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d19f856479
At some point I'll suggest moving this to libbpf, for now I'll experiment with ways to dump BPF maps set by events in 'perf trace', starting with a very basic dumper for the current very limited needs of the augmented_raw_syscalls code: dumping booleans. Having functions that apply to the map keys and values and do table lookup in things like syscall id to string tables should come next. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Martin KaFai Lau <kafai@fb.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Yonghong Song <yhs@fb.com> Link: https://lkml.kernel.org/n/tip-lz14w0esqyt1333aon05jpwc@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
72 lines
1.6 KiB
C
72 lines
1.6 KiB
C
// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
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#include "util/bpf_map.h"
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#include <bpf/bpf.h>
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#include <bpf/libbpf.h>
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include <unistd.h>
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static bool bpf_map_def__is_per_cpu(const struct bpf_map_def *def)
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{
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return def->type == BPF_MAP_TYPE_PERCPU_HASH ||
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def->type == BPF_MAP_TYPE_PERCPU_ARRAY ||
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def->type == BPF_MAP_TYPE_LRU_PERCPU_HASH ||
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def->type == BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE;
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}
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static void *bpf_map_def__alloc_value(const struct bpf_map_def *def)
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{
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if (bpf_map_def__is_per_cpu(def))
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return malloc(round_up(def->value_size, 8) * sysconf(_SC_NPROCESSORS_CONF));
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return malloc(def->value_size);
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}
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int bpf_map__fprintf(struct bpf_map *map, FILE *fp)
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{
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const struct bpf_map_def *def = bpf_map__def(map);
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void *prev_key = NULL, *key, *value;
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int fd = bpf_map__fd(map), err;
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int printed = 0;
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if (fd < 0)
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return fd;
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if (IS_ERR(def))
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return PTR_ERR(def);
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err = -ENOMEM;
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key = malloc(def->key_size);
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if (key == NULL)
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goto out;
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value = bpf_map_def__alloc_value(def);
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if (value == NULL)
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goto out_free_key;
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while ((err = bpf_map_get_next_key(fd, prev_key, key) == 0)) {
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int intkey = *(int *)key;
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if (!bpf_map_lookup_elem(fd, key, value)) {
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bool boolval = *(bool *)value;
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if (boolval)
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printed += fprintf(fp, "[%d] = %d,\n", intkey, boolval);
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} else {
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printed += fprintf(fp, "[%d] = ERROR,\n", intkey);
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}
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prev_key = key;
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}
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if (err == ENOENT)
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err = printed;
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free(value);
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out_free_key:
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free(key);
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out:
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return err;
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}
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