261 lines
7.0 KiB
C
261 lines
7.0 KiB
C
|
// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
|
||
|
|
|
||
|
|
#ifndef _GNU_SOURCE
|
||
|
|
#define _GNU_SOURCE
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#include <errno.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <linux/err.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <bpf/bpf.h>
|
||
|
|
#include "bpf-utils.h"
|
||
|
|
#include "debug.h"
|
||
|
|
|
||
|
|
struct bpil_array_desc {
|
||
|
|
int array_offset; /* e.g. offset of jited_prog_insns */
|
||
|
|
int count_offset; /* e.g. offset of jited_prog_len */
|
||
|
|
int size_offset; /* > 0: offset of rec size,
|
||
|
|
* < 0: fix size of -size_offset
|
||
|
|
*/
|
||
|
|
};
|
||
|
|
|
||
|
|
static struct bpil_array_desc bpil_array_desc[] = {
|
||
|
|
[PERF_BPIL_JITED_INSNS] = {
|
||
|
|
offsetof(struct bpf_prog_info, jited_prog_insns),
|
||
|
|
offsetof(struct bpf_prog_info, jited_prog_len),
|
||
|
|
-1,
|
||
|
|
},
|
||
|
|
[PERF_BPIL_XLATED_INSNS] = {
|
||
|
|
offsetof(struct bpf_prog_info, xlated_prog_insns),
|
||
|
|
offsetof(struct bpf_prog_info, xlated_prog_len),
|
||
|
|
-1,
|
||
|
|
},
|
||
|
|
[PERF_BPIL_MAP_IDS] = {
|
||
|
|
offsetof(struct bpf_prog_info, map_ids),
|
||
|
|
offsetof(struct bpf_prog_info, nr_map_ids),
|
||
|
|
-(int)sizeof(__u32),
|
||
|
|
},
|
||
|
|
[PERF_BPIL_JITED_KSYMS] = {
|
||
|
|
offsetof(struct bpf_prog_info, jited_ksyms),
|
||
|
|
offsetof(struct bpf_prog_info, nr_jited_ksyms),
|
||
|
|
-(int)sizeof(__u64),
|
||
|
|
},
|
||
|
|
[PERF_BPIL_JITED_FUNC_LENS] = {
|
||
|
|
offsetof(struct bpf_prog_info, jited_func_lens),
|
||
|
|
offsetof(struct bpf_prog_info, nr_jited_func_lens),
|
||
|
|
-(int)sizeof(__u32),
|
||
|
|
},
|
||
|
|
[PERF_BPIL_FUNC_INFO] = {
|
||
|
|
offsetof(struct bpf_prog_info, func_info),
|
||
|
|
offsetof(struct bpf_prog_info, nr_func_info),
|
||
|
|
offsetof(struct bpf_prog_info, func_info_rec_size),
|
||
|
|
},
|
||
|
|
[PERF_BPIL_LINE_INFO] = {
|
||
|
|
offsetof(struct bpf_prog_info, line_info),
|
||
|
|
offsetof(struct bpf_prog_info, nr_line_info),
|
||
|
|
offsetof(struct bpf_prog_info, line_info_rec_size),
|
||
|
|
},
|
||
|
|
[PERF_BPIL_JITED_LINE_INFO] = {
|
||
|
|
offsetof(struct bpf_prog_info, jited_line_info),
|
||
|
|
offsetof(struct bpf_prog_info, nr_jited_line_info),
|
||
|
|
offsetof(struct bpf_prog_info, jited_line_info_rec_size),
|
||
|
|
},
|
||
|
|
[PERF_BPIL_PROG_TAGS] = {
|
||
|
|
offsetof(struct bpf_prog_info, prog_tags),
|
||
|
|
offsetof(struct bpf_prog_info, nr_prog_tags),
|
||
|
|
-(int)sizeof(__u8) * BPF_TAG_SIZE,
|
||
|
|
},
|
||
|
|
|
||
|
|
};
|
||
|
|
|
||
|
|
static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info,
|
||
|
|
int offset)
|
||
|
|
{
|
||
|
|
__u32 *array = (__u32 *)info;
|
||
|
|
|
||
|
|
if (offset >= 0)
|
||
|
|
return array[offset / sizeof(__u32)];
|
||
|
|
return -(int)offset;
|
||
|
|
}
|
||
|
|
|
||
|
|
static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info,
|
||
|
