* [PATCH v3 1/3] perf bpf filter: Give terms their own enum
2024-05-24 20:52 [PATCH v3 0/3] Use BPF filters for a "perf top -u" workaround Ian Rogers
@ 2024-05-24 20:52 ` Ian Rogers
2024-05-24 20:52 ` [PATCH v3 2/3] perf bpf filter: Add uid and gid terms Ian Rogers
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Ian Rogers @ 2024-05-24 20:52 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
Ian Rogers, Adrian Hunter, Kan Liang, Changbin Du, Yang Jihong,
Andrii Nakryiko, John Fastabend, linux-perf-users, linux-kernel,
bpf
Give the term types their own enum so that additional terms can be
added that don't correspond to a PERF_SAMPLE_xx flag. The term values
are numerically ascending rather than bit field positions, this means
they need translating to a PERF_SAMPLE_xx bit field in certain places
using a shift.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/bpf-filter.c | 28 ++++----
tools/perf/util/bpf-filter.h | 5 +-
tools/perf/util/bpf-filter.l | 64 +++++++++---------
tools/perf/util/bpf-filter.y | 7 +-
tools/perf/util/bpf_skel/sample-filter.h | 37 ++++++++++-
tools/perf/util/bpf_skel/sample_filter.bpf.c | 69 +++++++++++++++-----
6 files changed, 141 insertions(+), 69 deletions(-)
diff --git a/tools/perf/util/bpf-filter.c b/tools/perf/util/bpf-filter.c
index b51544996046..f10148623a8e 100644
--- a/tools/perf/util/bpf-filter.c
+++ b/tools/perf/util/bpf-filter.c
@@ -17,11 +17,11 @@
#define FD(e, x, y) (*(int *)xyarray__entry(e->core.fd, x, y))
-#define __PERF_SAMPLE_TYPE(st, opt) { st, #st, opt }
-#define PERF_SAMPLE_TYPE(_st, opt) __PERF_SAMPLE_TYPE(PERF_SAMPLE_##_st, opt)
+#define __PERF_SAMPLE_TYPE(tt, st, opt) { tt, #st, opt }
+#define PERF_SAMPLE_TYPE(_st, opt) __PERF_SAMPLE_TYPE(PBF_TERM_##_st, PERF_SAMPLE_##_st, opt)
static const struct perf_sample_info {
- u64 type;
+ enum perf_bpf_filter_term type;
const char *name;
const char *option;
} sample_table[] = {
@@ -44,12 +44,12 @@ static const struct perf_sample_info {
PERF_SAMPLE_TYPE(DATA_PAGE_SIZE, "--data-page-size"),
};
-static const struct perf_sample_info *get_sample_info(u64 flags)
+static const struct perf_sample_info *get_sample_info(enum perf_bpf_filter_term type)
{
size_t i;
for (i = 0; i < ARRAY_SIZE(sample_table); i++) {
- if (sample_table[i].type == flags)
+ if (sample_table[i].type == type)
return &sample_table[i];
}
return NULL;
@@ -59,7 +59,8 @@ static int check_sample_flags(struct evsel *evsel, struct perf_bpf_filter_expr *
{
const struct perf_sample_info *info;
- if (evsel->core.attr.sample_type & expr->sample_flags)
+ if (expr->term >= PBF_TERM_SAMPLE_START && expr->term <= PBF_TERM_SAMPLE_END &&
+ (evsel->core.attr.sample_type & (1 << (expr->term - PBF_TERM_SAMPLE_START))))
return 0;
if (expr->op == PBF_OP_GROUP_BEGIN) {
@@ -72,10 +73,10 @@ static int check_sample_flags(struct evsel *evsel, struct perf_bpf_filter_expr *
return 0;
}
- info = get_sample_info(expr->sample_flags);
