WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-ia64-devel

[Xen-ia64-devel] [PATCH] [1/6] panic stack trace: import stack unwind fi

To: xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-ia64-devel] [PATCH] [1/6] panic stack trace: import stack unwind files from Linux
From: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>
Date: Wed, 28 Dec 2005 19:11:31 +0900
Delivery-date: Wed, 28 Dec 2005 15:11:21 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-ia64-devel-request@lists.xensource.com?subject=help>
List-id: Discussion of the ia64 port of Xen <xen-ia64-devel.lists.xensource.com>
List-post: <mailto:xen-ia64-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-ia64-devel>, <mailto:xen-ia64-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-ia64-devel>, <mailto:xen-ia64-devel-request@lists.xensource.com?subject=unsubscribe>
Sender: xen-ia64-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mutt/1.4.2.1i
1/6
imported 4 files related to stack unwind.


Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>

--
diff -r f218e6ba2653 -r df6a9e0d7e05 xen/arch/ia64/linux-xen/unwind.c
--- /dev/null   Thu Jan  1 00:00:00 1970 +0000
+++ b/xen/arch/ia64/linux-xen/unwind.c  Wed Dec 28 15:19:56 2005 +0900
@@ -0,0 +1,2291 @@
+/*
+ * Copyright (C) 1999-2004 Hewlett-Packard Co
+ *     David Mosberger-Tang <davidm@xxxxxxxxxx>
+ * Copyright (C) 2003 Fenghua Yu <fenghua.yu@xxxxxxxxx>
+ *     - Change pt_regs_off() to make it less dependant on pt_regs structure.
+ */
+/*
+ * This file implements call frame unwind support for the Linux
+ * kernel.  Parsing and processing the unwind information is
+ * time-consuming, so this implementation translates the unwind
+ * descriptors into unwind scripts.  These scripts are very simple
+ * (basically a sequence of assignments) and efficient to execute.
+ * They are cached for later re-use.  Each script is specific for a
+ * given instruction pointer address and the set of predicate values
+ * that the script depends on (most unwind descriptors are
+ * unconditional and scripts often do not depend on predicates at
+ * all).  This code is based on the unwind conventions described in
+ * the "IA-64 Software Conventions and Runtime Architecture" manual.
+ *
+ * SMP conventions:
+ *     o updates to the global unwind data (in structure "unw") are serialized
+ *       by the unw.lock spinlock
+ *     o each unwind script has its own read-write lock; a thread must acquire
+ *       a read lock before executing a script and must acquire a write lock
+ *       before modifying a script
+ *     o if both the unw.lock spinlock and a script's read-write lock must be
+ *       acquired, then the read-write lock must be acquired first.
+ */
+#include <linux/module.h>
+#include <linux/bootmem.h>
+#include <linux/elf.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <asm/unwind.h>
+
+#include <asm/delay.h>
+#include <asm/page.h>
+#include <asm/ptrace.h>
+#include <asm/ptrace_offsets.h>
+#include <asm/rse.h>
+#include <asm/sections.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+
+#include "entry.h"
+#include "unwind_i.h"
+
+#define UNW_LOG_CACHE_SIZE     7       /* each unw_script is ~256 bytes in 
size */
+#define UNW_CACHE_SIZE         (1 << UNW_LOG_CACHE_SIZE)
+
+#define UNW_LOG_HASH_SIZE      (UNW_LOG_CACHE_SIZE + 1)
+#define UNW_HASH_SIZE          (1 << UNW_LOG_HASH_SIZE)
+
+#define UNW_STATS      0       /* WARNING: this disabled interrupts for long 
time-spans!! */
+
+#ifdef UNW_DEBUG
+  static unsigned int unw_debug_level = UNW_DEBUG;
+#  define UNW_DEBUG_ON(n)      unw_debug_level >= n
+   /* Do not code a printk level, not all debug lines end in newline */
+#  define UNW_DPRINT(n, ...)  if (UNW_DEBUG_ON(n)) printk(__VA_ARGS__)
+#  define inline
+#else /* !UNW_DEBUG */
+#  define UNW_DEBUG_ON(n)  0
+#  define UNW_DPRINT(n, ...)
+#endif /* UNW_DEBUG */
+
+#if UNW_STATS
+# define STAT(x...)    x
+#else
+# define STAT(x...)
+#endif
+
+#define alloc_reg_state()      kmalloc(sizeof(struct unw_reg_state), 
GFP_ATOMIC)
+#define free_reg_state(usr)    kfree(usr)
+#define alloc_labeled_state()  kmalloc(sizeof(struct unw_labeled_state), 
GFP_ATOMIC)
+#define free_labeled_state(usr)        kfree(usr)
+
+typedef unsigned long unw_word;
+typedef unsigned char unw_hash_index_t;
+
+static struct {
+       spinlock_t lock;                        /* spinlock for unwind data */
+
+       /* 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];
+
+       /* maps a preserved register index (preg_index) to corresponding 
switch_stack offset: */
+       unsigned short sw_off[sizeof(struct unw_frame_info) / 8];
+
+       unsigned short lru_head;                /* index of lead-recently used 
script */
+       unsigned short lru_tail;                /* index of most-recently used 
script */
+
+       /* index into unw_frame_info for preserved register i */
+       unsigned short preg_index[UNW_NUM_REGS];
+
+       short pt_regs_offsets[32];
+
+       /* unwind table for the kernel: */
+       struct unw_table kernel_table;
+
+       /* unwind table describing the gate page (kernel code that is mapped 
into user space): */
+       size_t gate_table_size;
+       unsigned long *gate_table;
+
+       /* hash table that maps instruction pointer to script index: */
+       unsigned short hash[UNW_HASH_SIZE];
+
+       /* script cache: */
+       struct unw_script cache[UNW_CACHE_SIZE];
+
+# ifdef UNW_DEBUG
+       const char *preg_name[UNW_NUM_REGS];
+# endif
+# if UNW_STATS
+       struct {
+               struct {
+                       int lookups;
+                       int hinted_hits;
+                       int normal_hits;
+                       int collision_chain_traversals;
+               } cache;
+               struct {
+                       unsigned long build_time;
+                       unsigned long run_time;
+                       unsigned long parse_time;
+                       int builds;
+                       int news;
+                       int collisions;
+                       int runs;
+               } script;
+               struct {
+                       unsigned long init_time;
+                       unsigned long unwind_time;
+                       int inits;
+                       int unwinds;
+               } api;
+       } stat;
+# endif
+} unw = {
+       .tables = &unw.kernel_table,
+       .lock = SPIN_LOCK_UNLOCKED,
+       .save_order = {
+               UNW_REG_RP, UNW_REG_PFS, UNW_REG_PSP, UNW_REG_PR,
+               UNW_REG_UNAT, UNW_REG_LC, UNW_REG_FPSR, UNW_REG_PRI_UNAT_GR
+       },
+       .preg_index = {
+               offsetof(struct unw_frame_info, pri_unat_loc)/8,        /* 
PRI_UNAT_GR */
+               offsetof(struct unw_frame_info, pri_unat_loc)/8,        /* 
PRI_UNAT_MEM */
+               offsetof(struct unw_frame_info, bsp_loc)/8,
+               offsetof(struct unw_frame_info, bspstore_loc)/8,
+               offsetof(struct unw_frame_info, pfs_loc)/8,
+               offsetof(struct unw_frame_info, rnat_loc)/8,
+               offsetof(struct unw_frame_info, psp)/8,
+               offsetof(struct unw_frame_info, rp_loc)/8,
+               offsetof(struct unw_frame_info, r4)/8,
+               offsetof(struct unw_frame_info, r5)/8,
+               offsetof(struct unw_frame_info, r6)/8,
+               offsetof(struct unw_frame_info, r7)/8,
+               offsetof(struct unw_frame_info, unat_loc)/8,
+               offsetof(struct unw_frame_info, pr_loc)/8,
+               offsetof(struct unw_frame_info, lc_loc)/8,
+               offsetof(struct unw_frame_info, fpsr_loc)/8,
+               offsetof(struct unw_frame_info, b1_loc)/8,
+               offsetof(struct unw_frame_info, b2_loc)/8,
+               offsetof(struct unw_frame_info, b3_loc)/8,
+               offsetof(struct unw_frame_info, b4_loc)/8,
+               offsetof(struct unw_frame_info, b5_loc)/8,
+               offsetof(struct unw_frame_info, f2_loc)/8,
+               offsetof(struct unw_frame_info, f3_loc)/8,
+               offsetof(struct unw_frame_info, f4_loc)/8,
+               offsetof(struct unw_frame_info, f5_loc)/8,
+               offsetof(struct unw_frame_info, fr_loc[16 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[17 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[18 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[19 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[20 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[21 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[22 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[23 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[24 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[25 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[26 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[27 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[28 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[29 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[30 - 16])/8,
+               offsetof(struct unw_frame_info, fr_loc[31 - 16])/8,
+       },
+       .pt_regs_offsets = {
+               [0] = -1,
+               offsetof(struct pt_regs,  r1),
+               offsetof(struct pt_regs,  r2),
+               offsetof(struct pt_regs,  r3),
+               [4] = -1, [5] = -1, [6] = -1, [7] = -1,
+               offsetof(struct pt_regs,  r8),
+               offsetof(struct pt_regs,  r9),
+               offsetof(struct pt_regs, r10),
+               offsetof(struct pt_regs, r11),
+               offsetof(struct pt_regs, r12),
+               offsetof(struct pt_regs, r13),
+               offsetof(struct pt_regs, r14),
+               offsetof(struct pt_regs, r15),
+               offsetof(struct pt_regs, r16),
+               offsetof(struct pt_regs, r17),
+               offsetof(struct pt_regs, r18),
+               offsetof(struct pt_regs, r19),
+               offsetof(struct pt_regs, r20),
+               offsetof(struct pt_regs, r21),
+               offsetof(struct pt_regs, r22),
+               offsetof(struct pt_regs, r23),
+               offsetof(struct pt_regs, r24),
+               offsetof(struct pt_regs, r25),
+               offsetof(struct pt_regs, r26),
+               offsetof(struct pt_regs, r27),
+               offsetof(struct pt_regs, r28),
+               offsetof(struct pt_regs, r29),
+               offsetof(struct pt_regs, r30),
+               offsetof(struct pt_regs, r31),
+       },
+       .hash = { [0 ... UNW_HASH_SIZE - 1] = -1 },
+#ifdef UNW_DEBUG
+       .preg_name = {
+               "pri_unat_gr", "pri_unat_mem", "bsp", "bspstore", "ar.pfs", 
"ar.rnat", "psp", "rp",
+               "r4", "r5", "r6", "r7",
+               "ar.unat", "pr", "ar.lc", "ar.fpsr",
+               "b1", "b2", "b3", "b4", "b5",
+               "f2", "f3", "f4", "f5",
+               "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
+               "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31"
+       }
+#endif
+};
+
+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.
