Linux Audio

Check our new training course

Loading...
v6.2
  1// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
  2/* Copyright (c) 2018 Facebook */
  3
  4#include <string.h>
  5#include <stdlib.h>
  6#include <linux/err.h>
  7#include <linux/bpf.h>
  8#include "libbpf.h"
  9#include "libbpf_internal.h"
 10
 11struct bpf_prog_linfo {
 12	void *raw_linfo;
 13	void *raw_jited_linfo;
 14	__u32 *nr_jited_linfo_per_func;
 15	__u32 *jited_linfo_func_idx;
 16	__u32 nr_linfo;
 17	__u32 nr_jited_func;
 18	__u32 rec_size;
 19	__u32 jited_rec_size;
 20};
 21
 22static int dissect_jited_func(struct bpf_prog_linfo *prog_linfo,
 23			      const __u64 *ksym_func, const __u32 *ksym_len)
 24{
 25	__u32 nr_jited_func, nr_linfo;
 26	const void *raw_jited_linfo;
 27	const __u64 *jited_linfo;
 28	__u64 last_jited_linfo;
 29	/*
 30	 * Index to raw_jited_linfo:
 31	 *      i: Index for searching the next ksym_func
 32	 * prev_i: Index to the last found ksym_func
 33	 */
 34	__u32 i, prev_i;
 35	__u32 f; /* Index to ksym_func */
 36
 37	raw_jited_linfo = prog_linfo->raw_jited_linfo;
 38	jited_linfo = raw_jited_linfo;
 39	if (ksym_func[0] != *jited_linfo)
 40		goto errout;
 41
 42	prog_linfo->jited_linfo_func_idx[0] = 0;
 43	nr_jited_func = prog_linfo->nr_jited_func;
 44	nr_linfo = prog_linfo->nr_linfo;
 45
 46	for (prev_i = 0, i = 1, f = 1;
 47	     i < nr_linfo && f < nr_jited_func;
 48	     i++) {
 49		raw_jited_linfo += prog_linfo->jited_rec_size;
 50		last_jited_linfo = *jited_linfo;
 51		jited_linfo = raw_jited_linfo;
 52
 53		if (ksym_func[f] == *jited_linfo) {
 54			prog_linfo->jited_linfo_func_idx[f] = i;
 55
 56			/* Sanity check */
 57			if (last_jited_linfo - ksym_func[f - 1] + 1 >
 58			    ksym_len[f - 1])
 59				goto errout;
 60
 61			prog_linfo->nr_jited_linfo_per_func[f - 1] =
 62				i - prev_i;
 63			prev_i = i;
 64
 65			/*
 66			 * The ksym_func[f] is found in jited_linfo.
 67			 * Look for the next one.
 68			 */
 69			f++;
 70		} else if (*jited_linfo <= last_jited_linfo) {
 71			/* Ensure the addr is increasing _within_ a func */
 72			goto errout;
 73		}
 74	}
 75
 76	if (f != nr_jited_func)
 77		goto errout;
 78
 79	prog_linfo->nr_jited_linfo_per_func[nr_jited_func - 1] =
 80		nr_linfo - prev_i;
 81
 82	return 0;
 83
 84errout:
 85	return -EINVAL;
 86}
 87
 88void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo)
 89{
 90	if (!prog_linfo)
 91		return;
 92
 93	free(prog_linfo->raw_linfo);
 94	free(prog_linfo->raw_jited_linfo);
 95	free(prog_linfo->nr_jited_linfo_per_func);
 96	free(prog_linfo->jited_linfo_func_idx);
 97	free(prog_linfo);
 98}
 99
100struct bpf_prog_linfo *bpf_prog_linfo__new(const struct bpf_prog_info *info)
101{
102	struct bpf_prog_linfo *prog_linfo;
103	__u32 nr_linfo, nr_jited_func;
104	__u64 data_sz;
105
106	nr_linfo = info->nr_line_info;
107
108	if (!nr_linfo)
109		return errno = EINVAL, NULL;
110
111	/*
112	 * The min size that bpf_prog_linfo has to access for
113	 * searching purpose.
