On Fri, Jun 10, 2022 at 11:34 AM Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote: > > Em Thu, Jun 09, 2022 at 01:31:52PM -0700, Andrii Nakryiko escreveu: > > On Fri, Jun 3, 2022 at 1:45 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote: > > > > > > hi, > > > sending change we discussed some time ago [1] to get rid of > > > some deprecated functions we use in perf prologue code. > > > > > > Despite the gloomy discussion I think the final code does > > > not look that bad ;-) > > > > > > This patchset removes following libbpf functions from perf: > > > bpf_program__set_prep > > > bpf_program__nth_fd > > > struct bpf_prog_prep_result > > > > > > v4 changes: > > > - fix typo [Andrii] > > > > > > v3 changes: > > > - removed R0/R1 zero init in libbpf_prog_prepare_load_fn, > > > because it's not needed [Andrii] > > > - rebased/post on top of bpf-next/master which now has > > > all the needed perf/core changes > > > > > > v2 changes: > > > - use fallback section prog handler, so we don't need to > > > use section prefix [Andrii] > > > - realloc prog->insns array in bpf_program__set_insns [Andrii] > > > - squash patch 1 from previous version with > > > bpf_program__set_insns change [Daniel] > > > - patch 3 already merged [Arnaldo] > > > - added more comments > > > > > > thanks, > > > jirka > > > > > > > Arnaldo, can I get an ack from you for this patch set? Thank you! > > So, before these patches: > > [acme@quaco perf-urgent]$ git log --oneline -5 > 22905f78d181f446 (HEAD) libperf evsel: Open shouldn't leak fd on failure > a3c6da3dbd4bdf9c perf test: Fix "perf stat CSV output linter" test on s390 > 785cb9e85e8ba66f perf unwind: Fix uninitialized variable > 874c8ca1e60b2c56 netfs: Fix gcc-12 warning by embedding vfs inode in netfs_i_context > 3d9f55c57bc3659f Merge tag 'fs_for_v5.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs > [acme@quaco perf-urgent]$ sudo su - > [root@quaco ~]# perf -v > perf version 5.19.rc1.g22905f78d181 > [root@quaco ~]# perf test 42 > 42: BPF filter : > 42.1: Basic BPF filtering : Ok > 42.2: BPF pinning : Ok > 42.3: BPF prologue generation : Ok > [root@quaco ~]# > > And after: > > [acme@quaco perf-urgent]$ git log --oneline -5 > f8ec656242acf2de (HEAD -> perf/urgent) perf tools: Rework prologue generation code > a750a8dd7e5d2d4b perf tools: Register fallback libbpf section handler > d28f2a8ad42af160 libperf evsel: Open shouldn't leak fd on failure > a3c6da3dbd4bdf9c perf test: Fix "perf stat CSV output linter" test on s390 > 785cb9e85e8ba66f perf unwind: Fix uninitialized variable > [acme@quaco perf-urgent]$ sudo su - > [root@quaco ~]# perf -v > perf version 5.19.rc1.gf8ec656242ac > [root@quaco ~]# perf test 42 > 42: BPF filter : > 42.1: Basic BPF filtering : FAILED! > 42.2: BPF pinning : FAILED! > 42.3: BPF prologue generation : Ok > [root@quaco ~]# > > Jiri, can you try reproducing these? Do this require some other work > that is in bpf-next/master? Lemme try... > > Further details: > > [acme@quaco perf-urgent]$ clang -v > clang version 13.0.0 (five:git/llvm-project d667b96c98438edcc00ec85a3b151ac2dae862f3) > Target: x86_64-unknown-linux-gnu > Thread model: posix > InstalledDir: /usr/local/bin > Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/12 > Selected GCC installation: /usr/lib/gcc/x86_64-redhat-linux/12 > Candidate multilib: .;@m64 > Candidate multilib: 32;@m32 > Selected multilib: .;@m64 > [acme@quaco perf-urgent]$ cat /etc/fedora-release > Fedora release 36 (Thirty Six) > [acme@quaco perf-urgent]$ gcc -v > Using built-in specs. > COLLECT_GCC=/usr/bin/gcc > COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/12/lto-wrapper > OFFLOAD_TARGET_NAMES=nvptx-none > OFFLOAD_TARGET_DEFAULT=1 > Target: x86_64-redhat-linux > Configured with: ../configure --enable-bootstrap --enable-languages=c,c++,fortran,objc,obj-c++,ada,go,d,lto --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-shared --enable-threads=posix --enable-checking=release --enable-multilib --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-linker-build-id --with-gcc-major-version-only --enable-libstdcxx-backtrace --with-linker-hash-style=gnu --enable-plugin --enable-initfini-array --with-isl=/builddir/build/BUILD/gcc-12.1.1-20220507/obj-x86_64-redhat-linux/isl-install --enable-offload-targets=nvptx-none --without-cuda-driver --enable-offload-defaulted --enable-gnu-indirect-function --enable-cet --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux --with-build-config=bootstrap-lto --enable-link-serialization=1 > Thread model: posix > Supported LTO compression algorithms: zlib zstd > gcc version 12.1.1 20220507 (Red Hat 12.1.1-1) (GCC) > [acme@quaco perf-urgent]$ > > [root@quaco ~]# perf test -v 42 > 42: BPF filter : > 42.1: Basic BPF filtering : > --- start --- > test child forked, pid 638881 > Kernel build dir is set to /lib/modules/5.17.11-300.fc36.x86_64/build > set env: KBUILD_DIR=/lib/modules/5.17.11-300.fc36.x86_64/build > unset env: KBUILD_OPTS > include option is set to -nostdinc -I./arch/x86/include -I./arch/x86/include/generated -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h > set env: NR_CPUS=8 > set env: LINUX_VERSION_CODE=0x5110b > set env: CLANG_EXEC=/usr/lib64/ccache/clang > set env: CLANG_OPTIONS=-xc -g > set env: KERNEL_INC_OPTIONS=-nostdinc -I./arch/x86/include -I./arch/x86/include/generated -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h > set env: PERF_BPF_INC_OPTIONS=-I/home/acme/lib/perf/include/bpf > set env: WORKING_DIR=/lib/modules/5.17.11-300.fc36.x86_64/build > set env: CLANG_SOURCE=- > llvm compiling command template: echo '// SPDX-License-Identifier: GPL-2.0 > /* > * bpf-script-example.c > * Test basic LLVM building > */ > #ifndef LINUX_VERSION_CODE > # error Need LINUX_VERSION_CODE > # error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig' > #endif > #define BPF_ANY 0 > #define BPF_MAP_TYPE_ARRAY 2 > #define BPF_FUNC_map_lookup_elem 1 > #define BPF_FUNC_map_update_elem 2 > > static void *(*bpf_map_lookup_elem)(void *map, void *key) = > (void *) BPF_FUNC_map_lookup_elem; > static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) = > (void *) BPF_FUNC_map_update_elem; > > struct bpf_map_def { > unsigned int type; > unsigned int key_size; > unsigned int value_size; > unsigned int max_entries; > }; > > #define SEC(NAME) __attribute__((section(NAME), used)) > struct bpf_map_def SEC("maps") flip_table = { > .type = BPF_MAP_TYPE_ARRAY, > .key_size = sizeof(int), > .value_size = sizeof(int), > .max_entries = 1, > }; > > SEC("func=do_epoll_wait") > int bpf_func__SyS_epoll_pwait(void *ctx) > { > int ind =0; > int *flag = bpf_map_lookup_elem(&flip_table, &ind); > int new_flag; > if (!flag) > return 0; > /* flip flag and store back */ > new_flag = !*flag; > bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY); > return new_flag; > } > char _license[] SEC("license") = "GPL"; > int _version SEC("version") = LINUX_VERSION_CODE; > ' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $PERF_BPF_INC_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf $CLANG_EMIT_LLVM -O2 -o - $LLVM_OPTIONS_PIPE > llvm compiling command : echo '// SPDX-License-Identifier: GPL-2.0 > /* > * bpf-script-example.c > * Test basic LLVM building > */ > #ifndef LINUX_VERSION_CODE > # error Need LINUX_VERSION_CODE > # error Example: for 4.2 kernel, put 'clang-opt=-DLINUX_VERSION_CODE=0x40200 into llvm section of ~/.perfconfig' > #endif > #define BPF_ANY 0 > #define BPF_MAP_TYPE_ARRAY 2 > #define BPF_FUNC_map_lookup_elem 1 > #define BPF_FUNC_map_update_elem 2 > > static void *(*bpf_map_lookup_elem)(void *map, void *key) = > (void *) BPF_FUNC_map_lookup_elem; > static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) = > (void *) BPF_FUNC_map_update_elem; > > struct bpf_map_def { > unsigned int type; > unsigned int key_size; > unsigned int value_size; > unsigned int max_entries; > }; > > #define SEC(NAME) __attribute__((section(NAME), used)) > struct bpf_map_def SEC(maps) flip_table = { > .type = BPF_MAP_TYPE_ARRAY, > .key_size = sizeof(int), > .value_size = sizeof(int), > .max_entries = 1, > }; > > SEC(func=do_epoll_wait) > int bpf_func__SyS_epoll_pwait(void *ctx) > { > int ind =0; > int *flag = bpf_map_lookup_elem(&flip_table, &ind); > int new_flag; > if (!flag) > return 0; > /* flip flag and store back */ > new_flag = !