Message ID | 20230214050452.26390-2-namhyung@kernel.org (mailing list archive) |
---|---|
State | Not Applicable |
Delegated to: | BPF |
Headers | show |
Series | perf record: Implement BPF sample filter (v1) | expand |
On Mon, Feb 13, 2023 at 9:05 PM Namhyung Kim <namhyung@kernel.org> wrote: > > 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 <namhyung@kernel.org> > --- > tools/perf/util/Build | 16 +++++++++ > tools/perf/util/bpf-filter.c | 37 +++++++++++++++++++ > tools/perf/util/bpf-filter.h | 36 +++++++++++++++++++ > tools/perf/util/bpf-filter.l | 70 ++++++++++++++++++++++++++++++++++++ > tools/perf/util/bpf-filter.y | 52 +++++++++++++++++++++++++++ > 5 files changed, 211 insertions(+) > create mode 100644 tools/perf/util/bpf-filter.c > create mode 100644 tools/perf/util/bpf-filter.h > create mode 100644 tools/perf/util/bpf-filter.l > create mode 100644 tools/perf/util/bpf-filter.y > > diff --git a/tools/perf/util/Build b/tools/perf/util/Build > index 918b501f9bd8..6af73fb5c797 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 > @@ -266,6 +269,16 @@ $(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 > @@ -279,6 +292,7 @@ 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) > @@ -290,10 +304,12 @@ 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 000000000000..6b1148fcfb0e > --- /dev/null > +++ b/tools/perf/util/bpf-filter.c > @@ -0,0 +1,37 @@ > +// SPDX-License-Identifier: GPL-2.0 > +#include <stdlib.h> > + > +#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; > +} > \ No newline at end of file > diff --git a/tools/perf/util/bpf-filter.h b/tools/perf/util/bpf-filter.h > new file mode 100644 > index 000000000000..fd5b1164a322 > --- /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 <linux/list.h> > + > +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 */ > \ No newline at end of file > diff --git a/tools/perf/util/bpf-filter.l b/tools/perf/util/bpf-filter.l > new file mode 100644 > index 000000000000..34c6a9fd4fa4 > --- /dev/null > +++ b/tools/perf/util/bpf-filter.l > @@ -0,0 +1,70 @@ > +%option prefix="perf_bpf_filter_" > +%option noyywrap > + > +%{ > +#include <stdlib.h> > +#include <linux/perf_event.h> > + > +#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; > +} > + > +%} > + > +num_dec [0-9]+ > +num_hex 0[Xx][0-9a-fA-F]+ > + > +%% > + > +{num_dec} { return value(10); } > +{num_hex} { return value(16); } > + > +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 ','; } > +. { } > + > +%% > diff --git a/tools/perf/util/bpf-filter.y b/tools/perf/util/bpf-filter.y > new file mode 100644 > index 000000000000..0bf36ec30abf > --- /dev/null > +++ b/tools/perf/util/bpf-filter.y > @@ -0,0 +1,52 @@ > +%parse-param {struct list_head *expr_head} > + > +%{ > + > +#include <stdio.h> > +#include <string.h> > +#include <linux/compiler.h> > +#include <linux/list.h> > +#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 <expr> filter_term To avoid memory leaks for parse errors, I think you want here: %destructor { free($$); } <expr> Thanks, Ian > +%type <sample> BFT_SAMPLE > +%type <op> BFT_OP > +%type <num> BFT_NUM > + > +%% > + > +filter: > +filter ',' filter_term > +{ > + list_add(&$3->list, expr_head); > +} > +| > +filter_term > +{ > + list_add(&$1->list, expr_head); > +} > + > +filter_term: > +BFT_SAMPLE BFT_OP BFT_NUM > +{ > + $$ = perf_bpf_filter_expr__new($1, $2, $3); > +} > + > +%% > -- > 2.39.1.581.gbfd45094c4-goog >
On Tue, Feb 14, 2023 at 8:10 AM Ian Rogers <irogers@google.com> wrote: > > On Mon, Feb 13, 2023 at 9:05 PM Namhyung Kim <namhyung@kernel.org> wrote: [SNIP] > > diff --git a/tools/perf/util/bpf-filter.y b/tools/perf/util/bpf-filter.y > > new file mode 100644 > > index 000000000000..0bf36ec30abf > > --- /dev/null > > +++ b/tools/perf/util/bpf-filter.y > > @@ -0,0 +1,52 @@ > > +%parse-param {struct list_head *expr_head} > > + > > +%{ > > + > > +#include <stdio.h> > > +#include <string.h> > > +#include <linux/compiler.h> > > +#include <linux/list.h> > > +#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 <expr> filter_term > > To avoid memory leaks for parse errors, I think you want here: > %destructor { free($$); } <expr> Sure, thanks for the suggestion. Namhyung
diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 918b501f9bd8..6af73fb5c797 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 @@ -266,6 +269,16 @@ $(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 @@ -279,6 +292,7 @@ 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) @@ -290,10 +304,12 @@ 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 000000000000..6b1148fcfb0e --- /dev/null +++ b/tools/perf/util/bpf-filter.c @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdlib.h> + +#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; +} \ No newline at end of file diff --git a/tools/perf/util/bpf-filter.h b/tools/perf/util/bpf-filter.h new file mode 100644 index 000000000000..fd5b1164a322 --- /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 <linux/list.h> + +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 */ \ No newline at end of file diff --git a/tools/perf/util/bpf-filter.l b/tools/perf/util/bpf-filter.l new file mode 100644 index 000000000000..34c6a9fd4fa4 --- /dev/null +++ b/tools/perf/util/bpf-filter.l @@ -0,0 +1,70 @@ +%option prefix="perf_bpf_filter_" +%option noyywrap + +%{ +#include <stdlib.h> +#include <linux/perf_event.h> + +#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; +} + +%} + +num_dec [0-9]+ +num_hex 0[Xx][0-9a-fA-F]+ + +%% + +{num_dec} { return value(10); } +{num_hex} { return value(16); } + +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 ','; } +. { } + +%% diff --git a/tools/perf/util/bpf-filter.y b/tools/perf/util/bpf-filter.y new file mode 100644 index 000000000000..0bf36ec30abf --- /dev/null +++ b/tools/perf/util/bpf-filter.y @@ -0,0 +1,52 @@ +%parse-param {struct list_head *expr_head} + +%{ + +#include <stdio.h> +#include <string.h> +#include <linux/compiler.h> +#include <linux/list.h> +#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 <expr> filter_term +%type <sample> BFT_SAMPLE +%type <op> BFT_OP +%type <num> BFT_NUM + +%% + +filter: +filter ',' filter_term +{ + list_add(&$3->list, expr_head); +} +| +filter_term +{ + list_add(&$1->list, expr_head); +} + +filter_term: +BFT_SAMPLE BFT_OP BFT_NUM +{ + $$ = perf_bpf_filter_expr__new($1, $2, $3); +} + +%%
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 <namhyung@kernel.org> --- tools/perf/util/Build | 16 +++++++++ tools/perf/util/bpf-filter.c | 37 +++++++++++++++++++ tools/perf/util/bpf-filter.h | 36 +++++++++++++++++++ tools/perf/util/bpf-filter.l | 70 ++++++++++++++++++++++++++++++++++++ tools/perf/util/bpf-filter.y | 52 +++++++++++++++++++++++++++ 5 files changed, 211 insertions(+) create mode 100644 tools/perf/util/bpf-filter.c create mode 100644 tools/perf/util/bpf-filter.h create mode 100644 tools/perf/util/bpf-filter.l create mode 100644 tools/perf/util/bpf-filter.y