+ */
+static inline unsigned long
+pt_regs_off (unsigned long reg)
+{
+       short off = -1;
+
+       if (reg < ARRAY_SIZE(unw.pt_regs_offsets))
+               off = unw.pt_regs_offsets[reg];
+
+       if (off < 0) {
+               UNW_DPRINT(0, "unwind.%s: bad scratch reg r%lu\n", 
__FUNCTION__, reg);
+               off = 0;
+       }
+       return (unsigned long) off;
+}
+
+static inline struct pt_regs *
+get_scratch_regs (struct unw_frame_info *info)
+{
+       if (!info->pt) {
+               /* This should not happen with valid unwind info.  */
+               UNW_DPRINT(0, "unwind.%s: bad unwind info: resetting 
info->pt\n", __FUNCTION__);
+               if (info->flags & UNW_FLAG_INTERRUPT_FRAME)
+                       info->pt = (unsigned long) ((struct pt_regs *) 
info->psp - 1);
+               else
+                       info->pt = info->sp - 16;
+       }
+       UNW_DPRINT(3, "unwind.%s: sp 0x%lx pt 0x%lx\n", __FUNCTION__, info->sp, 
info->pt);
+       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)
+{
+       unsigned long *addr, *nat_addr, nat_mask = 0, dummy_nat;
+       struct unw_ireg *ireg;
+       struct pt_regs *pt;
+
+       if ((unsigned) regnum - 1 >= 127) {
+               if (regnum == 0 && !write) {
+                       *val = 0;       /* read r0 always returns 0 */
+                       *nat = 0;
+                       return 0;
+               }
+               UNW_DPRINT(0, "unwind.%s: trying to access non-existent r%u\n",
+                          __FUNCTION__, regnum);
+               return -1;
+       }
+
+       if (regnum < 32) {
+               if (regnum >= 4 && regnum <= 7) {
+                       /* access a preserved register */
+                       ireg = &info->r4 + (regnum - 4);
+                       addr = ireg->loc;
+                       if (addr) {
+                               nat_addr = addr + ireg->nat.off;
+                               switch (ireg->nat.type) {
+                                     case UNW_NAT_VAL:
+                                       /* simulate getf.sig/setf.sig */
+                                       if (write) {
+                                               if (*nat) {
+                                                       /* write NaTVal and be 
done with it */
+                                                       addr[0] = 0;
+                                                       addr[1] = 0x1fffe;
+                                                       return 0;
+                                               }
+                                               addr[1] = 0x1003e;
+                                       } else {
+                                               if (addr[0] == 0 && addr[1] == 
0x1ffe) {
+                                                       /* return NaT and be 
done with it */
+                                                       *val = 0;
+                                                       *nat = 1;
+                                                       return 0;
+                                               }
+                                       }
+                                       /* fall through */
+                                     case UNW_NAT_NONE:
+                                       dummy_nat = 0;
+                                       nat_addr = &dummy_nat;
+                                       break;
+
+                                     case UNW_NAT_MEMSTK:
+                                       nat_mask = (1UL << ((long) addr & 
0x1f8)/8);
+                                       break;
+
+                                     case UNW_NAT_REGSTK:
+                                       nat_addr = ia64_rse_rnat_addr(addr);
+                                       if ((unsigned long) addr < 
info->regstk.limit
+                                           || (unsigned long) addr >= 
info->regstk.top)
+                                       {
+                                               UNW_DPRINT(0, "unwind.%s: %p 
outside of regstk "
+                                                       "[0x%lx-0x%lx)\n",
+                                                       __FUNCTION__, (void *) 
addr,
+                                                       info->regstk.limit,
+                                                       info->regstk.top);
+                                               return -1;
+                                       }
+                                       if ((unsigned long) nat_addr >= 
info->regstk.top)
+                                               nat_addr = &info->sw->ar_rnat;
+                                       nat_mask = (1UL << 
ia64_rse_slot_num(addr));
+                                       break;
+                               }
+                       } else {
+                               addr = &info->sw->r4 + (regnum - 4);
+                               nat_addr = &info->sw->ar_unat;
+                               nat_mask = (1UL << ((long) addr & 0x1f8)/8);
+                       }
+               } else {
+                       /* access a scratch register */
+                       pt = get_scratch_regs(info);
+                       addr = (unsigned long *) ((unsigned long)pt + 
pt_regs_off(regnum));
+                       if (info->pri_unat_loc)
+                               nat_addr = info->pri_unat_loc;
+                       else
+                               nat_addr = &info->sw->caller_unat;
+                       nat_mask = (1UL << ((long) addr & 0x1f8)/8);
+               }
+       } else {
+               /* access a stacked register */
+               addr = ia64_rse_skip_regs((unsigned long *) info->bsp, regnum - 
32);
+               nat_addr = ia64_rse_rnat_addr(addr);
+               if ((unsigned long) addr < info->regstk.limit
+                   || (unsigned long) addr >= info->regstk.top)
+               {
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to access 
register outside "
+                                  "of rbs\n",  __FUNCTION__);
+                       return -1;
+               }
+               if ((unsigned long) nat_addr >= info->regstk.top)
+                       nat_addr = &info->sw->ar_rnat;
+               nat_mask = (1UL << ia64_rse_slot_num(addr));
+       }
+
+       if (write) {
+               if (read_only(addr)) {
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to write 
read-only location\n",
+                               __FUNCTION__);
+               } else {
+                       *addr = *val;
+                       if (*nat)
+                               *nat_addr |= nat_mask;
+                       else
+                               *nat_addr &= ~nat_mask;
+               }
+       } else {
+               if ((*nat_addr & nat_mask) == 0) {
+                       *val = *addr;
+                       *nat = 0;
+               } else {
+                       *val = 0;       /* if register is a NaT, *addr may 
contain kernel data! */
+                       *nat = 1;
+               }
+       }
+       return 0;
+}
+EXPORT_SYMBOL(unw_access_gr);
+
+int
+unw_access_br (struct unw_frame_info *info, int regnum, unsigned long *val, 
int write)
+{
+       unsigned long *addr;
+       struct pt_regs *pt;
+
+       switch (regnum) {
+               /* scratch: */
+             case 0: pt = get_scratch_regs(info); addr = &pt->b0; break;
+             case 6: pt = get_scratch_regs(info); addr = &pt->b6; break;
+             case 7: pt = get_scratch_regs(info); addr = &pt->b7; break;
+
+               /* preserved: */
+             case 1: case 2: case 3: case 4: case 5:
+               addr = *(&info->b1_loc + (regnum - 1));
+               if (!addr)
+                       addr = &info->sw->b1 + (regnum - 1);
+               break;
+
+             default:
+               UNW_DPRINT(0, "unwind.%s: trying to access non-existent b%u\n",
+                          __FUNCTION__, regnum);
+               return -1;
+       }
+       if (write)
+               if (read_only(addr)) {
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to write 
read-only location\n",
+                               __FUNCTION__);
+               } else
+                       *addr = *val;
+       else
+               *val = *addr;
+       return 0;
+}
+EXPORT_SYMBOL(unw_access_br);
+
+int
+unw_access_fr (struct unw_frame_info *info, int regnum, struct ia64_fpreg 
*val, int write)
+{
+       struct ia64_fpreg *addr = NULL;
+       struct pt_regs *pt;
+
+       if ((unsigned) (regnum - 2) >= 126) {
+               UNW_DPRINT(0, "unwind.%s: trying to access non-existent f%u\n",
+                          __FUNCTION__, regnum);
+               return -1;
+       }
+
+       if (regnum <= 5) {
+               addr = *(&info->f2_loc + (regnum - 2));
+               if (!addr)
+                       addr = &info->sw->f2 + (regnum - 2);
+       } else if (regnum <= 15) {
+               if (regnum <= 11) {
+                       pt = get_scratch_regs(info);
+                       addr = &pt->f6  + (regnum - 6);
+               }
+               else
+                       addr = &info->sw->f12 + (regnum - 12);
+       } else if (regnum <= 31) {
+               addr = info->fr_loc[regnum - 16];
+               if (!addr)
+                       addr = &info->sw->f16 + (regnum - 16);
+       } else {
+               struct task_struct *t = info->task;
+
+               if (write)
+                       ia64_sync_fph(t);
+               else
+                       ia64_flush_fph(t);
+               addr = t->thread.fph + (regnum - 32);
+       }
+
+       if (write)
+               if (read_only(addr)) {
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to write 
read-only location\n",
+                               __FUNCTION__);
+               } else
+                       *addr = *val;
+       else
+               *val = *addr;
+       return 0;
+}
+EXPORT_SYMBOL(unw_access_fr);
+
+int
+unw_access_ar (struct unw_frame_info *info, int regnum, unsigned long *val, 
int write)
+{
+       unsigned long *addr;
+       struct pt_regs *pt;
+
+       switch (regnum) {
+             case UNW_AR_BSP:
+               addr = info->bsp_loc;
+               if (!addr)
+                       addr = &info->sw->ar_bspstore;
+               break;
+
+             case UNW_AR_BSPSTORE:
+               addr = info->bspstore_loc;
+               if (!addr)
+                       addr = &info->sw->ar_bspstore;
