Em Wed, Mar 15, 2023 at 01:24:37PM -0300, Arnaldo Carvalho de Melo escreveu: > Em Tue, Mar 14, 2023 at 04:42:29PM -0700, Namhyung Kim escreveu: > > The BPF program will be attached to a perf_event and be triggered when > > it overflows. It'd iterate the filters map and compare the sample > > value according to the expression. If any of them fails, the sample > > would be dropped. > > > > Also it needs to have the corresponding sample data for the expression > > so it compares data->sample_flags with the given value. To access the > > sample data, it uses the bpf_cast_to_kern_ctx() kfunc which was added > > in v6.2 kernel. > > > > Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> > > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx> > > > I'm noticing this while building on a debian:11 container: > > GENSKEL /tmp/build/perf/util/bpf_skel/bperf_leader.skel.h > GENSKEL /tmp/build/perf/util/bpf_skel/bperf_follower.skel.h > GENSKEL /tmp/build/perf/util/bpf_skel/func_latency.skel.h > GENSKEL /tmp/build/perf/util/bpf_skel/bpf_prog_profiler.skel.h > GENSKEL /tmp/build/perf/util/bpf_skel/kwork_trace.skel.h > GENSKEL /tmp/build/perf/util/bpf_skel/sample_filter.skel.h > libbpf: failed to find BTF for extern 'bpf_cast_to_kern_ctx' [21] section: -2 > Error: failed to open BPF object file: No such file or directory > make[2]: *** [Makefile.perf:1085: /tmp/build/perf/util/bpf_skel/sample_filter.skel.h] Error 254 > make[2]: *** Deleting file '/tmp/build/perf/util/bpf_skel/sample_filter.skel.h' > make[2]: *** Waiting for unfinished jobs.... > make[1]: *** [Makefile.perf:236: sub-make] Error 2 > make: *** [Makefile:70: all] Error 2 > make: Leaving directory '/git/perf-6.3.0-rc1/tools/perf' > + exit 1 > [perfbuilder@five 11]$ Same thing on debian:10 libbpf: failed to find BTF for extern 'bpf_cast_to_kern_ctx' [21] section: -2 Error: failed to open BPF object file: No such file or directory make[2]: *** [Makefile.perf:1085: /tmp/build/perf/util/bpf_skel/sample_filter.skel.h] Error 254 make[2]: *** Deleting file '/tmp/build/perf/util/bpf_skel/sample_filter.skel.h' make[2]: *** Waiting for unfinished jobs.... make[1]: *** [Makefile.perf:236: sub-make] Error 2 make: *** [Makefile:70: all] Error 2 make: Leaving directory '/git/perf-6.3.0-rc1/tools/perf' + exit 1 [perfbuilder@five 10]$ Works with debian:experimental: [perfbuilder@five experimental]$ export BUILD_TARBALL=http://192.168.86.10/perf/perf-6.3.0-rc1.tar.xz [perfbuilder@five experimental]$ time dm . 1 147.54 debian:experimental : Ok gcc (Debian 12.2.0-14) 12.2.0 , Debian clang version 14.0.6 BUILD_TARBALL_HEAD=d34a77f6cd75d2a75c64e78f3d949a12903a7cf0 Both with: Debian clang version 14.0.6 Target: x86_64-pc-linux-gnu Thread model: posix InstalledDir: /usr/bin Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/12 Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/12 Candidate multilib: .;@m64 Selected multilib: .;@m64 + rm -rf /tmp/build/perf + mkdir /tmp/build/perf + make ARCH= CROSS_COMPILE= EXTRA_CFLAGS= -C tools/perf O=/tmp/build/perf CC=clang and: COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/12/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Debian 12.2.0-14' --with-bugurl=file:///usr/share/doc/gcc-12/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-12 --program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none=/build/gcc-12-bTRWOB/gcc-12-12.2.