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
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <string.h>
|
|
#include <assert.h>
|
|
#include <bpf/libbpf.h>
|
|
#include <bpf/bpf.h>
|
|
#include "trace_helpers.h"
|
|
|
|
int main(int ac, char **argv)
|
|
{
|
|
struct bpf_object *obj = NULL;
|
|
struct bpf_link *links[20];
|
|
long key, next_key, value;
|
|
struct bpf_program *prog;
|
|
int map_fd, i, j = 0;
|
|
char filename[256];
|
|
struct ksym *sym;
|
|
|
|
if (load_kallsyms()) {
|
|
printf("failed to process /proc/kallsyms\n");
|
|
return 2;
|
|
}
|
|
|
|
snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
|
|
obj = bpf_object__open_file(filename, NULL);
|
|
if (libbpf_get_error(obj)) {
|
|
fprintf(stderr, "ERROR: opening BPF object file failed\n");
|
|
obj = NULL;
|
|
goto cleanup;
|
|
}
|
|
|
|
/* load BPF program */
|
|
if (bpf_object__load(obj)) {
|
|
fprintf(stderr, "ERROR: loading BPF object file failed\n");
|
|
goto cleanup;
|
|
}
|
|
|
|
map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
|
|
if (map_fd < 0) {
|
|
fprintf(stderr, "ERROR: finding a map in obj file failed\n");
|
|
goto cleanup;
|
|
}
|
|
|
|
bpf_object__for_each_program(prog, obj) {
|
|
links[j] = bpf_program__attach(prog);
|
|
if (libbpf_get_error(links[j])) {
|
|
fprintf(stderr, "bpf_program__attach failed\n");
|
|
links[j] = NULL;
|
|
goto cleanup;
|
|
}
|
|
j++;
|
|
}
|
|
|
|
for (i = 0; i < 5; i++) {
|
|
key = 0;
|
|
printf("kprobing funcs:");
|
|
while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
|
|
bpf_map_lookup_elem(map_fd, &next_key, &value);
|
|
assert(next_key == value);
|
|
sym = ksym_search(value);
|
|
key = next_key;
|
|
if (!sym) {
|
|
printf("ksym not found. Is kallsyms loaded?\n");
|
|
continue;
|
|
}
|
|
|
|
printf(" %s", sym->name);
|
|
}
|
|
if (key)
|
|
printf("\n");
|
|
key = 0;
|
|
while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0)
|
|
bpf_map_delete_elem(map_fd, &next_key);
|
|
sleep(1);
|
|
}
|
|
|
|
cleanup:
|
|
for (j--; j >= 0; j--)
|
|
bpf_link__destroy(links[j]);
|
|
|
|
bpf_object__close(obj);
|
|
return 0;
|
|
}
|