|
int offset)
|
||
|
|
{
|
||
|
|
__u64 *array = (__u64 *)info;
|
||
|
|
|
||
|
|
if (offset >= 0)
|
||
|
|
return array[offset / sizeof(__u64)];
|
||
|
|
return -(int)offset;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset,
|
||
|
|
__u32 val)
|
||
|
|
{
|
||
|
|
__u32 *array = (__u32 *)info;
|
||
|
|
|
||
|
|
if (offset >= 0)
|
||
|
|
array[offset / sizeof(__u32)] = val;
|
||
|
|
}
|
||
|
|
|
||
|
|
static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset,
|
||
|
|
__u64 val)
|
||
|
|
{
|
||
|
|
__u64 *array = (__u64 *)info;
|
||
|
|
|
||
|
|
if (offset >= 0)
|
||
|
|
array[offset / sizeof(__u64)] = val;
|
||
|
|
}
|
||
|
|
|
||
|
|
struct perf_bpil *
|
||
|
|
get_bpf_prog_info_linear(int fd, __u64 arrays)
|
||
|
|
{
|
||
|
|
struct bpf_prog_info info = {};
|
||
|
|
struct perf_bpil *info_linear;
|
||
|
|
__u32 info_len = sizeof(info);
|
||
|
|
__u32 data_len = 0;
|
||
|
|
int i, err;
|
||
|
|
void *ptr;
|
||
|
|
|
||
|
|
if (arrays >> PERF_BPIL_LAST_ARRAY)
|
||
|
|
return ERR_PTR(-EINVAL);
|
||
|
|
|
||
|
|
/* step 1: get array dimensions */
|
||
|
|
err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
|
||
|
|
if (err) {
|
||
|
|
pr_debug("can't get prog info: %s", strerror(errno));
|
||
|
|
return ERR_PTR(-EFAULT);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* step 2: calculate total size of all arrays */
|
||
|
|
for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) {
|
||
|
|
bool include_array = (arrays & (1UL << i)) > 0;
|
||
|
|
struct bpil_array_desc *desc;
|
||
|
|
__u32 count, size;
|
||
|
|
|
||
|
|
desc = bpil_array_desc + i;
|
||
|
|
|
||
|
|
/* kernel is too old to support this field */
|
||
|
|
if (info_len < desc->array_offset + sizeof(__u32) ||
|
||
|
|
info_len < desc->count_offset + sizeof(__u32) ||
|
||
|
|
(desc->size_offset > 0 && info_len < (__u32)desc->size_offset))
|
||
|
|
include_array = false;
|
||
|
|
|
||
|
|
if (!include_array) {
|
||
|
|
arrays &= ~(1UL << i); /* clear the bit */
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
|
||
|
|
size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
|
||
|
|
|
||
|
|
data_len += roundup(count * size, sizeof(__u64));
|
||
|
|
}
|
||
|
|
|
||
|
|
/* step 3: allocate continuous memory */
|
||
|
|
info_linear = malloc(sizeof(struct perf_bpil) + data_len);
|
||
|
|
if (!info_linear)
|
||
|
|
return ERR_PTR(-ENOMEM);
|
||
|
|
|
||
|
|
/* step 4: fill data to info_linear->info */
|
||
|
|
info_linear->arrays = arrays;
|
||
|
|
memset(&info_linear->info, 0, sizeof(info));
|
||
|
|
ptr = info_linear->data;
|
||
|
|
|
||
|
|
for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) {
|
||
|
|
struct bpil_array_desc *desc;
|
||
|
|
__u32 count, size;
|
||
|
|
|
||
|
|
if ((arrays & (1UL << i)) == 0)
|
||
|
|
continue;
|
||
|
|
|
||
|
|
desc = bpil_array_desc + i;
|
||
|
|
count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
|
||
|
|
size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
|
||
|
|
