Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
4 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
5 */
6
7#include <stdio.h>
8#include <stdlib.h>
9#include <unistd.h>
10#include <errno.h>
11#include <signal.h>
12#include <fcntl.h>
13#include <sys/mman.h>
14#include <sys/ptrace.h>
15#include <sys/prctl.h>
16#include <sys/wait.h>
17#include <asm/unistd.h>
18#include <init.h>
19#include <longjmp.h>
20#include <os.h>
21
22void os_alarm_process(int pid)
23{
24 kill(pid, SIGALRM);
25}
26
27void os_kill_process(int pid, int reap_child)
28{
29 kill(pid, SIGKILL);
30 if (reap_child)
31 CATCH_EINTR(waitpid(pid, NULL, __WALL));
32}
33
34/* Kill off a ptraced child by all means available. kill it normally first,
35 * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from
36 * which it can't exit directly.
37 */
38
39void os_kill_ptraced_process(int pid, int reap_child)
40{
41 kill(pid, SIGKILL);
42 ptrace(PTRACE_KILL, pid);
43 ptrace(PTRACE_CONT, pid);
44 if (reap_child)
45 CATCH_EINTR(waitpid(pid, NULL, __WALL));
46}
47
48/* Don't use the glibc version, which caches the result in TLS. It misses some
49 * syscalls, and also breaks with clone(), which does not unshare the TLS.
50 */
51
52int os_getpid(void)
53{
54 return syscall(__NR_getpid);
55}
56
57int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len,
58 int r, int w, int x)
59{
60 void *loc;
61 int prot;
62
63 prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
64 (x ? PROT_EXEC : 0);
65
66 loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED,
67 fd, off);
68 if (loc == MAP_FAILED)
69 return -errno;
70 return 0;
71}
72
73int os_protect_memory(void *addr, unsigned long len, int r, int w, int x)
74{
75 int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
76 (x ? PROT_EXEC : 0));
77
78 if (mprotect(addr, len, prot) < 0)
79 return -errno;
80
81 return 0;
82}
83
84int os_unmap_memory(void *addr, int len)
85{
86 int err;
87
88 err = munmap(addr, len);
89 if (err < 0)
90 return -errno;
91 return 0;
92}
93
94#ifndef MADV_REMOVE
95#define MADV_REMOVE KERNEL_MADV_REMOVE
96#endif
97
98int os_drop_memory(void *addr, int length)
99{
100 int err;
101
102 err = madvise(addr, length, MADV_REMOVE);
103 if (err < 0)
104 err = -errno;
105 return err;
106}
107
108int __init can_drop_memory(void)
109{
110 void *addr;
111 int fd, ok = 0;
112
113 printk(UM_KERN_INFO "Checking host MADV_REMOVE support...");
114 fd = create_mem_file(UM_KERN_PAGE_SIZE);
115 if (fd < 0) {
116 printk(UM_KERN_ERR "Creating test memory file failed, "
117 "err = %d\n", -fd);
118 goto out;
119 }
120
121 addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
122 MAP_SHARED, fd, 0);
123 if (addr == MAP_FAILED) {
124 printk(UM_KERN_ERR "Mapping test memory file failed, "
125 "err = %d\n", -errno);
126 goto out_close;
127 }
128
129 if (madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0) {
130 printk(UM_KERN_ERR "MADV_REMOVE failed, err = %d\n", -errno);
131 goto out_unmap;
132 }
133
134 printk(UM_KERN_CONT "OK\n");
135 ok = 1;
136
137out_unmap:
138 munmap(addr, UM_KERN_PAGE_SIZE);
139out_close:
140 close(fd);
141out:
142 return ok;
143}
144
145static int os_page_mincore(void *addr)
146{
147 char vec[2];
148 int ret;
149
150 ret = mincore(addr, UM_KERN_PAGE_SIZE, vec);
151 if (ret < 0) {
152 if (errno == ENOMEM || errno == EINVAL)
153 return 0;
154 else
155 return -errno;
156 }
157
158 return vec[0] & 1;
159}
160
161int os_mincore(void *addr, unsigned long len)
162{
163 char *vec;
164 int ret, i;
165
166 if (len <= UM_KERN_PAGE_SIZE)
