2024-06-15 06:29:19

by Howard Chu

[permalink] [raw]
Subject: [PATCH v1] perf trace: Filter enum arguments with enum names

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,
};

Signed-off-by: Howard Chu <[email protected]>
Suggested-by: Arnaldo Carvalho de Melo <[email protected]>

---
tools/perf/builtin-trace.c | 89 ++++++++++++++++++++++++++++++++------
1 file changed, 76 insertions(+), 13 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index bd16679fb4c0..1148c3edee97 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -904,11 +904,36 @@ static size_t syscall_arg__scnprintf_getrandom_flags(char *bf, size_t size,
.strtoul = STUL_STRARRAY_FLAGS, \
.parm = &strarray__##array, }

-static int btf_enum_find_entry(struct btf *btf, char *type, struct syscall_arg_fmt *arg_fmt)
+#define SCA_GETRANDOM_FLAGS syscall_arg__scnprintf_getrandom_flags
+
+static const struct btf_type *btf_find_type(struct btf *btf, char *type)
{
const struct btf_type *bt;
+ int id = btf__find_by_name(btf, type);
+
+ if (id < 0)
+ return NULL;
+
+ bt = btf__type_by_id(btf, id);
+ if (bt == NULL)
+ return NULL;
+
+ return bt;
+}
+
+struct btf_parm {
+ struct btf *btf;
+ char *type;
+};
+
+static bool syscall_arg__strtoul_btf_enum(char *bf, size_t size, struct syscall_arg *arg, u64 *val)
+{
+ struct btf_parm *bparm = arg->parm;
+ struct btf *btf = bparm->btf;
+ char *type = bparm->type;
char enum_prefix[][16] = { "enum", "const enum" }, *ep;
- int id;
+ struct btf_enum *be;
+ const struct btf_type *bt;
size_t i;

for (i = 0; i < ARRAY_SIZE(enum_prefix); i++) {
@@ -917,11 +942,38 @@ static int btf_enum_find_entry(struct btf *btf, char *type, struct syscall_arg_f
type += strlen(ep) + 1;
}

- id = btf__find_by_name(btf, type);
- if (id < 0)
- return -1;
+ bt = btf_find_type(btf, type);
+ if (bt == NULL)
+ return false;

- bt = btf__type_by_id(btf, id);
+ for (be = btf_enum(bt), 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;
+}
+
+#define STUL_BTF_ENUM syscall_arg__strtoul_btf_enum
+
+static int btf_enum_find_entry(struct btf *btf, char *type, struct syscall_arg_fmt *arg_fmt)
+{
+ char enum_prefix[][16] = { "enum", "const enum" }, *ep;
+ const struct btf_type *bt;
+ size_t i;
+
+ for (i = 0; i < ARRAY_SIZE(enum_prefix); i++) {
+ ep = enum_prefix[i];
+ if (strlen(type) > strlen(ep) + 1 && strstarts(type, ep))
+ type += strlen(ep) + 1;
+ }
+
+ bt = btf_find_type(btf, type);
if (bt == NULL)
return -1;

@@ -1850,6 +1902,7 @@ 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);
@@ -3776,7 +3829,8 @@ 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);
@@ -3785,8 +3839,10 @@ 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;
}
@@ -3824,14 +3880,14 @@ 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);
@@ -3843,9 +3899,16 @@ 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,
- };
+ struct syscall_arg syscall_arg;
+ struct btf_parm bparm;
+
+ if (fmt->is_enum) {
+ bparm.btf = trace->btf;
+ bparm.type = type;
+ syscall_arg.parm = &bparm;
+ } else {
+ syscall_arg.parm = fmt->parm;
+ }

if (fmt->strtoul(right, right_size, &syscall_arg, &val)) {
char *n, expansion[19];
--
2.45.2