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 #include "kern_constants.h"
  29
  30 extern unsigned long batch_syscall_stub, __syscall_stub_start;
  31
  32 extern void wait_stub_done(int pid);
  33
  34 static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
  35                                               unsigned long *stack)
  36 {
  37         if(stack == NULL) {
  38                 stack = (unsigned long *) mm_idp->stack + 2;
  39                 *stack = 0;
  40         }
  41         return stack;
  42 }
  43
  44 static unsigned long syscall_regs[MAX_REG_NR];
  45
  46 static int __init init_syscall_regs(void)
  47 {
  48         get_safe_registers(syscall_regs, NULL);
  49         syscall_regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
  50                 ((unsigned long) &batch_syscall_stub -
  51                  (unsigned long) &__syscall_stub_start);
  52         return 0;
  53 }
  54
  55 __initcall(init_syscall_regs);
  56
  57 extern int proc_mm;
  58
  59 int single_count = 0;
  60 int multi_count = 0;
  61 int multi_op_count = 0;
  62
  63 static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
  64 {
  65         int n, i;
  66         long ret, offset;
  67         unsigned long * data;
  68         unsigned long * syscall;
  69         int err, pid = mm_idp->u.pid;
  70
  71         if(proc_mm)
  72                 /* FIXME: Need to look up userspace_pid by cpu */
  73                 pid = userspace_pid[0];
  74
  75         multi_count++;
  76
  77         n = ptrace_setregs(pid, syscall_regs);
  78         if(n < 0){
  79                 printk("Registers - \n");
  80                 for(i = 0; i < MAX_REG_NR; i++)
  81                         printk("\t%d\t0x%lx\n", i, syscall_regs[i]);
  82                 panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
  83                       -n);
  84         }
  85
  86         err = ptrace(PTRACE_CONT, pid, 0, 0);
  87         if(err)
  88                 panic("Failed to continue stub, pid = %d, errno = %d\n", pid,
  89                       errno);
  90
  91         wait_stub_done(pid);
  92
  93         /* When the stub stops, we find the following values on the
  94          * beginning of the stack:
  95          * (long )return_value
  96          * (long )offset to failed sycall-data (0, if no error)
  97          */
  98         ret = *((unsigned long *) mm_idp->stack);
  99         offset = *((unsigned long *) mm_idp->stack + 1);
 100         if (offset) {
 101                 data = (unsigned long *)(mm_idp->stack +
 102                                          offset - UML_CONFIG_STUB_DATA);
 103                 printk("do_syscall_stub : ret = %ld, offset = %ld, "
 104                        "data = %p\n", ret, offset, data);
 105                 syscall = (unsigned long *)((unsigned long)data + data[0]);
 106                 printk("do_syscall_stub: syscall %ld failed, return value = "
 107                        "0x%lx, expected return value = 0x%lx\n",
 108                        syscall[0], ret, syscall[7]);
 109                 printk("    syscall parameters: "
 110                        "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
 111                        syscall[1], syscall[2], syscall[3],
 112                        syscall[4], syscall[5], syscall[6]);
 113                 for(n = 1; n < data[0]/sizeof(long); n++) {
 114                         if(n == 1)
 115                                 printk("    additional syscall data:");
 116                         if(n % 4 == 1)
 117                                 printk("\n      ");
 118                         printk("  0x%lx", data[n]);
 119                 }
 120                 if(n > 1)
 121                         printk("\n");
 122         }
 123         else ret = 0;
 124
 125         *addr = check_init_stack(mm_idp, NULL);
 126
 127         return ret;
 128 }
 129
 130 long run_syscall_stub(struct mm_id * mm_idp, int syscall,
 131                       unsigned long *args, long expected, void **addr,
 132                       int done)
 133 {
 134         unsigned long *stack = check_init_stack(mm_idp, *addr);
 135
 136         if(done && *addr == NULL)
 137                 single_count++;
 138
 139         *stack += sizeof(long);
 140         stack += *stack / sizeof(long);
 141
 142         *stack++ = syscall;
 143         *stack++ = args[0];
 144         *stack++ = args[1];
 145         *stack++ = args[2];
 146         *stack++ = args[3];
 147         *stack++ = args[4];
 148         *stack++ = args[5];
 149         *stack++ = expected;
 150         *stack = 0;
 151         multi_op_count++;
 152
 153         if(!done && ((((unsigned long) stack) & ~UM_KERN_PAGE_MASK) <
 154                      UM_KERN_PAGE_SIZE - 10 * sizeof(long))){
 155                 *addr = stack;
 156                 return 0;
 157         }
 158
 159         return do_syscall_stub(mm_idp, addr);
 160 }
 161
 162 long syscall_stub_data(struct mm_id * mm_idp,
 163                        unsigned long *data, int data_count,
 164                        void **addr, void **stub_addr)
 165 {
 166         unsigned long *stack;
 167         int ret = 0;
 168
 169         /* If *addr still is uninitialized, it *must* contain NULL.