114	 */
115	if (info->line_info_rec_size <
116	    offsetof(struct bpf_line_info, file_name_off))
117		return errno = EINVAL, NULL;
118
119	prog_linfo = calloc(1, sizeof(*prog_linfo));
120	if (!prog_linfo)
121		return errno = ENOMEM, NULL;
122
123	/* Copy xlated line_info */
124	prog_linfo->nr_linfo = nr_linfo;
125	prog_linfo->rec_size = info->line_info_rec_size;
126	data_sz = (__u64)nr_linfo * prog_linfo->rec_size;
127	prog_linfo->raw_linfo = malloc(data_sz);
128	if (!prog_linfo->raw_linfo)
129		goto err_free;
130	memcpy(prog_linfo->raw_linfo, (void *)(long)info->line_info, data_sz);
131
132	nr_jited_func = info->nr_jited_ksyms;
133	if (!nr_jited_func ||
134	    !info->jited_line_info ||
135	    info->nr_jited_line_info != nr_linfo ||
136	    info->jited_line_info_rec_size < sizeof(__u64) ||
137	    info->nr_jited_func_lens != nr_jited_func ||
138	    !info->jited_ksyms ||
139	    !info->jited_func_lens)
140		/* Not enough info to provide jited_line_info */
141		return prog_linfo;
142
143	/* Copy jited_line_info */
144	prog_linfo->nr_jited_func = nr_jited_func;
145	prog_linfo->jited_rec_size = info->jited_line_info_rec_size;
146	data_sz = (__u64)nr_linfo * prog_linfo->jited_rec_size;
147	prog_linfo->raw_jited_linfo = malloc(data_sz);
148	if (!prog_linfo->raw_jited_linfo)
149		goto err_free;
150	memcpy(prog_linfo->raw_jited_linfo,
151	       (void *)(long)info->jited_line_info, data_sz);
152
153	/* Number of jited_line_info per jited func */
154	prog_linfo->nr_jited_linfo_per_func = malloc(nr_jited_func *
155						     sizeof(__u32));
156	if (!prog_linfo->nr_jited_linfo_per_func)
157		goto err_free;
158
159	/*
160	 * For each jited func,
161	 * the start idx to the "linfo" and "jited_linfo" array,
162	 */
163	prog_linfo->jited_linfo_func_idx = malloc(nr_jited_func *
164						  sizeof(__u32));
165	if (!prog_linfo->jited_linfo_func_idx)
166		goto err_free;
167
168	if (dissect_jited_func(prog_linfo,
169			       (__u64 *)(long)info->jited_ksyms,
170			       (__u32 *)(long)info->jited_func_lens))
171		goto err_free;
172
173	return prog_linfo;
174
175err_free:
176	bpf_prog_linfo__free(prog_linfo);
177	return errno = EINVAL, NULL;
178}
179
180const struct bpf_line_info *
181bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
182				__u64 addr, __u32 func_idx, __u32 nr_skip)
183{
184	__u32 jited_rec_size, rec_size, nr_linfo, start, i;
185	const void *raw_jited_linfo, *raw_linfo;
186	const __u64 *jited_linfo;
187
188	if (func_idx >= prog_linfo->nr_jited_func)
189		return errno = ENOENT, NULL;
190
191	nr_linfo = prog_linfo->nr_jited_linfo_per_func[func_idx];
192	if (nr_skip >= nr_linfo)
193		return errno = ENOENT, NULL;
194
195	start = prog_linfo->jited_linfo_func_idx[func_idx] + nr_skip;
196	jited_rec_size = prog_linfo->jited_rec_size;
197	raw_jited_linfo = prog_linfo->raw_jited_linfo +
198		(start * jited_rec_size);
199	jited_linfo = raw_jited_linfo;
200	if (addr < *jited_linfo)
201		return errno = ENOENT, NULL;
202
203	nr_linfo -= nr_skip;
204	rec_size = prog_linfo->rec_size;
205	raw_linfo = prog_linfo->raw_linfo + (start * rec_size);
206	for (i = 0; i < nr_linfo; i++) {
207		if (addr < *jited_linfo)
208			break;
209
210		raw_linfo += rec_size;
211		raw_jited_linfo += jited_rec_size;
212		jited_linfo = raw_jited_linfo;
213	}
214
215	return raw_linfo - rec_size;
216}
217
218const struct bpf_line_info *
219bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
220		      __u32 insn_off, __u32 nr_skip)
221{
222	const struct bpf_line_info *linfo;
