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