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 <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 inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
  49 {
  50         unsigned long regs[MAX_REG_NR];
  51         int n, i;
  52         long ret, offset;
  53         unsigned long * data;
  54         unsigned long * syscall;
  55         int pid = mm_idp->u.pid;
  56
  57         if(proc_mm)
  58 #warning Need to look up userspace_pid by cpu
  59                 pid = userspace_pid[0];
  60
  61         multi_count++;
  62
  63         get_safe_registers(regs, NULL);
  64         regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
  65                 ((unsigned long) &batch_syscall_stub -
  66                  (unsigned long) &__syscall_stub_start);
  67
  68         n = ptrace_setregs(pid, regs);
  69         if(n < 0){
  70                 printk("Registers - \n");
  71                 for(i = 0; i < MAX_REG_NR; i++)
  72                         printk("\t%d\t0x%lx\n", i, regs[i]);
  73                 panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
  74                       -n);
  75         }
  76
  77         wait_stub_done(pid, 0, "do_syscall_stub");
  78
  79         /* When the stub stops, we find the following values on the
  80          * beginning of the stack:
  81          * (long )return_value
  82          * (long )offset to failed sycall-data (0, if no error)
  83          */
  84         ret = *((unsigned long *) mm_idp->stack);
  85         offset = *((unsigned long *) mm_idp->stack + 1);
  86         if (offset) {
  87                 data = (unsigned long *)(mm_idp->stack +
  88                                          offset - UML_CONFIG_STUB_DATA);
  89                 printk("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("do_syscall_stub: syscall %ld failed, return value = "
  93                        "0x%lx, expected return value = 0x%lx\n",
  94                        syscall[0], ret, syscall[7]);
  95                 printk("    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("    additional syscall data:");
 102                         if(n % 4 == 1)
 103                                 printk("\n      ");
 104                         printk("  0x%lx", data[n]);
 105                 }
 106                 if(n > 1)
 107                         printk("\n");
 108         }
 109         else ret = 0;
 110
 111         *addr = check_init_stack(mm_idp, NULL);
 112
 113         return ret;
 114 }
 115
 116 long run_syscall_stub(struct mm_id * mm_idp, int syscall,
 117                       unsigned long *args, long expected, void **addr,
 118                       int done)
 119 {
 120         unsigned long *stack = check_init_stack(mm_idp, *addr);
 121
 122         if(done && *addr == NULL)
 123                 single_count++;
 124
 125         *stack += sizeof(long);
 126         stack += *stack / sizeof(long);
 127
 128         *stack++ = syscall;
 129         *stack++ = args[0];
 130         *stack++ = args[1];
 131         *stack++ = args[2];
 132         *stack++ = args[3];
 133         *stack++ = args[4];
 134         *stack++ = args[5];
 135         *stack++ = expected;
 136         *stack = 0;
 137         multi_op_count++;
 138
 139         if(!done && ((((unsigned long) stack) & ~PAGE_MASK) <
 140                      PAGE_SIZE - 10 * sizeof(long))){
 141                 *addr = stack;
 142                 return 0;
 143         }
 144
 145         return do_syscall_stub(mm_idp, addr);
 146 }
 147
 148 long syscall_stub_data(struct mm_id * mm_idp,
 149                        unsigned long *data, int data_count,
 150                        void **addr, void **stub_addr)
 151 {
 152         unsigned long *stack;
 153         int ret = 0;
 154
 155         /* If *addr still is uninitialized, it *must* contain NULL.
 156          * Thus in this case do_syscall_stub correctly won't be called.
 157          */
 158         if((((unsigned long) *addr) & ~PAGE_MASK) >=
 159            PAGE_SIZE - (10 + data_count) * sizeof(long)) {
 160                 ret = do_syscall_stub(mm_idp, addr);
 161                 /* in case of error, don't overwrite data on stack */
 162                 if(ret)
 163                         return ret;
 164         }
 165
 166         stack = check_init_stack(mm_idp, *addr);
 167         *addr = stack;
 168
 169         *stack = data_count * sizeof(long);
 170
 171         memcpy(stack + 1, data, data_count * sizeof(long));
 172
 173         *stub_addr = (void *)(((unsigned long)(stack + 1) & ~PAGE_MASK) +
 174                               UML_CONFIG_STUB_DATA);
 175
 176         return 0;
 177 }
 178
 179 int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
 180         int r, int w, int x, int phys_fd, unsigned long long offset,
 181         int done, void **data)
 182 {
 183         int prot, ret;
 184
 185         prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
 186                 (x ? PROT_EXEC : 0);
 187
 188         if(proc_mm){
 189                 struct proc_mm_op map;
 190                 int fd = mm_idp->u.mm_fd;
 191
 192                 map = ((struct proc_mm_op) { .op        = MM_MMAP,
 193                                        .u               =
 194                                        { .mmap  =
 195                                          { .addr        = virt,
 196                                            .len = len,
 197                                            .prot        = prot,
 198                                            .flags       = MAP_SHARED |
 199                                            MAP_FIXED,
 200                                            .fd  = phys_fd,
 201                                            .offset= offset
 202                                          } } } );
 203                 ret = os_write_file(fd, &map, sizeof(map));
 204                 if(ret != sizeof(map))
 205                         printk("map : /proc/mm map failed, err = %d\n", -ret);
 206                 else ret = 0;
 207         }
 208         else {
 209                 unsigned long args[] = { virt, len, prot,
 210                                          MAP_SHARED | MAP_FIXED, phys_fd,
 211                                          MMAP_OFFSET(offset) };
 212
 213                 ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
 214                                        data, done);
 215         }
 216
 217         return ret;
 218 }
 219
 220 int unmap(struct mm_id * mm_idp, void *addr, unsigned long len, int done,
 221           void **data)
 222 {
 223         int ret;
 224
 225         if(proc_mm){
 226                 struct proc_mm_op unmap;
 227                 int fd = mm_idp->u.mm_fd;
 228
 229                 unmap = ((struct proc_mm_op) { .op      = MM_MUNMAP,
 230                                          .u     =
 231                                          { .munmap      =
 232                                            { .addr      =
 233                                              (unsigned long) addr,
 234                                              .len               = len } } } );
 235                 ret = os_write_file(fd, &unmap, sizeof(unmap));
 236                 if(ret != sizeof(unmap))
 237                         printk("unmap - proc_mm write returned %d\n", ret);
 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             int r, int w, int x, int done, void **data)
 253 {
 254         struct proc_mm_op protect;
 255         int prot, ret;
 256
 257         prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
 258                 (x ? PROT_EXEC : 0);
 259         if(proc_mm){
 260                 int fd = mm_idp->u.mm_fd;
 261
 262                 protect = ((struct proc_mm_op) { .op    = MM_MPROTECT,
 263                                            .u   =
 264                                            { .mprotect  =
 265                                              { .addr    =
 266                                                (unsigned long) addr,
 267                                                .len     = len,
 268                                                .prot    = prot } } } );
 269
 270                 ret = os_write_file(fd, &protect, sizeof(protect));
 271                 if(ret != sizeof(protect))
 272                         printk("protect failed, err = %d", -ret);
 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 }
 284
 285 void before_mem_skas(unsigned long unused)
 286 {
 287 }