+               break;
+
+             case UNW_AR_PFS:
+               addr = info->pfs_loc;
+               if (!addr)
+                       addr = &info->sw->ar_pfs;
+               break;
+
+             case UNW_AR_RNAT:
+               addr = info->rnat_loc;
+               if (!addr)
+                       addr = &info->sw->ar_rnat;
+               break;
+
+             case UNW_AR_UNAT:
+               addr = info->unat_loc;
+               if (!addr)
+                       addr = &info->sw->caller_unat;
+               break;
+
+             case UNW_AR_LC:
+               addr = info->lc_loc;
+               if (!addr)
+                       addr = &info->sw->ar_lc;
+               break;
+
+             case UNW_AR_EC:
+               if (!info->cfm_loc)
+                       return -1;
+               if (write)
+                       *info->cfm_loc =
+                               (*info->cfm_loc & ~(0x3fUL << 52)) | ((*val & 
0x3f) << 52);
+               else
+                       *val = (*info->cfm_loc >> 52) & 0x3f;
+               return 0;
+
+             case UNW_AR_FPSR:
+               addr = info->fpsr_loc;
+               if (!addr)
+                       addr = &info->sw->ar_fpsr;
+               break;
+
+             case UNW_AR_RSC:
+               pt = get_scratch_regs(info);
+               addr = &pt->ar_rsc;
+               break;
+
+             case UNW_AR_CCV:
+               pt = get_scratch_regs(info);
+               addr = &pt->ar_ccv;
+               break;
+
+             case UNW_AR_CSD:
+               pt = get_scratch_regs(info);
+               addr = &pt->ar_csd;
+               break;
+
+             case UNW_AR_SSD:
+               pt = get_scratch_regs(info);
+               addr = &pt->ar_ssd;
+               break;
+
+             default:
+               UNW_DPRINT(0, "unwind.%s: trying to access non-existent ar%u\n",
+                          __FUNCTION__, regnum);
+               return -1;
+       }
+
+       if (write) {
+               if (read_only(addr)) {
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to write 
read-only location\n",
+                               __FUNCTION__);
+               } else
+                       *addr = *val;
+       } else
+               *val = *addr;
+       return 0;
+}
+EXPORT_SYMBOL(unw_access_ar);
+
+int
+unw_access_pr (struct unw_frame_info *info, unsigned long *val, int write)
+{
+       unsigned long *addr;
+
+       addr = info->pr_loc;
+       if (!addr)
+               addr = &info->sw->pr;
+
+       if (write) {
+               if (read_only(addr)) {
+                       UNW_DPRINT(0, "unwind.%s: ignoring attempt to write 
read-only location\n",
+                               __FUNCTION__);
+               } else
+                       *addr = *val;
+       } else
+               *val = *addr;
+       return 0;
+}
+EXPORT_SYMBOL(unw_access_pr);
+
+
+/* Routines to manipulate the state stack.  */
+
+static inline void
+push (struct unw_state_record *sr)
+{
+       struct unw_reg_state *rs;
+
+       rs = alloc_reg_state();
+       if (!rs) {
+               printk(KERN_ERR "unwind: cannot stack reg state!\n");
+               return;
+       }
+       memcpy(rs, &sr->curr, sizeof(*rs));
+       sr->curr.next = rs;
+}
+
+static void
+pop (struct unw_state_record *sr)
+{
+       struct unw_reg_state *rs = sr->curr.next;
+
+       if (!rs) {
+               printk(KERN_ERR "unwind: stack underflow!\n");
+               return;
+       }
+       memcpy(&sr->curr, rs, sizeof(*rs));
+       free_reg_state(rs);
+}
+
+/* Make a copy of the state stack.  Non-recursive to avoid stack overflows.  */
+static struct unw_reg_state *
+dup_state_stack (struct unw_reg_state *rs)
+{
+       struct unw_reg_state *copy, *prev = NULL, *first = NULL;
+
+       while (rs) {
+               copy = alloc_reg_state();
+               if (!copy) {
+                       printk(KERN_ERR "unwind.dup_state_stack: out of 
memory\n");
+                       return NULL;
+               }
+               memcpy(copy, rs, sizeof(*copy));
+               if (first)
+                       prev->next = copy;
+               else
+                       first = copy;
+               rs = rs->next;
+               prev = copy;
+       }
+       return first;
+}
+
+/* Free all stacked register states (but not RS itself).  */
+static void
+free_state_stack (struct unw_reg_state *rs)
+{
+       struct unw_reg_state *p, *next;
+
+       for (p = rs->next; p != NULL; p = next) {
+               next = p->next;
+               free_reg_state(p);
+       }
+       rs->next = NULL;
+}
+
+/* Unwind decoder routines */
+
+static enum unw_register_index __attribute_const__
+decode_abreg (unsigned char abreg, int memory)
+{
+       switch (abreg) {
+             case 0x04 ... 0x07: return UNW_REG_R4 + (abreg - 0x04);
+             case 0x22 ... 0x25: return UNW_REG_F2 + (abreg - 0x22);
+             case 0x30 ... 0x3f: return UNW_REG_F16 + (abreg - 0x30);
+             case 0x41 ... 0x45: return UNW_REG_B1 + (abreg - 0x41);
+             case 0x60: return UNW_REG_PR;
+             case 0x61: return UNW_REG_PSP;
+             case 0x62: return memory ? UNW_REG_PRI_UNAT_MEM : 
UNW_REG_PRI_UNAT_GR;
+             case 0x63: return UNW_REG_RP;
+             case 0x64: return UNW_REG_BSP;
+             case 0x65: return UNW_REG_BSPSTORE;
+             case 0x66: return UNW_REG_RNAT;
+             case 0x67: return UNW_REG_UNAT;
+             case 0x68: return UNW_REG_FPSR;
+             case 0x69: return UNW_REG_PFS;
+             case 0x6a: return UNW_REG_LC;
+             default:
+               break;
+       }
+       UNW_DPRINT(0, "unwind.%s: bad abreg=0x%x\n", __FUNCTION__, abreg);
+       return UNW_REG_LC;
+}
+
+static void
+set_reg (struct unw_reg_info *reg, enum unw_where where, int when, unsigned 
long val)
+{
+       reg->val = val;
+       reg->where = where;
+       if (reg->when == UNW_WHEN_NEVER)
+               reg->when = when;
+}
+
+static void
+alloc_spill_area (unsigned long *offp, unsigned long regsize,
+                 struct unw_reg_info *lo, struct unw_reg_info *hi)
+{
+       struct unw_reg_info *reg;
+
+       for (reg = hi; reg >= lo; --reg) {
+               if (reg->where == UNW_WHERE_SPILL_HOME) {
+                       reg->where = UNW_WHERE_PSPREL;
+                       *offp -= regsize;
+                       reg->val = *offp;
+               }
+       }
+}
+
+static inline void
+spill_next_when (struct unw_reg_info **regp, struct unw_reg_info *lim, 
unw_word t)
+{
+       struct unw_reg_info *reg;
+
+       for (reg = *regp; reg <= lim; ++reg) {
+               if (reg->where == UNW_WHERE_SPILL_HOME) {
+                       reg->when = t;
+                       *regp = reg + 1;
+                       return;
+               }
+       }
+       UNW_DPRINT(0, "unwind.%s: excess spill!\n",  __FUNCTION__);
+}
+
+static inline void
+finish_prologue (struct unw_state_record *sr)
+{
+       struct unw_reg_info *reg;
+       unsigned long off;
+       int i;
+
+       /*
+        * First, resolve implicit register save locations (see Section 
"11.4.2.3 Rules
+        * for Using Unwind Descriptors", rule 3):
+        */
+       for (i = 0; i < (int) ARRAY_SIZE(unw.save_order); ++i) {
+               reg = sr->curr.reg + unw.save_order[i];
+               if (reg->where == UNW_WHERE_GR_SAVE) {
+                       reg->where = UNW_WHERE_GR;
+                       reg->val = sr->gr_save_loc++;
+               }
+       }
+
+       /*
+        * Next, compute when the fp, general, and branch registers get
+        * saved.  This must come before alloc_spill_area() because
+        * we need to know which registers are spilled to their home
+        * locations.
+        */
+       if (sr->imask) {
+               unsigned char kind, mask = 0, *cp = sr->imask;
+               int t;
+               static const unsigned char limit[3] = {
+                       UNW_REG_F31, UNW_REG_R7, UNW_REG_B5
+               };
+               struct unw_reg_info *(regs[3]);
+
+               regs[0] = sr->curr.reg + UNW_REG_F2;
+               regs[1] = sr->curr.reg + UNW_REG_R4;
+               regs[2] = sr->curr.reg + UNW_REG_B1;
+
+               for (t = 0; t < sr->region_len; ++t) {
+                       if ((t & 3) == 0)
+                               mask = *cp++;
+                       kind = (mask >> 2*(3-(t & 3))) & 3;
+                       if (kind > 0)
+                               spill_next_when(&regs[kind - 1], sr->curr.reg + 
limit[kind - 1],
+                                               sr->region_start + t);
+               }
+       }
+       /*
+        * Next, lay out the memory stack spill area:
+        */
+       if (sr->any_spills) {
+               off = sr->spill_offset;
+               alloc_spill_area(&off, 16, sr->curr.reg + UNW_REG_F2, 
sr->curr.reg + UNW_REG_F31);
+               alloc_spill_area(&off,  8, sr->curr.reg + UNW_REG_B1, 
sr->curr.reg + UNW_REG_B5);
+               alloc_spill_area(&off,  8, sr->curr.reg + UNW_REG_R4, 
sr->curr.reg + UNW_REG_R7);
+       }
+}
+
+/*
+ * Region header descriptors.
+ */
+
+static void
+desc_prologue (int body, unw_word rlen, unsigned char mask, unsigned char 
grsave,
+              struct unw_state_record *sr)
+{
+       int i, region_start;
+
+       if (!(sr->in_body || sr->first_region))
+               finish_prologue(sr);
+       sr->first_region = 0;
+
+       /* check if we're done: */
+       if (sr->when_target < sr->region_start + sr->region_len) {
+               sr->done = 1;
+               return;
+       }
+
+       region_start = sr->region_start + sr->region_len;
+
+       for (i = 0; i < sr->epilogue_count; ++i)
+               pop(sr);
+       sr->epilogue_count = 0;
+       sr->epilogue_start = UNW_WHEN_NEVER;
+
+       sr->region_start = region_start;
+       sr->region_len = rlen;
+       sr->in_body = body;
+
+       if (!body) {
+               push(sr);
+
+               for (i = 0; i < 4; ++i) {
+                       if (mask & 0x8)
+                               set_reg(sr->curr.reg + unw.save_order[i], 
UNW_WHERE_GR,
+                                       sr->region_start + sr->region_len - 1, 
grsave++);
+                       mask <<= 1;
+               }
+               sr->gr_save_loc = grsave;
+               sr->any_spills = 0;
+               sr->imask = NULL;
+               sr->spill_offset = 0x10;        /* default to psp+16 */
+       }
+}
+
+/*
+ * Prologue descriptors.
