perf trace beauty: Beautify 'sendto's sockaddr arg

By just writing the collector in the augmented_raw_syscalls.c BPF
program:

  # perf trace -e sendto
  <SNIP>
  ping/23492 sendto(3, 0x56253bbef700, 64, NONE, { .family: PF_INET, port: 0, addr: 10.10.161.32 }, 0x10) = 64
  ping/23492 sendto(3, 0x56253bbef700, 64, NONE, { .family: PF_INET, port: 0, addr: 10.10.161.32 }, 0x10) = 64
  ping/23492 sendto(3, 0x56253bbef700, 64, NONE, { .family: PF_INET, port: 0, addr: 10.10.161.32 }, 0x10) = 64
  ping/23492 sendto(3, 0x56253bbef700, 64, NONE, { .family: PF_INET, port: 0, addr: 10.10.161.32 }, 0x10) = 64
  Socket Thread/3573 sendto(247, 0x7fb32d49c000, 120, NONE, { .family: PF_UNSPEC }, NULL) = 120
  DNS Res~er #18/11374 sendto(242, 0x7fb342cfe420, 20, NONE, { .family: PF_NETLINK }, 0xc) = 20
  DNS Res~er #18/11374 sendto(242, 0x7fb342cfcca0, 42, MSG_NOSIGNAL, { .family: PF_UNSPEC }, NULL) = 42
  DNS Res~er #18/11374 sendto(242, 0x7fb342cfcccc, 42, MSG_NOSIGNAL, { .family: PF_UNSPEC }, NULL) = 42
  ping/23492 sendto(3, 0x56253bbef700, 64, NONE, { .family: PF_INET, port: 0, addr: 10.10.161.32 }, 0x10) = 64
  Socket Thread/3573 sendto(242, 0x7fb308bb1c08, 296, NONE, { .family: PF_UNSPEC }, NULL) = 296
  ping/23492 sendto(3, 0x56253bbef700, 64, NONE, { .family: PF_INET, port: 0, addr: 10.10.161.32 }, 0x10) = 64
  ping/23492 sendto(3, 0x56253bbef700, 64, NONE, { .family: PF_INET, port: 0, addr: 10.10.161.32 }, 0x10) = 64
  ping/23492 sendto(3, 0x56253bbef700, 64, NONE, { .family: PF_INET, port: 0, addr: 10.10.161.32 }, 0x10) = 64
  ping/23492 sendto(3, 0x56253bbef700, 64, NONE, { .family: PF_INET, port: 0, addr: 10.10.161.32 }, 0x10) = 64
  ^C
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-p0l0rlvq19v5zf8qc2x2itow@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c
index d7a292d7ee2fa92da362271153425a963c7c2301..9c2228b01ee69ca36e079f6a54875c8f3e55d27c 100644 (file)
--- a/tools/perf/examples/bpf/augmented_raw_syscalls.c
+++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c
@@ -142,6 +142,27 @@ int sys_enter_connect(struct syscall_enter_args *args)
        return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, augmented_args, len + socklen);
 }
 
+SEC("!syscalls:sys_enter_sendto")
+int sys_enter_sendto(struct syscall_enter_args *args)
+{
+       int key = 0;
+       struct augmented_args_payload *augmented_args = bpf_map_lookup_elem(&augmented_args_tmp, &key);
+       const void *sockaddr_arg = (const void *)args->args[4];
+       unsigned int socklen = args->args[5];
+       unsigned int len = sizeof(augmented_args->args);
+
+        if (augmented_args == NULL)
+                return 1; /* Failure: don't filter */
+
+       if (socklen > sizeof(augmented_args->saddr))
+               socklen = sizeof(augmented_args->saddr);
+
+       probe_read(&augmented_args->saddr, socklen, sockaddr_arg);
+
+       /* If perf_event_output fails, return non-zero so that it gets recorded unaugmented */
+       return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, augmented_args, len + socklen);
+}
+
 SEC("!syscalls:sys_enter_open")
 int sys_enter_open(struct syscall_enter_args *args)
 {