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-12-bTRWOB/gcc-12-12.2.0/debian/tmp-gcn/usr --enable-offload-defaulted --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 12.2.0 (Debian 12.2.0-14) + make ARCH= CROSS_COMPILE= EXTRA_CFLAGS= -C tools/perf O=/tmp/build/perf make: Entering directory '/git/perf-6.3.0-rc1/tools/perf' > > > --- > > tools/perf/Makefile.perf | 2 +- > > tools/perf/util/bpf-filter.c | 64 ++++++++++ > > tools/perf/util/bpf-filter.h | 26 ++-- > > tools/perf/util/bpf_skel/sample-filter.h | 24 ++++ > > tools/perf/util/bpf_skel/sample_filter.bpf.c | 126 +++++++++++++++++++ > > tools/perf/util/evsel.h | 7 +- > > 6 files changed, 236 insertions(+), 13 deletions(-) > > create mode 100644 tools/perf/util/bpf_skel/sample-filter.h > > create mode 100644 tools/perf/util/bpf_skel/sample_filter.bpf.c > > > > diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf > > index dc9dda09b076..ed6b6a070f79 100644 > > --- a/tools/perf/Makefile.perf > > +++ b/tools/perf/Makefile.perf > > @@ -1050,7 +1050,7 @@ SKELETONS := $(SKEL_OUT)/bpf_prog_profiler.skel.h > > SKELETONS += $(SKEL_OUT)/bperf_leader.skel.h $(SKEL_OUT)/bperf_follower.skel.h > > SKELETONS += $(SKEL_OUT)/bperf_cgroup.skel.h $(SKEL_OUT)/func_latency.skel.h > > SKELETONS += $(SKEL_OUT)/off_cpu.skel.h $(SKEL_OUT)/lock_contention.skel.h > > -SKELETONS += $(SKEL_OUT)/kwork_trace.skel.h > > +SKELETONS += $(SKEL_OUT)/kwork_trace.skel.h $(SKEL_OUT)/sample_filter.skel.h > > > > $(SKEL_TMP_OUT) $(LIBAPI_OUTPUT) $(LIBBPF_OUTPUT) $(LIBPERF_OUTPUT) $(LIBSUBCMD_OUTPUT) $(LIBSYMBOL_OUTPUT): > > $(Q)$(MKDIR) -p $@ > > diff --git a/tools/perf/util/bpf-filter.c b/tools/perf/util/bpf-filter.c > > index c72e35d51240..f20e1bc03778 100644 > > --- a/tools/perf/util/bpf-filter.c > > +++ b/tools/perf/util/bpf-filter.c > > @@ -1,10 +1,74 @@ > > /* SPDX-License-Identifier: GPL-2.0 */ > > #include <stdlib.h> > > > > +#include <bpf/bpf.h> > > +#include <linux/err.h> > > +#include <internal/xyarray.h> > > + > > +#include "util/debug.h" > > +#include "util/evsel.h" > > + > > #include "util/bpf-filter.h" > > #include "util/bpf-filter-flex.h" > > #include "util/bpf-filter-bison.h" > > > > +#include "bpf_skel/sample-filter.h" > > +#include "bpf_skel/sample_filter.skel.h" > > + > > +#define FD(e, x, y) (*(int *)xyarray__entry(e->core.fd, x, y)) > > + > > +int perf_bpf_filter__prepare(struct evsel *evsel) > > +{ > > + int i, x, y, fd; > > + struct sample_filter_bpf *skel; > > + struct bpf_program *prog; > > + struct bpf_link *link; > > + struct perf_bpf_filter_expr *expr; > > + > > + skel = sample_filter_bpf__open_and_load(); > > + if (!skel) { > > + pr_err("Failed to load perf sample-filter BPF skeleton\n"); > > + return -1; > > + } > > + > > + i = 0; > > + fd = bpf_map__fd(skel->maps.filters); > > + list_for_each_entry(expr, &evsel->bpf_filters, list) { > > + struct perf_bpf_filter_entry entry = { > > + .op = expr->op, > > + .flags = expr->sample_flags, > > + .value = expr->val, > > + }; > > + bpf_map_update_elem(fd, &i, &entry, BPF_ANY); > > + i++; > > + } > > + > > + prog = skel->progs.perf_sample_filter; > > + for (x = 0; x < xyarray__max_x(evsel->core.fd); x++) { > > + for (y = 0; y < xyarray__max_y(evsel->core.fd); y++) { > > + link = bpf_program__attach_perf_event(prog, FD(evsel, x, y)); > > + if (IS_ERR(link)) { > > + pr_err("Failed to attach perf sample-filter program\n"); > > + return PTR_ERR(link); > > + } > > + } > > + } > > + evsel->bpf_skel = skel; > > + return 0; > > +} > > + > > +int