arch/xtensa/kernel/ptrace.c

   1 // TODO some minor issues
   2 /*
   3  * This file is subject to the terms and conditions of the GNU General Public
   4  * License.  See the file "COPYING" in the main directory of this archive
   5  * for more details.
   6  *
   7  * Copyright (C) 2001 - 2007  Tensilica Inc.
   8  *
   9  * Joe Taylor   <joe@tensilica.com, joetylr@yahoo.com>
  10  * Chris Zankel <chris@zankel.net>
  11  * Scott Foehner<sfoehner@yahoo.com>,
  12  * Kevin Chea
  13  * Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/sched.h>
  18 #include <linux/mm.h>
  19 #include <linux/errno.h>
  20 #include <linux/ptrace.h>
  21 #include <linux/smp.h>
  22 #include <linux/security.h>
  23 #include <linux/signal.h>
  24
  25 #include <asm/pgtable.h>
  26 #include <asm/page.h>
  27 #include <asm/uaccess.h>
  28 #include <asm/ptrace.h>
  29 #include <asm/elf.h>
  30 #include <asm/coprocessor.h>
  31
  32
  33 void user_enable_single_step(struct task_struct *child)
  34 {
  35         child->ptrace |= PT_SINGLESTEP;
  36 }
  37
  38 void user_disable_single_step(struct task_struct *child)
  39 {
  40         child->ptrace &= ~PT_SINGLESTEP;
  41 }
  42
  43 /*
  44  * Called by kernel/ptrace.c when detaching to disable single stepping.
  45  */
  46
  47 void ptrace_disable(struct task_struct *child)
  48 {
  49         /* Nothing to do.. */
  50 }
  51
  52 int ptrace_getregs(struct task_struct *child, void __user *uregs)
  53 {
  54         struct pt_regs *regs = task_pt_regs(child);
  55         xtensa_gregset_t __user *gregset = uregs;
  56         unsigned long wm = regs->wmask;
  57         unsigned long wb = regs->windowbase;
  58         int live, i;
  59
  60         if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
  61                 return -EIO;
  62
  63         __put_user(regs->pc, &gregset->pc);
  64         __put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps);
  65         __put_user(regs->lbeg, &gregset->lbeg);
  66         __put_user(regs->lend, &gregset->lend);
  67         __put_user(regs->lcount, &gregset->lcount);
  68         __put_user(regs->windowstart, &gregset->windowstart);
  69         __put_user(regs->windowbase, &gregset->windowbase);
  70
  71         live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16;
  72
  73         for (i = 0; i < live; i++)
  74                 __put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
  75         for (i = XCHAL_NUM_AREGS - (wm >> 4) * 4; i < XCHAL_NUM_AREGS; i++)
  76                 __put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
  77
  78         return 0;
  79 }
  80
  81 int ptrace_setregs(struct task_struct *child, void __user *uregs)
  82 {
  83         struct pt_regs *regs = task_pt_regs(child);
  84         xtensa_gregset_t *gregset = uregs;
  85         const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
  86         unsigned long ps;
  87         unsigned long wb;
  88
  89         if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
  90                 return -EIO;
  91
  92         __get_user(regs->pc, &gregset->pc);
  93         __get_user(ps, &gregset->ps);
  94         __get_user(regs->lbeg, &gregset->lbeg);
  95         __get_user(regs->lend, &gregset->lend);
  96         __get_user(regs->lcount, &gregset->lcount);
  97         __get_user(regs->windowstart, &gregset->windowstart);
  98         __get_user(wb, &gregset->windowbase);
  99
 100         regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);
 101
 102         if (wb >= XCHAL_NUM_AREGS / 4)
 103                 return -EFAULT;
 104
 105         regs->windowbase = wb;
 106
 107         if (wb != 0 &&  __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4,
 108                                          gregset->a, wb * 16))
 109                 return -EFAULT;
 110
 111         if (__copy_from_user(regs->areg, gregset->a + wb*4, (WSBITS-wb) * 16))
 112                 return -EFAULT;
 113
 114         return 0;
 115 }
 116
 117
 118 int ptrace_getxregs(struct task_struct *child, void __user *uregs)
