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
os_process_pc(int pid)26 unsigned 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
os_process_parent(int pid)58 int 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
os_stop_process(int pid)92 void os_stop_process(int pid)
93 {
94 kill(pid, SIGSTOP);
95 }
96
os_kill_process(int pid,int reap_child)97 void 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
os_ptrace_ldt(long pid,long addr,long data)108 long 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
os_kill_ptraced_process(int pid,int reap_child)124 void 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
os_getpid(void)137 int os_getpid(void)
138 {
139 return syscall(__NR_getpid);
140 }
141
os_getpgrp(void)142 int os_getpgrp(void)
143 {
144 return getpgrp();
145 }
146
os_map_memory(void * virt,int fd,unsigned long long off,unsigned long len,int r,int w,int x)147 int 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
os_protect_memory(void * addr,unsigned long len,int r,int w,int x)163 int 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
os_unmap_memory(void * addr,int len)174 int 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
os_drop_memory(void * addr,int length)188 int 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
can_drop_memory(void)198 int __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
227 out_unmap:
228 munmap(addr, UM_KERN_PAGE_SIZE);
229 out_close:
230 close(fd);
231 out:
232 return ok;
233 }
234
init_new_thread_signals(void)235 void 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