167 return os_page_mincore(addr);
168
169 vec = calloc(1, (len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE);
170 if (!vec)
171 return -ENOMEM;
172
173 ret = mincore(addr, UM_KERN_PAGE_SIZE, vec);
174 if (ret < 0) {
175 if (errno == ENOMEM || errno == EINVAL)
176 ret = 0;
177 else
178 ret = -errno;
179
180 goto out;
181 }
182
183 for (i = 0; i < ((len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); i++) {
184 if (!(vec[i] & 1)) {
185 ret = 0;
186 goto out;
187 }
188 }
189
190 ret = 1;
191out:
192 free(vec);
193 return ret;
194}
195
196void init_new_thread_signals(void)
197{
198 set_handler(SIGSEGV);
199 set_handler(SIGTRAP);
200 set_handler(SIGFPE);
201 set_handler(SIGILL);
202 set_handler(SIGBUS);
203 signal(SIGHUP, SIG_IGN);
204 set_handler(SIGIO);
205 signal(SIGWINCH, SIG_IGN);
206}
207
208void os_set_pdeathsig(void)
209{
210 prctl(PR_SET_PDEATHSIG, SIGKILL);
211}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
4 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
5 */
6
7#include <stdio.h>
8#include <stdlib.h>
9#include <unistd.h>
10#include <errno.h>
11#include <signal.h>
12#include <fcntl.h>
13#include <sys/mman.h>
14#include <sys/ptrace.h>
15#include <sys/wait.h>
16#include <asm/unistd.h>
17#include <init.h>
18#include <longjmp.h>
19#include <os.h>
20
21#define ARBITRARY_ADDR -1
22#define FAILURE_PID -1
23
24#define STAT_PATH_LEN sizeof("/proc/#######/stat\0")
25#define COMM_SCANF "%*[^)])"
26
27unsigned long os_process_pc(int pid)
28{
29 char proc_stat[STAT_PATH_LEN], buf[256];
30 unsigned long pc = ARBITRARY_ADDR;
31 int fd, err;
32
33 sprintf(proc_stat, "/proc/%d/stat", pid);
34 fd = open(proc_stat, O_RDONLY, 0);
35 if (fd < 0) {
36 printk(UM_KERN_ERR "os_process_pc - couldn't open '%s', "
37 "errno = %d\n", proc_stat, errno);
38 goto out;
39 }
40 CATCH_EINTR(err = read(fd, buf, sizeof(buf)));
41 if (err < 0) {
42 printk(UM_KERN_ERR "os_process_pc - couldn't read '%s', "
43 "err = %d\n", proc_stat, errno);
44 goto out_close;
45 }
46 os_close_file(fd);
47 pc = ARBITRARY_ADDR;
48 if (sscanf(buf, "%*d " COMM_SCANF " %*c %*d %*d %*d %*d %*d %*d %*d "
49 "%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d "
50 "%*d %*d %*d %*d %*d %lu", &pc) != 1)
51 printk(UM_KERN_ERR "os_process_pc - couldn't find pc in '%s'\n",
52 buf);
53 out_close:
54 close(fd);
55 out:
56 return pc;
57}
58
59int os_process_parent(int pid)
60{
61 char stat[STAT_PATH_LEN];
62 char data[256];
63 int parent = FAILURE_PID, n, fd;
64
65 if (pid == -1)
66 return parent;
67
68 snprintf(stat, sizeof(stat), "/proc/%d/stat", pid);
69 fd = open(stat, O_RDONLY, 0);
70 if (fd < 0) {
71 printk(UM_KERN_ERR "Couldn't open '%s', errno = %d\n", stat,
72 errno);
73 return parent;
74 }
75
76 CATCH_EINTR(n = read(fd, data, sizeof(data)));
77 close(fd);
78
79 if (n < 0) {
80 printk(UM_KERN_ERR "Couldn't read '%s', errno = %d\n", stat,
81 errno);
82 return parent;
83 }
84
85 parent = FAILURE_PID;
86 n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent);
87 if (n != 1)
88 printk(UM_KERN_ERR "Failed to scan '%s'\n", data);
89
90 return parent;
91}
92
93void os_alarm_process(int pid)
94{
95 kill(pid, SIGALRM);
96}
97
98void os_stop_process(int pid)
99{
100 kill(pid, SIGSTOP);
101}
102
103void os_kill_process(int pid, int reap_child)
104{
105 kill(pid, SIGKILL);
106 if (reap_child)
107 CATCH_EINTR(waitpid(pid, NULL, __WALL));
108}
109
110/* Kill off a ptraced child by all means available. kill it normally first,
111 * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from
112 * which it can't exit directly.
