From 514607e3c0f0e381aa4f6fe866b70b1fa9bfae74 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Wed, 2 Nov 2022 21:54:34 -0700 Subject: [PATCH] perf trace: hello fix libbpf 1.0+ compatibility Don't use deprecated and now broken map style. Avoid use of tools/perf/include/bpf/bpf.h and use the more regular BPF headers. Switch to raw_syscalls:sys_enter to avoid the evlist being empty and fixing generating output. Committer testing: # perf trace -e ~acme/git/perf/tools/perf/examples/bpf/hello.c --call-graph=dwarf --max-events 5 0.000 perf/206852 __bpf_stdout__(Hello, world) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __GI___sched_setaffinity_new (/usr/lib64/libc.so.6) 8.561 pipewire/2290 __bpf_stdout__(Hello, world) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __libc_read (/usr/lib64/libc.so.6) 8.571 pipewire/2290 __bpf_stdout__(Hello, world) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __GI___ioctl (/usr/lib64/libc.so.6) 8.586 pipewire/2290 __bpf_stdout__(Hello, world) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __GI___write (/usr/lib64/libc.so.6) 8.592 pipewire/2290 __bpf_stdout__(Hello, world) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) syscall_trace_enter.constprop.0 ([kernel.kallsyms]) do_syscall_64 ([kernel.kallsyms]) entry_SYSCALL_64_after_hwframe ([kernel.kallsyms]) __timerfd_settime (/usr/lib64/libc.so.6) # Signed-off-by: Ian Rogers Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: https://lore.kernel.org/r/20221103045437.163510-5-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/examples/bpf/hello.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/tools/perf/examples/bpf/hello.c b/tools/perf/examples/bpf/hello.c index cf3c2fdc7f79..e9080b0df158 100644 --- a/tools/perf/examples/bpf/hello.c +++ b/tools/perf/examples/bpf/hello.c @@ -1,9 +1,27 @@ -#include +// SPDX-License-Identifier: GPL-2.0 +#include +#include -int syscall_enter(openat)(void *args) +struct __bpf_stdout__ { + __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY); + __type(key, int); + __type(value, __u32); + __uint(max_entries, __NR_CPUS__); +} __bpf_stdout__ SEC(".maps"); + +#define puts(from) \ + ({ const int __len = sizeof(from); \ + char __from[sizeof(from)] = from; \ + bpf_perf_event_output(args, &__bpf_stdout__, BPF_F_CURRENT_CPU, \ + &__from, __len & (sizeof(from) - 1)); }) + +struct syscall_enter_args; + +SEC("raw_syscalls:sys_enter") +int sys_enter(struct syscall_enter_args *args) { puts("Hello, world\n"); return 0; } -license(GPL); +char _license[] SEC("license") = "GPL";