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 "kern_util.h"
  21 #include "task.h"
  22 #include "registers.h"
  23 #include "uml-config.h"
  24 #include "sysdep/ptrace.h"
  25 #include "sysdep/stub.h"
  26
  27 extern unsigned long batch_syscall_stub, __syscall_stub_start;
  28
  29 extern void wait_stub_done(int pid, int sig, char * fname);
  30
  31 static inline unsigned long *check_init_stack(struct mm_id * mm_idp,
  32                                               unsigned long *stack)
  33 {
  34         if(stack == NULL) {
  35                 stack = (unsigned long *) mm_idp->stack + 2;
  36                 *stack = 0;
  37         }
  38         return stack;
  39 }
  40
  41 extern int proc_mm;
  42
  43 int single_count = 0;
  44 int multi_count = 0;
  45 int multi_op_count = 0;
  46
  47 static inline long do_syscall_stub(struct mm_id * mm_idp, void **addr)
  48 {
  49         unsigned long regs[MAX_REG_NR];
  50         int n, i;
  51         long ret, offset;
  52         unsigned long * data;
  53         unsigned long * syscall;
  54         int 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, NULL);
  63         regs[REGS_IP_INDEX] = UML_CONFIG_STUB_CODE +
  64                 ((unsigned long) &batch_syscall_stub -
  65                  (unsigned long) &__syscall_stub_start);
  66
  67         n = ptrace_setregs(pid, regs);
  68         if(n < 0){
  69                 printk("Registers - \n");
  70                 for(i = 0; i < MAX_REG_NR; i++)
  71                         printk("\t%d\t0x%lx\n", i, regs[i]);
  72                 panic("do_syscall_stub : PTRACE_SETREGS failed, errno = %d\n",
  73                       -n);
  74         }
  75
  76         wait_stub_done(pid, 0, "do_syscall_stub");
  77
  78         /* When the stub stops, we find the following values on the
  79          * beginning of the stack:
  80          * (long )return_value
  81          * (long )offset to failed sycall-data (0, if no error)
  82          */
  83         ret = *((unsigned long *) mm_idp->stack);
  84         offset = *((unsigned long *) mm_idp->stack + 1);
  85         if (offset) {
  86                 data = (unsigned long *)(mm_idp->stack +
  87                                          offset - UML_CONFIG_STUB_DATA);
  88                 printk("do_syscall_stub : ret = %ld, offset = %ld, "
  89                        "data = %p\n", ret, offset, data);
  90                 syscall = (unsigned long *)((unsigned long)data + data[0]);
  91                 printk("do_syscall_stub: syscall %ld failed, return value = "
  92                        "0x%lx, expected return value = 0x%lx\n",
  93                        syscall[0], ret, syscall[7]);
  94                 printk("    syscall parameters: "
  95                        "0x%lx 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
  96                        syscall[1], syscall[2], syscall[3],
  97                        syscall[4], syscall[5], syscall[6]);
  98                 for(n = 1; n < data[0]/sizeof(long); n++) {
  99                         if(n == 1)
 100                                 printk("    additional syscall data:");
 101                         if(n % 4 == 1)
 102                                 printk("\n      ");
 103                         printk("  0x%lx", data[n]);
 104                 }
 105                 if(n > 1)
 106                         printk("\n");
 107         }
 108         else ret = 0;
 109
 110         *addr = check_init_stack(mm_idp, NULL);
 111
 112         return ret;
 113 }
 114
 115 long run_syscall_stub(struct mm_id * mm_idp, int syscall,
 116                       unsigned long *args, long expected, void **addr,
 117                       int done)
 118 {
 119         unsigned long *stack = check_init_stack(mm_idp, *addr);
 120
 121         if(done && *addr == NULL)
 122                 single_count++;
 123
 124         *stack += sizeof(long);
 125         stack += *stack / sizeof(long);
 126
 127         *stack++ = syscall;
 128         *stack++ = args[0];
 129         *stack++ = args[1];
 130         *stack++ = args[2];
 131         *stack++ = args[3];
 132         *stack++ = args[4];
 133         *stack++ = args[5];
 134         *stack++ = expected;
 135         *stack = 0;
 136         multi_op_count++;
 137
 138         if(!done && ((((unsigned long) stack) & ~PAGE_MASK) <
 139                      PAGE_SIZE - 10 * sizeof(long))){
 140                 *addr = stack;
 141                 return 0;
 142         }
 143
 144         return do_syscall_stub(mm_idp, addr);
 145 }
 146
 147 long syscall_stub_data(struct mm_id * mm_idp,
 148                        unsigned long *data, int data_count,
 149                        void **addr, void **stub_addr)
 150 {
 151         unsigned long *stack;
 152         int ret = 0;
 153
 154         /* If *addr still is uninitialized, it *must* contain NULL.