+ info = get_sample_info(expr->term);
if (info == NULL) {
- pr_err("Error: %s event does not have sample flags %lx\n",
- evsel__name(evsel), expr->sample_flags);
+ pr_err("Error: %s event does not have sample flags %d\n",
+ evsel__name(evsel), expr->term);
return -1;
}
@@ -105,7 +106,7 @@ int perf_bpf_filter__prepare(struct evsel *evsel)
struct perf_bpf_filter_entry entry = {
.op = expr->op,
.part = expr->part,
- .flags = expr->sample_flags,
+ .term = expr->term,
.value = expr->val,
};
@@ -122,7 +123,7 @@ int perf_bpf_filter__prepare(struct evsel *evsel)
struct perf_bpf_filter_entry group_entry = {
.op = group->op,
.part = group->part,
- .flags = group->sample_flags,
+ .term = group->term,
.value = group->val,
};
bpf_map_update_elem(fd, &i, &group_entry, BPF_ANY);
@@ -173,7 +174,8 @@ u64 perf_bpf_filter__lost_count(struct evsel *evsel)
return skel ? skel->bss->dropped : 0;
}
-struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, int part,
+struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(enum perf_bpf_filter_term term,
+ int part,
enum perf_bpf_filter_op op,
unsigned long val)
{
@@ -181,7 +183,7 @@ struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flag
expr = malloc(sizeof(*expr));
if (expr != NULL) {
- expr->sample_flags = sample_flags;
+ expr->term = term;
expr->part = part;
expr->op = op;
expr->val = val;
diff --git a/tools/perf/util/bpf-filter.h b/tools/perf/util/bpf-filter.h
index 7afd159411b8..cd6764442c16 100644
--- a/tools/perf/util/bpf-filter.h
+++ b/tools/perf/util/bpf-filter.h
@@ -11,14 +11,15 @@ struct perf_bpf_filter_expr {
struct list_head groups;
enum perf_bpf_filter_op op;
int part;
- unsigned long sample_flags;
+ enum perf_bpf_filter_term term;
unsigned long val;
};
struct evsel;
#ifdef HAVE_BPF_SKEL
-struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, int part,
+struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(enum perf_bpf_filter_term term,
+ int part,
enum perf_bpf_filter_op op,
unsigned long val);
int perf_bpf_filter__parse(struct list_head *expr_head, const char *str);
diff --git a/tools/perf/util/bpf-filter.l b/tools/perf/util/bpf-filter.l
index d4ff0f1345cd..62c959813466 100644
--- a/tools/perf/util/bpf-filter.l
+++ b/tools/perf/util/bpf-filter.l
@@ -9,16 +9,16 @@
#include "bpf-filter.h"
#include "bpf-filter-bison.h"
-static int sample(unsigned long sample_flag)
+static int sample(enum perf_bpf_filter_term term)
{
- perf_bpf_filter_lval.sample.type = sample_flag;
+ perf_bpf_filter_lval.sample.term = term;
perf_bpf_filter_lval.sample.part = 0;
return BFT_SAMPLE;
}
-static int sample_part(unsigned long sample_flag, int part)
+static int sample_part(enum perf_bpf_filter_term term, int part)
{
- perf_bpf_filter_lval.sample.type = sample_flag;
+ perf_bpf_filter_lval.sample.term = term;
perf_bpf_filter_lval.sample.part = part;
return BFT_SAMPLE;
}
@@ -67,34 +67,34 @@ ident [_a-zA-Z][_a-zA-Z0-9]+
