arch/um/kernel/skas/mem_user.c

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