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456d53554c
With the introduction of kprobe.multi, it is now possible to attach
multiple kprobes to a single BPF program without the need for multiple
definitions. Additionally, this method supports wildcard-based
matching, allowing for further simplification of BPF programs. In here,
an asterisk (*) wildcard is used to map to all symbols relevant to
spin_{lock|unlock}.
Furthermore, since kprobe.multi handles symbol matching, this commit
eliminates the need for the previous logic of reading the ksym table to
verify the existence of symbols.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-10-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
85 lines
1.8 KiB
C
85 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <stdio.h>
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#include <unistd.h>
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#include <string.h>
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#include <assert.h>
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#include <bpf/libbpf.h>
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#include <bpf/bpf.h>
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#include "trace_helpers.h"
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int main(int ac, char **argv)
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{
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struct bpf_object *obj = NULL;
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struct bpf_link *links[20];
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long key, next_key, value;
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struct bpf_program *prog;
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int map_fd, i, j = 0;
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char filename[256];
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struct ksym *sym;
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if (load_kallsyms()) {
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printf("failed to process /proc/kallsyms\n");
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return 2;
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}
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snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
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obj = bpf_object__open_file(filename, NULL);
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if (libbpf_get_error(obj)) {
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fprintf(stderr, "ERROR: opening BPF object file failed\n");
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obj = NULL;
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goto cleanup;
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}
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/* load BPF program */
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if (bpf_object__load(obj)) {
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fprintf(stderr, "ERROR: loading BPF object file failed\n");
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goto cleanup;
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}
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map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
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if (map_fd < 0) {
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fprintf(stderr, "ERROR: finding a map in obj file failed\n");
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goto cleanup;
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}
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bpf_object__for_each_program(prog, obj) {
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links[j] = bpf_program__attach(prog);
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if (libbpf_get_error(links[j])) {
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fprintf(stderr, "bpf_program__attach failed\n");
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links[j] = NULL;
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goto cleanup;
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}
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j++;
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}
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for (i = 0; i < 5; i++) {
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key = 0;
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printf("kprobing funcs:");
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while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
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bpf_map_lookup_elem(map_fd, &next_key, &value);
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assert(next_key == value);
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sym = ksym_search(value);
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key = next_key;
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if (!sym) {
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printf("ksym not found. Is kallsyms loaded?\n");
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continue;
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}
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printf(" %s", sym->name);
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}
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if (key)
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printf("\n");
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key = 0;
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while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0)
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bpf_map_delete_elem(map_fd, &next_key);
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sleep(1);
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}
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cleanup:
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for (j--; j >= 0; j--)
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bpf_link__destroy(links[j]);
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bpf_object__close(obj);
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return 0;
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}
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