223	__u32 rec_size, nr_linfo, i;
224	const void *raw_linfo;
225
226	nr_linfo = prog_linfo->nr_linfo;
227	if (nr_skip >= nr_linfo)
228		return errno = ENOENT, NULL;
229
230	rec_size = prog_linfo->rec_size;
231	raw_linfo = prog_linfo->raw_linfo + (nr_skip * rec_size);
232	linfo = raw_linfo;
233	if (insn_off < linfo->insn_off)
234		return errno = ENOENT, NULL;
235
236	nr_linfo -= nr_skip;
237	for (i = 0; i < nr_linfo; i++) {
238		if (insn_off < linfo->insn_off)
239			break;
240
241		raw_linfo += rec_size;
242		linfo = raw_linfo;
243	}
244
245	return raw_linfo - rec_size;
246}
v6.9.4
  1// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
  2/* Copyright (c) 2018 Facebook */
  3
  4#include <string.h>
  5#include <stdlib.h>
  6#include <linux/err.h>
  7#include <linux/bpf.h>
  8#include "libbpf.h"
  9#include "libbpf_internal.h"
 10
 11struct bpf_prog_linfo {
 12	void *raw_linfo;
 13	void *raw_jited_linfo;
 14	__u32 *nr_jited_linfo_per_func;
 15	__u32 *jited_linfo_func_idx;
 16	__u32 nr_linfo;
 17	__u32 nr_jited_func;
 18	__u32 rec_size;
 19	__u32 jited_rec_size;
 20};
 21
 22static int dissect_jited_func(struct bpf_prog_linfo *prog_linfo,
 23			      const __u64 *ksym_func, const __u32 *ksym_len)
 24{
 25	__u32 nr_jited_func, nr_linfo;
 26	const void *raw_jited_linfo;
 27	const __u64 *jited_linfo;
 28	__u64 last_jited_linfo;
 29	/*
 30	 * Index to raw_jited_linfo:
 31	 *      i: Index for searching the next ksym_func
 32	 * prev_i: Index to the last found ksym_func
 33	 */
 34	__u32 i, prev_i;
 35	__u32 f; /* Index to ksym_func */
 36
 37	raw_jited_linfo = prog_linfo->raw_jited_linfo;
 38	jited_linfo = raw_jited_linfo;
 39	if (ksym_func[0] != *jited_linfo)
 40		goto errout;
 41
 42	prog_linfo->jited_linfo_func_idx[0] = 0;
 43	nr_jited_func = prog_linfo->nr_jited_func;
 44	nr_linfo = prog_linfo->nr_linfo;
 45
 46	for (prev_i = 0, i = 1, f = 1;
 47	     i < nr_linfo && f < nr_jited_func;
 48	     i++) {
 49		raw_jited_linfo += prog_linfo->jited_rec_size;
 50		last_jited_linfo = *jited_linfo;
 51		jited_linfo = raw_jited_linfo;
 52
 53		if (ksym_func[f] == *jited_linfo) {
 54			prog_linfo->jited_linfo_func_idx[f] = i;
 55
 56			/* Sanity check */
 57			if (last_jited_linfo - ksym_func[f - 1] + 1 >
 58			    ksym_len[f - 1])
 59				goto errout;
 60
 61			prog_linfo->nr_jited_linfo_per_func[f - 1] =
 62				i - prev_i;
 63			prev_i = i;
 64
 65			/*
 66			 * The ksym_func[f] is found in jited_linfo.
 67			 * Look for the next one.
 68			 */
 69			f++;
 70		} else if (*jited_linfo <= last_jited_linfo) {
 71			/* Ensure the addr is increasing _within_ a func */
 72			goto errout;
 73		}
 74	}
 75
 76	if (f != nr_jited_func)
 77		goto errout;
 78
 79	prog_linfo->nr_jited_linfo_per_func[nr_jited_func - 1] =
 80		nr_linfo - prev_i;
 81
 82	return 0;
 83
 84errout:
 85	return -EINVAL;
 86}
 87
 88void bpf_prog_linfo__free(struct bpf_prog_linfo *prog_linfo)
 89{
 90	if (!prog_linfo)
 91		return;
 92
 93	free(prog_linfo->raw_linfo);
 94	free(prog_linfo->raw_jited_linfo);
 95	free(prog_linfo->nr_jited_linfo_per_func);
 96	free(prog_linfo->jited_linfo_func_idx);
 97	free(prog_linfo);
 98}
 99
100struct bpf_prog_linfo *bpf_prog_linfo__new(const struct bpf_prog_info *info)
101{
102	struct bpf_prog_linfo *prog_linfo;
103	__u32 nr_linfo, nr_jited_func;
104	__u64 data_sz;
105
106	nr_linfo = info->nr_line_info;
107
108	if (!nr_linfo)
109		return errno = EINVAL, NULL;
110
111	/*
112	 * The min size that bpf_prog_linfo has to access for
113	 * searching purpose.
