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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/*
2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <stdio.h>
7#include <unistd.h>
8#include <errno.h>
9#include <signal.h>
10#include <fcntl.h>
11#include <sys/mman.h>
12#include <sys/ptrace.h>
13#include <sys/wait.h>
14#include <asm/unistd.h>
15#include "init.h"
16#include "kern_constants.h"
17#include "longjmp.h"
18#include "os.h"
19#include "process.h"
20#include "skas_ptrace.h"
21#include "user.h"
22
23#define ARBITRARY_ADDR -1
24#define FAILURE_PID -1
25
26#define STAT_PATH_LEN sizeof("/proc/#######/stat\0")
27#define COMM_SCANF "%*[^)])"
28
29unsigned long os_process_pc(int pid)
30{
31 char proc_stat[STAT_PATH_LEN], buf[256];
32 unsigned long pc = ARBITRARY_ADDR;
33 int fd, err;
34
35 sprintf(proc_stat, "/proc/%d/stat", pid);
36 fd = open(proc_stat, O_RDONLY, 0);
37 if (fd < 0) {
38 printk(UM_KERN_ERR "os_process_pc - couldn't open '%s', "
39 "errno = %d\n", proc_stat, errno);
40 goto out;
41 }
42 CATCH_EINTR(err = read(fd, buf, sizeof(buf)));
43 if (err < 0) {
44 printk(UM_KERN_ERR "os_process_pc - couldn't read '%s', "
45 "err = %d\n", proc_stat, errno);
46 goto out_close;
47 }
48 os_close_file(fd);
49 pc = ARBITRARY_ADDR;
50 if (sscanf(buf, "%*d " COMM_SCANF " %*c %*d %*d %*d %*d %*d %*d %*d "
51 "%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d "
52 "%*d %*d %*d %*d %*d %lu", &pc) != 1)
53 printk(UM_KERN_ERR "os_process_pc - couldn't find pc in '%s'\n",
54 buf);
55 out_close:
56 close(fd);
57 out:
58 return pc;
59}
60
61int os_process_parent(int pid)
62{
63 char stat[STAT_PATH_LEN];
64 char data[256];
65 int parent = FAILURE_PID, n, fd;
66
67 if (pid == -1)
68 return parent;
69
70 snprintf(stat, sizeof(stat), "/proc/%d/stat", pid);
71 fd = open(stat, O_RDONLY, 0);
72 if (fd < 0) {
73 printk(UM_KERN_ERR "Couldn't open '%s', errno = %d\n", stat,
74 errno);
75 return parent;
76 }
77
78 CATCH_EINTR(n = read(fd, data, sizeof(data)));
79 close(fd);
80
81 if (n < 0) {
82 printk(UM_KERN_ERR "Couldn't read '%s', errno = %d\n", stat,
83 errno);
84 return parent;
85 }
86
87 parent = FAILURE_PID;
88 n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent);
89 if (n != 1)
90 printk(UM_KERN_ERR "Failed to scan '%s'\n", data);
91
92 return parent;
93}
94
95void os_stop_process(int pid)
96{
97 kill(pid, SIGSTOP);
98}
99
100void os_kill_process(int pid, int reap_child)
101{
102 kill(pid, SIGKILL);
103 if (reap_child)
104 CATCH_EINTR(waitpid(pid, NULL, __WALL));
105}
106
107/* This is here uniquely to have access to the userspace errno, i.e. the one
108 * used by ptrace in case of error.
109 */
110
111long os_ptrace_ldt(long pid, long addr, long data)
112{
113 int ret;
114
115 ret = ptrace(PTRACE_LDT, pid, addr, data);
116
117 if (ret < 0)
118 return -errno;
119 return ret;
120}
121
122/* Kill off a ptraced child by all means available. kill it normally first,
123 * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from
124 * which it can't exit directly.