+ */
+
+static inline void
+desc_abi (unsigned char abi, unsigned char context, struct unw_state_record 
*sr)
+{
+       if (abi == 3 && context == 'i') {
+               sr->flags |= UNW_FLAG_INTERRUPT_FRAME;
+               UNW_DPRINT(3, "unwind.%s: interrupt frame\n",  __FUNCTION__);
+       }
+       else
+               UNW_DPRINT(0, "unwind%s: ignoring 
unwabi(abi=0x%x,context=0x%x)\n",
+                               __FUNCTION__, abi, context);
+}
+
+static inline void
+desc_br_gr (unsigned char brmask, unsigned char gr, struct unw_state_record 
*sr)
+{
+       int i;
+
+       for (i = 0; i < 5; ++i) {
+               if (brmask & 1)
+                       set_reg(sr->curr.reg + UNW_REG_B1 + i, UNW_WHERE_GR,
+                               sr->region_start + sr->region_len - 1, gr++);
+               brmask >>= 1;
+       }
+}
+
+static inline void
+desc_br_mem (unsigned char brmask, struct unw_state_record *sr)
+{
+       int i;
+
+       for (i = 0; i < 5; ++i) {
+               if (brmask & 1) {
+                       set_reg(sr->curr.reg + UNW_REG_B1 + i, 
UNW_WHERE_SPILL_HOME,
+                               sr->region_start + sr->region_len - 1, 0);
+                       sr->any_spills = 1;
+               }
+               brmask >>= 1;
+       }
+}
+
+static inline void
+desc_frgr_mem (unsigned char grmask, unw_word frmask, struct unw_state_record 
*sr)
+{
+       int i;
+
+       for (i = 0; i < 4; ++i) {
+               if ((grmask & 1) != 0) {
+                       set_reg(sr->curr.reg + UNW_REG_R4 + i, 
UNW_WHERE_SPILL_HOME,
+                               sr->region_start + sr->region_len - 1, 0);
+                       sr->any_spills = 1;
+               }
+               grmask >>= 1;
+       }
+       for (i = 0; i < 20; ++i) {
+               if ((frmask & 1) != 0) {
+                       int base = (i < 4) ? UNW_REG_F2 : UNW_REG_F16 - 4;
+                       set_reg(sr->curr.reg + base + i, UNW_WHERE_SPILL_HOME,
+                               sr->region_start + sr->region_len - 1, 0);
+                       sr->any_spills = 1;
+               }
+               frmask >>= 1;
+       }
+}
+
+static inline void
+desc_fr_mem (unsigned char frmask, struct unw_state_record *sr)
+{
+       int i;
+
+       for (i = 0; i < 4; ++i) {
+               if ((frmask & 1) != 0) {
+                       set_reg(sr->curr.reg + UNW_REG_F2 + i, 
UNW_WHERE_SPILL_HOME,
+                               sr->region_start + sr->region_len - 1, 0);
+                       sr->any_spills = 1;
+               }
+               frmask >>= 1;
+       }
+}
+
+static inline void
+desc_gr_gr (unsigned char grmask, unsigned char gr, struct unw_state_record 
*sr)
+{
+       int i;
+
+       for (i = 0; i < 4; ++i) {
+               if ((grmask & 1) != 0)
+                       set_reg(sr->curr.reg + UNW_REG_R4 + i, UNW_WHERE_GR,
+                               sr->region_start + sr->region_len - 1, gr++);
+               grmask >>= 1;
+       }
+}
+
+static inline void
+desc_gr_mem (unsigned char grmask, struct unw_state_record *sr)
+{
+       int i;
+
+       for (i = 0; i < 4; ++i) {
+               if ((grmask & 1) != 0) {
+                       set_reg(sr->curr.reg + UNW_REG_R4 + i, 
UNW_WHERE_SPILL_HOME,
+                               sr->region_start + sr->region_len - 1, 0);
+                       sr->any_spills = 1;
+               }
+               grmask >>= 1;
+       }
+}
+
+static inline void
+desc_mem_stack_f (unw_word t, unw_word size, struct unw_state_record *sr)
+{
+       set_reg(sr->curr.reg + UNW_REG_PSP, UNW_WHERE_NONE,
+               sr->region_start + min_t(int, t, sr->region_len - 1), 16*size);
+}
+
+static inline void
+desc_mem_stack_v (unw_word t, struct unw_state_record *sr)
+{
+       sr->curr.reg[UNW_REG_PSP].when = sr->region_start + min_t(int, t, 
sr->region_len - 1);
+}
+
+static inline void
+desc_reg_gr (unsigned char reg, unsigned char dst, struct unw_state_record *sr)
+{
+       set_reg(sr->curr.reg + reg, UNW_WHERE_GR, sr->region_start + 
sr->region_len - 1, dst);
+}
+
+static inline void
+desc_reg_psprel (unsigned char reg, unw_word pspoff, struct unw_state_record 
*sr)
+{
+       set_reg(sr->curr.reg + reg, UNW_WHERE_PSPREL, sr->region_start + 
sr->region_len - 1,
+               0x10 - 4*pspoff);
+}
+
+static inline void
+desc_reg_sprel (unsigned char reg, unw_word spoff, struct unw_state_record *sr)
+{
+       set_reg(sr->curr.reg + reg, UNW_WHERE_SPREL, sr->region_start + 
sr->region_len - 1,
+               4*spoff);
+}
+
+static inline void
+desc_rp_br (unsigned char dst, struct unw_state_record *sr)
+{
+       sr->return_link_reg = dst;
+}
+
+static inline void
+desc_reg_when (unsigned char regnum, unw_word t, struct unw_state_record *sr)
+{
+       struct unw_reg_info *reg = sr->curr.reg + regnum;
+
+       if (reg->where == UNW_WHERE_NONE)
+               reg->where = UNW_WHERE_GR_SAVE;
+       reg->when = sr->region_start + min_t(int, t, sr->region_len - 1);
+}
+
+static inline void
+desc_spill_base (unw_word pspoff, struct unw_state_record *sr)
+{
+       sr->spill_offset = 0x10 - 4*pspoff;
+}
+
+static inline unsigned char *
+desc_spill_mask (unsigned char *imaskp, struct unw_state_record *sr)
+{
+       sr->imask = imaskp;
+       return imaskp + (2*sr->region_len + 7)/8;
+}
+
+/*
+ * Body descriptors.
+ */
+static inline void
+desc_epilogue (unw_word t, unw_word ecount, struct unw_state_record *sr)
+{
+       sr->epilogue_start = sr->region_start + sr->region_len - 1 - t;
+       sr->epilogue_count = ecount + 1;
+}
+
+static inline void
+desc_copy_state (unw_word label, struct unw_state_record *sr)
+{
+       struct unw_labeled_state *ls;
+
+       for (ls = sr->labeled_states; ls; ls = ls->next) {
+               if (ls->label == label) {
+                       free_state_stack(&sr->curr);
+                       memcpy(&sr->curr, &ls->saved_state, sizeof(sr->curr));
+                       sr->curr.next = dup_state_stack(ls->saved_state.next);
+                       return;
+               }
+       }
+       printk(KERN_ERR "unwind: failed to find state labeled 0x%lx\n", label);
+}
+
+static inline void
+desc_label_state (unw_word label, struct unw_state_record *sr)
+{
+       struct unw_labeled_state *ls;
+
+       ls = alloc_labeled_state();
+       if (!ls) {
+               printk(KERN_ERR "unwind.desc_label_state(): out of memory\n");
+               return;
+       }
+       ls->label = label;
+       memcpy(&ls->saved_state, &sr->curr, sizeof(ls->saved_state));
+       ls->saved_state.next = dup_state_stack(sr->curr.next);
+
+       /* insert into list of labeled states: */
+       ls->next = sr->labeled_states;
+       sr->labeled_states = ls;
+}
+
+/*
+ * General descriptors.
+ */
+
+static inline int
+desc_is_active (unsigned char qp, unw_word t, struct unw_state_record *sr)
+{
+       if (sr->when_target <= sr->region_start + min_t(int, t, sr->region_len 
- 1))
+               return 0;
+       if (qp > 0) {
+               if ((sr->pr_val & (1UL << qp)) == 0)
+                       return 0;
+               sr->pr_mask |= (1UL << qp);
+       }
+       return 1;
+}
+
+static inline void
+desc_restore_p (unsigned char qp, unw_word t, unsigned char abreg, struct 
unw_state_record *sr)
+{
+       struct unw_reg_info *r;
+
+       if (!desc_is_active(qp, t, sr))
+               return;
+
+       r = sr->curr.reg + decode_abreg(abreg, 0);
+       r->where = UNW_WHERE_NONE;
+       r->when = UNW_WHEN_NEVER;
+       r->val = 0;
+}
+
+static inline void
+desc_spill_reg_p (unsigned char qp, unw_word t, unsigned char abreg, unsigned 
char x,
+                    unsigned char ytreg, struct unw_state_record *sr)
+{
+       enum unw_where where = UNW_WHERE_GR;
+       struct unw_reg_info *r;
+
+       if (!desc_is_active(qp, t, sr))
+               return;
+
+       if (x)
+               where = UNW_WHERE_BR;
+       else if (ytreg & 0x80)
+               where = UNW_WHERE_FR;
+
+       r = sr->curr.reg + decode_abreg(abreg, 0);
+       r->where = where;
+       r->when = sr->region_start + min_t(int, t, sr->region_len - 1);
+       r->val = (ytreg & 0x7f);
+}
+
+static inline void
+desc_spill_psprel_p (unsigned char qp, unw_word t, unsigned char abreg, 
unw_word pspoff,
+                    struct unw_state_record *sr)
+{
+       struct unw_reg_info *r;
+
+       if (!desc_is_active(qp, t, sr))
+               return;
+
+       r = sr->curr.reg + decode_abreg(abreg, 1);
+       r->where = UNW_WHERE_PSPREL;
+       r->when = sr->region_start + min_t(int, t, sr->region_len - 1);
+       r->val = 0x10 - 4*pspoff;
+}
+
+static inline void
+desc_spill_sprel_p (unsigned char qp, unw_word t, unsigned char abreg, 
unw_word spoff,
+                      struct unw_state_record *sr)
+{
+       struct unw_reg_info *r;
+
+       if (!desc_is_active(qp, t, sr))
+               return;
+
+       r = sr->curr.reg + decode_abreg(abreg, 1);
+       r->where = UNW_WHERE_SPREL;
+       r->when = sr->region_start + min_t(int, t, sr->region_len - 1);
+       r->val = 4*spoff;
+}
+
+#define UNW_DEC_BAD_CODE(code)                 printk(KERN_ERR "unwind: 
unknown code 0x%02x\n", \
+                                                      code);
+
+/*
+ * region headers:
+ */
+#define UNW_DEC_PROLOGUE_GR(fmt,r,m,gr,arg)    desc_prologue(0,r,m,gr,arg)
+#define UNW_DEC_PROLOGUE(fmt,b,r,arg)          desc_prologue(b,r,0,32,arg)
+/*
+ * prologue descriptors:
+ */
+#define UNW_DEC_ABI(fmt,a,c,arg)               desc_abi(a,c,arg)
+#define UNW_DEC_BR_GR(fmt,b,g,arg)             desc_br_gr(b,g,arg)
+#define UNW_DEC_BR_MEM(fmt,b,arg)              desc_br_mem(b,arg)
+#define UNW_DEC_FRGR_MEM(fmt,g,f,arg)          desc_frgr_mem(g,f,arg)
+#define UNW_DEC_FR_MEM(fmt,f,arg)              desc_fr_mem(f,arg)
+#define UNW_DEC_GR_GR(fmt,m,g,arg)             desc_gr_gr(m,g,arg)
+#define UNW_DEC_GR_MEM(fmt,m,arg)              desc_gr_mem(m,arg)
+#define UNW_DEC_MEM_STACK_F(fmt,t,s,arg)       desc_mem_stack_f(t,s,arg)
+#define UNW_DEC_MEM_STACK_V(fmt,t,arg)         desc_mem_stack_v(t,arg)
+#define UNW_DEC_REG_GR(fmt,r,d,arg)            desc_reg_gr(r,d,arg)
+#define UNW_DEC_REG_PSPREL(fmt,r,o,arg)                desc_reg_psprel(r,o,arg)
+#define UNW_DEC_REG_SPREL(fmt,r,o,arg)         desc_reg_sprel(r,o,arg)
+#define UNW_DEC_REG_WHEN(fmt,r,t,arg)          desc_reg_when(r,t,arg)
+#define UNW_DEC_PRIUNAT_WHEN_GR(fmt,t,arg)     
desc_reg_when(UNW_REG_PRI_UNAT_GR,t,arg)
+#define UNW_DEC_PRIUNAT_WHEN_MEM(fmt,t,arg)    
desc_reg_when(UNW_REG_PRI_UNAT_MEM,t,arg)
+#define UNW_DEC_PRIUNAT_GR(fmt,r,arg)          
desc_reg_gr(UNW_REG_PRI_UNAT_GR,r,arg)
+#define UNW_DEC_PRIUNAT_PSPREL(fmt,o,arg)      
desc_reg_psprel(UNW_REG_PRI_UNAT_MEM,o,arg)
+#define UNW_DEC_PRIUNAT_SPREL(fmt,o,arg)       
desc_reg_sprel(UNW_REG_PRI_UNAT_MEM,o,arg)
+#define UNW_DEC_RP_BR(fmt,d,arg)               desc_rp_br(d,arg)
+#define UNW_DEC_SPILL_BASE(fmt,o,arg)          desc_spill_base(o,arg)
+#define UNW_DEC_SPILL_MASK(fmt,m,arg)          (m = desc_spill_mask(m,arg))
+/*
+ * body descriptors:
+ */
+#define UNW_DEC_EPILOGUE(fmt,t,c,arg)          desc_epilogue(t,c,arg)
+#define UNW_DEC_COPY_STATE(fmt,l,arg)          desc_copy_state(l,arg)
+#define UNW_DEC_LABEL_STATE(fmt,l,arg)         desc_label_state(l,arg)
+/*
+ * general unwind descriptors:
+ */
