysfs data.
 
 - Improve error reporting in the parsing of events, passing YYLTYPE to error routines,
   so that the output can show were the parsing error was found.
 
 - Add 'perf test' entries to check the parsing of events improvements.
 
 - Fix various leak for things detected by -fsanitize=address, mostly things that would
   be freed at tool exit, including:
 
   - Free evsel->filter on the destructor.
 
   - Allow tools to register a thread->priv destructor and use it in 'perf trace'.
 
   - Free evsel->priv in 'perf trace'.
 
   - Free string returned by synthesize_perf_probe_point() when the caller fails
     to do all it needs.
 
 - Adjust various compiler options to not consider errors some warnings when
   building with broken headers found in things like python, flex, bison, as we
   otherwise build with -Werror. Some for gcc, some for clang, some for some
   specific version of those, some for some specific version of flex or bison, or
   some specific combination of these components, bah.
 
 - Allow customization of clang options for BPF target, this helps building on
   gentoo where there are other oddities where BPF targets gets passed some compiler
   options intended for the native build, so building with WERROR=0 helps while
   these oddities are fixed.
 
 - Dont pass ERR_PTR() values to perf_session__delete() in 'perf top' and 'perf lock',
   fixing some segfaults when handling some odd failures.
 
 - Add LTO build option.
 
 - Fix format of unordered lists in the perf docs (tools/perf/Documentation).
 
 - Overhaul the bison files, using constructs such as YYNOMEM.
 
 - Remove unused tokens from the bison .y files.
 
 - Add more comments to various structs.
 
 - A few LoongArch enablement patches.
 
 Vendor events (JSON):
 
 - Add JSON metrics for Yitian 710 DDR (aarch64). Things like:
 
 	EventName, BriefDescription
 	visible_window_limit_reached_rd, "At least one entry in read queue reaches the visible window limit.",
 	visible_window_limit_reached_wr, "At least one entry in write queue reaches the visible window limit.",
 	op_is_dqsosc_mpc	       , "A DQS Oscillator MPC command to DRAM.",
 	op_is_dqsosc_mrr	       , "A DQS Oscillator MRR command to DRAM.",
 	op_is_tcr_mrr		       , "A Temperature Compensated Refresh(TCR) MRR command to DRAM.",
 
 - Add AmpereOne metrics (aarch64).
 
 - Update N2 and V2 metrics (aarch64) and events using Arm telemetry repo.
 
 - Update scale units and descriptions of common topdown metrics on aarch64. Things like:
 
   - "MetricExpr": "stall_slot_frontend / (#slots * cpu_cycles)",
   - "BriefDescription": "Frontend bound L1 topdown metric",
   + "MetricExpr": "100 * (stall_slot_frontend / (#slots * cpu_cycles))",
   + "BriefDescription": "This metric is the percentage of total slots that were stalled due to resource constraints in the frontend of the processor.",
 
 - Update events for intel: meteorlake to 1.04, sapphirerapids to 1.15, Icelake+ metric constraints.
 
 - Update files for the power10 platform.
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-tools-for-v6.6-1-2023-09-05' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools

Pull perf tools updates from Arnaldo Carvalho de Melo:
 "perf tools maintainership:

   - Add git information for perf-tools and perf-tools-next trees and
     branches to the MAINTAINERS file. That is where development now
     takes place and myself and Namhyung Kim have write access, more
     people to come as we emulate other maintainer groups.

  perf record:

   - Record kernel data maps when 'perf record --data' is used, so that
     global variables can be resolved and used in tools that do data
     profiling.

  perf trace:

   - Remove the old, experimental support for BPF events in which a .c
     file was passed as an event: "perf trace -e hello.c" to then get
     compiled and loaded.

     The only known usage for that, that shipped with the kernel as an
     example for such events, augmented the raw_syscalls tracepoints and
     was converted to a libbpf skeleton, reusing all the user space
     components and the BPF code connected to the syscalls.

     In the end just the way to glue the BPF part and the user space
     type beautifiers changed, now being performed by libbpf skeletons.

     The next step is to use BTF to do pretty printing of all syscall
     types, as discussed with Alan Maguire and others.