perf_bpf_filter__destroy(struct evsel *evsel) > > +{ > > + struct perf_bpf_filter_expr *expr, *tmp; > > + > > + list_for_each_entry_safe(expr, tmp, &evsel->bpf_filters, list) { > > + list_del(&expr->list); > > + free(expr); > > + } > > + sample_filter_bpf__destroy(evsel->bpf_skel); > > + return 0; > > +} > > + > > struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, > > enum perf_bpf_filter_op op, > > unsigned long val) > > diff --git a/tools/perf/util/bpf-filter.h b/tools/perf/util/bpf-filter.h > > index 93a0d3de038c..eb8e1ac43cdf 100644 > > --- a/tools/perf/util/bpf-filter.h > > +++ b/tools/perf/util/bpf-filter.h > > @@ -4,15 +4,7 @@ > > > > #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, > > -}; > > +#include "bpf_skel/sample-filter.h" > > > > struct perf_bpf_filter_expr { > > struct list_head list; > > @@ -21,16 +13,30 @@ struct perf_bpf_filter_expr { > > unsigned long val; > > }; > > > > +struct evsel; > > + > > #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); > > +int perf_bpf_filter__prepare(struct evsel *evsel); > > +int perf_bpf_filter__destroy(struct evsel *evsel); > > + > > #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; > > + return -EOPNOTSUPP; > > +} > > +static inline int perf_bpf_filter__prepare(struct evsel *evsel __maybe_unused) > > +{ > > + return -EOPNOTSUPP; > > +} > > +static inline int perf_bpf_filter__destroy(struct evsel *evsel __maybe_unused) > > +{ > > + return -EOPNOTSUPP; > > } > > #endif /* HAVE_BPF_SKEL*/ > > #endif /* PERF_UTIL_BPF_FILTER_H */ > > diff --git a/tools/perf/util/bpf_skel/sample-filter.h b/tools/perf/util/bpf_skel/sample-filter.h > > new file mode 100644 > > index 000000000000..862060bfda14 > > --- /dev/null > > +++ b/tools/perf/util/bpf_skel/sample-filter.h > > @@ -0,0 +1,24 @@ > > +#ifndef PERF_UTIL_BPF_SKEL_SAMPLE_FILTER_H > > +#define PERF_UTIL_BPF_SKEL_SAMPLE_FILTER_H > > + > > +#define MAX_FILTERS 32 > > + > > +/* supported filter operations */ > > +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 > > +}; > > + > > +/* BPF map entry for filtering */ > > +struct perf_bpf_filter_entry { > > + enum perf_bpf_filter_op op; > > + __u64 flags; > > + __u64 value; > > +}; > > + > > +#endif /* PERF_UTIL_BPF_SKEL_SAMPLE_FILTER_H */ > > \ No newline at end of file > > diff --git a/tools/perf/util/bpf_skel/sample_filter.bpf.c b/tools/perf/util/bpf_skel/sample_filter.bpf.c > > new file mode 100644 > > index 000000000000..c07256279c3e > > --- /dev/null > > +++ b/tools/perf/util/bpf_skel/sample_filter.bpf.c > > @@ -0,0 +1,126 @@ > > +// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > +// Copyright (c) 2023 Google > > +#include "vmlinux.h" > > +#include <bpf/bpf_helpers.h> > > +#include <bpf/bpf_tracing.h> > > +#include <bpf/bpf_core_read.h> > > + > > +#include "sample-filter.h" > > + > > +/* BPF map that will be filled by user space */ > > +struct filters { > > + __uint(type, BPF_MAP_TYPE_ARRAY); > > + __type(key, int); > > + __type(value, struct perf_bpf_filter_entry); > > + __uint(max_entries, MAX_FILTERS); > > +} filters SEC(".maps"); > > + > > +int dropped; > > + > > +void *bpf_cast_to_kern_ctx(void *) __ksym; > > + > > +/* new kernel perf_sample_data definition */ > > +struct perf_sample_data___new { > > + __u64 sample_flags; > > +} __attribute__((preserve_access_index)); > > + > > +/* helper function to return the given perf sample data */ > > +static inline __u64 perf_get_sample(struct bpf_perf_event_data_kern *kctx, > > + struct perf_bpf_filter_entry *entry) > > +{ > > + struct perf_sample_data___new *data = (void *)kctx->data; > > + > > + if (!bpf_core_field_exists(data->sample_flags) || > > + (data->sample_flags & entry->flags) == 0) > > + return 0; > > + > > + switch (entry->flags) { > > + case PERF_SAMPLE_IP: > > + return kctx->data->ip; > > + case PERF_SAMPLE_ID: > > + return kctx->data->id; > > + case PERF_SAMPLE_TID: > > + return kctx->data->tid_entry.tid; > > + case PERF_SAMPLE_CPU: > > + return kctx->data->cpu_entry.cpu; > > + case PERF_SAMPLE_TIME: > > + return kctx->data->time; > > + case PERF_SAMPLE_ADDR: > > + return kctx->data->addr; > > + case PERF_SAMPLE_PERIOD: > > + return kctx->data->period; > > + case PERF_SAMPLE_TRANSACTION: > > + return kctx->data->txn; > > + case PERF_SAMPLE_WEIGHT: > > + return kctx->data->weight.full; > > + case PERF_SAMPLE_PHYS_ADDR: > > + return kctx->data->phys_addr; > > + case PERF_SAMPLE_CODE_PAGE_SIZE: > > + return kctx->data->code_page_size; > > + case PERF_SAMPLE_DATA_PAGE_SIZE: > > + return kctx->data->data_page_size; > > + default: > > + break; > > + } > > + return 0; > > +} > > + > > +/* BPF program to be called from perf event overflow handler */ > > +SEC("perf_event") > > +int perf_sample_filter(void *ctx) > > +{ > > + struct bpf_perf_event_data_kern *kctx; > > + struct perf_bpf_filter_entry *entry; > > + __u64 sample_data; > > + int i; > > + > > + kctx = bpf_cast_to_kern_ctx(ctx); > > + > > + for (i = 0; i < MAX_FILTERS; i++) { > > + int key = i; /* needed for verifier :( */ > > + > > + entry = bpf_map_lookup_elem(&filters, &key); > > + if (entry == NULL) > > + break; > > + sample_data = perf_get_sample(kctx, entry); > > + > > + switch (entry->op) { > > + case PBF_OP_EQ: > > + if (!(sample_data == entry->value)) > > + goto drop; > > + break; > > + case PBF_OP_NEQ: > > + if (!(sample_data != entry->value)) > > + goto drop; > > + break; > > + case PBF_OP_GT: > > + if (!(sample_data > entry->value)) > > + goto drop; > > + break; > > + case PBF_OP_GE: > > + if (!(sample_data >= entry->value)) > > + goto drop; > > + break; > > + case PBF_OP_LT: > > + if (!(sample_data < entry->value)) > > + goto drop; > > + break; > > + case PBF_OP_LE: > > + if (!(sample_data <= entry->value)) > > + goto drop; > > + break; > > + case PBF_OP_AND: > > + if (!(sample_data & entry->value)) > > + goto drop; > > + break; > > + } > > + } > > + /* generate sample data */ > > + return 1; > > + > > +drop: > > + __sync_fetch_and_add(&dropped, 1); > > + return 0; > > +} > > + > > +char LICENSE[] SEC("license") = "Dual BSD/GPL"; > > diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h > > index c272c06565c0..68072ec655ce 100644 > > --- a/tools/perf/util/evsel.h > > +++ b/tools/perf/util/evsel.h > > @@ -150,8 +150,10 @@ struct evsel { > > */ > > struct bpf_counter_ops *bpf_counter_ops; > > > > - /* for perf-stat -b */ > > - struct list_head bpf_counter_list; > > + union { > > + struct list_head bpf_counter_list; /* for perf-stat -b */ > > + struct list_head bpf_filters; /* for perf-record --filter */ > > + }; > > > > /* for perf-stat --use-bpf */ > > int bperf_leader_prog_fd; > > @@ -159,6 +161,7 @@ struct evsel { > > union { > > struct bperf_leader_bpf *leader_skel; > > struct bperf_follower_bpf *follower_skel; > > + void *bpf_skel; > > }; > > unsigned long open_flags; > > int precise_ip_original; > > -- > > 2.40.0.rc1.284.g88254d51c5-goog > > > > -- > > - Arnaldo -- - Arnaldo