*flag; > bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY); > return new_flag; > } > char _license[] SEC(license) = GPL; > int _version SEC(version) = LINUX_VERSION_CODE; > ' | /usr/lib64/ccache/clang -D__KERNEL__ -D__NR_CPUS__=8 -DLINUX_VERSION_CODE=0x5110b -xc -g -I/home/acme/lib/perf/include/bpf -nostdinc -I./arch/x86/include -I./arch/x86/include/generated -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/compiler-version.h -include ./include/linux/kconfig.h -Wno-unused-value -Wno-pointer-sign -working-directory /lib/modules/5.17.11-300.fc36.x86_64/build -c - -target bpf -O2 -o - > libbpf: loading object '[basic_bpf_test]' from buffer > libbpf: elf: section(3) func=do_epoll_wait, size 192, link 0, flags 6, type=1 > libbpf: sec 'func=do_epoll_wait': found program 'bpf_func__SyS_epoll_pwait' at insn offset 0 (0 bytes), code size 24 insns (192 bytes) > libbpf: elf: section(4) .relfunc=do_epoll_wait, size 32, link 22, flags 0, type=9 > libbpf: elf: section(5) maps, size 16, link 0, flags 3, type=1 > libbpf: elf: section(6) license, size 4, link 0, flags 3, type=1 > libbpf: license of [basic_bpf_test] is GPL > libbpf: elf: section(7) version, size 4, link 0, flags 3, type=1 > libbpf: kernel version of [basic_bpf_test] is 5110b > libbpf: elf: section(13) .BTF, size 576, link 0, flags 0, type=1 > libbpf: elf: section(15) .BTF.ext, size 256, link 0, flags 0, type=1 > libbpf: elf: section(22) .symtab, size 336, link 1, flags 0, type=2 > libbpf: looking for externs among 14 symbols... > libbpf: collected 0 externs total > libbpf: elf: found 1 legacy map definitions (16 bytes) in [basic_bpf_test] > libbpf: map 'flip_table' (legacy): legacy map definitions are deprecated, use BTF-defined maps instead > libbpf: map 'flip_table' (legacy): at sec_idx 5, offset 0. > libbpf: map 11 is "flip_table" > libbpf: Use of BPF_ANNOTATE_KV_PAIR is deprecated, use BTF-defined maps in .maps section instead > libbpf: map:flip_table container_name:____btf_map_flip_table cannot be found in BTF. Missing BPF_ANNOTATE_KV_PAIR? > libbpf: sec '.relfunc=do_epoll_wait': collecting relocation for section(3) 'func=do_epoll_wait' > libbpf: sec '.relfunc=do_epoll_wait': relo #0: insn #4 against 'flip_table' > libbpf: prog 'bpf_func__SyS_epoll_pwait': found map 0 (flip_table, sec 5, off 0) for insn #4 > libbpf: sec '.relfunc=do_epoll_wait': relo #1: insn #17 against 'flip_table' > libbpf: prog 'bpf_func__SyS_epoll_pwait': found map 0 (flip_table, sec 5, off 0) for insn #17 > bpf: config program 'func=do_epoll_wait' > symbol:do_epoll_wait file:(null) line:0 offset:0 return:0 lazy:(null) > bpf: config 'func=do_epoll_wait' is ok > Looking at the vmlinux_path (8 entries long) > symsrc__init: build id mismatch for vmlinux. > Using /usr/lib/debug/lib/modules/5.17.11-300.fc36.x86_64/vmlinux for symbols > Open Debuginfo file: /usr/lib/debug/.build-id/f2/26f5d75e6842add57095a0615a1e5c16783dd7.debug > Try to find probe point from debuginfo. > Matched function: do_epoll_wait [38063fb] > Probe point found: do_epoll_wait+0 > Found 1 probe_trace_events. > Opening /sys/kernel/tracing//kprobe_events write=1 > Opening /sys/kernel/tracing//README write=0 > Writing event: p:perf_bpf_probe/func _text+3943040 > libbpf: map 'flip_table': created successfully, fd=4 > libbpf: prog 'bpf_func__SyS_epoll_pwait': BPF program load failed: Invalid argument > libbpf: prog 'bpf_func__SyS_epoll_pwait': -- BEGIN PROG LOAD LOG -- > Invalid insn code at line_info[11].insn_off Mismatched line_info. Jiri, I think we need to clear func_info and line_info in bpf_program__set_insns() because at that point func/line info can be mismatched and won't correspond to the actual set of instructions. Arnaldo, thanks for testing and providing details! > processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 > -- END PROG LOAD LOG -- > libbpf: failed to load program 'bpf_func__SyS_epoll_pwait' > libbpf: failed to load object '[basic_bpf_test]' > bpf: load objects failed: err=-22: (Invalid argument) > Failed to add events selected by BPF > Opening /sys/kernel/tracing//kprobe_events write=1 > Opening /sys/kernel/tracing//uprobe_events write=1 > Parsing probe_events: p:perf_bpf_probe/func _text+3943040 > Group:perf_bpf_probe Event:func probe:p > Writing event: -:perf_bpf_probe/func > test child finished with -1 [...]
