arch/um/os-Linux/skas/mem.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 <unistd.h>
  10 #include <sys/mman.h>
  11 #include <sys/wait.h>
  12 #include <asm/page.h>
  13 #include <asm/unistd.h>
  14 #include "mem_user.h"
  15 #include "mem.h"
  16 #include "skas.h"
  17 #include "user.h"
  18 #include "os.h"
  19 #include "proc_mm.h"
  20 #include "ptrace_user.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 #include "init.h"
  28
  29 extern unsigned long batch_syscall_stub, __syscall_stub_start;
  30
  31 extern void wait_stub_done(int pid);
  32
  33 static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
  34                                               unsigned long *stack)
  35 {
  36         if(stack == NULL) {
  37                 stack = (unsigned long *) mm_idp->stack + 2;
  38                 *stack = 0;
  39         }
  40         return stack;
  41 }
  42
  43 static unsigned long syscall_regs[MAX_REG_NR];
  44
  45 static int __init init_syscall_regs(void)
  46 {
  47         get_safe_registers(syscall_regs, NULL);
  48         syscall_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
  49                 ((unsigned long) &batch_syscall_stub -
  50                  (unsigned long) &__syscall_stub_start);
  51         return 0;
  52 }
  53
  54 __initcall(init_syscall_regs);
  55
  56 extern int proc_mm;
  57
  58 int single_count = 0;
  59 int multi_count = 0;
  60 int multi_op_count = 0;
  61
  62 static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
  63 {
  64         int n, i;
  65         long ret, offset;
  66         unsigned long * data;
  67         unsigned long * syscall;
  68         int err, pid = mm_idp->u.pid;
  69
  70         if(proc_mm)
  71 #warning Need to look up userspace_pid by cpu
  72                 pid = userspace_pid[0];
  73
  74         multi_count++;
  75
  76         n = ptrace_setregs(pid, syscall_regs);
  77         if(n < 0){
  78                 printk("Registers - \n");
  79                 for(i = 0; i < MAX_REG_NR; i++)
  80                         printk("\t%d\t0x%lx\n", i, syscall_regs[i]);
  81                 panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
  82                       -n);
  83         }
  84
  85         err = ptrace(PTRACE_CONT, pid, 0, 0);
  86         if(err)
  87                 panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
  88                       errno);
  89
  90         wait_stub_done(pid);
  91
  92         /* When the stub stops, we find the following values on the
  93          * beginning of the stack:
  94          * (long )return_value
  95          * (long )offset to failed sycall-data (0, if no error)
  96          */
  97         ret = *((unsigned long *) mm_idp->stack);
  98         offset = *((unsigned long *) mm_idp->stack + 1);
  99         if (offset) {
 100                 data = (unsigned long *)(mm_idp->stack +
 101                                          offset - UML_CONFIG_STUB_DATA);
 102                 printk("do_syscall_stub : ret = %ld, offset = %ld, "
 103                        "data = %p\n", ret, offset, data);
 104                 syscall = (unsigned long *)((unsigned long)data + data[0]);
 105                 printk("do_syscall_stub: syscall %ld failed, return value = "
 106                        "0x%lx, expected return value = 0x%lx\n",
 107                        syscall[0], ret, syscall[7]);
 108                 printk("    syscall parameters: "
 109                        "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
 110                        syscall[1], syscall[2], syscall[3],
 111                        syscall[4], syscall[5], syscall[6]);
 112                 for(n = 1; n < data[0]/sizeof(long); n++) {
 113                         if(n == 1)
 114                                 printk("    additional syscall data:");
 115                         if(n % 4 == 1)
 116                                 printk("\n      ");
 117                         printk("  0x%lx", data[n]);
 118                 }
 119                 if(n > 1)
 120                         printk("\n");
 121         }
 122         else ret = 0;
 123
 124         *addr = check_init_stack(mm_idp, NULL);
 125
 126         return ret;
 127 }
 128
 129 long run_syscall_stub(struct mm_id * mm_idp, int syscall,
 130                       unsigned long *args, long expected, void **addr,
 131                       int done)
 132 {
 133         unsigned long *stack = check_init_stack(mm_idp, *addr);
 134
 135         if(done && *addr == NULL)
 136                 single_count++;
 137
 138         *stack += sizeof(long);
 139         stack += *stack / sizeof(long);
 140
 141         *stack++ = syscall;
 142         *stack++ = args[0];
 143         *stack++ = args[1];
 144         *stack++ = args[2];
 145         *stack++ = args[3];
 146         *stack++ = args[4];
 147         *stack++ = args[5];
 148         *stack++ = expected;
 149         *stack = 0;
 150         multi_op_count++;
 151
 152         if(!done && ((((unsigned long) stack) & ~PAGE_MASK) <
 153                      PAGE_SIZE - 10 * sizeof(long))){
 154                 *addr = stack;
 155                 return 0;
 156         }
 157
 158         return do_syscall_stub(mm_idp, addr);
 159 }
 160
 161 long syscall_stub_data(struct mm_id * mm_idp,
 162                        unsigned long *data, int data_count,
 163                        void **addr, void **stub_addr)
 164 {
 165         unsigned long *stack;
 166         int ret = 0;
 167
 168         /* If *addr still is uninitialized, it *must* contain NULL.
