From: Arnaldo Carvalho de Melo <a...@redhat.com> I.e. for a syscall that has its second argument being a string, its difficult these days to find 'open' being used in the wild :-)
Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Luis Cláudio Gonçalves <lclau...@redhat.com> Cc: Namhyung Kim <namhy...@kernel.org> Link: https://lkml.kernel.org/n/tip-yf3kbzirqrukd3fb2sp5q...@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/builtin-trace.c | 1 + .../perf/examples/bpf/augmented_raw_syscalls.c | 17 +++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 872c9cc982a5..a681b8c2ee4e 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -836,6 +836,7 @@ static struct syscall_fmt { .arg = { [0] = { .scnprintf = SCA_FDAT, /* dfd */ }, [2] = { .scnprintf = SCA_OPEN_FLAGS, /* flags */ }, }, }, { .name = "openat", + .bpf_prog_name = { .sys_enter = "!syscalls:sys_enter_openat", }, .arg = { [0] = { .scnprintf = SCA_FDAT, /* dfd */ }, [2] = { .scnprintf = SCA_OPEN_FLAGS, /* flags */ }, }, }, { .name = "perf_event_open", diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c index c66474a6ccf4..661936f90fe0 100644 --- a/tools/perf/examples/bpf/augmented_raw_syscalls.c +++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c @@ -131,6 +131,23 @@ int sys_enter_open(struct syscall_enter_args *args) return perf_event_output(args, &__augmented_syscalls__, BPF_F_CURRENT_CPU, augmented_args, len); } +SEC("!syscalls:sys_enter_openat") +int sys_enter_openat(struct syscall_enter_args *args) +{ + int key = 0; + struct augmented_args_filename *augmented_args = bpf_map_lookup_elem(&augmented_filename_map, &key); + const void *filename_arg = (const void *)args->args[1]; + unsigned int len = sizeof(augmented_args->args); + + if (augmented_args == NULL) + return 1; /* Failure: don't filter */ + + len += augmented_filename__read(&augmented_args->filename, filename_arg, sizeof(augmented_args->filename.value)); + + /* 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); +} + SEC("raw_syscalls:sys_enter") int sys_enter(struct syscall_enter_args *args) { -- 2.21.0
