1// SPDX-License-Identifier: GPL-2.0
 2#include <errno.h>
 3#include <linux/unistd.h>
 4
 5#include <sys/ptrace.h>
 6#include <sys/syscall.h>
 7#include <unistd.h>
 8
 9#include <sysdep/tls.h>
10
11#ifndef PTRACE_GET_THREAD_AREA
12#define PTRACE_GET_THREAD_AREA 25
13#endif
14
15#ifndef PTRACE_SET_THREAD_AREA
16#define PTRACE_SET_THREAD_AREA 26
17#endif
18
19/* Checks whether host supports TLS, and sets *tls_min according to the value
20 * valid on the host.
21 * i386 host have it == 6; x86_64 host have it == 12, for i386 emulation. */
22void check_host_supports_tls(int *supports_tls, int *tls_min)
23{
24	/* Values for x86 and x86_64.*/
25	int val[] = {GDT_ENTRY_TLS_MIN_I386, GDT_ENTRY_TLS_MIN_X86_64};
26	int i;
27
28	for (i = 0; i < ARRAY_SIZE(val); i++) {
29		user_desc_t info;
30		info.entry_number = val[i];
31
32		if (syscall(__NR_get_thread_area, &info) == 0) {
33			*tls_min = val[i];
34			*supports_tls = 1;
35			return;
36		} else {
37			if (errno == EINVAL)
38				continue;
39			else if (errno == ENOSYS)
40				*supports_tls = 0;
41			return;
42		}
43	}
44
45	*supports_tls = 0;
46}
47
48int os_set_thread_area(user_desc_t *info, int pid)
49{
50	int ret;
51
52	ret = ptrace(PTRACE_SET_THREAD_AREA, pid, info->entry_number,
53		     (unsigned long) info);
54	if (ret < 0)
55		ret = -errno;
56	return ret;
57}
58
59int os_get_thread_area(user_desc_t *info, int pid)
60{
61	int ret;
62
63	ret = ptrace(PTRACE_GET_THREAD_AREA, pid, info->entry_number,
64		     (unsigned long) info);
65	if (ret < 0)
66		ret = -errno;
67	return ret;
68}

 
 1#include <errno.h>
 2#include <linux/unistd.h>
 3
 4#include <sys/ptrace.h>
 5#include <sys/syscall.h>
 6#include <unistd.h>
 7
 8#include <sysdep/tls.h>
 9
10#ifndef PTRACE_GET_THREAD_AREA
11#define PTRACE_GET_THREAD_AREA 25
12#endif
13
14#ifndef PTRACE_SET_THREAD_AREA
15#define PTRACE_SET_THREAD_AREA 26
16#endif
17
18/* Checks whether host supports TLS, and sets *tls_min according to the value
19 * valid on the host.
20 * i386 host have it == 6; x86_64 host have it == 12, for i386 emulation. */
21void check_host_supports_tls(int *supports_tls, int *tls_min)
22{
23	/* Values for x86 and x86_64.*/
24	int val[] = {GDT_ENTRY_TLS_MIN_I386, GDT_ENTRY_TLS_MIN_X86_64};
25	int i;
26
27	for (i = 0; i < ARRAY_SIZE(val); i++) {
28		user_desc_t info;
29		info.entry_number = val[i];
30
31		if (syscall(__NR_get_thread_area, &info) == 0) {
32			*tls_min = val[i];
33			*supports_tls = 1;
34			return;
35		} else {
36			if (errno == EINVAL)
37				continue;
38			else if (errno == ENOSYS)
39				*supports_tls = 0;
40				return;
41		}
42	}
43
44	*supports_tls = 0;
45}
46
47int os_set_thread_area(user_desc_t *info, int pid)
48{
49	int ret;
50
51	ret = ptrace(PTRACE_SET_THREAD_AREA, pid, info->entry_number,
52		     (unsigned long) info);
53	if (ret < 0)
54		ret = -errno;
55	return ret;
56}
57
58int os_get_thread_area(user_desc_t *info, int pid)
59{
60	int ret;
61
62	ret = ptrace(PTRACE_GET_THREAD_AREA, pid, info->entry_number,
63		     (unsigned long) info);
64	if (ret < 0)
65		ret = -errno;
66	return ret;
67}