From bc6cd664609b92aa437ed3f384e332faab5949c8 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 14 Dec 2018 13:55:57 +0000 Subject: [PATCH 1/5] tools: bpftool: add doc for -m option to bpftool-prog.rst The --mapcompat|-m option has been documented on the main bpftool.rst page, and on the interactive help. As this option is useful for loading programs with maps with the "bpftool prog load" command, it should also appear in the related bpftool-prog.rst documentation page. Let's add it. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/Documentation/bpftool-prog.rst | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index bb1aeb98b6da..b41e96ac0dfe 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -158,6 +158,9 @@ OPTIONS When showing BPF programs, show file names of pinned programs. + -m, --mapcompat + Allow loading maps with unknown map definitions. + EXAMPLES ======== **# bpftool prog show** From 32870ba4078c3b4deac7ccb35b078c9ab69488a3 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 14 Dec 2018 13:55:58 +0000 Subject: [PATCH 2/5] tools: bpftool: fix examples in documentation for bpftool prog Bring various fixes to the manual page for "bpftool prog" set of commands: - Fix typos ("dum" -> "dump") - Harmonise indentation and format for command output - Update date format for program load time - Add instruction numbers on program dumps - Fix JSON format for the example program listing Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- .../bpftool/Documentation/bpftool-prog.rst | 102 ++++++++++-------- 1 file changed, 55 insertions(+), 47 deletions(-) diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index b41e96ac0dfe..53920ffc48dd 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -164,80 +164,88 @@ OPTIONS EXAMPLES ======== **# bpftool prog show** + :: - 10: xdp name some_prog tag 005a3d2123620c8b gpl - loaded_at Sep 29/20:11 uid 0 - xlated 528B jited 370B memlock 4096B map_ids 10 + 10: xdp name some_prog tag 005a3d2123620c8b gpl + loaded_at 2017-09-29T20:11:00+0000 uid 0 + xlated 528B jited 370B memlock 4096B map_ids 10 **# bpftool --json --pretty prog show** :: - { - "programs": [{ - "id": 10, - "type": "xdp", - "tag": "005a3d2123620c8b", - "gpl_compatible": true, - "loaded_at": "Sep 29/20:11", - "uid": 0, - "bytes_xlated": 528, - "jited": true, - "bytes_jited": 370, - "bytes_memlock": 4096, - "map_ids": [10 - ] - } - ] - } + [{ + "id": 10, + "type": "xdp", + "tag": "005a3d2123620c8b", + "gpl_compatible": true, + "loaded_at": 1506715860, + "uid": 0, + "bytes_xlated": 528, + "jited": true, + "bytes_jited": 370, + "bytes_memlock": 4096, + "map_ids": [10 + ] + } + ] | | **# bpftool prog dump xlated id 10 file /tmp/t** | **# ls -l /tmp/t** -| -rw------- 1 root root 560 Jul 22 01:42 /tmp/t - -**# bpftool prog dum jited tag 005a3d2123620c8b** :: - push %rbp - mov %rsp,%rbp - sub $0x228,%rsp - sub $0x28,%rbp - mov %rbx,0x0(%rbp) + -rw------- 1 root root 560 Jul 22 01:42 /tmp/t + +**# bpftool prog dump jited tag 005a3d2123620c8b** + +:: + + 0: push %rbp + 1: mov %rsp,%rbp + 2: sub $0x228,%rsp + 3: sub $0x28,%rbp + 4: mov %rbx,0x0(%rbp) | | **# mount -t bpf none /sys/fs/bpf/** | **# bpftool prog pin id 10 /sys/fs/bpf/prog** | **# bpftool prog load ./my_prog.o /sys/fs/bpf/prog2** | **# ls -l /sys/fs/bpf/** -| -rw------- 1 root root 0 Jul 22 01:43 prog -| -rw------- 1 root root 0 Jul 22 01:44 prog2 - -**# bpftool prog dum jited pinned /sys/fs/bpf/prog opcodes** :: - push %rbp - 55 - mov %rsp,%rbp - 48 89 e5 - sub $0x228,%rsp - 48 81 ec 28 02 00 00 - sub $0x28,%rbp - 48 83 ed 28 - mov %rbx,0x0(%rbp) - 48 89 5d 00 + -rw------- 1 root root 0 Jul 22 01:43 prog + -rw------- 1 root root 0 Jul 22 01:44 prog2 + +**# bpftool prog dump jited pinned /sys/fs/bpf/prog opcodes** + +:: + + 0: push %rbp + 55 + 1: mov %rsp,%rbp + 48 89 e5 + 4: sub $0x228,%rsp + 48 81 ec 28 02 00 00 + b: sub $0x28,%rbp + 48 83 ed 28 + f: mov %rbx,0x0(%rbp) + 48 89 5d 00 | | **# bpftool prog load xdp1_kern.o /sys/fs/bpf/xdp1 type xdp map name rxcnt id 7** | **# bpftool prog show pinned /sys/fs/bpf/xdp1** -| 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl -| loaded_at 2018-06-25T16:17:31-0700 uid 0 -| xlated 488B jited 336B memlock 4096B map_ids 7 -| **# rm /sys/fs/bpf/xdp1** -| + +:: + + 9: xdp name xdp_prog1 tag 539ec6ce11b52f98 gpl + loaded_at 2018-06-25T16:17:31-0700 uid 0 + xlated 488B jited 336B memlock 4096B map_ids 7 + +**# rm /sys/fs/bpf/xdp1** SEE ALSO ======== From bd0fb9d0078edbfa2c983ad61901d90f1c0f5747 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 14 Dec 2018 13:55:59 +0000 Subject: [PATCH 3/5] tools: bpftool: add a prog array map update example to documentation Add an example in map documentation to show how to use bpftool in order to update the references to programs hold by prog array maps. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- .../bpf/bpftool/Documentation/bpftool-map.rst | 55 +++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst index 5318dcb2085e..3221be1b9ccc 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-map.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst @@ -170,6 +170,61 @@ The following three commands are equivalent: | **# bpftool map pin id 10 /sys/fs/bpf/map** | **# bpftool map del pinned /sys/fs/bpf/map key 13 00 07 00** +Note that map update can also be used in order to change the program references +hold by a program array map. This can be used, for example, to change the +programs used for tail-call jumps at runtime, without having to reload the +entry-point program. Below is an example for this use case: we load a program +defining a prog array map, and with a main function that contains a tail call +to other programs that can be used either to "process" packets or to "debug" +processing. Note that the prog array map MUST be pinned into the BPF virtual +file system for the map update to work successfully, as kernel flushes prog +array maps when they have no more references from user space (and the update +would be lost as soon as bpftool exits). + +| +| **# bpftool prog loadall tail_calls.o /sys/fs/bpf/foo type xdp** +| **# bpftool prog --bpffs** + +:: + + 545: xdp name main_func tag 674b4b5597193dc3 gpl + loaded_at 2018-12-12T15:02:58+0000 uid 0 + xlated 240B jited 257B memlock 4096B map_ids 294 + pinned /sys/fs/bpf/foo/xdp + 546: xdp name bpf_func_process tag e369a529024751fc gpl + loaded_at 2018-12-12T15:02:58+0000 uid 0 + xlated 200B jited 164B memlock 4096B + pinned /sys/fs/bpf/foo/process + 547: xdp name bpf_func_debug tag 0b597868bc7f0976 gpl + loaded_at 2018-12-12T15:02:58+0000 uid 0 + xlated 200B jited 164B memlock 4096B + pinned /sys/fs/bpf/foo/debug + +**# bpftool map** + +:: + + 294: prog_array name jmp_table flags 0x0 + key 4B value 4B max_entries 1 memlock 4096B + owner_prog_type xdp owner jited + +| +| **# bpftool map pin id 294 /sys/fs/bpf/bar** +| **# bpftool map dump pinned /sys/fs/bpf/bar** + +:: + + Found 0 elements + +| +| **# bpftool map update pinned /sys/fs/bpf/bar key 0 0 0 0 value pinned /sys/fs/bpf/foo/debug** +| **# bpftool map dump pinned /sys/fs/bpf/bar** + +:: + + key: 00 00 00 00 value: 22 02 00 00 + Found 1 element + SEE ALSO ======== **bpf**\ (2), From 8c03ecf712f5bbbb9d353ed69715aef3cc2b4029 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 14 Dec 2018 13:56:00 +0000 Subject: [PATCH 4/5] tools: bpftool: fix warning on struct bpf_prog_linfo definition The following warning appears when compiling bpftool without BFD support: main.h:198:23: warning: 'struct bpf_prog_linfo' declared inside parameter list will not be visible outside of this definition or declaration const struct bpf_prog_linfo *prog_linfo, Fix it by declaring struct bpf_prog_linfo even in the case BFD is not supported. Fixes: b053b439b72a ("bpf: libbpf: bpftool: Print bpf_line_info during prog dump") Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/main.