+#define UNW_DEC_SPILL_REG_P(f,p,t,a,x,y,arg)   desc_spill_reg_p(p,t,a,x,y,arg)
+#define UNW_DEC_SPILL_REG(f,t,a,x,y,arg)       desc_spill_reg_p(0,t,a,x,y,arg)
+#define UNW_DEC_SPILL_PSPREL_P(f,p,t,a,o,arg)  desc_spill_psprel_p(p,t,a,o,arg)
+#define UNW_DEC_SPILL_PSPREL(f,t,a,o,arg)      desc_spill_psprel_p(0,t,a,o,arg)
+#define UNW_DEC_SPILL_SPREL_P(f,p,t,a,o,arg)   desc_spill_sprel_p(p,t,a,o,arg)
+#define UNW_DEC_SPILL_SPREL(f,t,a,o,arg)       desc_spill_sprel_p(0,t,a,o,arg)
+#define UNW_DEC_RESTORE_P(f,p,t,a,arg)         desc_restore_p(p,t,a,arg)
+#define UNW_DEC_RESTORE(f,t,a,arg)             desc_restore_p(0,t,a,arg)
+
+#include "unwind_decoder.c"
+
+
+/* Unwind scripts. */
+
+static inline unw_hash_index_t
+hash (unsigned long ip)
+{
+#      define hashmagic        0x9e3779b97f4a7c16UL    /* based on 
(sqrt(5)/2-1)*2^64 */
+
+       return (ip >> 4)*hashmagic >> (64 - UNW_LOG_HASH_SIZE);
+#undef hashmagic
+}
+
+static inline long
+cache_match (struct unw_script *script, unsigned long ip, unsigned long pr)
+{
+       read_lock(&script->lock);
+       if (ip == script->ip && ((pr ^ script->pr_val) & script->pr_mask) == 0)
+               /* keep the read lock... */
+               return 1;
+       read_unlock(&script->lock);
+       return 0;
+}
+
+static inline struct unw_script *
+script_lookup (struct unw_frame_info *info)
+{
+       struct unw_script *script = unw.cache + info->hint;
+       unsigned short index;
+       unsigned long ip, pr;
+
+       if (UNW_DEBUG_ON(0))
+               return NULL;    /* Always regenerate scripts in debug mode */
+
+       STAT(++unw.stat.cache.lookups);
+
+       ip = info->ip;
+       pr = info->pr;
+
+       if (cache_match(script, ip, pr)) {
+               STAT(++unw.stat.cache.hinted_hits);
+               return script;
+       }
+
+       index = unw.hash[hash(ip)];
+       if (index >= UNW_CACHE_SIZE)
+               return NULL;
+
+       script = unw.cache + index;
+       while (1) {
+               if (cache_match(script, ip, pr)) {
+                       /* update hint; no locking required as single-word 
writes are atomic */
+                       STAT(++unw.stat.cache.normal_hits);
+                       unw.cache[info->prev_script].hint = script - unw.cache;
+                       return script;
+               }
+               if (script->coll_chain >= UNW_HASH_SIZE)
+                       return NULL;
+               script = unw.cache + script->coll_chain;
+               STAT(++unw.stat.cache.collision_chain_traversals);
+       }
+}
+
+/*
+ * On returning, a write lock for the SCRIPT is still being held.
+ */
+static inline struct unw_script *
+script_new (unsigned long ip)
+{
+       struct unw_script *script, *prev, *tmp;
+       unw_hash_index_t index;
+       unsigned short head;
+
+       STAT(++unw.stat.script.news);
+
+       /*
+        * Can't (easily) use cmpxchg() here because of ABA problem
+        * that is intrinsic in cmpxchg()...
+        */
+       head = unw.lru_head;
+       script = unw.cache + head;
+       unw.lru_head = script->lru_chain;
+
+       /*
+        * We'd deadlock here if we interrupted a thread that is holding a read 
lock on
+        * script->lock.  Thus, if the write_trylock() fails, we simply bail 
out.  The
+        * alternative would be to disable interrupts whenever we hold a 
read-lock, but
+        * that seems silly.
+        */
+       if (!write_trylock(&script->lock))
+               return NULL;
+
+       /* re-insert script at the tail of the LRU chain: */
+       unw.cache[unw.lru_tail].lru_chain = head;
+       unw.lru_tail = head;
+
+       /* remove the old script from the hash table (if it's there): */
+       if (script->ip) {
+               index = hash(script->ip);
+               tmp = unw.cache + unw.hash[index];
+               prev = NULL;
+               while (1) {
+                       if (tmp == script) {
+                               if (prev)
+                                       prev->coll_chain = tmp->coll_chain;
+                               else
+                                       unw.hash[index] = tmp->coll_chain;
+                               break;
+                       } else
+                               prev = tmp;
+                       if (tmp->coll_chain >= UNW_CACHE_SIZE)
+                       /* old script wasn't in the hash-table */
+                               break;
+                       tmp = unw.cache + tmp->coll_chain;
+               }
+       }
+
+       /* enter new script in the hash table */
+       index = hash(ip);
+       script->coll_chain = unw.hash[index];
+       unw.hash[index] = script - unw.cache;
+
+       script->ip = ip;        /* set new IP while we're holding the locks */
+
+       STAT(if (script->coll_chain < UNW_CACHE_SIZE) 
++unw.stat.script.collisions);
+
+       script->flags = 0;
+       script->hint = 0;
+       script->count = 0;
+       return script;
+}
+
+static void
+script_finalize (struct unw_script *script, struct unw_state_record *sr)
+{
+       script->pr_mask = sr->pr_mask;
+       script->pr_val = sr->pr_val;
+       /*
+        * We could down-grade our write-lock on script->lock here but
+        * the rwlock API doesn't offer atomic lock downgrading, so
+        * we'll just keep the write-lock and release it later when
+        * we're done using the script.
+        */
+}
+
+static inline void
+script_emit (struct unw_script *script, struct unw_insn insn)
+{
+       if (script->count >= UNW_MAX_SCRIPT_LEN) {
+               UNW_DPRINT(0, "unwind.%s: script exceeds maximum size of %u 
instructions!\n",
+                       __FUNCTION__, UNW_MAX_SCRIPT_LEN);
+               return;
+       }
+       script->insn[script->count++] = insn;
+}
+
+static inline void
+emit_nat_info (struct unw_state_record *sr, int i, struct unw_script *script)
+{
+       struct unw_reg_info *r = sr->curr.reg + i;
+       enum unw_insn_opcode opc;
+       struct unw_insn insn;
+       unsigned long val = 0;
+
+       switch (r->where) {
+             case UNW_WHERE_GR:
+               if (r->val >= 32) {
+                       /* register got spilled to a stacked register */
+                       opc = UNW_INSN_SETNAT_TYPE;
+                       val = UNW_NAT_REGSTK;
+               } else
+                       /* register got spilled to a scratch register */
+                       opc = UNW_INSN_SETNAT_MEMSTK;
+               break;
+
+             case UNW_WHERE_FR:
+               opc = UNW_INSN_SETNAT_TYPE;
+               val = UNW_NAT_VAL;
+               break;
+
+             case UNW_WHERE_BR:
+               opc = UNW_INSN_SETNAT_TYPE;
+               val = UNW_NAT_NONE;
+               break;
+
+             case UNW_WHERE_PSPREL:
+             case UNW_WHERE_SPREL:
+               opc = UNW_INSN_SETNAT_MEMSTK;
+               break;
+
+             default:
+               UNW_DPRINT(0, "unwind.%s: don't know how to emit nat info for 
where = %u\n",
+                          __FUNCTION__, r->where);
+               return;
+       }
+       insn.opc = opc;
+       insn.dst = unw.preg_index[i];
+       insn.val = val;
+       script_emit(script, insn);
+}
+
+static void
+compile_reg (struct unw_state_record *sr, int i, struct unw_script *script)
+{
+       struct unw_reg_info *r = sr->curr.reg + i;
+       enum unw_insn_opcode opc;
+       unsigned long val, rval;
+       struct unw_insn insn;
+       long need_nat_info;
+
+       if (r->where == UNW_WHERE_NONE || r->when >= sr->when_target)
+               return;
+
+       opc = UNW_INSN_MOVE;
+       val = rval = r->val;
+       need_nat_info = (i >= UNW_REG_R4 && i <= UNW_REG_R7);
+
+       switch (r->where) {
+             case UNW_WHERE_GR:
+               if (rval >= 32) {
+                       opc = UNW_INSN_MOVE_STACKED;
+                       val = rval - 32;
+               } else if (rval >= 4 && rval <= 7) {
+                       if (need_nat_info) {
+                               opc = UNW_INSN_MOVE2;
+                               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;
+                       val = pt_regs_off(rval);
+               }
+               break;
+
+             case UNW_WHERE_FR:
+               if (rval <= 5)
+                       val = unw.preg_index[UNW_REG_F2  + (rval -  2)];
+               else if (rval >= 16 && rval <= 31)
+                       val = unw.preg_index[UNW_REG_F16 + (rval - 16)];
+               else {
+                       opc = UNW_INSN_MOVE_SCRATCH;
+                       if (rval <= 11)
+                               val = offsetof(struct pt_regs, f6) + 16*(rval - 
6);
+                       else
+                               UNW_DPRINT(0, "unwind.%s: kernel may not touch 
f%lu\n",
+                                          __FUNCTION__, rval);
+               }
+               break;
+
+             case UNW_WHERE_BR:
+               if (rval >= 1 && rval <= 5)
+                       val = unw.preg_index[UNW_REG_B1 + (rval - 1)];
+               else {
+                       opc = UNW_INSN_MOVE_SCRATCH;
+                       if (rval == 0)
+                               val = offsetof(struct pt_regs, b0);
+                       else if (rval == 6)
+                               val = offsetof(struct pt_regs, b6);
+                       else
+                               val = offsetof(struct pt_regs, b7);
+               }
+               break;
+
+             case UNW_WHERE_SPREL:
+               opc = UNW_INSN_ADD_SP;
+               break;
+
+             case UNW_WHERE_PSPREL:
+               opc = UNW_INSN_ADD_PSP;
+               break;
+
+             default:
+               UNW_DPRINT(0, "unwind%s: register %u has unexpected `where' 
value of %u\n",
+                          __FUNCTION__, i, r->where);
+               break;
+       }
+       insn.opc = opc;
+       insn.dst = unw.preg_index[i];
+       insn.val = val;
+       script_emit(script, insn);
+       if (need_nat_info)
+               emit_nat_info(sr, i, script);
+
+       if (i == UNW_REG_PSP) {
+               /*
+                * info->psp must contain the _value_ of the previous
+                * sp, not it's save location.  We get this by
+                * dereferencing the value we just stored in
+                * info->psp:
+                */
+               insn.opc = UNW_INSN_LOAD;
+               insn.dst = insn.val = unw.preg_index[UNW_REG_PSP];
+               script_emit(script, insn);
+       }
+}
+
+static inline const struct unw_table_entry *
+lookup (struct unw_table *table, unsigned long rel_ip)
+{
+       const struct unw_table_entry *e = NULL;
+       unsigned long lo, hi, mid;
+
+       /* do a binary search for right entry: */
+       for (lo = 0, hi = table->length; lo < hi; ) {
+               mid = (lo + hi) / 2;
+               e = &table->array[mid];
+               if (rel_ip < e->start_offset)
+                       hi = mid;
+               else if (rel_ip >= e->end_offset)
+                       lo = mid + 1;
+               else
+                       break;
+       }
+       if (rel_ip < e->start_offset || rel_ip >= e->end_offset)
+               return NULL;
+       return e;
+}
+
+/*
+ * Build an unwind script that unwinds from state OLD_STATE to the
+ * entrypoint of the function that called OLD_STATE.
