[PATCH 014/107] perf trace: Look for default name for entries in the syscalls prog array

Arnaldo Carvalho de Melo
2019-07-30T03:04:14Z

From: Arnaldo Carvalho de Melo <acme@redhat.com>

I.e. just look for "!syscalls:sys_enter_" or "exit_" plus the syscall
name, that way we need just to add entries to the
augmented_raw_syscalls.c BPF source to add handlers.

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-6xavwddruokp6ohs7tf4qilb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-trace.c | 30 +++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index c64f7c99db15..5258399a1c94 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -830,13 +830,11 @@ static struct syscall_fmt {
{ .name = "newfstatat",
.arg = { [0] = { .scnprintf = SCA_FDAT, /* dfd */ }, }, },
{ .name = "open",
- .bpf_prog_name = { .sys_enter = "!syscalls:sys_enter_open", },
.arg = { [1] = { .scnprintf = SCA_OPEN_FLAGS, /* flags */ }, }, },
{ .name = "open_by_handle_at",
.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",
@@ -873,7 +871,6 @@ static struct syscall_fmt {
{ .name = "recvmsg",
.arg = { [2] = { .scnprintf = SCA_MSG_FLAGS, /* flags */ }, }, },
{ .name = "renameat",
- .bpf_prog_name = { .sys_enter = "!syscalls:sys_enter_renameat", },
.arg = { [0] = { .scnprintf = SCA_FDAT, /* olddirfd */ },
[2] = { .scnprintf = SCA_FDAT, /* newdirfd */ }, }, },
{ .name = "renameat2",
@@ -2778,12 +2775,27 @@ static struct bpf_program *trace__find_syscall_bpf_prog(struct trace *trace, str
{
struct bpf_program *prog;

- if (prog_name == NULL)
+ if (prog_name == NULL) {
+ char default_prog_name[256];
+ scnprintf(default_prog_name, sizeof(default_prog_name), "!syscalls:sys_%s_%s", type, sc->name);
+ prog = trace__find_bpf_program_by_title(trace, default_prog_name);
+ if (prog != NULL)
+ goto out_found;
+ if (sc->fmt && sc->fmt->alias) {
+ scnprintf(default_prog_name, sizeof(default_prog_name), "!syscalls:sys_%s_%s", type, sc->fmt->alias);
+ prog = trace__find_bpf_program_by_title(trace, default_prog_name);
+ if (prog != NULL)
+ goto out_found;
+ }
goto out_unaugmented;
+ }

prog = trace__find_bpf_program_by_title(trace, prog_name);
- if (prog != NULL)
+
+ if (prog != NULL) {
+out_found:
return prog;
+ }

pr_debug("Couldn't find BPF prog \"%s\" to associate with syscalls:sys_%s_%s, not augmenting it\n",
prog_name, type, sc->name);
@@ -2798,12 +2810,8 @@ static void trace__init_syscall_bpf_progs(struct trace *trace, int id)
if (sc == NULL)
return;

- if (sc->fmt != NULL) {
- sc->bpf_prog.sys_enter = trace__find_syscall_bpf_prog(trace, sc, sc->fmt->bpf_prog_name.sys_enter, "enter");
- sc->bpf_prog.sys_exit = trace__find_syscall_bpf_prog(trace, sc, sc->fmt->bpf_prog_name.sys_exit, "exit");
- } else {
- sc->bpf_prog.sys_enter = sc->bpf_prog.sys_exit = trace->syscalls.unaugmented_prog;
- }
+ sc->bpf_prog.sys_enter = trace__find_syscall_bpf_prog(trace, sc, sc->fmt ? sc->fmt->bpf_prog_name.sys_enter : NULL, "enter");
+ sc->bpf_prog.sys_exit = trace__find_syscall_bpf_prog(trace, sc, sc->fmt ? sc->fmt->bpf_prog_name.sys_exit : NULL, "exit");
}

static int trace__bpf_prog_sys_enter_fd(struct trace *trace, int id)
--
2.21.0