     Now, on a perf built with BUILD_BPF_SKEL=1 we get most if not all
     path/filenames/strings, some of the networking data structures,
     perf_event_attr, etc, i.e. systemwide tracing of nanosleep calls
     and perf_event_open syscalls while 'perf stat' runs 'sleep' for 5
     seconds:

      # perf trace -a -e *nanosleep,perf* perf stat -e cycles,instructions sleep 5
         0.000 (   9.034 ms): perf/327641 perf_event_open(attr_uptr: { type: 0 (PERF_TYPE_HARDWARE), size: 136, config: 0 (PERF_COUNT_HW_CPU_CYCLES), sample_type: IDENTIFIER, read_format: TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING, disabled: 1, inherit: 1, enable_on_exec: 1, exclude_guest: 1 }, pid: 327642 (perf), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 3
         9.039 (   0.006 ms): perf/327641 perf_event_open(attr_uptr: { type: 0 (PERF_TYPE_HARDWARE), size: 136, config: 0x1 (PERF_COUNT_HW_INSTRUCTIONS), sample_type: IDENTIFIER, read_format: TOTAL_TIME_ENABLED|TOTAL_TIME_RUNNING, disabled: 1, inherit: 1, enable_on_exec: 1, exclude_guest: 1 }, pid: 327642 (perf-exec), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
             ? (           ): gpm/991  ... [continued]: clock_nanosleep())               = 0
        10.133 (           ): sleep/327642 clock_nanosleep(rqtp: { .tv_sec: 5, .tv_nsec: 0 }, rmtp: 0x7ffd36f83ed0) ...
             ? (           ): pool-gsd-smart/3051  ... [continued]: clock_nanosleep())   = 0
        30.276 (           ): gpm/991 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffcc6f73710) ...
       223.215 (1000.430 ms): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) = 0
        30.276 (2000.394 ms): gpm/991  ... [continued]: clock_nanosleep())               = 0
      1230.814 (           ): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) ...
      1230.814 (1000.404 ms): pool-gsd-smart/3051  ... [continued]: clock_nanosleep())   = 0
      2030.886 (           ): gpm/991 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffcc6f73710) ...
      2237.709 (1000.153 ms): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) = 0
             ? (           ): crond/1172  ... [continued]: clock_nanosleep())            = 0
      3242.699 (           ): pool-gsd-smart/3051 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f6e7fffec90) ...
      2030.886 (2000.385 ms): gpm/991  ... [continued]: clock_nanosleep())               = 0
      3728.078 (           ): crond/1172 clock_nanosleep(rqtp: { .tv_sec: 60, .tv_nsec: 0 }, rmtp: 0x7ffe0971dcf0) ...
      3242.699 (1000.158 ms): pool-gsd-smart/3051  ... [continued]: clock_nanosleep())   = 0
      4031.409 (           ): gpm/991 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffcc6f73710) ...
        10.133 (5000.375 ms): sleep/327642  ... [continued]: clock_nanosleep())          = 0

      Performance counter stats for 'sleep 5':

             2,617,347      cycles
             1,855,997      instructions                     #    0.71  insn per cycle

           5.002282128 seconds time elapsed

           0.000855000 seconds user
           0.000852000 seconds sys

  perf annotate:

   - Building with binutils' libopcode now is opt-in (BUILD_NONDISTRO=1)
     for licensing reasons, and we missed a build test on
     tools/perf/tests makefile.

     Since we now default to NDEBUG=1, we ended up segfaulting when
     building with BUILD_NONDISTRO=1 because a needed initialization
     routine was being "error checked" via an assert.

     Fix it by explicitly checking the result and aborting instead if it
     fails.

     We better back propagate the error, but at least 'perf annotate' on
     samples collected for a BPF program is back working when perf is
     built with BUILD_NONDISTRO=1.

  perf report/top:

   - Add back TUI hierarchy mode header, that is seen when using 'perf
     report/top --hierarchy'.

   - Fix the number of entries for 'e' key in the TUI that was
     preventing navigation of lines when expanding an entry.

  perf report/script:

   - Support cross platform register handling, allowing a perf.data file
     collected on one architecture to have registers sampled correctly
     displayed when analysis tools such as 'perf report' and 'perf
     script' are used on a different architecture.

   - Fix handling of event attributes in pipe mode, i.e. when one uses:

  	perf record -o - | perf report -i -

     When no perf.data files are used.