{num_hex} { return value(16); }
{space} { }
-ip { return sample(PERF_SAMPLE_IP); }
-id { return sample(PERF_SAMPLE_ID); }
-tid { return sample(PERF_SAMPLE_TID); }
-pid { return sample_part(PERF_SAMPLE_TID, 1); }
-cpu { return sample(PERF_SAMPLE_CPU); }
-time { return sample(PERF_SAMPLE_TIME); }
-addr { return sample(PERF_SAMPLE_ADDR); }
-period { return sample(PERF_SAMPLE_PERIOD); }
-txn { return sample(PERF_SAMPLE_TRANSACTION); }
-weight { return sample(PERF_SAMPLE_WEIGHT); }
-weight1 { return sample_part(PERF_SAMPLE_WEIGHT_STRUCT, 1); }
-weight2 { return sample_part(PERF_SAMPLE_WEIGHT_STRUCT, 2); }
-weight3 { return sample_part(PERF_SAMPLE_WEIGHT_STRUCT, 3); }
-ins_lat { return sample_part(PERF_SAMPLE_WEIGHT_STRUCT, 2); } /* alias for weight2 */
-p_stage_cyc { return sample_part(PERF_SAMPLE_WEIGHT_STRUCT, 3); } /* alias for weight3 */
-retire_lat { return sample_part(PERF_SAMPLE_WEIGHT_STRUCT, 3); } /* alias for weight3 */
-phys_addr { return sample(PERF_SAMPLE_PHYS_ADDR); }
-code_pgsz { return sample(PERF_SAMPLE_CODE_PAGE_SIZE); }
-data_pgsz { return sample(PERF_SAMPLE_DATA_PAGE_SIZE); }
-mem_op { return sample_part(PERF_SAMPLE_DATA_SRC, 1); }
-mem_lvlnum { return sample_part(PERF_SAMPLE_DATA_SRC, 2); }
-mem_lvl { return sample_part(PERF_SAMPLE_DATA_SRC, 2); } /* alias for mem_lvlnum */
-mem_snoop { return sample_part(PERF_SAMPLE_DATA_SRC, 3); } /* include snoopx */
-mem_remote { return sample_part(PERF_SAMPLE_DATA_SRC, 4); }
-mem_lock { return sample_part(PERF_SAMPLE_DATA_SRC, 5); }
-mem_dtlb { return sample_part(PERF_SAMPLE_DATA_SRC, 6); }
-mem_blk { return sample_part(PERF_SAMPLE_DATA_SRC, 7); }
-mem_hops { return sample_part(PERF_SAMPLE_DATA_SRC, 8); }
+ip { return sample(PBF_TERM_IP); }
+id { return sample(PBF_TERM_ID); }
+tid { return sample(PBF_TERM_TID); }
+pid { return sample_part(PBF_TERM_TID, 1); }
+cpu { return sample(PBF_TERM_CPU); }
+time { return sample(PBF_TERM_TIME); }
+addr { return sample(PBF_TERM_ADDR); }
+period { return sample(PBF_TERM_PERIOD); }
+txn { return sample(PBF_TERM_TRANSACTION); }
+weight { return sample(PBF_TERM_WEIGHT); }
+weight1 { return sample_part(PBF_TERM_WEIGHT_STRUCT, 1); }
+weight2 { return sample_part(PBF_TERM_WEIGHT_STRUCT, 2); }
+weight3 { return sample_part(PBF_TERM_WEIGHT_STRUCT, 3); }
+ins_lat { return sample_part(PBF_TERM_WEIGHT_STRUCT, 2); } /* alias for weight2 */
+p_stage_cyc { return sample_part(PBF_TERM_WEIGHT_STRUCT, 3); } /* alias for weight3 */
+retire_lat { return sample_part(PBF_TERM_WEIGHT_STRUCT, 3); } /* alias for weight3 */
+phys_addr { return sample(PBF_TERM_PHYS_ADDR); }
+code_pgsz { return sample(PBF_TERM_CODE_PAGE_SIZE); }
+data_pgsz { return sample(PBF_TERM_DATA_PAGE_SIZE); }
+mem_op { return sample_part(PBF_TERM_DATA_SRC, 1); }
+mem_lvlnum { return sample_part(PBF_TERM_DATA_SRC, 2); }
+mem_lvl { return sample_part(PBF_TERM_DATA_SRC, 2); } /* alias for mem_lvlnum */
