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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
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_stop_process(int pid)
94{
95 kill(pid, SIGSTOP);
96}
97
98void 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
106
107
108
109long 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
121
122
123
124
125void 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
135
136
137
138int os_getpid(void)
139{
140 return syscall(__NR_getpid);
141}
142
143int os_getpgrp(void)
144{
145 return getpgrp();
146}
147
148int 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
164int 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
175int 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
189int 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
199int __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
228out_unmap:
229 munmap(addr, UM_KERN_PAGE_SIZE);
230out_close:
231 close(fd);
232out:
233 return ok;
234}
235
236static 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
252int 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;
282out:
283 free(vec);
284 return ret;
285}
286
287void 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