   - Handle files generated via pipe mode with a version of perf and
     then read also via pipe mode with a different version of perf,
     where the event attr record may have changed, use the record size
     field to properly support this version mismatch.

  perf probe:

   - Accessing global variables from uprobes isn't supported, make the
     error message state that instead of stating that some minimal
     kernel version is needed to have that feature. This seems just a
     tool limitation, the kernel probably has all that is needed.

  perf tests:

   - Fix a reference count related leak in the dlfilter v0 API where the
     result of a thread__find_symbol_fb() is not matched with an
     addr_location__exit() to drop the reference counts of the resolved
     components (machine, thread, map, symbol, etc). Add a dlfilter test
     to make sure that doesn't regresses.

   - Lots of fixes for the 'perf test' written in shell script related
     to problems found with the shellcheck utility.

   - Fixes for 'perf test' shell scripts testing features enabled when
     perf is built with BUILD_BPF_SKEL=1, such as 'perf stat' bpf
     counters.

   - Add perf record sample filtering test, things like the following
     example, that gets implemented as a BPF filter attached to the
     event:

       # perf record -e task-clock -c 10000 --filter 'ip < 0xffffffff00000000'

   - Improve the way the task_analyzer test checks if libtraceevent is
     linked, using 'perf version --build-options' instead of the more
     expensinve 'perf record -e "sched:sched_switch"'.

   - Add support for riscv in the mmap-basic test. (This went as well
     via the RiscV tree, same contents).

  libperf:

   - Implement riscv mmap support (This went as well via the RiscV tree,
     same contents).

  perf script:

   - New tool that converts perf.data files to the firefox profiler
     format so that one can use the visualizer at
     https://profiler.firefox.com/. Done by Anup Sharma as part of this
     year's Google Summer of Code.

     One can generate the output and upload it to the web interface but
     Anup also automated everything:

       perf script gecko -F 99 -a sleep 60

   - Support syscall name parsing on arm64.

   - Print "cgroup" field on the same line as "comm".

  perf bench:

   - Add new 'uprobe' benchmark to measure the overhead of uprobes
     with/without BPF programs attached to it.

   - breakpoints are not available on power9, skip that test.

  perf stat:

   - Add #num_cpus_online literal to be used in 'perf stat' metrics, and
     add this extra 'perf test' check that exemplifies its purpose:

  	TEST_ASSERT_VAL("#num_cpus_online",
                         expr__parse(&num_cpus_online, ctx, "#num_cpus_online") == 0);
  	TEST_ASSERT_VAL("#num_cpus", expr__parse(&num_cpus, ctx, "#num_cpus") == 0);
  	TEST_ASSERT_VAL("#num_cpus >= #num_cpus_online", num_cpus >= num_cpus_online);

  Miscellaneous:

   - Improve tool startup time by lazily reading PMU, JSON, sysfs data.

   - Improve error reporting in the parsing of events, passing YYLTYPE
     to error routines, so that the output can show were the parsing
     error was found.

   - Add 'perf test' entries to check the parsing of events
     improvements.

   - Fix various leak for things detected by -fsanitize=address, mostly
     things that would be freed at tool exit, including:

       - Free evsel->filter on the destructor.

       - Allow tools to register a thread->priv destructor and use it in
         'perf trace'.

       - Free evsel->priv in 'perf trace'.

       - Free string returned by synthesize_perf_probe_point() when the
         caller fails to do all it needs.

   - Adjust various compiler options to not consider errors some
     warnings when building with broken headers found in things like
     python, flex, bison, as we otherwise build with -Werror. Some for
     gcc, some for clang, some for some specific version of those, some
     for some specific version of flex or bison, or some specific
     combination of these components, bah.

   - Allow customization of clang options for BPF target, this helps
     building on gentoo where there are other oddities where BPF targets
     gets passed some compiler options intended for the native build, so
     building with WERROR=0 helps while these oddities are fixed.

   - Dont pass ERR_PTR() values to perf_session__delete() in 'perf top'
     and 'perf lock', fixing some segfaults when handling some odd
     failures.

   - Add LTO build option.

   - Fix format of unordered lists in the perf docs
     (tools/perf/Documentation)

   - Overhaul the bison files, using constructs such as YYNOMEM.

   - Remove unused tokens from the bison .y files.

   - Add more comments to various structs.

   - A few LoongArch enablement patches.

