From a742258af131e570a68ad8cf16cd2cc4692675a0 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Mon, 11 Mar 2019 22:30:40 -0700 Subject: [PATCH] perf bpf: Synthesize bpf events with bpf_program__get_prog_info_linear() With bpf_program__get_prog_info_linear, we can simplify the logic that synthesizes bpf events. This patch doesn't change the behavior of the code. Commiter notes: Needed this (for all four variables), suggested by Song, to overcome build failure on debian experimental cross building to MIPS 32-bit: - u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(info->prog_tags); + u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags); util/bpf-event.c: In function 'perf_event__synthesize_one_bpf_prog': util/bpf-event.c:143:35: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(info->prog_tags); ^ util/bpf-event.c:144:22: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] __u32 *prog_lens = (__u32 *)(info->jited_func_lens); ^ util/bpf-event.c:145:23: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] __u64 *prog_addrs = (__u64 *)(info->jited_ksyms); ^ util/bpf-event.c:146:22: error: cast to pointer from integer of different size [-Werror=int-to-pointer-cast] void *func_infos = (void *)(info->func_info); ^ cc1: all warnings being treated as errors Signed-off-by: Song Liu Reviewed-by: Jiri Olsa Cc: Alexei Starovoitov Cc: Daniel Borkmann Cc: kernel-team@fb.com Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stanislav Fomichev Link: http://lkml.kernel.org/r/20190312053051.2690567-5-songliubraving@fb.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/bpf-event.c | 118 +++++++++++++++----------------------------- 1 file changed, 40 insertions(+), 78 deletions(-) diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index ea012b7..e0cbe7f 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -3,7 +3,9 @@ #include #include #include +#include #include +#include #include "bpf-event.h" #include "debug.h" #include "symbol.h" @@ -49,99 +51,62 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool, { struct ksymbol_event *ksymbol_event = &event->ksymbol_event; struct bpf_event *bpf_event = &event->bpf_event; - u32 sub_prog_cnt, i, func_info_rec_size = 0; - u8 (*prog_tags)[BPF_TAG_SIZE] = NULL; - struct bpf_prog_info info = { .type = 0, }; - u32 info_len = sizeof(info); - void *func_infos = NULL; - u64 *prog_addrs = NULL; + struct bpf_prog_info_linear *info_linear; + struct bpf_prog_info *info; struct btf *btf = NULL; - u32 *prog_lens = NULL; bool has_btf = false; - char errbuf[512]; + u32 sub_prog_cnt, i; int err = 0; + u64 arrays; - /* Call bpf_obj_get_info_by_fd() to get sizes of arrays */ - err = bpf_obj_get_info_by_fd(fd, &info, &info_len); + arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS; + arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS; + arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO; + arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS; - if (err) { - pr_debug("%s: failed to get BPF program info: %s, aborting\n", - __func__, str_error_r(errno, errbuf, sizeof(errbuf))); + info_linear = bpf_program__get_prog_info_linear(fd, arrays); + if (IS_ERR_OR_NULL(info_linear)) { + info_linear = NULL; + pr_debug("%s: failed to get BPF program info. aborting\n", __func__); return -1; } - if (info_len < offsetof(struct bpf_prog_info, prog_tags)) { + + if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) { pr_debug("%s: the kernel is too old, aborting\n", __func__); return -2; } + info = &info_linear->info; + /* number of ksyms, func_lengths, and tags should match */ - sub_prog_cnt = info.nr_jited_ksyms; - if (sub_prog_cnt != info.nr_prog_tags || - sub_prog_cnt != info.nr_jited_func_lens) + sub_prog_cnt = info->nr_jited_ksyms; + if (sub_prog_cnt != info->nr_prog_tags || + sub_prog_cnt != info->nr_jited_func_lens) return -1; /* check BTF func info support */ - if (info.btf_id && info.nr_func_info && info.func_info_rec_size) { + if (info->btf_id && info->nr_func_info && info->func_info_rec_size) { /* btf func info number should be same as sub_prog_cnt */ - if (sub_prog_cnt != info.nr_func_info) { + if (sub_prog_cnt != info->nr_func_info) { pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__); - return -1; - } - if (btf__get_from_id(info.btf_id, &btf)) { - pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info.btf_id); - return -1; + err = -1; + goto out; } - func_info_rec_size = info.func_info_rec_size; - func_infos = calloc(sub_prog_cnt, func_info_rec_size); - if (!func_infos) { - pr_debug("%s: failed to allocate memory for func_infos, aborting\n", __func__); - return -1; + if (btf__get_from_id(info->btf_id, &btf)) { + pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id); + err = -1; + btf = NULL; + goto out; } has_btf = true; } - /* - * We need address, length, and tag for each sub program. - * Allocate memory and call bpf_obj_get_info_by_fd() again - */ - prog_addrs = calloc(sub_prog_cnt, sizeof(u64)); - if (!prog_addrs) { - pr_debug("%s: failed to allocate memory for prog_addrs, aborting\n", __func__); - goto out; - } - prog_lens = calloc(sub_prog_cnt, sizeof(u32)); - if (!prog_lens) { - pr_debug("%s: failed to allocate memory for prog_lens, aborting\n", __func__); - goto out; - } - prog_tags = calloc(sub_prog_cnt, BPF_TAG_SIZE); - if (!prog_tags) { - pr_debug("%s: failed to allocate memory for prog_tags, aborting\n", __func__); - goto out; - } - - memset(&info, 0, sizeof(info)); - info.nr_jited_ksyms = sub_prog_cnt; - info.nr_jited_func_lens = sub_prog_cnt; - info.nr_prog_tags = sub_prog_cnt; - info.jited_ksyms = ptr_to_u64(prog_addrs); - info.jited_func_lens = ptr_to_u64(prog_lens); - info.prog_tags = ptr_to_u64(prog_tags); - info_len = sizeof(info); - if (has_btf) { - info.nr_func_info = sub_prog_cnt; - info.func_info_rec_size = func_info_rec_size; - info.func_info = ptr_to_u64(func_infos); - } - - err = bpf_obj_get_info_by_fd(fd, &info, &info_len); - if (err) { - pr_debug("%s: failed to get BPF program info, aborting\n", __func__); - goto out; - } - /* Synthesize PERF_RECORD_KSYMBOL */ for (i = 0; i < sub_prog_cnt; i++) { + u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags); + __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); + __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); + void *func_infos = (void *)(uintptr_t)(info->func_info); const struct bpf_func_info *finfo; const char *short_name = NULL; const struct btf_type *t; @@ -163,13 +128,13 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool, KSYM_NAME_LEN - name_len, prog_tags[i], BPF_TAG_SIZE); if (has_btf) { - finfo = func_infos + i * info.func_info_rec_size; + finfo = func_infos + i * info->func_info_rec_size; t = btf__type_by_id(btf, finfo->type_id); short_name = btf__name_by_offset(btf, t->name_off); } else if (i == 0 && sub_prog_cnt == 1) { /* no subprog */ - if (info.name[0]) - short_name = info.name; + if (info->name[0]) + short_name = info->name; } else short_name = "F"; if (short_name) @@ -195,9 +160,9 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool, }, .type = PERF_BPF_EVENT_PROG_LOAD, .flags = 0, - .id = info.id, + .id = info->id, }; - memcpy(bpf_event->tag, prog_tags[i], BPF_TAG_SIZE); + memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE); memset((void *)event + event->header.size, 0, machine->id_hdr_size); event->header.size += machine->id_hdr_size; err = perf_tool__process_synth_event(tool, event, @@ -205,10 +170,7 @@ static int perf_event__synthesize_one_bpf_prog(struct perf_tool *tool, } out: - free(prog_tags); - free(prog_lens); - free(prog_addrs); - free(func_infos); + free(info_linear); free(btf); return err ? -1 : 0; } -- 2.7.4