V4L/DVB (7460): bttv: Bt832 - fix possible NULL pointer deref
[sfrench/cifs-2.6.git] / arch / xtensa / kernel / ptrace.c
index 5533c7850d53b33c11aee1063ef1536bd91a46fd..9486882ef0afa8318fca682d24ff3c382c18997b 100644 (file)
@@ -4,7 +4,7 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2001 - 2005  Tensilica Inc.
+ * Copyright (C) 2001 - 2007  Tensilica Inc.
  *
  * Joe Taylor  <joe@tensilica.com, joetylr@yahoo.com>
  * Chris Zankel <chris@zankel.net>
 #include <asm/uaccess.h>
 #include <asm/ptrace.h>
 #include <asm/elf.h>
-
-#define TEST_KERNEL    // verify kernel operations FIXME: remove
-
+#include <asm/coprocessor.h>
 
 /*
- * Called by kernel/ptrace.c when detaching..
- *
- * Make sure single step bits etc are not set.
+ * Called by kernel/ptrace.c when detaching to disable single stepping.
  */
 
 void ptrace_disable(struct task_struct *child)
@@ -43,136 +39,237 @@ void ptrace_disable(struct task_struct *child)
        /* Nothing to do.. */
 }
 
-long arch_ptrace(struct task_struct *child, long request, long addr, long data)
+int ptrace_getregs(struct task_struct *child, void __user *uregs)
 {
-       int ret = -EPERM;
+       struct pt_regs *regs = task_pt_regs(child);
+       xtensa_gregset_t __user *gregset = uregs;
+       unsigned long wm = regs->wmask;
+       unsigned long wb = regs->windowbase;
+       int live, i;
+
+       if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
+               return -EIO;
+
+       __put_user(regs->pc, &gregset->pc);
+       __put_user(regs->ps & ~(1 << PS_EXCM_BIT), &gregset->ps);
+       __put_user(regs->lbeg, &gregset->lbeg);
+       __put_user(regs->lend, &gregset->lend);
+       __put_user(regs->lcount, &gregset->lcount);
+       __put_user(regs->windowstart, &gregset->windowstart);
+       __put_user(regs->windowbase, &gregset->windowbase);
+
+       live = (wm & 2) ? 4 : (wm & 4) ? 8 : (wm & 8) ? 12 : 16;
+
+       for (i = 0; i < live; i++)
+               __put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
+       for (i = XCHAL_NUM_AREGS - (wm >> 4) * 4; i < XCHAL_NUM_AREGS; i++)
+               __put_user(regs->areg[i],gregset->a+((wb*4+i)%XCHAL_NUM_AREGS));
+
+       return 0;
+}
 
-       switch (request) {
-       case PTRACE_PEEKTEXT: /* read word at location addr. */
-       case PTRACE_PEEKDATA:
-               ret = generic_ptrace_peekdata(child, addr, data);
-               goto out;
+int ptrace_setregs(struct task_struct *child, void __user *uregs)
+{
+       struct pt_regs *regs = task_pt_regs(child);
+       xtensa_gregset_t *gregset = uregs;
+       const unsigned long ps_mask = PS_CALLINC_MASK | PS_OWB_MASK;
+       unsigned long ps;
+       unsigned long wb;
 
-       /* Read the word at location addr in the USER area.  */
+       if (!access_ok(VERIFY_WRITE, uregs, sizeof(xtensa_gregset_t)))
+               return -EIO;
 