114	 */
115	if (info->line_info_rec_size <
116	    offsetof(struct bpf_line_info, file_name_off))
117		return errno = EINVAL, NULL;
118
119	prog_linfo = calloc(1, sizeof(*prog_linfo));
120	if (!prog_linfo)
121		return errno = ENOMEM, NULL;
122
123	/* Copy xlated line_info */
124	prog_linfo->nr_linfo = nr_linfo;
125	prog_linfo->rec_size = info->line_info_rec_size;
126	data_sz = (__u64)nr_linfo * prog_linfo->rec_size;
127	prog_linfo->raw_linfo = malloc(data_sz);
128	if (!prog_linfo->raw_linfo)
129		goto err_free;
130	memcpy(prog_linfo->raw_linfo, (void *)(long)info->line_info, data_sz);
131
132	nr_jited_func = info->nr_jited_ksyms;
133	if (!nr_jited_func ||
134	    !info->jited_line_info ||
135	    info->nr_jited_line_info != nr_linfo ||
136	    info->jited_line_info_rec_size < sizeof(__u64) ||
137	    info->nr_jited_func_lens != nr_jited_func ||
138	    !info->jited_ksyms ||
139	    !info->jited_func_lens)
140		/* Not enough info to provide jited_line_info */
141		return prog_linfo;
142
143	/* Copy jited_line_info */
144	prog_linfo->nr_jited_func = nr_jited_func;
145	prog_linfo->jited_rec_size = info->jited_line_info_rec_size;
146	data_sz = (__u64)nr_linfo * prog_linfo->jited_rec_size;
147	prog_linfo->raw_jited_linfo = malloc(data_sz);
148	if (!prog_linfo->raw_jited_linfo)
149		goto err_free;
150	memcpy(prog_linfo->raw_jited_linfo,
151	       (void *)(long)info->jited_line_info, data_sz);
152
153	/* Number of jited_line_info per jited func */
154	prog_linfo->nr_jited_linfo_per_func = malloc(nr_jited_func *
155						     sizeof(__u32));
156	if (!prog_linfo->nr_jited_linfo_per_func)
157		goto err_free;
158
159	/*
160	 * For each jited func,
161	 * the start idx to the "linfo" and "jited_linfo" array,
162	 */
163	prog_linfo->jited_linfo_func_idx = malloc(nr_jited_func *
164						  sizeof(__u32));
165	if (!prog_linfo->jited_linfo_func_idx)
166		goto err_free;
167
168	if (dissect_jited_func(prog_linfo,
169			       (__u64 *)(long)info->jited_ksyms,
170			       (__u32 *)(long)info->jited_func_lens))
171		goto err_free;
172
173	return prog_linfo;
174
175err_free:
176	bpf_prog_linfo__free(prog_linfo);
177	return errno = EINVAL, NULL;
178}
179
180const struct bpf_line_info *
181bpf_prog_linfo__lfind_addr_func(const struct bpf_prog_linfo *prog_linfo,
182				__u64 addr, __u32 func_idx, __u32 nr_skip)
183{
184	__u32 jited_rec_size, rec_size, nr_linfo, start, i;
185	const void *raw_jited_linfo, *raw_linfo;
186	const __u64 *jited_linfo;
187
188	if (func_idx >= prog_linfo->nr_jited_func)
189		return errno = ENOENT, NULL;
190
191	nr_linfo = prog_linfo->nr_jited_linfo_per_func[func_idx];
192	if (nr_skip >= nr_linfo)
193		return errno = ENOENT, NULL;
194
195	start = prog_linfo->jited_linfo_func_idx[func_idx] + nr_skip;
196	jited_rec_size = prog_linfo->jited_rec_size;
197	raw_jited_linfo = prog_linfo->raw_jited_linfo +
198		(start * jited_rec_size);
199	jited_linfo = raw_jited_linfo;
200	if (addr < *jited_linfo)
201		return errno = ENOENT, NULL;
202
203	nr_linfo -= nr_skip;
204	rec_size = prog_linfo->rec_size;
205	raw_linfo = prog_linfo->raw_linfo + (start * rec_size);
206	for (i = 0; i < nr_linfo; i++) {
207		if (addr < *jited_linfo)
208			break;
209
210		raw_linfo += rec_size;
211		raw_jited_linfo += jited_rec_size;
212		jited_linfo = raw_jited_linfo;
213	}
214
215	return raw_linfo - rec_size;
216}
217
218const struct bpf_line_info *
219bpf_prog_linfo__lfind(const struct bpf_prog_linfo *prog_linfo,
220		      __u32 insn_off, __u32 nr_skip)
221{
222	const struct bpf_line_info *linfo;
223	__u32 rec_size, nr_linfo, i;
224	const void *raw_linfo;
225
226	nr_linfo = prog_linfo->nr_linfo;
227	if (nr_skip >= nr_linfo)
228		return errno = ENOENT, NULL;
229
230	rec_size = prog_linfo->rec_size;
231	raw_linfo = prog_linfo->raw_linfo + (nr_skip * rec_size);
232	linfo = raw_linfo;
233	if (insn_off < linfo->insn_off)
234		return errno = ENOENT, NULL;
235
236	nr_linfo -= nr_skip;
237	for (i = 0; i < nr_linfo; i++) {
238		if (insn_off < linfo->insn_off)
239			break;
240
241		raw_linfo += rec_size;
242		linfo = raw_linfo;
243	}
244
245	return raw_linfo - rec_size;
246}