+ */
+static inline struct unw_script *
+build_script (struct unw_frame_info *info)
+{
+       const struct unw_table_entry *e = NULL;
+       struct unw_script *script = NULL;
+       struct unw_labeled_state *ls, *next;
+       unsigned long ip = info->ip;
+       struct unw_state_record sr;
+       struct unw_table *table;
+       struct unw_reg_info *r;
+       struct unw_insn insn;
+       u8 *dp, *desc_end;
+       u64 hdr;
+       int i;
+       STAT(unsigned long start, parse_start;)
+
+       STAT(++unw.stat.script.builds; start = ia64_get_itc());
+
+       /* build state record */
+       memset(&sr, 0, sizeof(sr));
+       for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r)
+               r->when = UNW_WHEN_NEVER;
+       sr.pr_val = info->pr;
+
+       UNW_DPRINT(3, "unwind.%s: ip 0x%lx\n", __FUNCTION__, ip);
+       script = script_new(ip);
+       if (!script) {
+               UNW_DPRINT(0, "unwind.%s: failed to create unwind script\n",  
__FUNCTION__);
+               STAT(unw.stat.script.build_time += ia64_get_itc() - start);
+               return NULL;
+       }
+       unw.cache[info->prev_script].hint = script - unw.cache;
+
+       /* search the kernels and the modules' unwind tables for IP: */
+
+       STAT(parse_start = ia64_get_itc());
+
+       for (table = unw.tables; table; table = table->next) {
+               if (ip >= table->start && ip < table->end) {
+                       e = lookup(table, ip - table->segment_base);
+                       break;
+               }
+       }
+       if (!e) {
+               /* no info, return default unwinder (leaf proc, no mem stack, 
no saved regs)  */
+               UNW_DPRINT(1, "unwind.%s: no unwind info for ip=0x%lx (prev 
ip=0x%lx)\n",
+                       __FUNCTION__, ip, unw.cache[info->prev_script].ip);
+               sr.curr.reg[UNW_REG_RP].where = UNW_WHERE_BR;
+               sr.curr.reg[UNW_REG_RP].when = -1;
+               sr.curr.reg[UNW_REG_RP].val = 0;
+               compile_reg(&sr, UNW_REG_RP, script);
+               script_finalize(script, &sr);
+               STAT(unw.stat.script.parse_time += ia64_get_itc() - 
parse_start);
+               STAT(unw.stat.script.build_time += ia64_get_itc() - start);
+               return script;
+       }
+
+       sr.when_target = (3*((ip & ~0xfUL) - (table->segment_base + 
e->start_offset))/16
+                         + (ip & 0xfUL));
+       hdr = *(u64 *) (table->segment_base + e->info_offset);
+       dp =   (u8 *)  (table->segment_base + e->info_offset + 8);
+       desc_end = dp + 8*UNW_LENGTH(hdr);
+
+       while (!sr.done && dp < desc_end)
+               dp = unw_decode(dp, sr.in_body, &sr);
+
+       if (sr.when_target > sr.epilogue_start) {
+               /*
+                * sp has been restored and all values on the memory stack below
+                * psp also have been restored.
+                */
+               sr.curr.reg[UNW_REG_PSP].val = 0;
+               sr.curr.reg[UNW_REG_PSP].where = UNW_WHERE_NONE;
+               sr.curr.reg[UNW_REG_PSP].when = UNW_WHEN_NEVER;
+               for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r)
+                       if ((r->where == UNW_WHERE_PSPREL && r->val <= 0x10)
+                           || r->where == UNW_WHERE_SPREL)
+                       {
+                               r->val = 0;
+                               r->where = UNW_WHERE_NONE;
+                               r->when = UNW_WHEN_NEVER;
+                       }
+       }
+
+       script->flags = sr.flags;
+
+       /*
+        * If RP did't get saved, generate entry for the return link
+        * register.
+        */
+       if (sr.curr.reg[UNW_REG_RP].when >= sr.when_target) {
+               sr.curr.reg[UNW_REG_RP].where = UNW_WHERE_BR;
+               sr.curr.reg[UNW_REG_RP].when = -1;
+               sr.curr.reg[UNW_REG_RP].val = sr.return_link_reg;
+               UNW_DPRINT(1, "unwind.%s: using default for rp at ip=0x%lx 
where=%d val=0x%lx\n",
+                          __FUNCTION__, ip, sr.curr.reg[UNW_REG_RP].where,
+                          sr.curr.reg[UNW_REG_RP].val);
+       }
+
+#ifdef UNW_DEBUG
+       UNW_DPRINT(1, "unwind.%s: state record for func 0x%lx, t=%u:\n",
+               __FUNCTION__, table->segment_base + e->start_offset, 
sr.when_target);
+       for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r) {
+               if (r->where != UNW_WHERE_NONE || r->when != UNW_WHEN_NEVER) {
+                       UNW_DPRINT(1, "  %s <- ", unw.preg_name[r - 
sr.curr.reg]);
+                       switch (r->where) {
+                             case UNW_WHERE_GR:     UNW_DPRINT(1, "r%lu", 
r->val); break;
+                             case UNW_WHERE_FR:     UNW_DPRINT(1, "f%lu", 
r->val); break;
+                             case UNW_WHERE_BR:     UNW_DPRINT(1, "b%lu", 
r->val); break;
+                             case UNW_WHERE_SPREL:  UNW_DPRINT(1, 
"[sp+0x%lx]", r->val); break;
+                             case UNW_WHERE_PSPREL: UNW_DPRINT(1, 
"[psp+0x%lx]", r->val); break;
+                             case UNW_WHERE_NONE:
+                               UNW_DPRINT(1, "%s+0x%lx", unw.preg_name[r - 
sr.curr.reg], r->val);
+                               break;
+
+                             default:
+                               UNW_DPRINT(1, "BADWHERE(%d)", r->where);
+                               break;
+                       }
+                       UNW_DPRINT(1, "\t\t%d\n", r->when);
+               }
+       }
+#endif
+
+       STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start);
+
+       /* translate state record into unwinder instructions: */
+
+       /*
+        * First, set psp if we're dealing with a fixed-size frame;
+        * subsequent instructions may depend on this value.
+        */
+       if (sr.when_target > sr.curr.reg[UNW_REG_PSP].when
+           && (sr.curr.reg[UNW_REG_PSP].where == UNW_WHERE_NONE)
+           && sr.curr.reg[UNW_REG_PSP].val != 0) {
+               /* new psp is sp plus frame size */
+               insn.opc = UNW_INSN_ADD;
+               insn.dst = offsetof(struct unw_frame_info, psp)/8;
+               insn.val = sr.curr.reg[UNW_REG_PSP].val;        /* frame size */
+               script_emit(script, insn);
+       }
+
+       /* determine where the primary UNaT is: */
+       if (sr.when_target < sr.curr.reg[UNW_REG_PRI_UNAT_GR].when)
+               i = UNW_REG_PRI_UNAT_MEM;
+       else if (sr.when_target < sr.curr.reg[UNW_REG_PRI_UNAT_MEM].when)
+               i = UNW_REG_PRI_UNAT_GR;
+       else if (sr.curr.reg[UNW_REG_PRI_UNAT_MEM].when > 
sr.curr.reg[UNW_REG_PRI_UNAT_GR].when)
+               i = UNW_REG_PRI_UNAT_MEM;
+       else
+               i = UNW_REG_PRI_UNAT_GR;
+
+       compile_reg(&sr, i, script);
+
+       for (i = UNW_REG_BSP; i < UNW_NUM_REGS; ++i)
+               compile_reg(&sr, i, script);
+
+       /* free labeled register states & stack: */
+
+       STAT(parse_start = ia64_get_itc());
+       for (ls = sr.labeled_states; ls; ls = next) {
+               next = ls->next;
+               free_state_stack(&ls->saved_state);
+               free_labeled_state(ls);
+       }
+       free_state_stack(&sr.curr);
+       STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start);
+
+       script_finalize(script, &sr);
+       STAT(unw.stat.script.build_time += ia64_get_itc() - start);
+       return script;
+}
+
+/*
+ * Apply the unwinding actions represented by OPS and update SR to
+ * reflect the state that existed upon entry to the function that this
+ * unwinder represents.