 155          * Thus in this case do_syscall_stub correctly won't be called.
 156          */
 157         if((((unsigned long) *addr) & ~PAGE_MASK) >=
 158            PAGE_SIZE - (10 + data_count) * sizeof(long)) {
 159                 ret = do_syscall_stub(mm_idp, addr);
 160                 /* in case of error, don't overwrite data on stack */
 161                 if(ret)
 162                         return ret;
 163         }
 164
 165         stack = check_init_stack(mm_idp, *addr);
 166         *addr = stack;
 167
 168         *stack = data_count * sizeof(long);
 169
 170         memcpy(stack + 1, data, data_count * sizeof(long));
 171
 172         *stub_addr = (void *)(((unsigned long)(stack + 1) & ~PAGE_MASK) +
 173                               UML_CONFIG_STUB_DATA);
 174
 175         return 0;
 176 }
 177
 178 int map(struct mm_id * mm_idp, unsigned long virt, unsigned long len,
 179         int r, int w, int x, int phys_fd, unsigned long long offset,
 180         int done, void **data)
 181 {
 182         int prot, ret;
 183
 184         prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
 185                 (x ? PROT_EXEC : 0);
 186
 187         if(proc_mm){
 188                 struct proc_mm_op map;
 189                 int fd = mm_idp->u.mm_fd;
 190
 191                 map = ((struct proc_mm_op) { .op        = MM_MMAP,
 192                                        .u               =
 193                                        { .mmap  =
 194                                          { .addr        = virt,
 195                                            .len = len,
 196                                            .prot        = prot,
 197                                            .flags       = MAP_SHARED |
 198                                            MAP_FIXED,
 199                                            .fd  = phys_fd,
 200                                            .offset= offset
 201                                          } } } );
 202                 ret = os_write_file(fd, &map, sizeof(map));
 203                 if(ret != sizeof(map))
 204                         printk("map : /proc/mm map failed, err = %d\n", -ret);
 205                 else ret = 0;
 206         }
 207         else {
 208                 unsigned long args[] = { virt, len, prot,
 209                                          MAP_SHARED | MAP_FIXED, phys_fd,
 210                                          MMAP_OFFSET(offset) };
 211
 212                 ret = run_syscall_stub(mm_idp, STUB_MMAP_NR, args, virt,
 213                                        data, done);
 214         }
 215
 216         return ret;
 217 }
 218
 219 int unmap(struct mm_id * mm_idp, void *addr, unsigned long len, int done,
 220           void **data)
 221 {
 222         int ret;
 223
 224         if(proc_mm){
 225                 struct proc_mm_op unmap;
 226                 int fd = mm_idp->u.mm_fd;
 227
 228                 unmap = ((struct proc_mm_op) { .op      = MM_MUNMAP,
 229                                          .u     =
 230                                          { .munmap      =
 231                                            { .addr      =
 232                                              (unsigned long) addr,
 233                                              .len               = len } } } );
 234                 ret = os_write_file(fd, &unmap, sizeof(unmap));
 235                 if(ret != sizeof(unmap))
 236                         printk("unmap - proc_mm write returned %d\n", ret);
 237                 else ret = 0;
 238         }
 239         else {
 240                 unsigned long args[] = { (unsigned long) addr, len, 0, 0, 0,
 241                                          0 };
 242
 243                 ret = run_syscall_stub(mm_idp, __NR_munmap, args, 0,
 244                                        data, done);
 245         }
 246
 247         return ret;
 248 }
 249
 250 int protect(struct mm_id * mm_idp, unsigned long addr, unsigned long len,
 251             int r, int w, int x, int done, void **data)
 252 {
 253         struct proc_mm_op protect;
 254         int prot, ret;
 255
 256         prot = (r ? PROT_READ : 0) | (w ? PROT_WRITE : 0) |
 257                 (x ? PROT_EXEC : 0);
 258         if(proc_mm){
 259                 int fd = mm_idp->u.mm_fd;
 260
 261                 protect = ((struct proc_mm_op) { .op    = MM_MPROTECT,
 262                                            .u   =
 263                                            { .mprotect  =
 264                                              { .addr    =
 265                                                (unsigned long) addr,
 266                                                .len     = len,
 267                                                .prot    = prot } } } );
 268
 269                 ret = os_write_file(fd, &protect, sizeof(protect));
 270                 if(ret != sizeof(protect))
 271                         printk("protect failed, err = %d", -ret);
 272                 else ret = 0;
 273         }
 274         else {
 275                 unsigned long args[] = { addr, len, prot, 0, 0, 0 };
 276
 277                 ret = run_syscall_stub(mm_idp, __NR_mprotect, args, 0,
 278                                        data, done);
 279         }
 280
 281         return ret;
 282 }
 283
 284 void before_mem_skas(unsigned long unused)
 285 {
 286 }