+mem_snoop { return sample_part(PBF_TERM_DATA_SRC, 3); } /* include snoopx */
+mem_remote { return sample_part(PBF_TERM_DATA_SRC, 4); }
+mem_lock { return sample_part(PBF_TERM_DATA_SRC, 5); }
+mem_dtlb { return sample_part(PBF_TERM_DATA_SRC, 6); }
+mem_blk { return sample_part(PBF_TERM_DATA_SRC, 7); }
+mem_hops { return sample_part(PBF_TERM_DATA_SRC, 8); }
"==" { return operator(PBF_OP_EQ); }
"!=" { return operator(PBF_OP_NEQ); }
diff --git a/tools/perf/util/bpf-filter.y b/tools/perf/util/bpf-filter.y
index 0e4d6de3c2ad..0c56fccb8874 100644
--- a/tools/perf/util/bpf-filter.y
+++ b/tools/perf/util/bpf-filter.y
@@ -27,7 +27,7 @@ static void perf_bpf_filter_error(struct list_head *expr __maybe_unused,
{
unsigned long num;
struct {
- unsigned long type;
+ enum perf_bpf_filter_term term;
int part;
} sample;
enum perf_bpf_filter_op op;
@@ -62,7 +62,8 @@ filter_term BFT_LOGICAL_OR filter_expr
if ($1->op == PBF_OP_GROUP_BEGIN) {
expr = $1;
} else {
- expr = perf_bpf_filter_expr__new(0, 0, PBF_OP_GROUP_BEGIN, 1);
+ expr = perf_bpf_filter_expr__new(PBF_TERM_NONE, /*part=*/0,
+ PBF_OP_GROUP_BEGIN, /*val=*/1);
list_add_tail(&$1->list, &expr->groups);
}
expr->val++;
@@ -78,7 +79,7 @@ filter_expr
filter_expr:
BFT_SAMPLE BFT_OP BFT_NUM
{
- $$ = perf_bpf_filter_expr__new($1.type, $1.part, $2, $3);
+ $$ = perf_bpf_filter_expr__new($1.term, $1.part, $2, $3);
}
%%
diff --git a/tools/perf/util/bpf_skel/sample-filter.h b/tools/perf/util/bpf_skel/sample-filter.h
index 2e96e1ab084a..25f780022951 100644
--- a/tools/perf/util/bpf_skel/sample-filter.h
+++ b/tools/perf/util/bpf_skel/sample-filter.h
@@ -16,12 +16,45 @@ enum perf_bpf_filter_op {
PBF_OP_GROUP_END,
};
+enum perf_bpf_filter_term {
+ /* No term is in use. */
+ PBF_TERM_NONE = 0,
+ /* Terms that correspond to PERF_SAMPLE_xx values. */
+ PBF_TERM_SAMPLE_START = PBF_TERM_NONE + 1,
+ PBF_TERM_IP = PBF_TERM_SAMPLE_START + 0, /* SAMPLE_IP = 1U << 0 */
+ PBF_TERM_TID = PBF_TERM_SAMPLE_START + 1, /* SAMPLE_TID = 1U << 1 */
+ PBF_TERM_TIME = PBF_TERM_SAMPLE_START + 2, /* SAMPLE_TIME = 1U << 2 */
+ PBF_TERM_ADDR = PBF_TERM_SAMPLE_START + 3, /* SAMPLE_ADDR = 1U << 3 */
+ __PBF_UNUSED_TERM4 = PBF_TERM_SAMPLE_START + 4, /* SAMPLE_READ = 1U << 4 */
+ __PBF_UNUSED_TERM5 = PBF_TERM_SAMPLE_START + 5, /* SAMPLE_CALLCHAIN = 1U << 5 */
+ PBF_TERM_ID = PBF_TERM_SAMPLE_START + 6, /* SAMPLE_ID = 1U << 6 */
+ PBF_TERM_CPU = PBF_TERM_SAMPLE_START + 7, /* SAMPLE_CPU = 1U << 7 */
+ PBF_TERM_PERIOD = PBF_TERM_SAMPLE_START + 8, /* SAMPLE_PERIOD = 1U << 8 */
+ __PBF_UNUSED_TERM9 = PBF_TERM_SAMPLE_START + 9, /* SAMPLE_STREAM_ID = 1U << 9 */
+ __PBF_UNUSED_TERM10 = PBF_TERM_SAMPLE_START + 10, /* SAMPLE_RAW = 1U << 10 */
+ __PBF_UNUSED_TERM11 = PBF_TERM_SAMPLE_START + 11, /* SAMPLE_BRANCH_STACK = 1U << 11 */
+ __PBF_UNUSED_TERM12 = PBF_TERM_SAMPLE_START + 12, /* SAMPLE_REGS_USER = 1U << 12 */
