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 "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, NULL);
  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 }