![Daniel T. Lee](/assets/img/avatar_default.png)
Since, ksym_search added with verification logic for symbols existence, it could return NULL when the kernel symbols are not loaded. This commit will add NULL check logic after ksym_search. Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
58 lines
1.2 KiB
C
58 lines
1.2 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 <linux/bpf.h>
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#include <string.h>
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#include <assert.h>
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#include <sys/resource.h>
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#include "libbpf.h"
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#include "bpf_load.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 rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
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long key, next_key, value;
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char filename[256];
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struct ksym *sym;
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int i;
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snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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setrlimit(RLIMIT_MEMLOCK, &r);
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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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if (load_bpf_file(filename)) {
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printf("%s", bpf_log_buf);
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return 1;
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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[0], &key, &next_key) == 0) {
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bpf_map_lookup_elem(map_fd[0], &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[0], &key, &next_key) == 0)
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bpf_map_delete_elem(map_fd[0], &next_key);
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sleep(1);
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}
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return 0;
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}
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