1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <errno.h>
3*4882a593Smuzhiyun #include <linux/unistd.h>
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun #include <sys/ptrace.h>
6*4882a593Smuzhiyun #include <sys/syscall.h>
7*4882a593Smuzhiyun #include <unistd.h>
8*4882a593Smuzhiyun
9*4882a593Smuzhiyun #include <sysdep/tls.h>
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #ifndef PTRACE_GET_THREAD_AREA
12*4882a593Smuzhiyun #define PTRACE_GET_THREAD_AREA 25
13*4882a593Smuzhiyun #endif
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #ifndef PTRACE_SET_THREAD_AREA
16*4882a593Smuzhiyun #define PTRACE_SET_THREAD_AREA 26
17*4882a593Smuzhiyun #endif
18*4882a593Smuzhiyun
19*4882a593Smuzhiyun /* Checks whether host supports TLS, and sets *tls_min according to the value
20*4882a593Smuzhiyun * valid on the host.
21*4882a593Smuzhiyun * i386 host have it == 6; x86_64 host have it == 12, for i386 emulation. */
check_host_supports_tls(int * supports_tls,int * tls_min)22*4882a593Smuzhiyun void check_host_supports_tls(int *supports_tls, int *tls_min)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun /* Values for x86 and x86_64.*/
25*4882a593Smuzhiyun int val[] = {GDT_ENTRY_TLS_MIN_I386, GDT_ENTRY_TLS_MIN_X86_64};
26*4882a593Smuzhiyun int i;
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun for (i = 0; i < ARRAY_SIZE(val); i++) {
29*4882a593Smuzhiyun user_desc_t info;
30*4882a593Smuzhiyun info.entry_number = val[i];
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun if (syscall(__NR_get_thread_area, &info) == 0) {
33*4882a593Smuzhiyun *tls_min = val[i];
34*4882a593Smuzhiyun *supports_tls = 1;
35*4882a593Smuzhiyun return;
36*4882a593Smuzhiyun } else {
37*4882a593Smuzhiyun if (errno == EINVAL)
38*4882a593Smuzhiyun continue;
39*4882a593Smuzhiyun else if (errno == ENOSYS)
40*4882a593Smuzhiyun *supports_tls = 0;
41*4882a593Smuzhiyun return;
42*4882a593Smuzhiyun }
43*4882a593Smuzhiyun }
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun *supports_tls = 0;
46*4882a593Smuzhiyun }
47*4882a593Smuzhiyun
os_set_thread_area(user_desc_t * info,int pid)48*4882a593Smuzhiyun int os_set_thread_area(user_desc_t *info, int pid)
49*4882a593Smuzhiyun {
50*4882a593Smuzhiyun int ret;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun ret = ptrace(PTRACE_SET_THREAD_AREA, pid, info->entry_number,
53*4882a593Smuzhiyun (unsigned long) info);
54*4882a593Smuzhiyun if (ret < 0)
55*4882a593Smuzhiyun ret = -errno;
56*4882a593Smuzhiyun return ret;
57*4882a593Smuzhiyun }
58*4882a593Smuzhiyun
os_get_thread_area(user_desc_t * info,int pid)59*4882a593Smuzhiyun int os_get_thread_area(user_desc_t *info, int pid)
60*4882a593Smuzhiyun {
61*4882a593Smuzhiyun int ret;
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun ret = ptrace(PTRACE_GET_THREAD_AREA, pid, info->entry_number,
64*4882a593Smuzhiyun (unsigned long) info);
65*4882a593Smuzhiyun if (ret < 0)
66*4882a593Smuzhiyun ret = -errno;
67*4882a593Smuzhiyun return ret;
68*4882a593Smuzhiyun }
69