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 "kern_constants.h"
13 #include "as-layout.h"
14 #include "mm_id.h"
15 #include "os.h"
16 #include "proc_mm.h"
17 #include "ptrace_user.h"
18 #include "registers.h"
19 #include "skas.h"
20 #include "user.h"
21 #include "sysdep/ptrace.h"
22 #include "sysdep/stub.h"
23
24 extern unsigned long batch_syscall_stub, __syscall_stub_start;
25
26 extern void wait_stub_done(int pid);
27
28 static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
29 unsigned long *stack)
30 {
31 if (stack == NULL) {
32 stack = (unsigned long *) mm_idp->stack + 2;
33 *stack = 0;
34 }
35 return stack;
36 }
37
38 static unsigned long syscall_regs[MAX_REG_NR];
39
40 static int __init init_syscall_regs(void)
41 {
42 get_safe_registers(syscall_regs);
43 syscall_regs[REGS_IP_INDEX] = STUB_CODE +
44 ((unsigned long) &batch_syscall_stub -
45 (unsigned long) &__syscall_stub_start);
46 return 0;
47 }
48
49 __initcall(init_syscall_regs);
50
51 extern int proc_mm;
52
53 int single_count = 0;
54 int multi_count = 0;
55 int multi_op_count = 0;
56
57 static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
58 {
59 int n, i;
60 long ret, offset;
61 unsigned long * data;
62 unsigned long * syscall;
63 int err, pid = mm_idp->u.pid;
64
65 if (proc_mm)
66 /* FIXME: Need to look up userspace_pid by cpu */
67 pid = userspace_pid[0];
68
69 multi_count++;
70
71 n = ptrace_setregs(pid, syscall_regs);
72 if (n < 0) {
73 printk(UM_KERN_ERR "Registers - \n");
74 for (i = 0; i < MAX_REG_NR; i++)
75 printk(UM_KERN_ERR "\t%d\t0x%lx\n", i, syscall_regs[i]);
76 panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
77 -n);
78 }
79
80 err = ptrace(PTRACE_CONT, pid, 0, 0);
81 if (err)
82 panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
83 errno);
84
85 wait_stub_done(pid);
86
87 /*
88 * When the stub stops, we find the following values on the
89 * beginning of the stack:
90 * (long )return_value
91 * (long )offset to failed sycall-data (0, if no error)
92 */
93 ret = *((unsigned long *) mm_idp->stack);
94 offset = *((unsigned long *) mm_idp->stack + 1);
95 if (offset) {
96 data = (unsigned long *)(mm_idp->stack + offset - STUB_DATA);
97 printk(UM_KERN_ERR "do_syscall_stub : ret = %ld, offset = %ld, "
98 "data = %p\n", ret, offset, data);
99 syscall = (unsigned long *)((unsigned long)data + data[0]);
100 printk(UM_KERN_ERR "do_syscall_stub: syscall %ld failed, "
101 "return value = 0x%lx, expected return value = 0x%lx\n",
102 syscall[0], ret, syscall[7]);
103 printk(UM_KERN_ERR " syscall parameters: "
104 "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
105 syscall[1], syscall[2], syscall[3],
106 syscall[4], syscall[5], syscall[6]);
107 for (n = 1; n < data[0]/sizeof(long); n++) {
108 if (n == 1)
109 printk(UM_KERN_ERR " additional syscall "
110 "data:");
111 if (n % 4 == 1)
112 printk("\n" UM_KERN_ERR " ");
113 printk(" 0x%lx", data[n]);
114 }
115 if (n > 1)
116 printk("\n");
117 }
118 else ret = 0;
119
120 *addr = check_init_stack(mm_idp, NULL);
121
122 return ret;
123 }
124
125 long run_syscall_stub(struct mm_id * mm_idp, int syscall,
126 unsigned long *args, long expected, void **addr,
127 int done)
128 {
129 unsigned long *stack = check_init_stack(mm_idp, *addr);
130
131 if (done && *addr == NULL)
132 single_count++;
133
134 *stack += sizeof(long);
135 stack += *stack / sizeof(long);
136
137 *stack++ = syscall;
138 *stack++ = args[0];
139 *stack++ = args[1];
140 *stack++ = args[2];
141 *stack++ = args[3];
142 *stack++ = args[4];
143 *stack++ = args[5];
144 *stack++ = expected;
145 *stack = 0;
146 multi_op_count++;
147
148 if (!done && ((((unsigned long) stack) & ~UM_KERN_PAGE_MASK) <
149 UM_KERN_PAGE_SIZE - 10 * sizeof(long))) {
150 *addr = stack;
151 return 0;
152 }
153
154 return do_syscall_stub(mm_idp, addr);
155 }
156
157 long syscall_stub_data(struct mm_id * mm_idp,
158 unsigned long *data, int data_count,
159 void **addr, void **stub_addr)
160 {
161 unsigned long *stack;
162 int ret = 0;
163
164 /*
165 * If *addr still is uninitialized, it *must* contain NULL.
