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;
  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                 panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
  71                       n);
  72
  73         wait_stub_done(pid, 0, "do_syscall_stub");
  74
  75         /* When the stub stops, we find the following values on the
  76          * beginning of the stack:
  77          * (long )return_value
  78          * (long )offset to failed sycall-data (0, if no error)
  79          */
  80         ret = *((unsigned long *) mm_idp->stack);
  81         offset = *((unsigned long *) mm_idp->stack + 1);
  82         if (offset) {
  83                 data = (unsigned long *)(mm_idp->stack +
  84                                          offset - UML_CONFIG_STUB_DATA);
  85                 printk("do_syscall_stub : ret = %ld, offset = %ld, "
  86                        "data = %p\n", ret, offset, data);
  87                 syscall = (unsigned long *)((unsigned long)data + data[0]);
  88                 printk("do_syscall_stub: syscall %ld failed, return value = "
  89                        "0x%lx, expected return value = 0x%lx\n",
  90                        syscall[0], ret, syscall[7]);
  91                 printk("    syscall parameters: "
  92                        "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
  93                        syscall[1], syscall[2], syscall[3],
  94                        syscall[4], syscall[5], syscall[6]);
  95                 for(n = 1; n < data[0]/sizeof(long); n++) {
  96                         if(n == 1)
  97                                 printk("    additional syscall data:");
  98                         if(n % 4 == 1)
  99                                 printk("\n      ");
 100                         printk("  0x%lx", data[n]);
 101                 }
 102                 if(n > 1)
 103                         printk("\n");
 104         }
 105         else ret = 0;
 106
 107         *addr = check_init_stack(mm_idp, NULL);
 108
 109         return ret;
 110 }
 111
 112 long run_syscall_stub(struct mm_id * mm_idp, int syscall,
 113                       unsigned long *args, long expected, void **addr,
 114                       int done)
 115 {
 116         unsigned long *stack = check_init_stack(mm_idp, *addr);
 117
 118         if(done && *addr == NULL)
 119                 single_count++;
 120
 121         *stack += sizeof(long);
 122         stack += *stack / sizeof(long);
 123
 124         *stack++ = syscall;
 125         *stack++ = args[0];
 126         *stack++ = args[1];
 127         *stack++ = args[2];
 128         *stack++ = args[3];
 129         *stack++ = args[4];
 130         *stack++ = args[5];
 131         *stack++ = expected;
 132         *stack = 0;
 133         multi_op_count++;
 134
 135         if(!done && ((((unsigned long) stack) & ~PAGE_MASK) <
 136                      PAGE_SIZE - 10 * sizeof(long))){
 137                 *addr = stack;
 138                 return 0;
 139         }
 140
 141         return do_syscall_stub(mm_idp, addr);
 142 }
 143
 144 long syscall_stub_data(struct mm_id * mm_idp,
 145                        unsigned long *data, int data_count,
 146                        void **addr, void **stub_addr)
 147 {
 148         unsigned long *stack;
 149         int ret = 0;
 150
 151         /* If *addr still is uninitialized, it *must* contain NULL.
 152          * Thus in this case do_syscall_stub correctly won't be called.
 153          */
 154         if((((unsigned long) *addr) & ~PAGE_MASK) >=
 155            PAGE_SIZE - (10 + data_count) * sizeof(long)) {
 156                 ret = do_syscall_stub(mm_idp, addr);
 157                 /* in case of error, don't overwrite data on stack */
 158                 if(ret)
 159                         return ret;
 160         }
 161
 162         stack = check_init_stack(mm_idp, *addr);
 163         *addr = stack;
 164
 165         *stack = data_count * sizeof(long);
 166
 167         memcpy(stack + 1, data, data_count * sizeof(long));
 168
 169         *stub_addr = (void *)(((unsigned long)(stack + 1) & ~PAGE_MASK) +
 170                               UML_CONFIG_STUB_DATA);
 171
 172         return 0;
 173 }
 174
 175 int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
 176         int r, int w, int x, int phys_fd, unsigned long long offset,
 177         int done, void **data)
 178 {
 179         int prot, ret;
 180
 181         prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
 182                 (x ? PROT_EXEC : 0);
 183
 184         if(proc_mm){
 185                 struct proc_mm_op map;
 186                 int fd = mm_idp->u.mm_fd;
 187
 188                 map = ((struct proc_mm_op) { .op        = MM_MMAP,
 189                                        .u               =
 190                                        { .mmap  =
 191                                          { .addr        = virt,
 192                                            .len = len,
 193                                            .prot        = prot,
 194                                            .flags       = MAP_SHARED |
 195                                            MAP_FIXED,
 196                                            .fd  = phys_fd,
 197                                            .offset= offset
 198                                          } } } );
 199                 ret = os_write_file(fd, &map, sizeof(map));
 200                 if(ret != sizeof(map))
 201                         printk("map : /proc/mm map failed, err = %d\n", -ret);
 202                 else ret = 0;
 203         }
 204         else {
 205                 unsigned long args[] = { virt, len, prot,
 206                                          MAP_SHARED | MAP_FIXED, phys_fd,
 207                                          MMAP_OFFSET(offset) };
 208
 209                 ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
 210                                        data, done);
 211         }
 212
 213         return ret;
 214 }
 215
 216 int unmap(struct mm_id * mm_idp, void *addr, unsigned long len, int done,
 217           void **data)
 218 {
 219         int ret;
 220
 221         if(proc_mm){
 222                 struct proc_mm_op unmap;
 223                 int fd = mm_idp->u.mm_fd;
 224
 225                 unmap = ((struct proc_mm_op) { .op      = MM_MUNMAP,
 226                                          .u     =
 227                                          { .munmap      =
 228                                            { .addr      =
 229                                              (unsigned long) addr,
 230                                              .len               = len } } } );
 231                 ret = os_write_file(fd, &unmap, sizeof(unmap));
 232                 if(ret != sizeof(unmap))
 233                         printk("unmap - proc_mm write returned %d\n", ret);
 234                 else ret = 0;
 235         }
 236         else {
 237                 unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
 238                                          0 };
 239
 240                 ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
 241                                        data, done);
 242         }
 243
 244         return ret;
 245 }
 246
 247 int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 248             int r, int w, int x, int done, void **data)
 249 {
 250         struct proc_mm_op protect;
 251         int prot, ret;
 252
 253         prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
 254                 (x ? PROT_EXEC : 0);
 255         if(proc_mm){
 256                 int fd = mm_idp->u.mm_fd;
 257
 258                 protect = ((struct proc_mm_op) { .op    = MM_MPROTECT,
 259                                            .u   =
 260                                            { .mprotect  =
 261                                              { .addr    =
 262                                                (unsigned long) addr,
 263                                                .len     = len,
 264                                                .prot    = prot } } } );
 265
 266                 ret = os_write_file(fd, &protect, sizeof(protect));
 267                 if(ret != sizeof(protect))
 268                         printk("protect failed, err = %d", -ret);
 269                 else ret = 0;
 270         }
 271         else {
 272                 unsigned long args[] = { addr, len, prot, 0, 0, 0 };
 273
 274                 ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
 275                                        data, done);
 276         }
 277
 278         return ret;
 279 }
 280
 281 void before_mem_skas(unsigned long unused)
 282 {
 283 }