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 <stdlib.h>
8 #include <unistd.h>
9 #include <errno.h>
10 #include <signal.h>
11 #include <fcntl.h>
12 #include <sys/mman.h>
13 #include <sys/ptrace.h>
14 #include <sys/wait.h>
15 #include <asm/unistd.h>
16 #include <init.h>
17 #include <longjmp.h>
18 #include <os.h>
19 #include <skas_ptrace.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
os_process_pc(int pid)27 unsigned 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
os_process_parent(int pid)59 int 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
os_stop_process(int pid)93 void os_stop_process(int pid)
94 {
95 kill(pid, SIGSTOP);
96 }
97
os_kill_process(int pid,int reap_child)98 void os_kill_process(int pid, int reap_child)
99 {
100 kill(pid, SIGKILL);
101 if (reap_child)
102 CATCH_EINTR(waitpid(pid, NULL, __WALL));
103 }
104
105 /* This is here uniquely to have access to the userspace errno, i.e. the one
106 * used by ptrace in case of error.
107 */
108
os_ptrace_ldt(long pid,long addr,long data)109 long os_ptrace_ldt(long pid, long addr, long data)
110 {
111 int ret;
112
113 ret = ptrace(PTRACE_LDT, pid, addr, data);
114
115 if (ret < 0)
116 return -errno;
117 return ret;
118 }
119
120 /* Kill off a ptraced child by all means available. kill it normally first,
121 * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from
122 * which it can't exit directly.
123 */
124
os_kill_ptraced_process(int pid,int reap_child)125 void os_kill_ptraced_process(int pid, int reap_child)
126 {
127 kill(pid, SIGKILL);
128 ptrace(PTRACE_KILL, pid);
129 ptrace(PTRACE_CONT, pid);
130 if (reap_child)
131 CATCH_EINTR(waitpid(pid, NULL, __WALL));
132 }
133
134 /* Don't use the glibc version, which caches the result in TLS. It misses some
135 * syscalls, and also breaks with clone(), which does not unshare the TLS.
136 */
137
os_getpid(void)138 int os_getpid(void)
139 {
140 return syscall(__NR_getpid);
141 }
142
os_getpgrp(void)143 int os_getpgrp(void)
144 {
145 return getpgrp();
146 }
147
os_map_memory(void * virt,int fd,unsigned long long off,unsigned long len,int r,int w,int x)148 int os_map_memory(void *virt, int fd, unsigned long long off, unsigned long len,
149 int r, int w, int x)
150 {
151 void *loc;
152 int prot;
153
154 prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
155 (x ? PROT_EXEC : 0);
156
157 loc = mmap64((void *) virt, len, prot, MAP_SHARED | MAP_FIXED,
158 fd, off);
159 if (loc == MAP_FAILED)
160 return -errno;
161 return 0;
162 }
163
os_protect_memory(void * addr,unsigned long len,int r,int w,int x)164 int os_protect_memory(void *addr, unsigned long len, int r, int w, int x)
165 {
166 int prot = ((r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
167 (x ? PROT_EXEC : 0));
168
169 if (mprotect(addr, len, prot) < 0)
170 return -errno;
171
172 return 0;
173 }
174
os_unmap_memory(void * addr,int len)175 int os_unmap_memory(void *addr, int len)
176 {
177 int err;
178
179 err = munmap(addr, len);
180 if (err < 0)
181 return -errno;
182 return 0;
183 }
184
185 #ifndef MADV_REMOVE
186 #define MADV_REMOVE KERNEL_MADV_REMOVE
187 #endif
188
os_drop_memory(void * addr,int length)189 int os_drop_memory(void *addr, int length)
190 {
191 int err;
192
193 err = madvise(addr, length, MADV_REMOVE);
194 if (err < 0)
195 err = -errno;
196 return err;
197 }
198
can_drop_memory(void)199 int __init can_drop_memory(void)
200 {
201 void *addr;
202 int fd, ok = 0;
203
204 printk(UM_KERN_INFO "Checking host MADV_REMOVE support...");
205 fd = create_mem_file(UM_KERN_PAGE_SIZE);
206 if (fd < 0) {
207 printk(UM_KERN_ERR "Creating test memory file failed, "
208 "err = %d\n", -fd);
209 goto out;
210 }
211
212 addr = mmap64(NULL, UM_KERN_PAGE_SIZE, PROT_READ | PROT_WRITE,
213 MAP_SHARED, fd, 0);
214 if (addr == MAP_FAILED) {
215 printk(UM_KERN_ERR "Mapping test memory file failed, "
216 "err = %d\n", -errno);
217 goto out_close;
218 }
219
220 if (madvise(addr, UM_KERN_PAGE_SIZE, MADV_REMOVE) != 0) {
221 printk(UM_KERN_ERR "MADV_REMOVE failed, err = %d\n", -errno);
222 goto out_unmap;
223 }
224
225 printk(UM_KERN_CONT "OK\n");
226 ok = 1;
227
228 out_unmap:
229 munmap(addr, UM_KERN_PAGE_SIZE);
230 out_close:
231 close(fd);
232 out:
233 return ok;
234 }
235
os_page_mincore(void * addr)236 static int os_page_mincore(void *addr)
237 {
238 char vec[2];
239 int ret;
240
241 ret = mincore(addr, UM_KERN_PAGE_SIZE, vec);
242 if (ret < 0) {
243 if (errno == ENOMEM || errno == EINVAL)
244 return 0;
245 else
246 return -errno;
247 }
248
249 return vec[0] & 1;
250 }
251
os_mincore(void * addr,unsigned long len)252 int os_mincore(void *addr, unsigned long len)
253 {
254 char *vec;
255 int ret, i;
256
257 if (len <= UM_KERN_PAGE_SIZE)
258 return os_page_mincore(addr);
259
260 vec = calloc(1, (len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE);
261 if (!vec)
262 return -ENOMEM;
263
264 ret = mincore(addr, UM_KERN_PAGE_SIZE, vec);
265 if (ret < 0) {
266 if (errno == ENOMEM || errno == EINVAL)
267 ret = 0;
268 else
269 ret = -errno;
270
271 goto out;
272 }
273
274 for (i = 0; i < ((len + UM_KERN_PAGE_SIZE - 1) / UM_KERN_PAGE_SIZE); i++) {
275 if (!(vec[i] & 1)) {
276 ret = 0;
277 goto out;
278 }
279 }
280
281 ret = 1;
282 out:
283 free(vec);
284 return ret;
285 }
286
init_new_thread_signals(void)287 void init_new_thread_signals(void)
288 {
289 set_handler(SIGSEGV);
290 set_handler(SIGTRAP);
291 set_handler(SIGFPE);
292 set_handler(SIGILL);
293 set_handler(SIGBUS);
294 signal(SIGHUP, SIG_IGN);
295 set_handler(SIGIO);
296 signal(SIGWINCH, SIG_IGN);
297 }
298