166 * Thus in this case do_syscall_stub correctly won't be called.
167 */
168 if ((((unsigned long) *addr) & ~UM_KERN_PAGE_MASK) >=
169 UM_KERN_PAGE_SIZE - (10 + data_count) * sizeof(long)) {
170 ret = do_syscall_stub(mm_idp, addr);
171 /* in case of error, don't overwrite data on stack */
172 if (ret)
173 return ret;
174 }
175
176 stack = check_init_stack(mm_idp, *addr);
177 *addr = stack;
178
179 *stack = data_count * sizeof(long);
180
181 memcpy(stack + 1, data, data_count * sizeof(long));
182
183 *stub_addr = (void *)(((unsigned long)(stack + 1) &
184 ~UM_KERN_PAGE_MASK) + STUB_DATA);
185
186 return 0;
187 }
188
189 int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot,
190 int phys_fd, unsigned long long offset, int done, void **data)
191 {
192 int ret;
193
194 if (proc_mm) {
195 struct proc_mm_op map;
196 int fd = mm_idp->u.mm_fd;
197
198 map = ((struct proc_mm_op) { .op = MM_MMAP,
199 .u =
200 { .mmap =
201 { .addr = virt,
202 .len = len,
203 .prot = prot,
204 .flags = MAP_SHARED |
205 MAP_FIXED,
206 .fd = phys_fd,
207 .offset= offset
208 } } } );
209 CATCH_EINTR(ret = write(fd, &map, sizeof(map)));
210 if (ret != sizeof(map)) {
211 ret = -errno;
212 printk(UM_KERN_ERR "map : /proc/mm map failed, "
213 "err = %d\n", -ret);
214 }
215 else ret = 0;
216 }
217 else {
218 unsigned long args[] = { virt, len, prot,
219 MAP_SHARED | MAP_FIXED, phys_fd,
220 MMAP_OFFSET(offset) };
221
222 ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
223 data, done);
224 }
225
226 return ret;
227 }
228
229 int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
230 int done, void **data)
231 {
232 int ret;
233
234 if (proc_mm) {
235 struct proc_mm_op unmap;
236 int fd = mm_idp->u.mm_fd;
237
238 unmap = ((struct proc_mm_op) { .op = MM_MUNMAP,
239 .u =
240 { .munmap =
241 { .addr =
242 (unsigned long) addr,
243 .len = len } } } );
244 CATCH_EINTR(ret = write(fd, &unmap, sizeof(unmap)));
245 if (ret != sizeof(unmap)) {
246 ret = -errno;
247 printk(UM_KERN_ERR "unmap - proc_mm write returned "
248 "%d\n", ret);
249 }
250 else ret = 0;
251 }
252 else {
253 unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
254 0 };
255
256 ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
257 data, done);
258 }
259
260 return ret;
261 }
262
263 int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
264 unsigned int prot, int done, void **data)
265 {
266 struct proc_mm_op protect;
267 int ret;
268
269 if (proc_mm) {
270 int fd = mm_idp->u.mm_fd;
271
272 protect = ((struct proc_mm_op) { .op = MM_MPROTECT,
273 .u =
274 { .mprotect =
275 { .addr =
276 (unsigned long) addr,
277 .len = len,
278 .prot = prot } } } );
279
280 CATCH_EINTR(ret = write(fd, &protect, sizeof(protect)));
281 if (ret != sizeof(protect)) {
282 ret = -errno;
283 printk(UM_KERN_ERR "protect failed, err = %d", -ret);
284 }
285 else ret = 0;
286 }
287 else {
288 unsigned long args[] = { addr, len, prot, 0, 0, 0 };
289
290 ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
291 data, done);
292 }
293
294 return ret;
295 }
296
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