[PATCH v3 4/8] perf trace: Filter enum arguments with enum names

Howard Chu
2024-06-24T18:12:21Z

Before:

perf $ ./perf trace -e timer:hrtimer_start --filter='mode!=HRTIMER_MODE_ABS_PINNED_HARD' --max-events=1
No resolver (strtoul) for "mode" in "timer:hrtimer_start", can't set filter "(mode!=HRTIMER_MODE_ABS_PINNED_HARD) && (common_pid != 281988)"

After:

perf $ ./perf trace -e timer:hrtimer_start --filter='mode!=HRTIMER_MODE_ABS_PINNED_HARD' --max-events=1
0.000 :0/0 timer:hrtimer_start(hrtimer: 0xffff9498a6ca5f18, function: 0xffffffffa77a5be0, expires: 12351248764875, softexpires: 12351248764875, mode: HRTIMER_MODE_ABS)

&& and ||:

perf $ ./perf trace -e timer:hrtimer_start --filter='mode != HRTIMER_MODE_ABS_PINNED_HARD && mode != HRTIMER_MODE_ABS' --max-events=1
0.000 Hyprland/534 timer:hrtimer_start(hrtimer: 0xffff9497801a84d0, function: 0xffffffffc04cdbe0, expires: 12639434638458, softexpires: 12639433638458, mode: HRTIMER_MODE_REL)

perf $ ./perf trace -e timer:hrtimer_start --filter='mode == HRTIMER_MODE_REL || mode == HRTIMER_MODE_PINNED' --max-events=1
0.000 ldlck-test/60639 timer:hrtimer_start(hrtimer: 0xffffb16404ee7bf8, function: 0xffffffffa7790420, expires: 12772614418016, softexpires: 12772614368016, mode: HRTIMER_MODE_REL)

Switching it up, using both enum name and integer value(--filter='mode == HRTIMER_MODE_ABS_PINNED_HARD || mode == 0'):

perf $ ./perf trace -e timer:hrtimer_start --filter='mode == HRTIMER_MODE_ABS_PINNED_HARD || mode == 0' --max-events=3
0.000 :0/0 timer:hrtimer_start(hrtimer: 0xffff9498a6ca5f18, function: 0xffffffffa77a5be0, expires: 12601748739825, softexpires: 12601748739825, mode: HRTIMER_MODE_ABS_PINNED_HARD)
0.036 :0/0 timer:hrtimer_start(hrtimer: 0xffff9498a6ca5f18, function: 0xffffffffa77a5be0, expires: 12518758748124, softexpires: 12518758748124, mode: HRTIMER_MODE_ABS_PINNED_HARD)
0.172 tmux: server/41881 timer:hrtimer_start(hrtimer: 0xffffb164081e7838, function: 0xffffffffa7790420, expires: 12518768255836, softexpires: 12518768205836, mode: HRTIMER_MODE_ABS)

P.S.
perf $ pahole hrtimer_mode
enum hrtimer_mode {
HRTIMER_MODE_ABS = 0,
HRTIMER_MODE_REL = 1,
HRTIMER_MODE_PINNED = 2,
HRTIMER_MODE_SOFT = 4,
HRTIMER_MODE_HARD = 8,
HRTIMER_MODE_ABS_PINNED = 2,
HRTIMER_MODE_REL_PINNED = 3,
HRTIMER_MODE_ABS_SOFT = 4,
HRTIMER_MODE_REL_SOFT = 5,
HRTIMER_MODE_ABS_PINNED_SOFT = 6,
HRTIMER_MODE_REL_PINNED_SOFT = 7,
HRTIMER_MODE_ABS_HARD = 8,
HRTIMER_MODE_REL_HARD = 9,
HRTIMER_MODE_ABS_PINNED_HARD = 10,
HRTIMER_MODE_REL_PINNED_HARD = 11,
};

Committer testing:

root@x1:~# perf trace -e timer:hrtimer_start --filter='mode != HRTIMER_MODE_ABS' --max-events=2
0.000 :0/0 timer:hrtimer_start(hrtimer: 0xffff8d4eff2a5050, function: 0xffffffff9e22ddd0, expires: 241502326000000, softexpires: 241502326000000, mode: HRTIMER_MODE_ABS_PINNED_HARD)
18446744073709.488 :0/0 timer:hrtimer_start(hrtimer: 0xffff8d4eff425050, function: 0xffffffff9e22ddd0, expires: 241501814000000, softexpires: 241501814000000, mode: HRTIMER_MODE_ABS_PINNED_HARD)
root@x1:~# perf trace -e timer:hrtimer_start --filter='mode != HRTIMER_MODE_ABS && mode != HRTIMER_MODE_ABS_PINNED_HARD' --max-events=2
0.000 podman/510644 timer:hrtimer_start(hrtimer: 0xffffa2024f5f7dd0, function: 0xffffffff9e2170c0, expires: 241530497418194, softexpires: 241530497368194, mode: HRTIMER_MODE_REL)
40.251 gnome-shell/2484 timer:hrtimer_start(hrtimer: 0xffff8d48bda17650, function: 0xffffffffc0661550, expires: 241550528619247, softexpires: 241550527619247, mode: HRTIMER_MODE_REL)
root@x1:~# perf trace -v -e timer:hrtimer_start --filter='mode != HRTIMER_MODE_ABS && mode != HRTIMER_MODE_ABS_PINNED_HARD && mode != HRTIMER_MODE_REL' --max-events=2
Using CPUID GenuineIntel-6-BA-3
vmlinux BTF loaded
<SNIP>
0
0xa
0x1
New filter for timer:hrtimer_start: (mode != 0 && mode != 0xa && mode != 0x1) && (common_pid != 524049 && common_pid != 4041)
mmap size 528384B
^Croot@x1:~#

Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Howard Chu <howardchu95@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.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>
Link: https://lore.kernel.org/lkml/ZnCcliuecJABD5FN@x1
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-trace.c | 62 ++++++++++++++++++++++++++++++++++----
1 file changed, 56 insertions(+), 6 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index b75d96a4ad55..774bb3534df4 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -932,6 +932,37 @@ static int syscall_arg_fmt__cache_btf_enum(struct syscall_arg_fmt *arg_fmt, stru
return arg_fmt->type == NULL ? -1 : 0;
}

+static bool syscall_arg__strtoul_btf_enum(char *bf, size_t size, struct syscall_arg *arg, u64 *val)
+{
+ const struct btf_type *bt;
+ char *type = arg->parm;
+ struct btf_enum *be;
+ struct btf *btf;
+
+ trace__load_vmlinux_btf(arg->trace);
+
+ btf = arg->trace->btf;
+ if (btf == NULL)
+ return false;
+
+ if (syscall_arg_fmt__cache_btf_enum(arg->fmt, btf, type) < 0)
+ return false;
+
+ bt = arg->fmt->type;
+ be = btf_enum(bt);
+ for (int i = 0; i < btf_vlen(bt); ++i, ++be) {
+ const char *name = btf__name_by_offset(btf, be->name_off);
+ int max_len = max(size, strlen(name));
+
+ if (strncmp(name, bf, max_len) == 0) {
+ *val = be->val;
+ return true;
+ }
+ }
+
+ return false;
+}
+
static size_t btf_enum_scnprintf(const struct btf_type *type, struct btf *btf, char *bf, size_t size, int val)
{
struct btf_enum *be = btf_enum(type);
@@ -965,8 +996,16 @@ static size_t trace__btf_enum_scnprintf(struct trace *trace __maybe_unused, stru
{
return 0;
}
+
+static bool syscall_arg__strtoul_btf_enum(char *bf __maybe_unused, size_t size __maybe_unused,
+ struct syscall_arg *arg __maybe_unused, u64 *val __maybe_unused)
+{
+ return false;
+}
#endif // HAVE_LIBBPF_SUPPORT

+#define STUL_BTF_ENUM syscall_arg__strtoul_btf_enum
+
#define STRARRAY(name, array) \
{ .scnprintf = SCA_STRARRAY, \
.strtoul = STUL_STRARRAY, \
@@ -1867,6 +1906,7 @@ syscall_arg_fmt__init_array(struct syscall_arg_fmt *arg, struct tep_format_field
arg->scnprintf = SCA_FD;
} else if (strstr(field->type, "enum") && use_btf != NULL) {
*use_btf = arg->is_enum = true;
+ arg->strtoul = STUL_BTF_ENUM;
} else {
const struct syscall_arg_fmt *fmt =
syscall_arg_fmt__find_by_name(field->name);
@@ -3792,7 +3832,8 @@ static int ordered_events__deliver_event(struct ordered_events *oe,
return __trace__deliver_event(trace, event->event);
}

-static struct syscall_arg_fmt *evsel__find_syscall_arg_fmt_by_name(struct evsel *evsel, char *arg)
+static struct syscall_arg_fmt *evsel__find_syscall_arg_fmt_by_name(struct evsel *evsel, char *arg,
+ char **type)
{
struct tep_format_field *field;
struct syscall_arg_fmt *fmt = __evsel__syscall_arg_fmt(evsel);
@@ -3801,13 +3842,15 @@ static struct syscall_arg_fmt *evsel__find_syscall_arg_fmt_by_name(struct evsel
return NULL;

for (field = evsel->tp_format->format.fields; field; field = field->next, ++fmt)
- if (strcmp(field->name, arg) == 0)
+ if (strcmp(field->name, arg) == 0) {
+ *type = field->type;
return fmt;
+ }

return NULL;
}

-static int trace__expand_filter(struct trace *trace __maybe_unused, struct evsel *evsel)
+static int trace__expand_filter(struct trace *trace, struct evsel *evsel)
{
char *tok, *left = evsel->filter, *new_filter = evsel->filter;

@@ -3840,14 +3883,14 @@ static int trace__expand_filter(struct trace *trace __maybe_unused, struct evsel
struct syscall_arg_fmt *fmt;
int left_size = tok - left,
right_size = right_end - right;
- char arg[128];
+ char arg[128], *type;

while (isspace(left[left_size - 1]))
--left_size;

scnprintf(arg, sizeof(arg), "%.*s", left_size, left);

- fmt = evsel__find_syscall_arg_fmt_by_name(evsel, arg);
+ fmt = evsel__find_syscall_arg_fmt_by_name(evsel, arg, &type);
if (fmt == NULL) {
pr_err("\"%s\" not found in \"%s\", can't set filter \"%s\"\n",
arg, evsel->name, evsel->filter);
@@ -3860,9 +3903,16 @@ static int trace__expand_filter(struct trace *trace __maybe_unused, struct evsel
if (fmt->strtoul) {
u64 val;
struct syscall_arg syscall_arg = {
- .parm = fmt->parm,
+ .trace = trace,
+ .fmt = fmt,
};

+ if (fmt->is_enum) {
+ syscall_arg.parm = type;
+ } else {
+ syscall_arg.parm = fmt->parm;
+ }
+
if (fmt->strtoul(right, right_size, &syscall_arg, &val)) {
char *n, expansion[19];
int expansion_lenght = scnprintf(expansion, sizeof(expansion), "%#" PRIx64, val);
--
2.45.2