  Vendor events (JSON):

   - Add JSON metrics for Yitian 710 DDR (aarch64). Things like:

  	EventName, BriefDescription
  	visible_window_limit_reached_rd, "At least one entry in read queue reaches the visible window limit.",
  	visible_window_limit_reached_wr, "At least one entry in write queue reaches the visible window limit.",
  	op_is_dqsosc_mpc	       , "A DQS Oscillator MPC command to DRAM.",
  	op_is_dqsosc_mrr	       , "A DQS Oscillator MRR command to DRAM.",
  	op_is_tcr_mrr		       , "A Temperature Compensated Refresh(TCR) MRR command to DRAM.",

   - Add AmpereOne metrics (aarch64).

   - Update N2 and V2 metrics (aarch64) and events using Arm telemetry
     repo.

   - Update scale units and descriptions of common topdown metrics on
     aarch64. Things like:
       - "MetricExpr": "stall_slot_frontend / (#slots * cpu_cycles)",
       - "BriefDescription": "Frontend bound L1 topdown metric",
       + "MetricExpr": "100 * (stall_slot_frontend / (#slots * cpu_cycles))",
       + "BriefDescription": "This metric is the percentage of total slots that were stalled due to resource constraints in the frontend of the processor.",

   - Update events for intel: meteorlake to 1.04, sapphirerapids to
     1.15, Icelake+ metric constraints.

   - Update files for the power10 platform"

* tag 'perf-tools-for-v6.6-1-2023-09-05' of git://git.kernel.org/pub/scm/linux/kernel/git/perf/perf-tools: (217 commits)
  perf parse-events: Fix driver config term
  perf parse-events: Fixes relating to no_value terms
  perf parse-events: Fix propagation of term's no_value when cloning
  perf parse-events: Name the two term enums
  perf list: Don't print Unit for "default_core"
  perf vendor events intel: Fix modifier in tma_info_system_mem_parallel_reads for skylake
  perf dlfilter: Avoid leak in v0 API test use of resolve_address()
  perf metric: Add #num_cpus_online literal
  perf pmu: Remove str from perf_pmu_alias
  perf parse-events: Make common term list to strbuf helper
  perf parse-events: Minor help message improvements
  perf pmu: Avoid uninitialized use of alias->str
  perf jevents: Use "default_core" for events with no Unit
  perf test stat_bpf_counters_cgrp: Enhance perf stat cgroup BPF counter test
  perf test shell stat_bpf_counters: Fix test on Intel
  perf test shell record_bpf_filter: Skip 6.2 kernel
  libperf: Get rid of attr.id field
  perf tools: Convert to perf_record_header_attr_id()
  libperf: Add perf_record_header_attr_id()
  perf tools: Handle old data in PERF_RECORD_ATTR
  ...
2023-09-09 20:06:17 -07:00
Yonghong Song ed5285a148 libbpf: Add __percpu_kptr macro definition
Add __percpu_kptr macro definition in bpf_helpers.h.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230827152800.1998492-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:18 -07:00
Andrii Nakryiko 3903802bb9 libbpf: Add basic BTF sanity validation
Implement a simple and straightforward BTF sanity check when parsing BTF
data. Right now it's very basic and just validates that all the string
offsets and type IDs are within valid range. For FUNC we also check that
it points to FUNC_PROTO kinds.

Even with such simple checks it fixes a bunch of crashes found by OSS
fuzzer ([0]-[5]) and will allow fuzzer to make further progress.

Some other invariants will be checked in follow up patches (like
ensuring there is no infinite type loops), but this seems like a good
start already.

Adding FUNC -> FUNC_PROTO check revealed that one of selftests has
a problem with FUNC pointing to VAR instead, so fix it up in the same
commit.

  [0] https://github.com/libbpf/libbpf/issues/482
  [1] https://github.com/libbpf/libbpf/issues/483
  [2] https://github.com/libbpf/libbpf/issues/485
  [3] https://github.com/libbpf/libbpf/issues/613
  [4] https://github.com/libbpf/libbpf/issues/618
  [5] https://github.com/libbpf/libbpf/issues/619

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Reviewed-by: Song Liu <song@kernel.org>
Closes: https://github.com/libbpf/libbpf/issues/617
Link: https://lore.kernel.org/bpf/20230825202152.1813394-1-andrii@kernel.org
2023-09-08 08:42:17 -07:00
Linus Torvalds e0152e7481 RISC-V Patches for the 6.6 Merge Window, Part 1
* Support for the new "riscv,isa-extensions" and "riscv,isa-base" device
   tree interfaces for probing extensions.
 * Support for userspace access to the performance counters.
 * Support for more instructions in kprobes.
 * Crash kernels can be allocated above 4GiB.
 * Support for KCFI.
 * Support for ELFs in !MMU configurations.
 * ARCH_KMALLOC_MINALIGN has been reduced to 8.
 * mmap() defaults to sv48-sized addresses, with longer addresses hidden
   behind a hint (similar to Arm and Intel).
 * Also various fixes and cleanups.
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Merge tag 'riscv-for-linus-6.6-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for the new "riscv,isa-extensions" and "riscv,isa-base"
   device tree interfaces for probing extensions