125 */
126
127void os_kill_ptraced_process(int pid, int reap_child)
128{
129 kill(pid, SIGKILL);
130 ptrace(PTRACE_KILL, pid);
131 ptrace(PTRACE_CONT, pid);
132 if (reap_child)
133 CATCH_EINTR(waitpid(pid, NULL, __WALL));
134}
135
136/* Don't use the glibc version, which caches the result in TLS. It misses some
137 * syscalls, and also breaks with clone(), which does not unshare the TLS.
138 */
139
140int os_getpid(void)
141{
142 return syscall(__NR_getpid);
143}
144
145int os_getpgrp(void)
146{
147 return getpgrp();
148}
149
150int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len,
151 int r, int w, int x)
152{
153 void *loc;
154 int prot;
155
156 prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
157 (x ? PROT_EXEC : 0);
158
159 loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED,
160 fd, off);
161 if (loc == MAP_FAILED)
162 return -errno;
163 return 0;
164}
165
166int os_protect_memory(void *addr, unsigned long len, int r, int w, int x)
167{
168 int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
169 (x ? PROT_EXEC : 0));
170
171 if (mprotect(addr, len, prot) < 0)
172 return -errno;
173
174 return 0;
175}
176
177int os_unmap_memory(void *addr, int len)
178{
179 int err;
180
181 err = munmap(addr, len);
182 if (err < 0)
183 return -errno;
184 return 0;
185}
186
187#ifndef MADV_REMOVE
188#define MADV_REMOVE KERNEL_MADV_REMOVE
189#endif
190
191int os_drop_memory(void *addr, int length)
192{
193 int err;
194
195 err = madvise(addr, length, MADV_REMOVE);
196 if (err < 0)
197 err = -errno;
198 return err;
199}
200
201int __init can_drop_memory(void)
202{
203 void *addr;
204 int fd, ok = 0;
205
206 printk(UM_KERN_INFO "Checking host MADV_REMOVE support...");
207 fd = create_mem_file(UM_KERN_PAGE_SIZE);
208 if (fd < 0) {
209 printk(UM_KERN_ERR "Creating test memory file failed, "
210 "err = %d\n", -fd);
211 goto out;
212 }
213
214 addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
215 MAP_SHARED, fd, 0);
216 if (addr == MAP_FAILED) {
217 printk(UM_KERN_ERR "Mapping test memory file failed, "
218 "err = %d\n", -errno);
219 goto out_close;
220 }
221
222 if (madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0) {
223 printk(UM_KERN_ERR "MADV_REMOVE failed, err = %d\n", -errno);
224 goto out_unmap;
225 }
226
227 printk(UM_KERN_CONT "OK\n");
228 ok = 1;
229
230out_unmap:
231 munmap(addr, UM_KERN_PAGE_SIZE);
232out_close:
233 close(fd);
234out:
235 return ok;
236}
237
238void init_new_thread_signals(void)
239{
240 set_handler(SIGSEGV, (__sighandler_t) sig_handler, SA_ONSTACK,
241 SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
242 set_handler(SIGTRAP, (__sighandler_t) sig_handler, SA_ONSTACK,
243 SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
244 set_handler(SIGFPE, (__sighandler_t) sig_handler, SA_ONSTACK,
245 SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
246 set_handler(SIGILL, (__sighandler_t) sig_handler, SA_ONSTACK,
247 SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
248 set_handler(SIGBUS, (__sighandler_t) sig_handler, SA_ONSTACK,
249 SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
250 signal(SIGHUP, SIG_IGN);
251
252 set_handler(SIGIO, (__sighandler_t) sig_handler,
253 SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGALRM,
254 SIGVTALRM, -1);
255 signal(SIGWINCH, SIG_IGN);
256 signal(SIGTERM, SIG_DFL);
257}
258
259int run_kernel_thread(int (*fn)(void *), void *arg, jmp_buf **jmp_ptr)
260{
261 jmp_buf buf;
262 int n;
263
264 *jmp_ptr = &buf;
265 n = UML_SETJMP(&buf);
266 if (n != 0)
267 return n;
268 (*fn)(arg);
269 return 0;
270}