+ __PBF_UNUSED_TERM13 = PBF_TERM_SAMPLE_START + 13, /* SAMPLE_STACK_USER = 1U << 13 */
+ PBF_TERM_WEIGHT = PBF_TERM_SAMPLE_START + 14, /* SAMPLE_WEIGHT = 1U << 14 */
+ PBF_TERM_DATA_SRC = PBF_TERM_SAMPLE_START + 15, /* SAMPLE_DATA_SRC = 1U << 15 */
+ __PBF_UNUSED_TERM16 = PBF_TERM_SAMPLE_START + 16, /* SAMPLE_IDENTIFIER = 1U << 16 */
+ PBF_TERM_TRANSACTION = PBF_TERM_SAMPLE_START + 17, /* SAMPLE_TRANSACTION = 1U << 17 */
+ __PBF_UNUSED_TERM18 = PBF_TERM_SAMPLE_START + 18, /* SAMPLE_REGS_INTR = 1U << 18 */
+ PBF_TERM_PHYS_ADDR = PBF_TERM_SAMPLE_START + 19, /* SAMPLE_PHYS_ADDR = 1U << 19 */
+ __PBF_UNUSED_TERM20 = PBF_TERM_SAMPLE_START + 20, /* SAMPLE_AUX = 1U << 20 */
+ __PBF_UNUSED_TERM21 = PBF_TERM_SAMPLE_START + 21, /* SAMPLE_CGROUP = 1U << 21 */
+ PBF_TERM_DATA_PAGE_SIZE = PBF_TERM_SAMPLE_START + 22, /* SAMPLE_DATA_PAGE_SIZE = 1U << 22 */
+ PBF_TERM_CODE_PAGE_SIZE = PBF_TERM_SAMPLE_START + 23, /* SAMPLE_CODE_PAGE_SIZE = 1U << 23 */
+ PBF_TERM_WEIGHT_STRUCT = PBF_TERM_SAMPLE_START + 24, /* SAMPLE_WEIGHT_STRUCT = 1U << 24 */
+ PBF_TERM_SAMPLE_END = PBF_TERM_WEIGHT_STRUCT,
+};
+
/* BPF map entry for filtering */
struct perf_bpf_filter_entry {
enum perf_bpf_filter_op op;
__u32 part; /* sub-sample type info when it has multiple values */
- __u64 flags; /* perf sample type flags */
+ enum perf_bpf_filter_term term;
__u64 value;
};
-#endif /* PERF_UTIL_BPF_SKEL_SAMPLE_FILTER_H */
\ No newline at end of file
+#endif /* PERF_UTIL_BPF_SKEL_SAMPLE_FILTER_H */
diff --git a/tools/perf/util/bpf_skel/sample_filter.bpf.c b/tools/perf/util/bpf_skel/sample_filter.bpf.c
index fb94f5280626..5ac1778ff66e 100644
--- a/tools/perf/util/bpf_skel/sample_filter.bpf.c
+++ b/tools/perf/util/bpf_skel/sample_filter.bpf.c
@@ -48,31 +48,54 @@ static inline __u64 perf_get_sample(struct bpf_perf_event_data_kern *kctx,
{
struct perf_sample_data___new *data = (void *)kctx->data;
- if (!bpf_core_field_exists(data->sample_flags) ||
- (data->sample_flags & entry->flags) == 0)
+ if (!bpf_core_field_exists(data->sample_flags))
return 0;
- switch (entry->flags) {
- case PERF_SAMPLE_IP:
+#define BUILD_CHECK_SAMPLE(x) \
+ _Static_assert((1 << (PBF_TERM_##x - PBF_TERM_SAMPLE_START)) == PERF_SAMPLE_##x, \
+ "Mismatched PBF term to sample bit " #x)
+ BUILD_CHECK_SAMPLE(IP);
+ BUILD_CHECK_SAMPLE(TID);
+ BUILD_CHECK_SAMPLE(TIME);
+ BUILD_CHECK_SAMPLE(ADDR);
+ BUILD_CHECK_SAMPLE(ID);
+ BUILD_CHECK_SAMPLE(CPU);
+ BUILD_CHECK_SAMPLE(PERIOD);
+ BUILD_CHECK_SAMPLE(WEIGHT);
+ BUILD_CHECK_SAMPLE(DATA_SRC);
+ BUILD_CHECK_SAMPLE(TRANSACTION);
+ BUILD_CHECK_SAMPLE(PHYS_ADDR);
+ BUILD_CHECK_SAMPLE(DATA_PAGE_SIZE);
+ BUILD_CHECK_SAMPLE(CODE_PAGE_SIZE);
+ BUILD_CHECK_SAMPLE(WEIGHT_STRUCT);
+#undef BUILD_CHECK_SAMPLE
+
+ /* For sample terms check the sample bit is set. */
+ if (entry->term >= PBF_TERM_SAMPLE_START && entry->term <= PBF_TERM_SAMPLE_END &&
+ (data->sample_flags & (1 << (entry->term - PBF_TERM_SAMPLE_START))) == 0)
+ return 0;
+
