Commit f412eed9 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Daniel Borkmann
Browse files

tools: bpftool: add simple perf event output reader 



Users of BPF sooner or later discover perf_event_output() helpers
and BPF_MAP_TYPE_PERF_EVENT_ARRAY.  Dumping this array type is
not possible, however, we can add simple reading of perf events.
Create a new event_pipe subcommand for maps, this sub command
will only work with BPF_MAP_TYPE_PERF_EVENT_ARRAY maps.

Parts of the code from samples/bpf/trace_output_user.c.

Signed-off-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: default avatarQuentin Monnet <quentin.monnet@netronome.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent e64d5256

tools/bpf/bpftool/Documentation/bpftool-map.rst

+23 −6
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ MAP COMMANDS 
|	**bpftool** **map getnext**    *MAP* [**key** *DATA*]

|	**bpftool** **map delete**     *MAP*  **key** *DATA*

|	**bpftool** **map pin**        *MAP*  *FILE*

|	**bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*]

|	**bpftool** **map help**

|

|	*MAP* := { **id** *MAP_ID* | **pinned** *FILE* }
@@ -76,6 +77,22 @@ DESCRIPTION 


		  Note: *FILE* must be located in *bpffs* mount.



	**bpftool** **map event_pipe** *MAP* [**cpu** *N* **index** *M*]

		  Read events from a BPF_MAP_TYPE_PERF_EVENT_ARRAY map.



		  Install perf rings into a perf event array map and dump

		  output of any bpf_perf_event_output() call in the kernel.

		  By default read the number of CPUs on the system and

		  install perf ring for each CPU in the corresponding index

		  in the array.



		  If **cpu** and **index** are specified, install perf ring

		  for given **cpu** at **index** in the array (single ring).



		  Note that installing a perf ring into an array will silently

		  replace any existing ring.  Any other application will stop

		  receiving events if it installed its rings earlier.



	**bpftool map help**

		  Print short help message.

tools/bpf/bpftool/Documentation/bpftool.rst

+1 −1
Original line number Diff line number Diff line
@@ -23,7 +23,7 @@ SYNOPSIS 


	*MAP-COMMANDS* :=

	{ **show** | **list** | **dump** | **update** | **lookup** | **getnext** | **delete**

	| **pin** | **help** }

	| **pin** | **event_pipe** | **help** }



	*PROG-COMMANDS* := { **show** | **list** | **dump jited** | **dump xlated** | **pin**

	| **load** | **help** }

tools/bpf/bpftool/Makefile

+6 −1
Original line number Diff line number Diff line
@@ -39,7 +39,12 @@ CC = gcc 


CFLAGS += -O2

CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wshadow -Wno-missing-field-initializers

CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ -I$(srctree)/tools/include/uapi -I$(srctree)/tools/include -I$(srctree)/tools/lib/bpf -I$(srctree)/kernel/bpf/

CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \

	-I$(srctree)/kernel/bpf/ \

	-I$(srctree)/tools/include \

	-I$(srctree)/tools/include/uapi \

	-I$(srctree)/tools/lib/bpf \

	-I$(srctree)/tools/perf

CFLAGS += -DBPFTOOL_VERSION='"$(BPFTOOL_VERSION)"'

LIBS = -lelf -lbfd -lopcodes $(LIBBPF)

tools/bpf/bpftool/bash-completion/bpftool

+34 −2
Original line number Diff line number Diff line 
# bpftool(8) bash completion                               -*- shell-script -*-

#

# Copyright (C) 2017 Netronome Systems, Inc.

# Copyright (C) 2017-2018 Netronome Systems, Inc.

#

# This software is dual licensed under the GNU General License

# Version 2, June 1991 as shown in the file COPYING in the top-level
@@ -79,6 +79,14 @@ _bpftool_get_map_ids() 
        command sed -n 's/.*"id": \(.*\),$/\1/p' )" -- "$cur" ) )

}



_bpftool_get_perf_map_ids()

{

    COMPREPLY+=( $( compgen -W "$( bpftool -jp map  2>&1 | \

        command grep -C2 perf_event_array | \

        command sed -n 's/.*"id": \(.*\),$/\1/p' )" -- "$cur" ) )

}





_bpftool_get_prog_ids()

{

    COMPREPLY+=( $( compgen -W "$( bpftool -jp prog 2>&1 | \
@@ -359,10 +367,34 @@ _bpftool() 
                    fi

                    return 0

                    ;;

                event_pipe)

                    case $prev in

                        $command)

                            COMPREPLY=( $( compgen -W "$MAP_TYPE" -- "$cur" ) )

                            return 0

                            ;;

                        id)

                            _bpftool_get_perf_map_ids

                            return 0

                            ;;

                        cpu)

                            return 0

                            ;;

                        index)

                            return 0

                            ;;

                        *)

                            _bpftool_once_attr 'cpu'

                            _bpftool_once_attr 'index'

                            return 0

                            ;;

                    esac

                    ;;

                *)

                    [[ $prev == $object ]] && \

                        COMPREPLY=( $( compgen -W 'delete dump getnext help \

                            lookup pin show list update' -- "$cur" ) )

                            lookup pin event_pipe show list update' -- \

                            "$cur" ) )

                    ;;

            esac

            ;;

tools/bpf/bpftool/common.c

+19 −0
Original line number Diff line number Diff line
@@ -331,6 +331,16 @@ char *get_fdinfo(int fd, const char *key) 
	return NULL;

}



void print_data_json(uint8_t *data, size_t len)

{

	unsigned int i;



	jsonw_start_array(json_wtr);

	for (i = 0; i < len; i++)

		jsonw_printf(json_wtr, "%d", data[i]);

	jsonw_end_array(json_wtr);

}



void print_hex_data_json(uint8_t *data, size_t len)

{

	unsigned int i;
@@ -421,6 +431,15 @@ void delete_pinned_obj_table(struct pinned_obj_table *tab) 
	}

}



unsigned int get_page_size(void)

{

	static int result;



	if (!result)

		result = getpagesize();

	return result;

}



unsigned int get_possible_cpus(void)

{

	static unsigned int result;

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