 - Support for userspace access to the performance counters

 - Support for more instructions in kprobes

 - Crash kernels can be allocated above 4GiB

 - Support for KCFI

 - Support for ELFs in !MMU configurations

 - ARCH_KMALLOC_MINALIGN has been reduced to 8

 - mmap() defaults to sv48-sized addresses, with longer addresses hidden
   behind a hint (similar to Arm and Intel)

 - Also various fixes and cleanups

* tag 'riscv-for-linus-6.6-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (51 commits)
  lib/Kconfig.debug: Restrict DEBUG_INFO_SPLIT for RISC-V
  riscv: support PREEMPT_DYNAMIC with static keys
  riscv: Move create_tmp_mapping() to init sections
  riscv: Mark KASAN tmp* page tables variables as static
  riscv: mm: use bitmap_zero() API
  riscv: enable DEBUG_FORCE_FUNCTION_ALIGN_64B
  riscv: remove redundant mv instructions
  RISC-V: mm: Document mmap changes
  RISC-V: mm: Update pgtable comment documentation
  RISC-V: mm: Add tests for RISC-V mm
  RISC-V: mm: Restrict address space for sv39,sv48,sv57
  riscv: enable DMA_BOUNCE_UNALIGNED_KMALLOC for !dma_coherent
  riscv: allow kmalloc() caches aligned to the smallest value
  riscv: support the elf-fdpic binfmt loader
  binfmt_elf_fdpic: support 64-bit systems
  riscv: Allow CONFIG_CFI_CLANG to be selected
  riscv/purgatory: Disable CFI
  riscv: Add CFI error handling
  riscv: Add ftrace_stub_graph
  riscv: Add types to indirectly called assembly functions
  ...
2023-09-01 08:09:48 -07:00
Namhyung Kim c091c78b73 libperf: Get rid of attr.id field
Now there's no in-tree user of the field.  To remove the possible bug
later, let's get rid of the 'id' field and add a comment for that.

Signed-off-by: Namhyung 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>
Link: https://lore.kernel.org/r/20230825152552.112913-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-08-29 14:16:14 -03:00
Namhyung Kim baec60800d libperf: Add perf_record_header_attr_id()
The HEADER_ATTR record has an event attr followed by the id array.  But
perf data from a different version could have different size of attr.

So it cannot just use event->attr.id to access the array.  Let's add the
perf_record_header_attr_id() macro to calculate the start of the array.

Signed-off-by: Namhyung 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>
Link: https://lore.kernel.org/r/20230825152552.112913-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2023-08-29 14:16:14 -03:00
Andrii Nakryiko f3bdb54f09 libbpf: fix signedness determination in CO-RE relo handling logic
Extracting btf_int_encoding() is only meaningful for BTF_KIND_INT, so we
need to check that first before inferring signedness.

Closes: https://github.com/libbpf/libbpf/issues/704
Reported-by: Lorenz Bauer <lmb@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230824000016.2658017-2-andrii@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-08-23 21:13:48 -07:00
Daniel Xu 068ca522d5 libbpf: Add bpf_object__unpin()
For bpf_object__pin_programs() there is bpf_object__unpin_programs().
Likewise bpf_object__unpin_maps() for bpf_object__pin_maps().

But no bpf_object__unpin() for bpf_object__pin(). Adding the former adds
symmetry to the API.

It's also convenient for cleanup in application code. It's an API I
would've used if it was available for a repro I was writing earlier.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/b2f9d41da4a350281a0b53a804d11b68327e14e5.1692832478.git.dxu@dxuuu.xyz
2023-08-23 17:10:09 -07:00
Hao Luo 29d67fdebc libbpf: Free btf_vmlinux when closing bpf_object
I hit a memory leak when testing bpf_program__set_attach_target().
Basically, set_attach_target() may allocate btf_vmlinux, for example,
when setting attach target for bpf_iter programs. But btf_vmlinux
is freed only in bpf_object_load(), which means if we only open
bpf object but not load it, setting attach target may leak
btf_vmlinux.