 169          * Thus in this case do_syscall_stub correctly won't be called.
 170          */
 171         if((((unsigned long) *addr) & ~PAGE_MASK) >=
 172            PAGE_SIZE - (10 + data_count) * sizeof(long)) {
 173                 ret = do_syscall_stub(mm_idp, addr);
 174                 /* in case of error, don't overwrite data on stack */
 175                 if(ret)
 176                         return ret;
 177         }
 178
 179         stack = check_init_stack(mm_idp, *addr);
 180         *addr = stack;
 181
 182         *stack = data_count * sizeof(long);
 183
 184         memcpy(stack + 1, data, data_count * sizeof(long));
 185
 186         *stub_addr = (void *)(((unsigned long)(stack + 1) & ~PAGE_MASK) +
 187                               UML_CONFIG_STUB_DATA);
 188
 189         return 0;
 190 }
 191
 192 int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot,
 193         int phys_fd, unsigned long long offset, int done, void **data)
 194 {
 195         int ret;
 196
 197         if(proc_mm){
 198                 struct proc_mm_op map;
 199                 int fd = mm_idp->u.mm_fd;
 200
 201                 map = ((struct proc_mm_op) { .op        = MM_MMAP,
 202                                        .u               =
 203                                        { .mmap  =
 204                                          { .addr        = virt,
 205                                            .len = len,
 206                                            .prot        = prot,
 207                                            .flags       = MAP_SHARED |
 208                                            MAP_FIXED,
 209                                            .fd  = phys_fd,
 210                                            .offset= offset
 211                                          } } } );
 212                 CATCH_EINTR(ret = write(fd, &map, sizeof(map)));
 213                 if(ret != sizeof(map)){
 214                         ret = -errno;
 215                         printk("map : /proc/mm map failed, err = %d\n", -ret);
 216                 }
 217                 else ret = 0;
 218         }
 219         else {
 220                 unsigned long args[] = { virt, len, prot,
 221                                          MAP_SHARED | MAP_FIXED, phys_fd,
 222                                          MMAP_OFFSET(offset) };
 223
 224                 ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
 225                                        data, done);
 226         }
 227
 228         return ret;
 229 }
 230
 231 int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 232           int done, void **data)
 233 {
 234         int ret;
 235
 236         if(proc_mm){
 237                 struct proc_mm_op unmap;
 238                 int fd = mm_idp->u.mm_fd;
 239
 240                 unmap = ((struct proc_mm_op) { .op      = MM_MUNMAP,
 241                                          .u     =
 242                                          { .munmap      =
 243                                            { .addr      =
 244                                              (unsigned long) addr,
 245                                              .len               = len } } } );
 246                 CATCH_EINTR(ret = write(fd, &unmap, sizeof(unmap)));
 247                 if(ret != sizeof(unmap)){
 248                         ret = -errno;
 249                         printk("unmap - proc_mm write returned %d\n", ret);
 250                 }
 251                 else ret = 0;
 252         }
 253         else {
 254                 unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
 255                                          0 };
 256
 257                 ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
 258                                        data, done);
 259         }
 260
 261         return ret;
 262 }
 263
 264 int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 265             unsigned int prot, int done, void **data)
 266 {
 267         struct proc_mm_op protect;
 268         int ret;
 269
 270         if(proc_mm){
 271                 int fd = mm_idp->u.mm_fd;
 272
 273                 protect = ((struct proc_mm_op) { .op    = MM_MPROTECT,
 274                                            .u   =
 275                                            { .mprotect  =
 276                                              { .addr    =
 277                                                (unsigned long) addr,
 278                                                .len     = len,
 279                                                .prot    = prot } } } );
 280
 281                 CATCH_EINTR(ret = write(fd, &protect, sizeof(protect)));
 282                 if(ret != sizeof(protect)){
 283                         ret = -errno;
 284                         printk("protect failed, err = %d", -ret);
 285                 }
 286                 else ret = 0;
 287         }
 288         else {
 289                 unsigned long args[] = { addr, len, prot, 0, 0, 0 };
 290
 291                 ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
 292                                        data, done);
 293         }
 294
 295         return ret;
 296 }
 297
 298 void before_mem_skas(unsigned long unused)
 299 {
 300 }