1 /*
2 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6 #include <stddef.h>
7 #include <unistd.h>
8 #include <errno.h>
9 #include <string.h>
10 #include <sys/mman.h>
11 #include <init.h>
12 #include <as-layout.h>
13 #include <mm_id.h>
14 #include <os.h>
15 #include <proc_mm.h>
16 #include <ptrace_user.h>
17 #include <registers.h>
18 #include <skas.h>
19 #include <sysdep/ptrace.h>
20 #include <sysdep/stub.h>
21
22 extern unsigned long batch_syscall_stub, __syscall_stub_start;
23
24 extern void wait_stub_done(int pid);
25
check_init_stack(struct mm_id * mm_idp,unsigned long * stack)26 static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
27 unsigned long *stack)
28 {
29 if (stack == NULL) {
30 stack = (unsigned long *) mm_idp->stack + 2;
31 *stack = 0;
32 }
33 return stack;
34 }
35
36 static unsigned long syscall_regs[MAX_REG_NR];
37
init_syscall_regs(void)38 static int __init init_syscall_regs(void)
39 {
40 get_safe_registers(syscall_regs, NULL);
41 syscall_regs[REGS_IP_INDEX] = STUB_CODE +
42 ((unsigned long) &batch_syscall_stub -
43 (unsigned long) &__syscall_stub_start);
44 return 0;
45 }
46
47 __initcall(init_syscall_regs);
48
49 extern int proc_mm;
50
do_syscall_stub(struct mm_id * mm_idp,void ** addr)51 static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
52 {
53 int n, i;
54 long ret, offset;
55 unsigned long * data;
56 unsigned long * syscall;
57 int err, pid = mm_idp->u.pid;
58
59 if (proc_mm)
60 /* FIXME: Need to look up userspace_pid by cpu */
61 pid = userspace_pid[0];
62
63 n = ptrace_setregs(pid, syscall_regs);
64 if (n < 0) {
65 printk(UM_KERN_ERR "Registers - \n");
66 for (i = 0; i < MAX_REG_NR; i++)
67 printk(UM_KERN_ERR "\t%d\t0x%lx\n", i, syscall_regs[i]);
68 panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
69 -n);
70 }
71
72 err = ptrace(PTRACE_CONT, pid, 0, 0);
73 if (err)
74 panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
75 errno);
76
77 wait_stub_done(pid);
78
79 /*
80 * When the stub stops, we find the following values on the
81 * beginning of the stack:
82 * (long )return_value
83 * (long )offset to failed sycall-data (0, if no error)
84 */
85 ret = *((unsigned long *) mm_idp->stack);
86 offset = *((unsigned long *) mm_idp->stack + 1);
87 if (offset) {
88 data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA);
89 printk(UM_KERN_ERR "do_syscall_stub : ret = %ld, offset = %ld, "
90 "data = %p\n", ret, offset, data);
91 syscall = (unsigned long *)((unsigned long)data + data[0]);
92 printk(UM_KERN_ERR "do_syscall_stub: syscall %ld failed, "
93 "return value = 0x%lx, expected return value = 0x%lx\n",
94 syscall[0], ret, syscall[7]);
95 printk(UM_KERN_ERR " syscall parameters: "
96 "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
97 syscall[1], syscall[2], syscall[3],
98 syscall[4], syscall[5], syscall[6]);
99 for (n = 1; n < data[0]/sizeof(long); n++) {
100 if (n == 1)
101 printk(UM_KERN_ERR " additional syscall "
102 "data:");
103 if (n % 4 == 1)
104 printk("\n" UM_KERN_ERR " ");
105 printk(" 0x%lx", data[n]);
106 }
107 if (n > 1)
108 printk("\n");
109 }
110 else ret = 0;
111
112 *addr = check_init_stack(mm_idp, NULL);
113
114 return ret;
115 }
116
run_syscall_stub(struct mm_id * mm_idp,int syscall,unsigned long * args,long expected,void ** addr,int done)117 long run_syscall_stub(struct mm_id * mm_idp, int syscall,
118 unsigned long *args, long expected, void **addr,
119 int done)
120 {
121 unsigned long *stack = check_init_stack(mm_idp, *addr);
122
123 *stack += sizeof(long);
124 stack += *stack / sizeof(long);
125
126 *stack++ = syscall;
127 *stack++ = args[0];
128 *stack++ = args[1];
129 *stack++ = args[2];
130 *stack++ = args[3];
131 *stack++ = args[4];
132 *stack++ = args[5];
133 *stack++ = expected;
134 *stack = 0;
135
136 if (!done && ((((unsigned long) stack) & ~UM_KERN_PAGE_MASK) <
137 UM_KERN_PAGE_SIZE - 10 * sizeof(long))) {
138 *addr = stack;
139 return 0;
140 }
141
142 return do_syscall_stub(mm_idp, addr);
143 }
144
syscall_stub_data(struct mm_id * mm_idp,unsigned long * data,int data_count,void ** addr,void ** stub_addr)145 long syscall_stub_data(struct mm_id * mm_idp,
146 unsigned long *data, int data_count,
147 void **addr, void **stub_addr)
148 {
149 unsigned long *stack;
150 int ret = 0;
151
152 /*
153 * If *addr still is uninitialized, it *must* contain NULL.