 119 {
 120         struct pt_regs *regs = task_pt_regs(child);
 121         struct thread_info *ti = task_thread_info(child);
 122         elf_xtregs_t __user *xtregs = uregs;
 123         int ret = 0;
 124
 125         if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t)))
 126                 return -EIO;
 127
 128 #if XTENSA_HAVE_COPROCESSORS
 129         /* Flush all coprocessor registers to memory. */
 130         coprocessor_flush_all(ti);
 131         ret |= __copy_to_user(&xtregs->cp0, &ti->xtregs_cp,
 132                               sizeof(xtregs_coprocessor_t));
 133 #endif
 134         ret |= __copy_to_user(&xtregs->opt, &regs->xtregs_opt,
 135                               sizeof(xtregs->opt));
 136         ret |= __copy_to_user(&xtregs->user,&ti->xtregs_user,
 137                               sizeof(xtregs->user));
 138
 139         return ret ? -EFAULT : 0;
 140 }
 141
 142 int ptrace_setxregs(struct task_struct *child, void __user *uregs)
 143 {
 144         struct thread_info *ti = task_thread_info(child);
 145         struct pt_regs *regs = task_pt_regs(child);
 146         elf_xtregs_t *xtregs = uregs;
 147         int ret = 0;
 148
 149         if (!access_ok(VERIFY_READ, uregs, sizeof(elf_xtregs_t)))
 150                 return -EFAULT;
 151
 152 #if XTENSA_HAVE_COPROCESSORS
 153         /* Flush all coprocessors before we overwrite them. */
 154         coprocessor_flush_all(ti);
 155         coprocessor_release_all(ti);
 156
 157         ret |= __copy_from_user(&ti->xtregs_cp, &xtregs->cp0,
 158                                 sizeof(xtregs_coprocessor_t));
 159 #endif
 160         ret |= __copy_from_user(&regs->xtregs_opt, &xtregs->opt,
 161                                 sizeof(xtregs->opt));
 162         ret |= __copy_from_user(&ti->xtregs_user, &xtregs->user,
 163                                 sizeof(xtregs->user));
 164
 165         return ret ? -EFAULT : 0;
 166 }
 167
 168 int ptrace_peekusr(struct task_struct *child, long regno, long __user *ret)
 169 {
 170         struct pt_regs *regs;
 171         unsigned long tmp;
 172
 173         regs = task_pt_regs(child);
 174         tmp = 0;  /* Default return value. */
 175
 176         switch(regno) {
 177
 178                 case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
 179                         tmp = regs->areg[regno - REG_AR_BASE];
 180                         break;
 181
 182                 case REG_A_BASE ... REG_A_BASE + 15:
 183                         tmp = regs->areg[regno - REG_A_BASE];
 184                         break;
 185
 186                 case REG_PC:
 187                         tmp = regs->pc;
 188                         break;
 189
 190                 case REG_PS:
 191                         /* Note:  PS.EXCM is not set while user task is running;
 192                          * its being set in regs is for exception handling
 193                          * convenience.  */
 194                         tmp = (regs->ps & ~(1 << PS_EXCM_BIT));
 195                         break;
 196
 197                 case REG_WB:
 198                         break;          /* tmp = 0 */
 199
 200                 case REG_WS:
 201                 {
 202                         unsigned long wb = regs->windowbase;
 203                         unsigned long ws = regs->windowstart;
 204                         tmp = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<<WSBITS)-1);
 205                         break;
 206                 }
 207                 case REG_LBEG:
 208                         tmp = regs->lbeg;
 209                         break;
 210
 211                 case REG_LEND:
 212                         tmp = regs->lend;
 213                         break;
 214
 215                 case REG_LCOUNT:
 216                         tmp = regs->lcount;
 217                         break;
 218
 219                 case REG_SAR:
 220                         tmp = regs->sar;
 221                         break;
 222
 223                 case SYSCALL_NR:
 224                         tmp = regs->syscall;