-       case PTRACE_PEEKUSR:
-               {
-               struct pt_regs *regs;
-               unsigned long tmp;
+       __get_user(regs->pc, &gregset->pc);
+       __get_user(ps, &gregset->ps);
+       __get_user(regs->lbeg, &gregset->lbeg);
+       __get_user(regs->lend, &gregset->lend);
+       __get_user(regs->lcount, &gregset->lcount);
+       __get_user(regs->windowstart, &gregset->windowstart);
+       __get_user(wb, &gregset->windowbase);
+
+       regs->ps = (regs->ps & ~ps_mask) | (ps & ps_mask) | (1 << PS_EXCM_BIT);
+
+       if (wb >= XCHAL_NUM_AREGS / 4)
+               return -EFAULT;
+
+       regs->windowbase = wb;
+
+       if (wb != 0 &&  __copy_from_user(regs->areg + XCHAL_NUM_AREGS - wb * 4,
+                                        gregset->a, wb * 16))
+               return -EFAULT;
+
+       if (__copy_from_user(regs->areg, gregset->a + wb*4, (WSBITS-wb) * 16))
+               return -EFAULT;
+
+       return 0;
+}
+
+
+int ptrace_getxregs(struct task_struct *child, void __user *uregs)
+{
+       struct pt_regs *regs = task_pt_regs(child);
+       struct thread_info *ti = task_thread_info(child);
+       elf_xtregs_t __user *xtregs = uregs;
+       int ret = 0;
+
+       if (!access_ok(VERIFY_WRITE, uregs, sizeof(elf_xtregs_t)))
+               return -EIO;
+
+#if XTENSA_HAVE_COPROCESSORS
+       /* Flush all coprocessor registers to memory. */
+       coprocessor_flush_all(ti);
+       ret |= __copy_to_user(&xtregs->cp0, &ti->xtregs_cp,
+                             sizeof(xtregs_coprocessor_t));
+#endif
+       ret |= __copy_to_user(&xtregs->opt, &regs->xtregs_opt,
+                             sizeof(xtregs->opt));
+       ret |= __copy_to_user(&xtregs->user,&ti->xtregs_user,
+                             sizeof(xtregs->user));
+
+       return ret ? -EFAULT : 0;
+}
+
+int ptrace_setxregs(struct task_struct *child, void __user *uregs)
+{
+       struct thread_info *ti = task_thread_info(child);
+       struct pt_regs *regs = task_pt_regs(child);
+       elf_xtregs_t *xtregs = uregs;
+       int ret = 0;
+
+#if XTENSA_HAVE_COPROCESSORS
+       /* Flush all coprocessors before we overwrite them. */
+       coprocessor_flush_all(ti);
+       coprocessor_release_all(ti);
+
+       ret |= __copy_from_user(&ti->xtregs_cp, &xtregs->cp0, 
+                               sizeof(xtregs_coprocessor_t));
+#endif
+       ret |= __copy_from_user(&regs->xtregs_opt, &xtregs->opt,
+                               sizeof(xtregs->opt));
+       ret |= __copy_from_user(&ti->xtregs_user, &xtregs->user,
+                               sizeof(xtregs->user));
+
+       return ret ? -EFAULT : 0;
+}
+
+int ptrace_peekusr(struct task_struct *child, long regno, long __user *ret)
+{
+       struct pt_regs *regs;
+       unsigned long tmp;
 
-               regs = task_pt_regs(child);
-               tmp = 0;  /* Default return value. */
+       regs = task_pt_regs(child);
+       tmp = 0;  /* Default return value. */
 
-               switch(addr) {
+       switch(regno) {
 
                case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
-                       {
-                       int ar = addr - REG_AR_BASE - regs->windowbase * 4;
-                       ar &= (XCHAL_NUM_AREGS - 1);
-                       if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0)
-                               tmp = regs->areg[ar];
-                       else
-                               ret = -EIO;
+                       tmp = regs->areg[regno - REG_AR_BASE];
                        break;
-                       }
+
                case REG_A_BASE ... REG_A_BASE + 15:
-                       tmp = regs->areg[addr - REG_A_BASE];
+                       tmp = regs->areg[regno - REG_A_BASE];
                        break;
+
                case REG_PC:
                        tmp = regs->pc;
                        break;
+
                case REG_PS:
                        /* Note:  PS.EXCM is not set while user task is running;
                         * its being set in regs is for exception handling
                         * convenience.  */
                        tmp = (regs->ps & ~(1 << PS_EXCM_BIT));
                        break;
+
                case REG_WB:
-                       tmp = regs->windowbase;
-                       break;
+                       break;          /* tmp = 0 */
+
                case REG_WS:
-                       tmp = regs->windowstart;
+               {
+                       unsigned long wb = regs->windowbase;
+                       unsigned long ws = regs->windowstart;
+                       tmp = ((ws>>wb) | (ws<<(WSBITS-wb))) & ((1<<WSBITS)-1);
                        break;
+               }
                case REG_LBEG:
                        tmp = regs->lbeg;
                        break;
+
                case REG_LEND:
                        tmp = regs->lend;
                        break;
+
                case REG_LCOUNT:
                        tmp = regs->lcount;
                        break;
+
                case REG_SAR:
                        tmp = regs->sar;
                        break;
-               case REG_DEPC:
-                       tmp = regs->depc;
-                       break;
-               case REG_EXCCAUSE:
-                       tmp = regs->exccause;
-                       break;
-               case REG_EXCVADDR:
-                       tmp = regs->excvaddr;
-                       break;
+
                case SYSCALL_NR:
                        tmp = regs->syscall;
                        break;
-               default:
-                       tmp = 0;
-                       ret = -EIO;
-                       goto out;
-               }
-               ret = put_user(tmp, (unsigned long *) data);
-               goto out;
-               }
 
-       case PTRACE_POKETEXT: /* write the word at location addr. */
-       case PTRACE_POKEDATA:
-               ret = generic_ptrace_pokedata(child, addr, data);
-               goto out;
+               default:
+                       return -EIO;
+       }
+       return put_user(tmp, ret);
+}
 
-       case PTRACE_POKEUSR:
-               {
-               struct pt_regs *regs;
-               regs = task_pt_regs(child);
+int ptrace_pokeusr(struct task_struct *child, long regno, long val)
+{
+       struct pt_regs *regs;
+       regs = task_pt_regs(child);
 