So let's free btf_vmlinux in bpf_object__close() anyway.

Signed-off-by: Hao Luo <haoluo@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230822193840.1509809-1-haoluo@google.com
2023-08-22 16:16:31 -07:00
Jiri Olsa 5902da6d8a libbpf: Add uprobe multi link support to bpf_program__attach_usdt
Adding support for usdt_manager_attach_usdt to use uprobe_multi
link to attach to usdt probes.

The uprobe_multi support is detected before the usdt program is
loaded and its expected_attach_type is set accordingly.

If uprobe_multi support is detected the usdt_manager_attach_usdt
gathers uprobes info and calls bpf_program__attach_uprobe to
create all needed uprobes.

If uprobe_multi support is not detected the old behaviour stays.

Also adding usdt.s program section for sleepable usdt probes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-18-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-21 15:51:26 -07:00
Jiri Olsa 7e1b468123 libbpf: Add uprobe multi link detection
Adding uprobe-multi link detection. It will be used later in
bpf_program__attach_usdt function to check and use uprobe_multi
link over standard uprobe links.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-17-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-21 15:51:26 -07:00
Jiri Olsa 5bfdd32dd5 libbpf: Add support for u[ret]probe.multi[.s] program sections
Adding support for several uprobe_multi program sections
to allow auto attach of multi_uprobe programs.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-16-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-21 15:51:26 -07:00
Jiri Olsa 3140cf121c libbpf: Add bpf_program__attach_uprobe_multi function
Adding bpf_program__attach_uprobe_multi function that
allows to attach multiple uprobes with uprobe_multi link.

The user can specify uprobes with direct arguments:

  binary_path/func_pattern/pid

or with struct bpf_uprobe_multi_opts opts argument fields:

  const char **syms;
  const unsigned long *offsets;
  const unsigned long *ref_ctr_offsets;
  const __u64 *cookies;

User can specify 2 mutually exclusive set of inputs:

 1) use only path/func_pattern/pid arguments

 2) use path/pid with allowed combinations of:
    syms/offsets/ref_ctr_offsets/cookies/cnt

    - syms and offsets are mutually exclusive
    - ref_ctr_offsets and cookies are optional

Any other usage results in error.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-15-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-21 15:51:26 -07:00
Jiri Olsa 5054a303f8 libbpf: Add bpf_link_create support for multi uprobes
Adding new uprobe_multi struct to bpf_link_create_opts object
to pass multiple uprobe data to link_create attr uapi.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-14-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-21 15:51:26 -07:00
Jiri Olsa e613d1d0f7 libbpf: Add elf_resolve_pattern_offsets function
Adding elf_resolve_pattern_offsets function that looks up
offsets for symbols specified by pattern argument.

The 'pattern' argument allows wildcards (*?' supported).

Offsets are returned in allocated array together with its
size and needs to be released by the caller.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-13-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-21 15:51:26 -07:00
Jiri Olsa 7ace84c689 libbpf: Add elf_resolve_syms_offsets function
Adding elf_resolve_syms_offsets function that looks up
offsets for symbols specified in syms array argument.

Offsets are returned in allocated array with the 'cnt' size,
that needs to be released by the caller.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-12-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-21 15:51:26 -07:00
Jiri Olsa 3774705db1 libbpf: Add elf symbol iterator
Adding elf symbol iterator object (and some functions) that follow
open-coded iterator pattern and some functions to ease up iterating
elf object symbols.

The idea is to iterate single symbol section with:

  struct elf_sym_iter iter;
  struct elf_sym *sym;

  if (elf_sym_iter_new(&iter, elf, binary_path, SHT_DYNSYM))
        goto error;

  while ((sym = elf_sym_iter_next(&iter))) {
        ...
  }

I considered opening the elf inside the iterator and iterate all symbol
sections, but then it gets more complicated wrt user checks for when
the next section is processed.

Plus side is the we don't need 'exit' function, because caller/user is
in charge of that.

The returned iterated symbol object from elf_sym_iter_next function
is placed inside the struct elf_sym_iter, so no extra allocation or
argument is needed.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-21 15:51:26 -07:00
Jiri Olsa f90eb70d44 libbpf: Add elf_open/elf_close functions
Adding elf_open/elf_close functions and using it in
elf_find_func_offset_from_file function. It will be
used in following changes to save some common code.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-10-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-08-21 15:51:26 -07:00