+ */
+static inline void
+run_script (struct unw_script *script, struct unw_frame_info *state)
+{
+       struct unw_insn *ip, *limit, next_insn;
+       unsigned long opc, dst, val, off;
+       unsigned long *s = (unsigned long *) state;
+       STAT(unsigned long start;)
+
+       STAT(++unw.stat.script.runs; start = ia64_get_itc());
+       state->flags = script->flags;
+       ip = script->insn;
+       limit = script->insn + script->count;
+       next_insn = *ip;
+
+       while (ip++ < limit) {
+               opc = next_insn.opc;
+               dst = next_insn.dst;
+               val = next_insn.val;
+               next_insn = *ip;
+
+         redo:
+               switch (opc) {
+                     case UNW_INSN_ADD:
+                       s[dst] += val;
+                       break;
+
+                     case UNW_INSN_MOVE2:
+                       if (!s[val])
+                               goto lazy_init;
+                       s[dst+1] = s[val+1];
+                       s[dst] = s[val];
+                       break;
+
+                     case UNW_INSN_MOVE:
+                       if (!s[val])
+                               goto lazy_init;
+                       s[dst] = s[val];
+                       break;
+
+                     case UNW_INSN_MOVE_SCRATCH:
+                       if (state->pt) {
+                               s[dst] = (unsigned long) 
get_scratch_regs(state) + val;
+                       } else {
+                               s[dst] = 0;
+                               UNW_DPRINT(0, "unwind.%s: no state->pt, 
dst=%ld, val=%ld\n",
+                                          __FUNCTION__, dst, val);
+                       }
+                       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);
+                       break;
+
+                     case UNW_INSN_ADD_PSP:
+                       s[dst] = state->psp + val;
+                       break;
+
+                     case UNW_INSN_ADD_SP:
+                       s[dst] = state->sp + val;
+                       break;
+
+                     case UNW_INSN_SETNAT_MEMSTK:
+                       if (!state->pri_unat_loc)
+                               state->pri_unat_loc = &state->sw->caller_unat;
+                       /* register off. is a multiple of 8, so the least 3 
bits (type) are 0 */
+                       s[dst+1] = ((unsigned long) state->pri_unat_loc - 
s[dst]) | UNW_NAT_MEMSTK;
+                       break;
+
+                     case UNW_INSN_SETNAT_TYPE:
+                       s[dst+1] = val;
+                       break;
+
+                     case UNW_INSN_LOAD:
+#ifdef UNW_DEBUG
+                       if ((s[val] & (local_cpu_data->unimpl_va_mask | 0x7)) 
!= 0
+                           || s[val] < TASK_SIZE)
+                       {
+                               UNW_DPRINT(0, "unwind.%s: rejecting bad 
psp=0x%lx\n",
+                                          __FUNCTION__, s[val]);
+                               break;
+                       }
+#endif
+                       s[dst] = *(unsigned long *) s[val];
+                       break;
+               }
+       }
+       STAT(unw.stat.script.run_time += ia64_get_itc() - start);
+       return;
+
+  lazy_init:
+       off = unw.sw_off[val];
+       s[val] = (unsigned long) state->sw + off;
+       if (off >= offsetof(struct switch_stack, r4) && off <= offsetof(struct 
switch_stack, r7))
+               /*
+                * We're initializing a general register: init NaT info, too.  
Note that
+                * the offset is a multiple of 8 which gives us the 3 bits 
needed for
+                * the type field.
+                */
+               s[val+1] = (offsetof(struct switch_stack, ar_unat) - off) | 
UNW_NAT_MEMSTK;
+       goto redo;
+}
+
+static int
+find_save_locs (struct unw_frame_info *info)
+{
+       int have_write_lock = 0;
+       struct unw_script *scr;
+       unsigned long flags = 0;
+
+       if ((info->ip & (local_cpu_data->unimpl_va_mask | 0xf)) || info->ip < 
TASK_SIZE) {
+               /* don't let obviously bad addresses pollute the cache */
+               /* FIXME: should really be level 0 but it occurs too often. KAO 
*/
+               UNW_DPRINT(1, "unwind.%s: rejecting bad ip=0x%lx\n", 
__FUNCTION__, info->ip);
+               info->rp_loc = NULL;
+               return -1;
+       }
+
+       scr = script_lookup(info);
+       if (!scr) {
+               spin_lock_irqsave(&unw.lock, flags);
+               scr = build_script(info);
+               if (!scr) {
+                       spin_unlock_irqrestore(&unw.lock, flags);
+                       UNW_DPRINT(0,
+                                  "unwind.%s: failed to locate/build unwind 
script for ip %lx\n",
+                                  __FUNCTION__, info->ip);
+                       return -1;
+               }
+               have_write_lock = 1;
+       }
+       info->hint = scr->hint;
+       info->prev_script = scr - unw.cache;
+
+       run_script(scr, info);
+
+       if (have_write_lock) {
+               write_unlock(&scr->lock);
+               spin_unlock_irqrestore(&unw.lock, flags);
+       } else
+               read_unlock(&scr->lock);
+       return 0;
+}
+
+int
+unw_unwind (struct unw_frame_info *info)
+{
+       unsigned long prev_ip, prev_sp, prev_bsp;
+       unsigned long ip, pr, num_regs;
+       STAT(unsigned long start, flags;)
+       int retval;
+
+       STAT(local_irq_save(flags); ++unw.stat.api.unwinds; start = 
ia64_get_itc());
+
+       prev_ip = info->ip;
+       prev_sp = info->sp;
+       prev_bsp = info->bsp;
+
+       /* restore the ip */
+       if (!info->rp_loc) {
+               /* FIXME: should really be level 0 but it occurs too often. KAO 
*/
+               UNW_DPRINT(1, "unwind.%s: failed to locate return link 
(ip=0x%lx)!\n",
+                          __FUNCTION__, info->ip);
+               STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; 
local_irq_restore(flags));
+               return -1;
+       }
+       ip = info->ip = *info->rp_loc;
+       if (ip < GATE_ADDR) {
+               UNW_DPRINT(2, "unwind.%s: reached user-space (ip=0x%lx)\n", 
__FUNCTION__, ip);
+               STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; 
local_irq_restore(flags));
+               return -1;
+       }
+
+       /* restore the cfm: */
+       if (!info->pfs_loc) {
+               UNW_DPRINT(0, "unwind.%s: failed to locate ar.pfs!\n", 
__FUNCTION__);
+               STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; 
local_irq_restore(flags));
+               return -1;
+       }
+       info->cfm_loc = info->pfs_loc;
+
+       /* restore the bsp: */
+       pr = info->pr;
+       num_regs = 0;
+       if ((info->flags & UNW_FLAG_INTERRUPT_FRAME)) {
+               info->pt = info->sp + 16;
+               if ((pr & (1UL << PRED_NON_SYSCALL)) != 0)
+                       num_regs = *info->cfm_loc & 0x7f;               /* size 
of frame */
+               info->pfs_loc =
+                       (unsigned long *) (info->pt + offsetof(struct pt_regs, 
ar_pfs));
+               UNW_DPRINT(3, "unwind.%s: interrupt_frame pt 0x%lx\n", 
__FUNCTION__, info->pt);
+       } else
+               num_regs = (*info->cfm_loc >> 7) & 0x7f;        /* size of 
locals */
+       info->bsp = (unsigned long) ia64_rse_skip_regs((unsigned long *) 
info->bsp, -num_regs);
+       if (info->bsp < info->regstk.limit || info->bsp > info->regstk.top) {
+               UNW_DPRINT(0, "unwind.%s: bsp (0x%lx) out of range 
[0x%lx-0x%lx]\n",
+                       __FUNCTION__, info->bsp, info->regstk.limit, 
info->regstk.top);
+               STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; 
local_irq_restore(flags));
+               return -1;
+       }
+
+       /* restore the sp: */
+       info->sp = info->psp;
+       if (info->sp < info->memstk.top || info->sp > info->memstk.limit) {
+               UNW_DPRINT(0, "unwind.%s: sp (0x%lx) out of range 
[0x%lx-0x%lx]\n",
+                       __FUNCTION__, info->sp, info->memstk.top, 
info->memstk.limit);
+               STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; 
local_irq_restore(flags));
+               return -1;
+       }
+
+       if (info->ip == prev_ip && info->sp == prev_sp && info->bsp == 
prev_bsp) {
+               UNW_DPRINT(0, "unwind.%s: ip, sp, bsp unchanged; stopping here 
(ip=0x%lx)\n",
+                          __FUNCTION__, ip);
+               STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; 
local_irq_restore(flags));
+               return -1;
+       }
+
+       /* as we unwind, the saved ar.unat becomes the primary unat: */
+       info->pri_unat_loc = info->unat_loc;
+
+       /* finally, restore the predicates: */
+       unw_get_pr(info, &info->pr);
+
+       retval = find_save_locs(info);
+       STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; 
local_irq_restore(flags));
+       return retval;
+}
+EXPORT_SYMBOL(unw_unwind);
+
+int
+unw_unwind_to_user (struct unw_frame_info *info)
+{
+       unsigned long ip, sp, pr = 0;
+
+       while (unw_unwind(info) >= 0) {
+               unw_get_sp(info, &sp);
+               if ((long)((unsigned long)info->task + IA64_STK_OFFSET - sp)
+                   < IA64_PT_REGS_SIZE) {
+                       UNW_DPRINT(0, "unwind.%s: ran off the top of the kernel 
stack\n",
+                                  __FUNCTION__);
+                       break;
+               }
+               if (unw_is_intr_frame(info) &&
+                   (pr & (1UL << PRED_USER_STACK)))
+                       return 0;
+               if (unw_get_pr (info, &pr) < 0) {
+                       unw_get_rp(info, &ip);
+                       UNW_DPRINT(0, "unwind.%s: failed to read "
+                                  "predicate register (ip=0x%lx)\n",
+                               __FUNCTION__, ip);
+                       return -1;
+               }
+       }
+       unw_get_ip(info, &ip);
+       UNW_DPRINT(0, "unwind.%s: failed to unwind to user-level (ip=0x%lx)\n",
+                  __FUNCTION__, ip);
+       return -1;
+}
+EXPORT_SYMBOL(unw_unwind_to_user);
+
+static void
+init_frame_info (struct unw_frame_info *info, struct task_struct *t,
+                struct switch_stack *sw, unsigned long stktop)
+{
+       unsigned long rbslimit, rbstop, stklimit;
+       STAT(unsigned long start, flags;)
+
+       STAT(local_irq_save(flags); ++unw.stat.api.inits; start = 
ia64_get_itc());
+
+       /*
+        * Subtle stuff here: we _could_ unwind through the switch_stack frame 
but we
+        * don't want to do that because it would be slow as each preserved 
register would
+        * have to be processed.  Instead, what we do here is zero out the 
frame info and
+        * start the unwind process at the function that created the 
switch_stack frame.
+        * When a preserved value in switch_stack needs to be accessed, 
run_script() will
+        * initialize the appropriate pointer on demand.
