From: Namhyung Kim Date: Tue, 14 Mar 2023 23:42:28 +0000 (-0700) Subject: perf bpf filter: Introduce basic BPF filter expression X-Git-Tag: v6.6.7~2868^2~258 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=990a71e904f6ec2d7d84eecb37e5127b75721985;p=platform%2Fkernel%2Flinux-starfive.git perf bpf filter: Introduce basic BPF filter expression This implements a tiny parser for the filter expressions used for BPF. Each expression will be converted to struct perf_bpf_filter_expr and be passed to a BPF map. For now, I'd like to start with the very basic comparisons like EQ or GT. The LHS should be a term for sample data and the RHS is a number. The expressions are connected by a comma. For example, period > 10000 ip < 0x1000000000000, cpu == 3 Signed-off-by: Namhyung Kim Acked-by: Jiri Olsa Cc: Adrian Hunter Cc: Andi Kleen Cc: Hao Luo Cc: Ian Rogers Cc: Ingo Molnar Cc: James Clark Cc: Kan Liang Cc: Leo Yan Cc: Peter Zijlstra Cc: Ravi Bangoria Cc: Song Liu Cc: Stephane Eranian Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230314234237.3008956-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 0806bc03..bd18fe5 100644 --- a/tools/perf/util/Build +++ b/tools/perf/util/Build @@ -154,6 +154,9 @@ perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter.o perf-$(CONFIG_PERF_BPF_SKEL) += bpf_counter_cgroup.o perf-$(CONFIG_PERF_BPF_SKEL) += bpf_ftrace.o perf-$(CONFIG_PERF_BPF_SKEL) += bpf_off_cpu.o +perf-$(CONFIG_PERF_BPF_SKEL) += bpf-filter.o +perf-$(CONFIG_PERF_BPF_SKEL) += bpf-filter-flex.o +perf-$(CONFIG_PERF_BPF_SKEL) += bpf-filter-bison.o ifeq ($(CONFIG_LIBTRACEEVENT),y) perf-$(CONFIG_PERF_BPF_SKEL) += bpf_lock_contention.o @@ -267,6 +270,16 @@ $(OUTPUT)util/pmu-bison.c $(OUTPUT)util/pmu-bison.h: util/pmu.y $(Q)$(call echo-cmd,bison)$(BISON) -v $< -d $(PARSER_DEBUG_BISON) $(BISON_FILE_PREFIX_MAP) \ -o $(OUTPUT)util/pmu-bison.c -p perf_pmu_ +$(OUTPUT)util/bpf-filter-flex.c $(OUTPUT)util/bpf-filter-flex.h: util/bpf-filter.l $(OUTPUT)util/bpf-filter-bison.c + $(call rule_mkdir) + $(Q)$(call echo-cmd,flex)$(FLEX) -o $(OUTPUT)util/bpf-filter-flex.c \ + --header-file=$(OUTPUT)util/bpf-filter-flex.h $(PARSER_DEBUG_FLEX) $< + +$(OUTPUT)util/bpf-filter-bison.c $(OUTPUT)util/bpf-filter-bison.h: util/bpf-filter.y + $(call rule_mkdir) + $(Q)$(call echo-cmd,bison)$(BISON) -v $< -d $(PARSER_DEBUG_BISON) $(BISON_FILE_PREFIX_MAP) \ + -o $(OUTPUT)util/bpf-filter-bison.c -p perf_bpf_filter_ + FLEX_GE_26 := $(shell expr $(shell $(FLEX) --version | sed -e 's/flex \([0-9]\+\).\([0-9]\+\)/\1\2/g') \>\= 26) ifeq ($(FLEX_GE_26),1) flex_flags := -Wno-switch-enum -Wno-switch-default -Wno-unused-function -Wno-redundant-decls -Wno-sign-compare -Wno-unused-parameter -Wno-missing-prototypes -Wno-missing-declarations @@ -280,6 +293,7 @@ endif CFLAGS_parse-events-flex.o += $(flex_flags) CFLAGS_pmu-flex.o += $(flex_flags) CFLAGS_expr-flex.o += $(flex_flags) +CFLAGS_bpf-filter-flex.o += $(flex_flags) bison_flags := -DYYENABLE_NLS=0 BISON_GE_35 := $(shell expr $(shell $(BISON) --version | grep bison | sed -e 's/.\+ \([0-9]\+\).\([0-9]\+\)/\1\2/g') \>\= 35) @@ -291,10 +305,12 @@ endif CFLAGS_parse-events-bison.o += $(bison_flags) CFLAGS_pmu-bison.o += -DYYLTYPE_IS_TRIVIAL=0 $(bison_flags) CFLAGS_expr-bison.o += -DYYLTYPE_IS_TRIVIAL=0 $(bison_flags) +CFLAGS_bpf-filter-bison.o += -DYYLTYPE_IS_TRIVIAL=0 $(bison_flags) $(OUTPUT)util/parse-events.o: $(OUTPUT)util/parse-events-flex.c $(OUTPUT)util/parse-events-bison.c $(OUTPUT)util/pmu.o: $(OUTPUT)util/pmu-flex.c $(OUTPUT)util/pmu-bison.c $(OUTPUT)util/expr.o: $(OUTPUT)util/expr-flex.c $(OUTPUT)util/expr-bison.c +$(OUTPUT)util/bpf-filter.o: $(OUTPUT)util/bpf-filter-flex.c $(OUTPUT)util/bpf-filter-bison.c CFLAGS_bitmap.o += -Wno-unused-parameter -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))" CFLAGS_find_bit.o += -Wno-unused-parameter -DETC_PERFCONFIG="BUILD_STR($(ETC_PERFCONFIG_SQ))" diff --git a/tools/perf/util/bpf-filter.c b/tools/perf/util/bpf-filter.c new file mode 100644 index 0000000..c72e35d --- /dev/null +++ b/tools/perf/util/bpf-filter.c @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include + +#include "util/bpf-filter.h" +#include "util/bpf-filter-flex.h" +#include "util/bpf-filter-bison.h" + +struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, + enum