 170          * Thus in this case do_syscall_stub correctly won't be called.
 171          */
 172         if((((unsigned long) *addr) & ~UM_KERN_PAGE_MASK) >=
 173            UM_KERN_PAGE_SIZE - (10 + data_count) * sizeof(long)) {
 174                 ret = do_syscall_stub(mm_idp, addr);
 175                 /* in case of error, don't overwrite data on stack */
 176                 if(ret)
 177                         return ret;
 178         }
 179
 180         stack = check_init_stack(mm_idp, *addr);
 181         *addr = stack;
 182
 183         *stack = data_count * sizeof(long);
 184
 185         memcpy(stack + 1, data, data_count * sizeof(long));
 186
 187         *stub_addr = (void *)(((unsigned long)(stack + 1) &
 188                                ~UM_KERN_PAGE_MASK) + UML_CONFIG_STUB_DATA);
 189
 190         return 0;
 191 }
 192
 193 int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len, int prot,
 194         int phys_fd, unsigned long long offset, int done, void **data)
 195 {
 196         int ret;
 197
 198         if(proc_mm){
 199                 struct proc_mm_op map;
 200                 int fd = mm_idp->u.mm_fd;
 201
 202                 map = ((struct proc_mm_op) { .op        = MM_MMAP,
 203                                        .u               =
 204                                        { .mmap  =
 205                                          { .addr        = virt,
 206                                            .len = len,
 207                                            .prot        = prot,
 208                                            .flags       = MAP_SHARED |
 209                                            MAP_FIXED,
 210                                            .fd  = phys_fd,
 211                                            .offset= offset
 212                                          } } } );
 213                 CATCH_EINTR(ret = write(fd, &map, sizeof(map)));
 214                 if(ret != sizeof(map)){
 215                         ret = -errno;
 216                         printk("map : /proc/mm map failed, err = %d\n", -ret);
 217                 }
 218                 else ret = 0;
 219         }
 220         else {
 221                 unsigned long args[] = { virt, len, prot,
 222                                          MAP_SHARED | MAP_FIXED, phys_fd,
 223                                          MMAP_OFFSET(offset) };
 224
 225                 ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
 226                                        data, done);
 227         }
 228
 229         return ret;
 230 }
 231
 232 int unmap(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 233           int done, void **data)
 234 {
 235         int ret;
 236
 237         if(proc_mm){
 238                 struct proc_mm_op unmap;
 239                 int fd = mm_idp->u.mm_fd;
 240
 241                 unmap = ((struct proc_mm_op) { .op      = MM_MUNMAP,
 242                                          .u     =
 243                                          { .munmap      =
 244                                            { .addr      =
 245                                              (unsigned long) addr,
 246                                              .len               = len } } } );
 247                 CATCH_EINTR(ret = write(fd, &unmap, sizeof(unmap)));
 248                 if(ret != sizeof(unmap)){
 249                         ret = -errno;
 250                         printk("unmap - proc_mm write returned %d\n", ret);
 251                 }
 252                 else ret = 0;
 253         }
 254         else {
 255                 unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
 256                                          0 };
 257
 258                 ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
 259                                        data, done);
 260         }
 261
 262         return ret;
 263 }
 264
 265 int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 266             unsigned int prot, int done, void **data)
 267 {
 268         struct proc_mm_op protect;
 269         int ret;
 270
 271         if(proc_mm){
 272                 int fd = mm_idp->u.mm_fd;
 273
 274                 protect = ((struct proc_mm_op) { .op    = MM_MPROTECT,
 275                                            .u   =
 276                                            { .mprotect  =
 277                                              { .addr    =
 278                                                (unsigned long) addr,
 279                                                .len     = len,
 280                                                .prot    = prot } } } );
 281
 282                 CATCH_EINTR(ret = write(fd, &protect, sizeof(protect)));
 283                 if(ret != sizeof(protect)){
 284                         ret = -errno;
 285                         printk("protect failed, err = %d", -ret);
 286                 }
 287                 else ret = 0;
 288         }
 289         else {
 290                 unsigned long args[] = { addr, len, prot, 0, 0, 0 };
 291
 292                 ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
 293                                        data, done);
 294         }
 295
 296         return ret;
 297 }
 298
 299 void before_mem_skas(unsigned long unused)
 300 {
 301 }