154 * Thus in this case do_syscall_stub correctly won't be called.
155 */
156 if ((((unsigned long) *addr) & ~UM_KERN_PAGE_MASK) >=
157 UM_KERN_PAGE_SIZE - (10 + data_count) * sizeof(long)) {
158 ret = do_syscall_stub(mm_idp, addr);
159 /* in case of error, don't overwrite data on stack */
160 if (ret)
161 return ret;
162 }
163
164 stack = check_init_stack(mm_idp, *addr);
165 *addr = stack;
166
167 *stack = data_count * sizeof(long);
168
169 memcpy(stack + 1, data, data_count * sizeof(long));
170
171 *stub_addr = (void *)(((unsigned long)(stack + 1) &
172 ~UM_KERN_PAGE_MASK) + STUB_DATA);
173
174 return 0;
175 }
176
map(struct mm_id * mm_idp,unsigned long virt,unsigned long len,int prot,int phys_fd,unsigned long long offset,int done,void ** data)177 int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot,
178 int phys_fd, unsigned long long offset, int done, void **data)
179 {
180 int ret;
181
182 if (proc_mm) {
183 struct proc_mm_op map;
184 int fd = mm_idp->u.mm_fd;
185
186 map = ((struct proc_mm_op) { .op = MM_MMAP,
187 .u =
188 { .mmap =
189 { .addr = virt,
190 .len = len,
191 .prot = prot,
192 .flags = MAP_SHARED |
193 MAP_FIXED,
194 .fd = phys_fd,
195 .offset= offset
196 } } } );
197 CATCH_EINTR(ret = write(fd, &map, sizeof(map)));
198 if (ret != sizeof(map)) {
199 ret = -errno;
200 printk(UM_KERN_ERR "map : /proc/mm map failed, "
201 "err = %d\n", -ret);
202 }
203 else ret = 0;
204 }
205 else {
206 unsigned long args[] = { virt, len, prot,
207 MAP_SHARED | MAP_FIXED, phys_fd,
208 MMAP_OFFSET(offset) };
209
210 ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
211 data, done);
212 }
213
214 return ret;
215 }
216
unmap(struct mm_id * mm_idp,unsigned long addr,unsigned long len,int done,void ** data)217 int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
218 int done, void **data)
219 {
220 int ret;
221
222 if (proc_mm) {
223 struct proc_mm_op unmap;
224 int fd = mm_idp->u.mm_fd;
225
226 unmap = ((struct proc_mm_op) { .op = MM_MUNMAP,
227 .u =
228 { .munmap =
229 { .addr =
230 (unsigned long) addr,
231 .len = len } } } );
232 CATCH_EINTR(ret = write(fd, &unmap, sizeof(unmap)));
233 if (ret != sizeof(unmap)) {
234 ret = -errno;
235 printk(UM_KERN_ERR "unmap - proc_mm write returned "
236 "%d\n", ret);
237 }
238 else ret = 0;
239 }
240 else {
241 unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
242 0 };
243
244 ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
245 data, done);
246 }
247
248 return ret;
249 }
250
protect(struct mm_id * mm_idp,unsigned long addr,unsigned long len,unsigned int prot,int done,void ** data)251 int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
252 unsigned int prot, int done, void **data)
253 {
254 struct proc_mm_op protect;
255 int ret;
256
257 if (proc_mm) {
258 int fd = mm_idp->u.mm_fd;
259
260 protect = ((struct proc_mm_op) { .op = MM_MPROTECT,
261 .u =
262 { .mprotect =
263 { .addr =
264 (unsigned long) addr,
265 .len = len,
266 .prot = prot } } } );
267
268 CATCH_EINTR(ret = write(fd, &protect, sizeof(protect)));
269 if (ret != sizeof(protect)) {
270 ret = -errno;
271 printk(UM_KERN_ERR "protect failed, err = %d", -ret);
272 }
273 else ret = 0;
274 }
275 else {
276 unsigned long args[] = { addr, len, prot, 0, 0, 0 };
277
278 ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
279 data, done);
280 }
281
282 return ret;
283 }
284