perf_bpf_filter_op op, + unsigned long val) +{ + struct perf_bpf_filter_expr *expr; + + expr = malloc(sizeof(*expr)); + if (expr != NULL) { + expr->sample_flags = sample_flags; + expr->op = op; + expr->val = val; + } + return expr; +} + +int perf_bpf_filter__parse(struct list_head *expr_head, const char *str) +{ + YY_BUFFER_STATE buffer; + int ret; + + buffer = perf_bpf_filter__scan_string(str); + + ret = perf_bpf_filter_parse(expr_head); + + perf_bpf_filter__flush_buffer(buffer); + perf_bpf_filter__delete_buffer(buffer); + perf_bpf_filter_lex_destroy(); + + return ret; +} diff --git a/tools/perf/util/bpf-filter.h b/tools/perf/util/bpf-filter.h new file mode 100644 index 0000000..93a0d3d --- /dev/null +++ b/tools/perf/util/bpf-filter.h @@ -0,0 +1,36 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef PERF_UTIL_BPF_FILTER_H +#define PERF_UTIL_BPF_FILTER_H + +#include + +enum perf_bpf_filter_op { + PBF_OP_EQ, + PBF_OP_NEQ, + PBF_OP_GT, + PBF_OP_GE, + PBF_OP_LT, + PBF_OP_LE, + PBF_OP_AND, +}; + +struct perf_bpf_filter_expr { + struct list_head list; + enum perf_bpf_filter_op op; + unsigned long sample_flags; + unsigned long val; +}; + +#ifdef HAVE_BPF_SKEL +struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, + enum perf_bpf_filter_op op, + unsigned long val); +int perf_bpf_filter__parse(struct list_head *expr_head, const char *str); +#else /* !HAVE_BPF_SKEL */ +static inline int perf_bpf_filter__parse(struct list_head *expr_head __maybe_unused, + const char *str __maybe_unused) +{ + return -ENOSYS; +} +#endif /* HAVE_BPF_SKEL*/ +#endif /* PERF_UTIL_BPF_FILTER_H */ diff --git a/tools/perf/util/bpf-filter.l b/tools/perf/util/bpf-filter.l new file mode 100644 index 0000000..f6c0b74 --- /dev/null +++ b/tools/perf/util/bpf-filter.l @@ -0,0 +1,82 @@ +%option prefix="perf_bpf_filter_" +%option noyywrap + +%{ +#include +#include +#include + +#include "bpf-filter.h" +#include "bpf-filter-bison.h" + +static int sample(unsigned long sample_flag) +{ + perf_bpf_filter_lval.sample = sample_flag; + return BFT_SAMPLE; +} + +static int operator(enum perf_bpf_filter_op op) +{ + perf_bpf_filter_lval.op = op; + return BFT_OP; +} + +static int value(int base) +{ + long num; + + errno = 0; + num = strtoul(perf_bpf_filter_text, NULL, base); + if (errno) + return BFT_ERROR; + + perf_bpf_filter_lval.num = num; + return BFT_NUM; +} + +static int error(const char *str) +{ + printf("perf_bpf_filter: Unexpected filter %s: %s\n", str, perf_bpf_filter_text); + return BFT_ERROR; +} + +%} + +num_dec [0-9]+ +num_hex 0[Xx][0-9a-fA-F]+ +space [ \t]+ +ident [_a-zA-Z][_a-zA-Z0-9]+ + +%% + +{num_dec} { return value(10); } +{num_hex} { return value(16); } +{space} { } + +ip { return sample(PERF_SAMPLE_IP); } +id { return sample(PERF_SAMPLE_ID); } +tid { return sample(PERF_SAMPLE_TID); } +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); } +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); } + +"==" { return operator(PBF_OP_EQ); } +"!=" { return operator(PBF_OP_NEQ); } +">" { return operator(PBF_OP_GT); } +"<" { return operator(PBF_OP_LT); } +">=" { return operator(PBF_OP_GE); } +"<=" { return operator(PBF_OP_LE); } +"&" { return operator(PBF_OP_AND); } + +"," { return ','; } + +{ident} { return error("ident"); } +. { return error("input"); } + +%% diff --git a/tools/perf/util/bpf-filter.y b/tools/perf/util/bpf-filter.y new file mode 100644 index 0000000..13eca61 --- /dev/null +++ b/tools/perf/util/bpf-filter.y @@ -0,0 +1,54 @@ +%parse-param {struct list_head *expr_head} +%define parse.error verbose + +%{ + +#include +#include +#include +#include +#include "bpf-filter.h" + +static void perf_bpf_filter_error(struct list_head *expr __maybe_unused, + char const *msg) +{ + printf("perf_bpf_filter: %s\n", msg); +} + +%} + +%union +{ + unsigned long num; + unsigned long sample; + enum perf_bpf_filter_op op; + struct perf_bpf_filter_expr *expr; +} + +%token BFT_SAMPLE BFT_OP BFT_ERROR BFT_NUM +%type filter_term +%destructor { free ($$); } +%type BFT_SAMPLE +%type BFT_OP +%type BFT_NUM + +%% + +filter: +filter ',' filter_term +{ + list_add_tail(&$3->list, expr_head); +} +| +filter_term +{ + list_add_tail(&$1->list, expr_head); +} + +filter_term: +BFT_SAMPLE BFT_OP BFT_NUM +{ + $$ = perf_bpf_filter_expr__new($1, $2, $3); +} + +%%