patch-2_6_7-vs1_9_1_12

[linux-2.6.git] / arch / ia64 / kernel / unwind.c

diff --git a/arch/ia64/kernel/unwind.c b/arch/ia64/kernel/unwind.c
index 6a715d8..e8be972 100644 (file)
--- a/arch/ia64/kernel/unwind.c
+++ b/arch/ia64/kernel/unwind.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 1999-2003 Hewlett-Packard Co
+ * Copyright (C) 1999-2004 Hewlett-Packard Co
  *     David Mosberger-Tang <davidm@hpl.hp.com>
  * Copyright (C) 2003 Fenghua Yu <fenghua.yu@intel.com>
  *     - Change pt_regs_off() to make it less dependant on pt_regs structure.
@@ -89,6 +89,8 @@ static struct {
        /* list of unwind tables (one per load-module) */
        struct unw_table *tables;
 
+       unsigned long r0;                       /* constant 0 for r0 */
+
        /* table of registers that prologues can save (and order in which they're saved): */
        const unsigned char save_order[8];
 
@@ -239,7 +241,11 @@ static struct {
 #endif
 };
 
-/* Unwind accessors.  */
+static inline int
+read_only (void *addr)
+{
+       return (unsigned long) ((char *) addr - (char *) &unw.r0) < sizeof(unw.r0);
+}
 
 /*
  * Returns offset of rREG in struct pt_regs.
@@ -274,6 +280,8 @@ get_scratch_regs (struct unw_frame_info *info)
        return (struct pt_regs *) info->pt;
 }
 
+/* Unwind accessors.  */
+
 int
 unw_access_gr (struct unw_frame_info *info, int regnum, unsigned long *val, char *nat, int write)
 {
@@ -377,11 +385,15 @@ unw_access_gr (struct unw_frame_info *info, int regnum, unsigned long *val, char
        }
 
        if (write) {
-               *addr = *val;
-               if (*nat)
-                       *nat_addr |= nat_mask;
-               else
-                       *nat_addr &= ~nat_mask;
+               if (read_only(addr))
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n");
+               else {
+                       *addr = *val;
+                       if (*nat)
+                               *nat_addr |= nat_mask;
+                       else
+                               *nat_addr &= ~nat_mask;
+               }
        } else {
                if ((*nat_addr & nat_mask) == 0) {
                        *val = *addr;
@@ -420,7 +432,10 @@ unw_access_br (struct unw_frame_info *info, int regnum, unsigned long *val, int
                return -1;
        }
        if (write)
-               *addr = *val;
+               if (read_only(addr))
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n");
+               else
+                       *addr = *val;
        else
                *val = *addr;
        return 0;
@@ -465,7 +480,10 @@ unw_access_fr (struct unw_frame_info *info, int regnum, struct ia64_fpreg *val,
        }
 
        if (write)
-               *addr = *val;
+               if (read_only(addr))
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n");
+               else
+                       *addr = *val;
        else
                *val = *addr;
        return 0;
@@ -557,9 +575,12 @@ unw_access_ar (struct unw_frame_info *info, int regnum, unsigned long *val, int
                return -1;
        }
 
-       if (write)
-               *addr = *val;
-       else
+       if (write) {
+               if (read_only(addr))
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n");
+               else
+                       *addr = *val;
+       } else
                *val = *addr;
        return 0;
 }
@@ -574,9 +595,12 @@ unw_access_pr (struct unw_frame_info *info, unsigned long *val, int write)
        if (!addr)
                addr = &info->sw->pr;
 
-       if (write)
-               *addr = *val;
-       else
+       if (write) {
+               if (read_only(addr))
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n");
+               else
+                       *addr = *val;
+       } else
                *val = *addr;
        return 0;
 }
@@ -1407,6 +1431,9 @@ compile_reg (struct unw_state_record *sr, int i, struct unw_script *script)
                                need_nat_info = 0;
                        }
                        val = unw.preg_index[UNW_REG_R4 + (rval - 4)];
+               } else if (rval == 0) {
+                       opc = UNW_INSN_MOVE_CONST;
+                       val = 0;
                } else {
                        /* register got spilled to a scratch register */
                        opc = UNW_INSN_MOVE_SCRATCH;
@@ -1729,6 +1756,17 @@ run_script (struct unw_script *script, struct unw_frame_info *state)
                        }
                        break;
 
+                     case UNW_INSN_MOVE_CONST:
+                       if (val == 0)
+                               s[dst] = (unsigned long) &unw.r0;
+                       else {
+                               s[dst] = 0;
+                               UNW_DPRINT(0, "unwind.%s: UNW_INSN_MOVE_CONST bad val=%ld\n",
+                                          __FUNCTION__, val);
+                       }
+                       break;
+
+
                      case UNW_INSN_MOVE_STACKED:
                        s[dst] = (unsigned long) ia64_rse_skip_regs((unsigned long *)state->bsp,
                                                                    val);