+ switch (entry->term) {
+ case PBF_TERM_IP:
return kctx->data->ip;
- case PERF_SAMPLE_ID:
+ case PBF_TERM_ID:
return kctx->data->id;
- case PERF_SAMPLE_TID:
+ case PBF_TERM_TID:
if (entry->part)
return kctx->data->tid_entry.pid;
else
return kctx->data->tid_entry.tid;
- case PERF_SAMPLE_CPU:
+ case PBF_TERM_CPU:
return kctx->data->cpu_entry.cpu;
- case PERF_SAMPLE_TIME:
+ case PBF_TERM_TIME:
return kctx->data->time;
- case PERF_SAMPLE_ADDR:
+ case PBF_TERM_ADDR:
return kctx->data->addr;
- case PERF_SAMPLE_PERIOD:
+ case PBF_TERM_PERIOD:
return kctx->data->period;
- case PERF_SAMPLE_TRANSACTION:
+ case PBF_TERM_TRANSACTION:
return kctx->data->txn;
- case PERF_SAMPLE_WEIGHT_STRUCT:
+ case PBF_TERM_WEIGHT_STRUCT:
if (entry->part == 1)
return kctx->data->weight.var1_dw;
if (entry->part == 2)
@@ -80,15 +103,15 @@ static inline __u64 perf_get_sample(struct bpf_perf_event_data_kern *kctx,
if (entry->part == 3)
return kctx->data->weight.var3_w;
/* fall through */
- case PERF_SAMPLE_WEIGHT:
+ case PBF_TERM_WEIGHT:
return kctx->data->weight.full;
- case PERF_SAMPLE_PHYS_ADDR:
+ case PBF_TERM_PHYS_ADDR:
return kctx->data->phys_addr;
- case PERF_SAMPLE_CODE_PAGE_SIZE:
+ case PBF_TERM_CODE_PAGE_SIZE:
return kctx->data->code_page_size;
- case PERF_SAMPLE_DATA_PAGE_SIZE:
+ case PBF_TERM_DATA_PAGE_SIZE:
return kctx->data->data_page_size;
- case PERF_SAMPLE_DATA_SRC:
+ case PBF_TERM_DATA_SRC:
if (entry->part == 1)
return kctx->data->data_src.mem_op;
if (entry->part == 2)
@@ -117,6 +140,18 @@ static inline __u64 perf_get_sample(struct bpf_perf_event_data_kern *kctx,
}
/* return the whole word */
return kctx->data->data_src.val;
+ case PBF_TERM_NONE:
+ case __PBF_UNUSED_TERM4:
+ case __PBF_UNUSED_TERM5:
+ case __PBF_UNUSED_TERM9:
+ case __PBF_UNUSED_TERM10:
+ case __PBF_UNUSED_TERM11:
+ case __PBF_UNUSED_TERM12:
+ case __PBF_UNUSED_TERM13:
+ case __PBF_UNUSED_TERM16:
+ case __PBF_UNUSED_TERM18:
+ case __PBF_UNUSED_TERM20:
+ case __PBF_UNUSED_TERM21:
default:
break;
}
--
2.45.1.288.g0e0cd299f1-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 2/3] perf bpf filter: Add uid and gid terms
2024-05-24 20:52 [PATCH v3 0/3] Use BPF filters for a "perf top -u" workaround Ian Rogers
2024-05-24 20:52 ` [PATCH v3 1/3] perf bpf filter: Give terms their own enum Ian Rogers
@ 2024-05-24 20:52 ` Ian Rogers
2024-05-24 20:52 ` [PATCH v3 3/3] perf top: Allow filters on events Ian Rogers
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Ian Rogers @ 2024-05-24 20:52 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
Ian Rogers, Adrian Hunter, Kan Liang, Changbin Du, Yang Jihong,
Andrii Nakryiko, John Fastabend, linux-perf-users, linux-kernel,
bpf
Allow the BPF filter to use the uid and gid terms determined by the
bpf_get_current_uid_gid BPF helper. For example, the following will
record the cpu-clock event system wide discarding samples that don't
belong to the current user.
