xref: /linux/arch/um/os-Linux/process.c (revision 54a8a2220c936a47840c9a3d74910c5a56fae2ed)
1 /*
2  * Copyright (C) 2002 Jeff Dike (jdike@addtoit.com)
3  * Licensed under the GPL
4  */
5 
6 #include <unistd.h>
7 #include <stdio.h>
8 #include <errno.h>
9 #include <signal.h>
10 #include <setjmp.h>
11 #include <linux/unistd.h>
12 #include <sys/mman.h>
13 #include <sys/wait.h>
14 #include "ptrace_user.h"
15 #include "os.h"
16 #include "user.h"
17 #include "user_util.h"
18 #include "signal_user.h"
19 #include "process.h"
20 #include "irq_user.h"
21 #include "kern_util.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 
29 unsigned long os_process_pc(int pid)
30 {
31 	char proc_stat[STAT_PATH_LEN], buf[256];
32 	unsigned long pc;
33 	int fd, err;
34 
35 	sprintf(proc_stat, "/proc/%d/stat", pid);
36 	fd = os_open_file(proc_stat, of_read(OPENFLAGS()), 0);
37 	if(fd < 0){
38 		printk("os_process_pc - couldn't open '%s', err = %d\n",
39 		       proc_stat, -fd);
40 		return(ARBITRARY_ADDR);
41 	}
42 	err = os_read_file(fd, buf, sizeof(buf));
43 	if(err < 0){
44 		printk("os_process_pc - couldn't read '%s', err = %d\n",
45 		       proc_stat, -err);
46 		os_close_file(fd);
47 		return(ARBITRARY_ADDR);
48 	}
49 	os_close_file(fd);
50 	pc = ARBITRARY_ADDR;
51 	if(sscanf(buf, "%*d " COMM_SCANF " %*c %*d %*d %*d %*d %*d %*d %*d "
52 		  "%*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d %*d "
53 		  "%*d %*d %*d %*d %*d %lu", &pc) != 1){
54 		printk("os_process_pc - couldn't find pc in '%s'\n", buf);
55 	}
56 	return(pc);
57 }
58 
59 int os_process_parent(int pid)
60 {
61 	char stat[STAT_PATH_LEN];
62 	char data[256];
63 	int parent, n, fd;
64 
65 	if(pid == -1) return(-1);
66 
67 	snprintf(stat, sizeof(stat), "/proc/%d/stat", pid);
68 	fd = os_open_file(stat, of_read(OPENFLAGS()), 0);
69 	if(fd < 0){
70 		printk("Couldn't open '%s', err = %d\n", stat, -fd);
71 		return(FAILURE_PID);
72 	}
73 
74 	n = os_read_file(fd, data, sizeof(data));
75 	os_close_file(fd);
76 
77 	if(n < 0){
78 		printk("Couldn't read '%s', err = %d\n", stat, -n);
79 		return(FAILURE_PID);
80 	}
81 
82 	parent = FAILURE_PID;
83 	n = sscanf(data, "%*d " COMM_SCANF " %*c %d", &parent);
84 	if(n != 1)
85 		printk("Failed to scan '%s'\n", data);
86 
87 	return(parent);
88 }
89 
90 void os_stop_process(int pid)
91 {
92 	kill(pid, SIGSTOP);
93 }
94 
95 void os_kill_process(int pid, int reap_child)
96 {
97 	kill(pid, SIGKILL);
98 	if(reap_child)
99 		CATCH_EINTR(waitpid(pid, NULL, 0));
100 
101 }
102 
103 /* Kill off a ptraced child by all means available.  kill it normally first,
104  * then PTRACE_KILL it, then PTRACE_CONT it in case it's in a run state from
105  * which it can't exit directly.
106  */
107 
108 void os_kill_ptraced_process(int pid, int reap_child)
109 {
110 	kill(pid, SIGKILL);
111 	ptrace(PTRACE_KILL, pid);
112 	ptrace(PTRACE_CONT, pid);
113 	if(reap_child)
114 		CATCH_EINTR(waitpid(pid, NULL, 0));
115 }
116 
117 void os_usr1_process(int pid)
118 {
119 	kill(pid, SIGUSR1);
120 }
121 
122 /* Don't use the glibc version, which caches the result in TLS. It misses some
123  * syscalls, and also breaks with clone(), which does not unshare the TLS.
124  */
125 
126 inline _syscall0(pid_t, getpid)
127 
128 int os_getpid(void)
129 {
130 	return(getpid());
131 }
132 
133 int os_getpgrp(void)
134 {
135 	return getpgrp();
136 }
137 
138 int 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 
154 int 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         return(0);
162 }
163 
164 int os_unmap_memory(void *addr, int len)
165 {
166         int err;
167 
168         err = munmap(addr, len);
169 	if(err < 0)
170 		return(-errno);
171         return(0);
172 }
173 
174 void init_new_thread_stack(void *sig_stack, void (*usr1_handler)(int))
175 {
176 	int flags = 0, pages;
177 
178 	if(sig_stack != NULL){
179 		pages = (1 << UML_CONFIG_KERNEL_STACK_ORDER);
180 		set_sigstack(sig_stack, pages * page_size());
181 		flags = SA_ONSTACK;
182 	}
183 	if(usr1_handler) set_handler(SIGUSR1, usr1_handler, flags, -1);
184 }
185 
186 void init_new_thread_signals(int altstack)
187 {
188 	int flags = altstack ? SA_ONSTACK : 0;
189 
190 	set_handler(SIGSEGV, (__sighandler_t) sig_handler, flags,
191 		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
192 	set_handler(SIGTRAP, (__sighandler_t) sig_handler, flags,
193 		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
194 	set_handler(SIGFPE, (__sighandler_t) sig_handler, flags,
195 		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
196 	set_handler(SIGILL, (__sighandler_t) sig_handler, flags,
197 		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
198 	set_handler(SIGBUS, (__sighandler_t) sig_handler, flags,
199 		    SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
200 	set_handler(SIGUSR2, (__sighandler_t) sig_handler,
201 		    flags, SIGUSR1, SIGIO, SIGWINCH, SIGALRM, SIGVTALRM, -1);
202 	signal(SIGHUP, SIG_IGN);
203 
204 	init_irq_signals(altstack);
205 }
206 
207 int run_kernel_thread(int (*fn)(void *), void *arg, void **jmp_ptr)
208 {
209        sigjmp_buf buf;
210        int n;
211 
212        *jmp_ptr = &buf;
213        n = sigsetjmp(buf, 1);
214        if(n != 0)
215                return(n);
216        (*fn)(arg);
217        return(0);
218 }
219 
220 /*
221  * Overrides for Emacs so that we follow Linus's tabbing style.
222  * Emacs will notice this stuff at the end of the file and automatically
223  * adjust the settings for this buffer only.  This must remain at the end
224  * of the file.
225  * ---------------------------------------------------------------------------
226  * Local variables:
227  * c-file-style: "linux"
228  * End:
229  */
230