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index d2beb88f0e2e..9487345b04a7 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -147,8 +147,8 @@ int prog_parse_fd(int *argc, char ***argv); int map_parse_fd(int *argc, char ***argv); int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len); -#ifdef HAVE_LIBBFD_SUPPORT struct bpf_prog_linfo; +#ifdef HAVE_LIBBFD_SUPPORT void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes, const char *arch, const char *disassembler_options, const struct btf *btf, From c101189bc9680675a2686bafe908015a07a0da51 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 14 Dec 2018 13:56:01 +0000 Subject: [PATCH 5/5] tools: bpftool: fix -Wmissing declaration warnings Help compiler check arguments for several utility functions used to print items to the console by adding the "printf" attribute when declaring those functions. Also, declare as "static" two functions that are only used in prog.c. All of them discovered by compiling bpftool with -Wmissing-format-attribute -Wmissing-declarations. Signed-off-by: Quentin Monnet Reviewed-by: Jakub Kicinski Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/common.c | 4 ++-- tools/bpf/bpftool/json_writer.c | 6 ++++-- tools/bpf/bpftool/prog.c | 4 ++-- tools/bpf/bpftool/xlated_dumper.c | 7 ++++--- 4 files changed, 12 insertions(+), 9 deletions(-) diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index 99e4027dde75..24582e8a96fb 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -28,7 +28,7 @@ #define BPF_FS_MAGIC 0xcafe4a11 #endif -void p_err(const char *fmt, ...) +void __printf(1, 2) p_err(const char *fmt, ...) { va_list ap; @@ -46,7 +46,7 @@ void p_err(const char *fmt, ...) va_end(ap); } -void p_info(const char *fmt, ...) +void __printf(1, 2) p_info(const char *fmt, ...) { va_list ap; diff --git a/tools/bpf/bpftool/json_writer.c b/tools/bpf/bpftool/json_writer.c index a07d17918725..bff7ee026680 100644 --- a/tools/bpf/bpftool/json_writer.c +++ b/tools/bpf/bpftool/json_writer.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "json_writer.h" @@ -157,7 +158,8 @@ void jsonw_name(json_writer_t *self, const char *name) putc(' ', self->out); } -void jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap) +void __printf(2, 0) +jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap) { jsonw_eor(self); putc('"', self->out); @@ -165,7 +167,7 @@ void jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap) putc('"', self->out); } -void jsonw_printf(json_writer_t *self, const char *fmt, ...) +void __printf(2, 3) jsonw_printf(json_writer_t *self, const char *fmt, ...) { va_list ap; diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index ee51279be9c7..2d1bb7d6ff51 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -32,7 +32,7 @@ static const char * const attach_type_strings[] = { [__MAX_BPF_ATTACH_TYPE] = NULL, }; -enum bpf_attach_type parse_attach_type(const char *str) +static enum bpf_attach_type parse_attach_type(const char *str) { enum bpf_attach_type type; @@ -798,7 +798,7 @@ struct map_replace { char *name; }; -int map_replace_compar(const void *p1, const void *p2) +static int map_replace_compar(const void *p1, const void *p2) { const struct map_replace *a = p1, *b = p2; diff --git a/tools/bpf/bpftool/xlated_dumper.c b/tools/bpf/bpftool/xlated_dumper.c index 640ffe86a655..7073dbe1ff27 100644 --- a/tools/bpf/bpftool/xlated_dumper.c +++ b/tools/bpf/bpftool/xlated_dumper.c @@ -81,7 +81,7 @@ struct kernel_sym *kernel_syms_search(struct dump_data *dd, sizeof(*dd->sym_mapping), kernel_syms_cmp) : NULL; } -static void print_insn(void *private_data, const char *fmt, ...) +static void __printf(2, 3) print_insn(void *private_data, const char *fmt, ...) { va_list args; @@ -90,7 +90,7 @@ static void print_insn(void *private_data, const char *fmt, ...) va_end(args); } -static void +static void __printf(2, 3) print_insn_for_graph(void *private_data, const char *fmt, ...) { char buf[64], *p; @@ -121,7 +121,8 @@ print_insn_for_graph(void *private_data, const char *fmt, ...) printf("%s", buf); } -static void print_insn_json(void *private_data, const char *fmt, ...) +static void __printf(2, 3) +print_insn_json(void *private_data, const char *fmt, ...) { unsigned int l = strlen(fmt); char chomped_fmt[l];