bpf_prog_info_set_offset_u32(&info_linear->info,
|
||
|
|
desc->count_offset, count);
|
||
|
|
bpf_prog_info_set_offset_u32(&info_linear->info,
|
||
|
|
desc->size_offset, size);
|
||
|
|
bpf_prog_info_set_offset_u64(&info_linear->info,
|
||
|
|
desc->array_offset,
|
||
|
|
ptr_to_u64(ptr));
|
||
|
|
ptr += roundup(count * size, sizeof(__u64));
|
||
|
|
}
|
||
|
|
|
||
|
|
/* step 5: call syscall again to get required arrays */
|
||
|
|
err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len);
|
||
|
|
if (err) {
|
||
|
|
pr_debug("can't get prog info: %s", strerror(errno));
|
||
|
|
free(info_linear);
|
||
|
|
return ERR_PTR(-EFAULT);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* step 6: verify the data */
|
||
|
|
for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) {
|
||
|
|
struct bpil_array_desc *desc;
|
||
|
|
__u32 v1, v2;
|
||
|
|
|
||
|
|
if ((arrays & (1UL << i)) == 0)
|
||
|
|
continue;
|
||
|
|
|
||
|
|
desc = bpil_array_desc + i;
|
||
|
|
v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
|
||
|
|
v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
|
||
|
|
desc->count_offset);
|
||
|
|
if (v1 != v2)
|
||
|
|
pr_warning("%s: mismatch in element count\n", __func__);
|
||
|
|
|
||
|
|
v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
|
||
|
|
v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
|
||
|
|
desc->size_offset);
|
||
|
|
if (v1 != v2)
|
||
|
|
pr_warning("%s: mismatch in rec size\n", __func__);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* step 7: update info_len and data_len */
|
||
|
|
info_linear->info_len = sizeof(struct bpf_prog_info);
|
||
|
|
info_linear->data_len = data_len;
|
||
|
|
|
||
|
|
return info_linear;
|
||
|
|
}
|
||
|
|
|
||
|
|
void bpil_addr_to_offs(struct perf_bpil *info_linear)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) {
|
||
|
|
struct bpil_array_desc *desc;
|
||
|
|
__u64 addr, offs;
|
||
|
|
|
||
|
|
if ((info_linear->arrays & (1UL << i)) == 0)
|
||
|
|
continue;
|
||
|
|
|
||
|
|
desc = bpil_array_desc + i;
|
||
|
|
addr = bpf_prog_info_read_offset_u64(&info_linear->info,
|
||
|
|
desc->array_offset);
|
||
|
|
offs = addr - ptr_to_u64(info_linear->data);
|
||
|
|
bpf_prog_info_set_offset_u64(&info_linear->info,
|
||
|
|
desc->array_offset, offs);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void bpil_offs_to_addr(struct perf_bpil *info_linear)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
for (i = PERF_BPIL_FIRST_ARRAY; i < PERF_BPIL_LAST_ARRAY; ++i) {
|
||
|
|
struct bpil_array_desc *desc;
|
||
|
|
__u64 addr, offs;
|
||
|
|
|
||
|
|
if ((info_linear->arrays & (1UL << i)) == 0)
|
||
|
|
continue;
|
||
|
|
|
||
|
|
desc = bpil_array_desc + i;
|
||
|
|
offs = bpf_prog_info_read_offset_u64(&info_linear->info,
|
||
|
|
desc->array_offset);
|
||
|
|
addr = offs + ptr_to_u64(info_linear->data);
|
||
|
|
bpf_prog_info_set_offset_u64(&info_linear->info,
|
||
|
|
desc->array_offset, addr);
|
||
|
|
}
|
||
|
|
}
|