 225                         break;
 226
 227                 default:
 228                         return -EIO;
 229         }
 230         return put_user(tmp, ret);
 231 }
 232
 233 int ptrace_pokeusr(struct task_struct *child, long regno, long val)
 234 {
 235         struct pt_regs *regs;
 236         regs = task_pt_regs(child);
 237
 238         switch (regno) {
 239                 case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
 240                         regs->areg[regno - REG_AR_BASE] = val;
 241                         break;
 242
 243                 case REG_A_BASE ... REG_A_BASE + 15:
 244                         regs->areg[regno - REG_A_BASE] = val;
 245                         break;
 246
 247                 case REG_PC:
 248                         regs->pc = val;
 249                         break;
 250
 251                 case SYSCALL_NR:
 252                         regs->syscall = val;
 253                         break;
 254
 255                 default:
 256                         return -EIO;
 257         }
 258         return 0;
 259 }
 260
 261 long arch_ptrace(struct task_struct *child, long request,
 262                  unsigned long addr, unsigned long data)
 263 {
 264         int ret = -EPERM;
 265         void __user *datap = (void __user *) data;
 266
 267         switch (request) {
 268         case PTRACE_PEEKTEXT:   /* read word at location addr. */
 269         case PTRACE_PEEKDATA:
 270                 ret = generic_ptrace_peekdata(child, addr, data);
 271                 break;
 272
 273         case PTRACE_PEEKUSR:    /* read register specified by addr. */
 274                 ret = ptrace_peekusr(child, addr, datap);
 275                 break;
 276
 277         case PTRACE_POKETEXT:   /* write the word at location addr. */
 278         case PTRACE_POKEDATA:
 279                 ret = generic_ptrace_pokedata(child, addr, data);
 280                 break;
 281
 282         case PTRACE_POKEUSR:    /* write register specified by addr. */
 283                 ret = ptrace_pokeusr(child, addr, data);
 284                 break;
 285
 286         case PTRACE_GETREGS:
 287                 ret = ptrace_getregs(child, datap);
 288                 break;
 289
 290         case PTRACE_SETREGS:
 291                 ret = ptrace_setregs(child, datap);
 292                 break;
 293
 294         case PTRACE_GETXTREGS:
 295                 ret = ptrace_getxregs(child, datap);
 296                 break;
 297
 298         case PTRACE_SETXTREGS:
 299                 ret = ptrace_setxregs(child, datap);
 300                 break;
 301
 302         default:
 303                 ret = ptrace_request(child, request, addr, data);
 304                 break;
 305         }
 306
 307         return ret;
 308 }
 309
 310 void do_syscall_trace(void)
 311 {
 312         /*
 313          * The 0x80 provides a way for the tracing parent to distinguish
 314          * between a syscall stop and SIGTRAP delivery
 315          */
 316         ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
 317
 318         /*
 319          * this isn't the same as continuing with a signal, but it will do
 320          * for normal use.  strace only continues with a signal if the
 321          * stopping signal is not SIGTRAP.  -brl
 322          */
 323         if (current->exit_code) {
 324                 send_sig(current->exit_code, current, 1);
 325                 current->exit_code = 0;
 326         }
 327 }
 328
 329 void do_syscall_trace_enter(struct pt_regs *regs)
 330 {
 331         if (test_thread_flag(TIF_SYSCALL_TRACE)
 332                         && (current->ptrace & PT_PTRACED))
 333                 do_syscall_trace();
 334
 335 #if 0
 336         audit_syscall_entry(current, AUDIT_ARCH_XTENSA..);
 337 #endif
 338 }
 339
 340 void do_syscall_trace_leave(struct pt_regs *regs)
 341 {
 342         if ((test_thread_flag(TIF_SYSCALL_TRACE))
 343                         && (current->ptrace & PT_PTRACED))
 344                 do_syscall_trace();
 345 }