$ perf record -e cpu-clock --filter "uid == $(id -u)" -a sleep 0.1
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/Documentation/perf-record.txt | 2 +-
tools/perf/util/bpf-filter.c | 5 +++++
tools/perf/util/bpf-filter.l | 2 ++
tools/perf/util/bpf_skel/sample-filter.h | 3 +++
tools/perf/util/bpf_skel/sample_filter.bpf.c | 4 ++++
5 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 6015fdd08fb6..059bc40c5ee1 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -200,7 +200,7 @@ OPTIONS
ip, id, tid, pid, cpu, time, addr, period, txn, weight, phys_addr,
code_pgsz, data_pgsz, weight1, weight2, weight3, ins_lat, retire_lat,
p_stage_cyc, mem_op, mem_lvl, mem_snoop, mem_remote, mem_lock,
- mem_dtlb, mem_blk, mem_hops
+ mem_dtlb, mem_blk, mem_hops, uid, gid
The <operator> can be one of:
==, !=, >, >=, <, <=, &
diff --git a/tools/perf/util/bpf-filter.c b/tools/perf/util/bpf-filter.c
index f10148623a8e..04f98b6bb291 100644
--- a/tools/perf/util/bpf-filter.c
+++ b/tools/perf/util/bpf-filter.c
@@ -63,6 +63,11 @@ static int check_sample_flags(struct evsel *evsel, struct perf_bpf_filter_expr *
(evsel->core.attr.sample_type & (1 << (expr->term - PBF_TERM_SAMPLE_START))))
return 0;
+ if (expr->term == PBF_TERM_UID || expr->term == PBF_TERM_GID) {
+ /* Not dependent on the sample_type as computed from a BPF helper. */
+ return 0;
+ }
+
if (expr->op == PBF_OP_GROUP_BEGIN) {
struct perf_bpf_filter_expr *group;
diff --git a/tools/perf/util/bpf-filter.l b/tools/perf/util/bpf-filter.l
index 62c959813466..2a7c839f3fae 100644
--- a/tools/perf/util/bpf-filter.l
+++ b/tools/perf/util/bpf-filter.l
@@ -95,6 +95,8 @@ mem_lock { return sample_part(PBF_TERM_DATA_SRC, 5); }
mem_dtlb { return sample_part(PBF_TERM_DATA_SRC, 6); }
mem_blk { return sample_part(PBF_TERM_DATA_SRC, 7); }
mem_hops { return sample_part(PBF_TERM_DATA_SRC, 8); }
+uid { return sample(PBF_TERM_UID); }
+gid { return sample(PBF_TERM_GID); }
"==" { return operator(PBF_OP_EQ); }
"!=" { return operator(PBF_OP_NEQ); }
diff --git a/tools/perf/util/bpf_skel/sample-filter.h b/tools/perf/util/bpf_skel/sample-filter.h
index 25f780022951..350efa121026 100644
--- a/tools/perf/util/bpf_skel/sample-filter.h
+++ b/tools/perf/util/bpf_skel/sample-filter.h
@@ -47,6 +47,9 @@ enum perf_bpf_filter_term {
PBF_TERM_CODE_PAGE_SIZE = PBF_TERM_SAMPLE_START + 23, /* SAMPLE_CODE_PAGE_SIZE = 1U << 23 */
PBF_TERM_WEIGHT_STRUCT = PBF_TERM_SAMPLE_START + 24, /* SAMPLE_WEIGHT_STRUCT = 1U << 24 */
PBF_TERM_SAMPLE_END = PBF_TERM_WEIGHT_STRUCT,
+ /* Terms computed from BPF helpers. */
+ PBF_TERM_UID,
+ PBF_TERM_GID,
};
/* BPF map entry for filtering */
diff --git a/tools/perf/util/bpf_skel/sample_filter.bpf.c b/tools/perf/util/bpf_skel/sample_filter.bpf.c
index 5ac1778ff66e..f59985101973 100644
--- a/tools/perf/util/bpf_skel/sample_filter.bpf.c
+++ b/tools/perf/util/bpf_skel/sample_filter.bpf.c
@@ -140,6 +140,10 @@ static inline __u64 perf_get_sample(struct bpf_perf_event_data_kern *kctx,
}
/* return the whole word */
return kctx->data->data_src.val;
+ case PBF_TERM_UID:
+ return bpf_get_current_uid_gid() & 0xFFFFFFFF;
+ case PBF_TERM_GID:
+ return bpf_get_current_uid_gid() >> 32;
case PBF_TERM_NONE:
case __PBF_UNUSED_TERM4:
case __PBF_UNUSED_TERM5:
--