-               switch (addr) {
+       switch (regno) {
                case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1:
-                       {
-                       int ar = addr - REG_AR_BASE - regs->windowbase * 4;
-                       if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0)
-                               regs->areg[ar & (XCHAL_NUM_AREGS - 1)] = data;
-                       else
-                               ret = -EIO;
+                       regs->areg[regno - REG_AR_BASE] = val;
                        break;
-                       }
+
                case REG_A_BASE ... REG_A_BASE + 15:
-                       regs->areg[addr - REG_A_BASE] = data;
+                       regs->areg[regno - REG_A_BASE] = val;
                        break;
+
                case REG_PC:
-                       regs->pc = data;
+                       regs->pc = val;
                        break;
+
                case SYSCALL_NR:
-                       regs->syscall = data;
-                       break;
-#ifdef TEST_KERNEL
-               case REG_WB:
-                       regs->windowbase = data;
-                       break;
-               case REG_WS:
-                       regs->windowstart = data;
+                       regs->syscall = val;
                        break;
-#endif
 
                default:
-                       /* The rest are not allowed. */
-                       ret = -EIO;
-                       break;
-               }
+                       return -EIO;
+       }
+       return 0;
+}
+
+long arch_ptrace(struct task_struct *child, long request, long addr, long data)
+{
+       int ret = -EPERM;
+
+       switch (request) {
+       case PTRACE_PEEKTEXT:   /* read word at location addr. */
+       case PTRACE_PEEKDATA:
+               ret = generic_ptrace_peekdata(child, addr, data);
+               break;
+
+       case PTRACE_PEEKUSR:    /* read register specified by addr. */
+               ret = ptrace_peekusr(child, addr, (void __user *) data);
+               break;
+
+       case PTRACE_POKETEXT:   /* write the word at location addr. */
+       case PTRACE_POKEDATA:
+               ret = generic_ptrace_pokedata(child, addr, data);
+               break;
+
+       case PTRACE_POKEUSR:    /* write register specified by addr. */
+               ret = ptrace_pokeusr(child, addr, data);
                break;
-               }
 
        /* continue and stop at next (return from) syscall */
+
        case PTRACE_SYSCALL:
        case PTRACE_CONT: /* restart after signal. */
        {
@@ -217,98 +314,26 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                break;
 
        case PTRACE_GETREGS:
-       {
-               /* 'data' points to user memory in which to write.
-                * Mainly due to the non-live register values, we
-                * reformat the register values into something more
-                * standard.  For convenience, we use the handy
-                * elf_gregset_t format. */
-
-               xtensa_gregset_t format;
-               struct pt_regs *regs = task_pt_regs(child);
-
-               do_copy_regs (&format, regs, child);
-
-               /* Now, copy to user space nice and easy... */
-               ret = 0;
-               if (copy_to_user((void *)data, &format, sizeof(elf_gregset_t)))
-                       ret = -EFAULT;
+               ret = ptrace_getregs(child, (void __user *) data);
                break;
-       }
 
        case PTRACE_SETREGS:
-       {
-               /* 'data' points to user memory that contains the new
-                * values in the elf_gregset_t format. */
-
-               xtensa_gregset_t format;
-               struct pt_regs *regs = task_pt_regs(child);
-
-               if (copy_from_user(&format,(void *)data,sizeof(elf_gregset_t))){
-                       ret = -EFAULT;
-                       break;
-               }
-
-               /* FIXME: Perhaps we want some sanity checks on
-                * these user-space values?  See ARM version.  Are
-                * debuggers a security concern? */
-
-               do_restore_regs (&format, regs, child);
-
-               ret = 0;
-               break;
-       }
-
-       case PTRACE_GETFPREGS:
-       {
-               /* 'data' points to user memory in which to write.
-                * For convenience, we use the handy
-                * elf_fpregset_t format. */
-
-               elf_fpregset_t fpregs;
-               struct pt_regs *regs = task_pt_regs(child);
-
-               do_save_fpregs (&fpregs, regs, child);
-
-               /* Now, copy to user space nice and easy... */
-               ret = 0;
-               if (copy_to_user((void *)data, &fpregs, sizeof(elf_fpregset_t)))
-                       ret = -EFAULT;
-
+               ret = ptrace_setregs(child, (void __user *) data);
                break;
-       }
-
-       case PTRACE_SETFPREGS:
-       {
-               /* 'data' points to user memory that contains the new
-                * values in the elf_fpregset_t format.
-                */
-               elf_fpregset_t fpregs;
-               struct pt_regs *regs = task_pt_regs(child);
 
-               ret = 0;
-               if (copy_from_user(&fpregs, (void *)data, sizeof(elf_fpregset_t))) {
-                       ret = -EFAULT;
-                       break;
-               }
-
-               if (do_restore_fpregs (&fpregs, regs, child))
-                       ret = -EIO;
+       case PTRACE_GETXTREGS:
+               ret = ptrace_getxregs(child, (void __user *) data);
                break;
-       }
 
-       case PTRACE_GETFPREGSIZE:
-               /* 'data' points to 'unsigned long' set to the size
-                * of elf_fpregset_t
-                */
-               ret = put_user(sizeof(elf_fpregset_t), (unsigned long *) data);
+       case PTRACE_SETXTREGS:
+               ret = ptrace_setxregs(child, (void __user *) data);
                break;
 
        default:
                ret = ptrace_request(child, request, addr, data);
-               goto out;
+               break;
        }
- out:
+
        return ret;
 }