From: Quentin Monnet Date: Fri, 30 Jul 2021 21:54:34 +0000 (+0100) Subject: tools: bpftool: Document and add bash completion for -L, -B options X-Git-Tag: accepted/tizen/unified/20230118.172025~6527^2~345^2^2~1 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8cc8c6357c8fa763c650f1bddb69871a254f427c;p=platform%2Fkernel%2Flinux-rpi.git tools: bpftool: Document and add bash completion for -L, -B options The -L|--use-loader option for using loader programs when loading, or when generating a skeleton, did not have any documentation or bash completion. Same thing goes for -B|--base-btf, used to pass a path to a base BTF object for split BTF such as BTF for kernel modules. This patch documents and adds bash completion for those options. Fixes: 75fa1777694c ("tools/bpftool: Add bpftool support for split BTF") Fixes: d510296d331a ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.") Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20210730215435.7095-7-quentin@isovalent.com --- diff --git a/tools/bpf/bpftool/Documentation/bpftool-btf.rst b/tools/bpf/bpftool/Documentation/bpftool-btf.rst index 1d37f38..88b28aa 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-btf.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-btf.rst @@ -12,7 +12,8 @@ SYNOPSIS **bpftool** [*OPTIONS*] **btf** *COMMAND* - *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | {**-d** | **--debug** } } + *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | {**-d** | **--debug** } | + { **-B** | **--base-btf** } } *COMMANDS* := { **dump** | **help** } @@ -73,6 +74,20 @@ OPTIONS ======= .. include:: common_options.rst + -B, --base-btf *FILE* + Pass a base BTF object. Base BTF objects are typically used + with BTF objects for kernel modules. To avoid duplicating + all kernel symbols required by modules, BTF objects for + modules are "split", they are built incrementally on top of + the kernel (vmlinux) BTF object. So the base BTF reference + should usually point to the kernel BTF. + + When the main BTF object to process (for example, the + module BTF to dump) is passed as a *FILE*, bpftool attempts + to autodetect the path for the base object, and passing + this option is optional. When the main BTF object is passed + through other handles, this option becomes necessary. + EXAMPLES ======== **# bpftool btf dump id 1226** @@ -217,3 +232,34 @@ All the standard ways to specify map or program are supported: **# bpftool btf dump prog tag b88e0a09b1d9759d** **# bpftool btf dump prog pinned /sys/fs/bpf/prog_name** + +| +| **# bpftool btf dump file /sys/kernel/btf/i2c_smbus** +| (or) +| **# I2C_SMBUS_ID=$(bpftool btf show -p | jq '.[] | select(.name=="i2c_smbus").id')** +| **# bpftool btf dump id ${I2C_SMBUS_ID} -B /sys/kernel/btf/vmlinux** + +:: + + [104848] STRUCT 'i2c_smbus_alert' size=40 vlen=2 + 'alert' type_id=393 bits_offset=0 + 'ara' type_id=56050 bits_offset=256 + [104849] STRUCT 'alert_data' size=12 vlen=3 + 'addr' type_id=16 bits_offset=0 + 'type' type_id=56053 bits_offset=32 + 'data' type_id=7 bits_offset=64 + [104850] PTR '(anon)' type_id=104848 + [104851] PTR '(anon)' type_id=104849 + [104852] FUNC 'i2c_register_spd' type_id=84745 linkage=static + [104853] FUNC 'smbalert_driver_init' type_id=1213 linkage=static + [104854] FUNC_PROTO '(anon)' ret_type_id=18 vlen=1 + 'ara' type_id=56050 + [104855] FUNC 'i2c_handle_smbus_alert' type_id=104854 linkage=static + [104856] FUNC 'smbalert_remove' type_id=104854 linkage=static + [104857] FUNC_PROTO '(anon)' ret_type_id=18 vlen=2 + 'ara' type_id=56050 + 'id' type_id=56056 + [104858] FUNC 'smbalert_probe' type_id=104857 linkage=static + [104859] FUNC 'smbalert_work' type_id=9695 linkage=static + [104860] FUNC 'smbus_alert' type_id=71367 linkage=static + [104861] FUNC 'smbus_do_alert' type_id=84827 linkage=static diff --git a/tools/bpf/bpftool/Documentation/bpftool-gen.rst b/tools/bpf/bpftool/Documentation/bpftool-gen.rst index 709b93f..2ef2f2d 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-gen.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-gen.rst @@ -12,7 +12,8 @@ SYNOPSIS **bpftool** [*OPTIONS*] **gen** *COMMAND* - *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } } + *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } | + { **-L** | **--use-loader** } } *COMMAND* := { **object** | **skeleton** | **help** } @@ -152,6 +153,12 @@ OPTIONS ======= .. include:: common_options.rst + -L, --use-loader + For skeletons, generate a "light" skeleton (also known as "loader" + skeleton). A light skeleton contains a loader eBPF program. It does + not use the majority of the libbpf infrastructure, and does not need + libelf. + EXAMPLES ======== **$ cat example1.bpf.c** diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst index 4b8412f..2ea5df3 