arch/um/os-Linux/skas/mem.c

   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
  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
  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 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
 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
 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
 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
 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
 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 }