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