100644 --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst @@ -13,7 +13,8 @@ SYNOPSIS **bpftool** [*OPTIONS*] **prog** *COMMAND* *OPTIONS* := { { **-j** | **--json** } [{ **-p** | **--pretty** }] | { **-d** | **--debug** } | - { **-f** | **--bpffs** } | { **-m** | **--mapcompat** } | { **-n** | **--nomount** } } + { **-f** | **--bpffs** } | { **-m** | **--mapcompat** } | { **-n** | **--nomount** } | + { **-L** | **--use-loader** } } *COMMANDS* := { **show** | **list** | **dump xlated** | **dump jited** | **pin** | **load** @@ -224,6 +225,20 @@ OPTIONS Do not automatically attempt to mount any virtual file system (such as tracefs or BPF virtual file system) when necessary. + -L, --use-loader + Load program as a "loader" program. This is useful to debug + the generation of such programs. When this option is in + use, bpftool attempts to load the programs from the object + file into the kernel, but does not pin them (therefore, the + *PATH* must not be provided). + + When combined with the **-d**\ \|\ **--debug** option, + additional debug messages are generated, and the execution + of the loader program will use the **bpf_trace_printk**\ () + helper to log each step of loading BTF, creating the maps, + and loading the programs (see **bpftool prog tracelog** as + a way to dump those messages). + EXAMPLES ======== **# bpftool prog show** @@ -327,3 +342,16 @@ EXAMPLES 40176203 cycles (83.05%) 42518139 instructions # 1.06 insns per cycle (83.39%) 123 llc_misses # 2.89 LLC misses per million insns (83.15%) + +| +| Output below is for the trace logs. +| Run in separate terminals: +| **# bpftool prog tracelog** +| **# bpftool prog load -L -d file.o** + +:: + + bpftool-620059 [004] d... 2634685.517903: bpf_trace_printk: btf_load size 665 r=5 + bpftool-620059 [004] d... 2634685.517912: bpf_trace_printk: map_create sample_map idx 0 type 2 value_size 4 value_btf_id 0 r=6 + bpftool-620059 [004] d... 2634685.517997: bpf_trace_printk: prog_load sample insn_cnt 13 r=7 + bpftool-620059 [004] d... 2634685.517999: bpf_trace_printk: close(5) = 0 diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool index 1521a72..1341354 100644 --- a/tools/bpf/bpftool/bash-completion/bpftool +++ b/tools/bpf/bpftool/bash-completion/bpftool @@ -260,7 +260,8 @@ _bpftool() # Deal with options if [[ ${words[cword]} == -* ]]; then - local c='--version --json --pretty --bpffs --mapcompat --debug' + local c='--version --json --pretty --bpffs --mapcompat --debug \ + --use-loader --base-btf' COMPREPLY=( $( compgen -W "$c" -- "$cur" ) ) return 0 fi @@ -278,7 +279,7 @@ _bpftool() _sysfs_get_netdevs return 0 ;; - file|pinned) + file|pinned|-B|--base-btf) _filedir return 0 ;; @@ -291,7 +292,8 @@ _bpftool() # Remove all options so completions don't have to deal with them. local i for (( i=1; i < ${#words[@]}; )); do - if [[ ${words[i]::1} == - ]]; then + if [[ ${words[i]::1} == - ]] && + [[ ${words[i]} != "-B" ]] && [[ ${words[i]} != "--base-btf" ]]; then words=( "${words[@]:0:i}" "${words[@]:i+1}" ) [[ $i -le $cword ]] && cword=$(( cword - 1 )) else diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c index 3c5fc9b..f7e5ff3 100644 --- a/tools/bpf/bpftool/btf.c +++ b/tools/bpf/bpftool/btf.c @@ -981,7 +981,8 @@ static int do_help(int argc, char **argv) " FORMAT := { raw | c }\n" " " HELP_SPEC_MAP "\n" " " HELP_SPEC_PROGRAM "\n" - " " HELP_SPEC_OPTIONS " }\n" + " " HELP_SPEC_OPTIONS " |\n" + " {-B|--base-btf} }\n" "", bin_name, "btf"); diff --git a/tools/bpf/bpftool/cgroup.c b/tools/bpf/bpftool/cgroup.c index c42f437..3571a28 100644 --- a/tools/bpf/bpftool/cgroup.c +++ b/tools/bpf/bpftool/cgroup.c @@ -502,7 +502,7 @@ static int do_help(int argc, char **argv) " " HELP_SPEC_ATTACH_FLAGS "\n" " " HELP_SPEC_PROGRAM "\n" " " HELP_SPEC_OPTIONS " |\n" - " {-f|--bpffs} } + " {-f|--bpffs} }\n" "", bin_name, argv[-2]); diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c index d4225f7..d40d92b 100644 --- a/tools/bpf/bpftool/gen.c +++ b/tools/bpf/bpftool/gen.c @@ -1026,7 +1026,8 @@ static int do_help(int argc, char **argv) " %1$s %2$s skeleton FILE [name OBJECT_NAME]\n" " %1$s %2$s help\n" "\n" - " " HELP_SPEC_OPTIONS " }\n" + " " HELP_SPEC_OPTIONS " |\n" + " {-L|--use-loader} }\n" "", bin_name, "gen"); diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index a205f71..9c3e343 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -2260,7 +2260,8 @@ static int do_help(int argc, char **argv) " stream_parser | flow_dissector }\n" " METRIC := { cycles | instructions | l1d_loads | llc_misses | itlb_misses | dtlb_misses }\n" " " HELP_SPEC_OPTIONS " |\n" - " {-f|--bpffs} | {-m|--mapcompat} | {-n|--nomount} }\n" + " {-f|--bpffs} | {-m|--mapcompat} | {-n|--nomount} |\n" + " {-L|--use-loader} }\n" "", bin_name, argv[-2]);