2.45.1.288.g0e0cd299f1-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH v3 3/3] perf top: Allow filters on events
2024-05-24 20:52 [PATCH v3 0/3] Use BPF filters for a "perf top -u" workaround Ian Rogers
2024-05-24 20:52 ` [PATCH v3 1/3] perf bpf filter: Give terms their own enum Ian Rogers
2024-05-24 20:52 ` [PATCH v3 2/3] perf bpf filter: Add uid and gid terms Ian Rogers
@ 2024-05-24 20:52 ` Ian Rogers
2024-05-30 6:03 ` [PATCH v3 0/3] Use BPF filters for a "perf top -u" workaround Namhyung Kim
2024-05-31 21:14 ` Namhyung Kim
4 siblings, 0 replies; 6+ messages in thread
From: Ian Rogers @ 2024-05-24 20:52 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Mark Rutland, Alexander Shishkin, Jiri Olsa,
Ian Rogers, Adrian Hunter, Kan Liang, Changbin Du, Yang Jihong,
Andrii Nakryiko, John Fastabend, linux-perf-users, linux-kernel,
bpf
Allow filters to be added to perf top events. One use is to workaround
issues with:
```
$ perf top --uid="$(id -u)"
```
which tries to scan /proc find processes belonging to the uid and can
fail in such a pid terminates between the scan and the
perf_event_open reporting:
```
Error:
The sys_perf_event_open() syscall returned with 3 (No such process) for event (cycles:P).
/bin/dmesg | grep -i perf may provide additional information.
```
A similar filter:
```
$ perf top -e cycles:P --filter "uid == $(id -u)"
```
doesn't fail this way.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/Documentation/perf-top.txt | 4 ++++
tools/perf/builtin-top.c | 9 +++++++++
2 files changed, 13 insertions(+)
diff --git a/tools/perf/Documentation/perf-top.txt b/tools/perf/Documentation/perf-top.txt
index a754875fa5bb..667e5102075e 100644
--- a/tools/perf/Documentation/perf-top.txt
+++ b/tools/perf/Documentation/perf-top.txt
@@ -43,6 +43,10 @@ Default is to monitor all CPUS.
encoding with the layout of the event control registers as described
by entries in /sys/bus/event_source/devices/cpu/format/*.
+--filter=<filter>::
+ Event filter. This option should follow an event selector (-e). For
+ syntax see linkperf:perf-record[1].
+
-E <entries>::
--entries=<entries>::
Display this many functions.
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 1d6aef51c122..e8cbbf10d361 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1055,6 +1055,13 @@ static int perf_top__start_counters(struct perf_top *top)
}
}
+ if (evlist__apply_filters(evlist, &counter)) {
+ pr_err("failed to set filter \"%s\" on event %s with %d (%s)\n",
+ counter->filter ?: "BPF", evsel__name(counter), errno,
+ str_error_r(errno, msg, sizeof(msg)));
+ goto out_err;
+ }
+
if (evlist__mmap(evlist, opts->mmap_pages) < 0) {
ui__error("Failed to mmap with %d (%s)\n",
errno, str_error_r(errno, msg, sizeof(msg)));
@@ -1462,6 +1469,8 @@ int cmd_top(int argc, const char **argv)
OPT_CALLBACK('e', "event", &parse_events_option_args, "event",
"event selector. use 'perf list' to list available events",
parse_events_option),
+ OPT_CALLBACK(0, "filter", &top.evlist, "filter",
+ "event filter", parse_filter),
OPT_U64('c', "count", &opts->user_interval, "event period to sample"),
OPT_STRING('p', "pid", &target->pid, "pid",
"profile events on existing process id"),
--
2.45.1.288.g0e0cd299f1-goog
^ permalink raw reply related [flat|nested] 6+ messages in thread