113 */
114
115void os_kill_ptraced_process(int pid, int reap_child)
116{
117 kill(pid, SIGKILL);
118 ptrace(PTRACE_KILL, pid);
119 ptrace(PTRACE_CONT, pid);
120 if (reap_child)
121 CATCH_EINTR(waitpid(pid, NULL, __WALL));
122}
123
124/* Don't use the glibc version, which caches the result in TLS. It misses some
125 * syscalls, and also breaks with clone(), which does not unshare the TLS.
126 */
127
128int os_getpid(void)
129{
130 return syscall(__NR_getpid);
131}
132
133int os_getpgrp(void)
134{
135 return getpgrp();
136}
137
138int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len,
139 int r, int w, int x)
140{
141 void *loc;
142 int prot;
143
144 prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
145 (x ? PROT_EXEC : 0);
146
147 loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED,
148 fd, off);
149 if (loc == MAP_FAILED)
150 return -errno;
151 return 0;
152}
153
154int os_protect_memory(void *addr, unsigned long len, int r, int w, int x)
155{
156 int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
157 (x ? PROT_EXEC : 0));
158
159 if (mprotect(addr, len, prot) < 0)
160 return -errno;
161
162 return 0;
163}
164
165int os_unmap_memory(void *addr, int len)
166{
167 int err;
168
169 err = munmap(addr, len);
170 if (err < 0)
171 return -errno;
172 return 0;
173}
174
175#ifndef MADV_REMOVE
176#define MADV_REMOVE KERNEL_MADV_REMOVE
177#endif
178
179int os_drop_memory(void *addr, int length)
180{
181 int err;
182
183 err = madvise(addr, length, MADV_REMOVE);
184 if (err < 0)
185 err = -errno;
186 return err;
187}
188
189int __init can_drop_memory(void)
190{
191 void *addr;
192 int fd, ok = 0;
193
194 printk(UM_KERN_INFO "Checking host MADV_REMOVE support...");
195 fd = create_mem_file(UM_KERN_PAGE_SIZE);
196 if (fd < 0) {
197 printk(UM_KERN_ERR "Creating test memory file failed, "
198 "err = %d\n", -fd);
199 goto out;
200 }
201
202 addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
203 MAP_SHARED, fd, 0);
204 if (addr == MAP_FAILED) {
205 printk(UM_KERN_ERR "Mapping test memory file failed, "
206 "err = %d\n", -errno);
207 goto out_close;
208 }
209
210 if (madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0) {
211 printk(UM_KERN_ERR "MADV_REMOVE failed, err = %d\n", -errno);
212 goto out_unmap;
213 }
214
215 printk(UM_KERN_CONT "OK\n");
216 ok = 1;
217
218out_unmap:
219 munmap(addr, UM_KERN_PAGE_SIZE);
220out_close:
221 close(fd);
222out:
223 return ok;
224}
225
226static int os_page_mincore(void *addr)
227{
228 char vec[2];
229 int ret;
230
231 ret = mincore(addr, UM_KERN_PAGE_SIZE, vec);
232 if (ret < 0) {
233 if (errno == ENOMEM || errno == EINVAL)
234 return 0;
235 else
236 return -errno;
237 }
238
239 return vec[0] & 1;
240}
241
242int os_mincore(void *addr, unsigned long len)
243{
244 char *vec;
245 int ret, i;
246
247 if (len <= UM_KERN_PAGE_SIZE)
248 return os_page_mincore(addr);
249
250 vec = calloc(1, (len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE);
251 if (!vec)
252 return -ENOMEM;
253
254 ret = mincore(addr, UM_KERN_PAGE_SIZE, vec);
255 if (ret < 0) {
256 if (errno == ENOMEM || errno == EINVAL)
257 ret = 0;
258 else
259 ret = -errno;
260
261 goto out;
262 }
263
264 for (i = 0; i < ((len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); i++) {
265 if (!(vec[i] & 1)) {
266 ret = 0;
267 goto out;
268 }
269 }
270
271 ret = 1;
272out:
273 free(vec);
274 return ret;
275}
276
277void init_new_thread_signals(void)
278{
279 set_handler(SIGSEGV);
280 set_handler(SIGTRAP);
281 set_handler(SIGFPE);
282 set_handler(SIGILL);
283 set_handler(SIGBUS);
284 signal(SIGHUP, SIG_IGN);
285 set_handler(SIGIO);
286 signal(SIGWINCH, SIG_IGN);
287}