+        */
+       memset(info, 0, sizeof(*info));
+
+       rbslimit = (unsigned long) t + IA64_RBS_OFFSET;
+       rbstop   = sw->ar_bspstore;
+       if (rbstop - (unsigned long) t >= IA64_STK_OFFSET)
+               rbstop = rbslimit;
+
+       stklimit = (unsigned long) t + IA64_STK_OFFSET;
+       if (stktop <= rbstop)
+               stktop = rbstop;
+
+       info->regstk.limit = rbslimit;
+       info->regstk.top   = rbstop;
+       info->memstk.limit = stklimit;
+       info->memstk.top   = stktop;
+       info->task = t;
+       info->sw  = sw;
+       info->sp = info->psp = stktop;
+       info->pr = sw->pr;
+       UNW_DPRINT(3, "unwind.%s:\n"
+                  "  task   0x%lx\n"
+                  "  rbs = [0x%lx-0x%lx)\n"
+                  "  stk = [0x%lx-0x%lx)\n"
+                  "  pr     0x%lx\n"
+                  "  sw     0x%lx\n"
+                  "  sp     0x%lx\n",
+                  __FUNCTION__, (unsigned long) t, rbslimit, rbstop, stktop, 
stklimit,
+                  info->pr, (unsigned long) info->sw, info->sp);
+       STAT(unw.stat.api.init_time += ia64_get_itc() - start; 
local_irq_restore(flags));
+}
+
+void
+unw_init_frame_info (struct unw_frame_info *info, struct task_struct *t, 
struct switch_stack *sw)
+{
+       unsigned long sol;
+
+       init_frame_info(info, t, sw, (unsigned long) (sw + 1) - 16);
+       info->cfm_loc = &sw->ar_pfs;
+       sol = (*info->cfm_loc >> 7) & 0x7f;
+       info->bsp = (unsigned long) ia64_rse_skip_regs((unsigned long *) 
info->regstk.top, -sol);
+       info->ip = sw->b0;
+       UNW_DPRINT(3, "unwind.%s:\n"
+                  "  bsp    0x%lx\n"
+                  "  sol    0x%lx\n"
+                  "  ip     0x%lx\n",
+                  __FUNCTION__, info->bsp, sol, info->ip);
+       find_save_locs(info);
+}
+
+EXPORT_SYMBOL(unw_init_frame_info);
+
+void
+unw_init_from_blocked_task (struct unw_frame_info *info, struct task_struct *t)
+{
+       struct switch_stack *sw = (struct switch_stack *) (t->thread.ksp + 16);
+
+       UNW_DPRINT(1, "unwind.%s\n", __FUNCTION__);
+       unw_init_frame_info(info, t, sw);
+}
+EXPORT_SYMBOL(unw_init_from_blocked_task);
+
+static void
+init_unwind_table (struct unw_table *table, const char *name, unsigned long 
segment_base,
+                  unsigned long gp, const void *table_start, const void 
*table_end)
+{
+       const struct unw_table_entry *start = table_start, *end = table_end;
+
+       table->name = name;
+       table->segment_base = segment_base;
+       table->gp = gp;
+       table->start = segment_base + start[0].start_offset;
+       table->end = segment_base + end[-1].end_offset;
+       table->array = start;
+       table->length = end - start;
+}
+
+void *
+unw_add_unwind_table (const char *name, unsigned long segment_base, unsigned 
long gp,
+                     const void *table_start, const void *table_end)
+{
+       const struct unw_table_entry *start = table_start, *end = table_end;
+       struct unw_table *table;
+       unsigned long flags;
+
+       if (end - start <= 0) {
+               UNW_DPRINT(0, "unwind.%s: ignoring attempt to insert empty 
unwind table\n",
+                          __FUNCTION__);
+               return NULL;
+       }
+
+       table = kmalloc(sizeof(*table), GFP_USER);
+       if (!table)
+               return NULL;
+
+       init_unwind_table(table, name, segment_base, gp, table_start, 
table_end);
+
+       spin_lock_irqsave(&unw.lock, flags);
+       {
+               /* keep kernel unwind table at the front (it's searched most 
commonly): */
+               table->next = unw.tables->next;
+               unw.tables->next = table;
+       }
+       spin_unlock_irqrestore(&unw.lock, flags);
+
+       return table;
+}
+
+void
+unw_remove_unwind_table (void *handle)
+{
+       struct unw_table *table, *prev;
+       struct unw_script *tmp;
+       unsigned long flags;
+       long index;
+
+       if (!handle) {
+               UNW_DPRINT(0, "unwind.%s: ignoring attempt to remove 
non-existent unwind table\n",
+                          __FUNCTION__);
+               return;
+       }
+
+       table = handle;
+       if (table == &unw.kernel_table) {
+               UNW_DPRINT(0, "unwind.%s: sorry, freeing the kernel's unwind 
table is a "
+                          "no-can-do!\n", __FUNCTION__);
+               return;
+       }
+
+       spin_lock_irqsave(&unw.lock, flags);
+       {
+               /* first, delete the table: */
+
+               for (prev = (struct unw_table *) &unw.tables; prev; prev = 
prev->next)
+                       if (prev->next == table)
+                               break;
+               if (!prev) {
+                       UNW_DPRINT(0, "unwind.%s: failed to find unwind table 
%p\n",
+                                  __FUNCTION__, (void *) table);
+                       spin_unlock_irqrestore(&unw.lock, flags);
+                       return;
+               }
+               prev->next = table->next;
+       }
+       spin_unlock_irqrestore(&unw.lock, flags);
+
+       /* next, remove hash table entries for this table */
+
+       for (index = 0; index <= UNW_HASH_SIZE; ++index) {
+               tmp = unw.cache + unw.hash[index];
+               if (unw.hash[index] >= UNW_CACHE_SIZE
+                   || tmp->ip < table->start || tmp->ip >= table->end)
+                       continue;
+
+               write_lock(&tmp->lock);
+               {
+                       if (tmp->ip >= table->start && tmp->ip < table->end) {
+                               unw.hash[index] = tmp->coll_chain;
+                               tmp->ip = 0;
+                       }
+               }
+               write_unlock(&tmp->lock);
+       }
+
+       kfree(table);
+}
+
+static int __init
+create_gate_table (void)
+{
+       const struct unw_table_entry *entry, *start, *end;
+       unsigned long *lp, segbase = GATE_ADDR;
+       size_t info_size, size;
+       char *info;
+       Elf64_Phdr *punw = NULL, *phdr = (Elf64_Phdr *) (GATE_ADDR + 
GATE_EHDR->e_phoff);
+       int i;
+
+       for (i = 0; i < GATE_EHDR->e_phnum; ++i, ++phdr)
+               if (phdr->p_type == PT_IA_64_UNWIND) {
+                       punw = phdr;
+                       break;
+               }
+
+       if (!punw) {
+               printk("%s: failed to find gate DSO's unwind table!\n", 
__FUNCTION__);
+               return 0;
+       }
+
+       start = (const struct unw_table_entry *) punw->p_vaddr;
+       end = (struct unw_table_entry *) ((char *) start + punw->p_memsz);
+       size  = 0;
+
+       unw_add_unwind_table("linux-gate.so", segbase, 0, start, end);
+
+       for (entry = start; entry < end; ++entry)
+               size += 3*8 + 8 + 8*UNW_LENGTH(*(u64 *) (segbase + 
entry->info_offset));
+       size += 8;      /* reserve space for "end of table" marker */
+
+       unw.gate_table = kmalloc(size, GFP_KERNEL);
+       if (!unw.gate_table) {
+               unw.gate_table_size = 0;
+               printk(KERN_ERR "%s: unable to create unwind data for gate 
page!\n", __FUNCTION__);
+               return 0;
+       }
+       unw.gate_table_size = size;
+
+       lp = unw.gate_table;
+       info = (char *) unw.gate_table + size;
+
+       for (entry = start; entry < end; ++entry, lp += 3) {
+               info_size = 8 + 8*UNW_LENGTH(*(u64 *) (segbase + 
entry->info_offset));
+               info -= info_size;
+               memcpy(info, (char *) segbase + entry->info_offset, info_size);
+
+               lp[0] = segbase + entry->start_offset;          /* start */
+               lp[1] = segbase + entry->end_offset;            /* end */
+               lp[2] = info - (char *) unw.gate_table;         /* info */
+       }
+       *lp = 0;        /* end-of-table marker */
+       return 0;
+}
+
+__initcall(create_gate_table);
+
+void __init
+unw_init (void)
+{
+       extern char __gp[];
+       extern void unw_hash_index_t_is_too_narrow (void);
+       long i, off;
+
+       if (8*sizeof(unw_hash_index_t) < UNW_LOG_HASH_SIZE)
+               unw_hash_index_t_is_too_narrow();
+
+       unw.sw_off[unw.preg_index[UNW_REG_PRI_UNAT_GR]] = SW(CALLER_UNAT);
+       unw.sw_off[unw.preg_index[UNW_REG_BSPSTORE]] = SW(AR_BSPSTORE);
+       unw.sw_off[unw.preg_index[UNW_REG_PFS]] = SW(AR_PFS);
+       unw.sw_off[unw.preg_index[UNW_REG_RP]] = SW(B0);
+       unw.sw_off[unw.preg_index[UNW_REG_UNAT]] = SW(CALLER_UNAT);
+       unw.sw_off[unw.preg_index[UNW_REG_PR]] = SW(PR);
+       unw.sw_off[unw.preg_index[UNW_REG_LC]] = SW(AR_LC);
+       unw.sw_off[unw.preg_index[UNW_REG_FPSR]] = SW(AR_FPSR);
+       for (i = UNW_REG_R4, off = SW(R4); i <= UNW_REG_R7; ++i, off += 8)
+               unw.sw_off[unw.preg_index[i]] = off;
+       for (i = UNW_REG_B1, off = SW(B1); i <= UNW_REG_B5; ++i, off += 8)
+               unw.sw_off[unw.preg_index[i]] = off;
+       for (i = UNW_REG_F2, off = SW(F2); i <= UNW_REG_F5; ++i, off += 16)
+               unw.sw_off[unw.preg_index[i]] = off;
+       for (i = UNW_REG_F16, off = SW(F16); i <= UNW_REG_F31; ++i, off += 16)
+               unw.sw_off[unw.preg_index[i]] = off;
+
+       for (i = 0; i < UNW_CACHE_SIZE; ++i) {
+               if (i > 0)
+                       unw.cache[i].lru_chain = (i - 1);
+               unw.cache[i].coll_chain = -1;
+               rwlock_init(&unw.cache[i].lock);
+       }
+       unw.lru_head = UNW_CACHE_SIZE - 1;
+       unw.lru_tail = 0;
+
+       init_unwind_table(&unw.kernel_table, "kernel", KERNEL_START, (unsigned 
long) __gp,
+                         __start_unwind, __end_unwind);
+}
+
+/*
+ * DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED
+ *
+ *     This system call has been deprecated.  The new and improved way to get
+ *     at the kernel's unwind info is via the gate DSO.  The address of the
+ *     ELF header for this DSO is passed to user-level via AT_SYSINFO_EHDR.
+ *
+ * DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED
+ *
+ * This system call copies the unwind data into the buffer pointed to by BUF 
and returns
+ * the size of the unwind data.  If BUF_SIZE is smaller than the size of the 
unwind data
+ * or if BUF is NULL, nothing is copied, but the system call still returns the 
size of the
+ * unwind data.
+ *
+ * The first portion of the unwind data contains an unwind table and rest 
contains the
+ * associated unwind info (in no particular order).  The unwind table consists 
of a table
+ * of entries of the form:
+ *
+ *     u64 start;      (64-bit address of start of function)
+ *     u64 end;        (64-bit address of start of function)
+ *     u64 info;       (BUF-relative offset to unwind info)
+ *
+ * The end of the unwind table is indicated by an entry with a START address 
of zero.
+ *
+ * Please see the IA-64 Software Conventions and Runtime Architecture manual 
for details
+ * on the format of the unwind info.
+ *
+ * ERRORS
+ *     EFAULT  BUF points outside your accessible address space.
+ */
+asmlinkage long
+sys_getunwind (void __user *buf, size_t buf_size)
+{
+       if (buf && buf_size >= unw.gate_table_size)
+               if (copy_to_user(buf, unw.gate_table, unw.gate_table_size) != 0)
+                       return -EFAULT;
+       return unw.gate_table_size;
+}
diff -r f218e6ba2653 -r df6a9e0d7e05 xen/arch/ia64/linux-xen/unwind_decoder.c
--- /dev/null   Thu Jan  1 00:00:00 1970 +0000
+++ b/xen/arch/ia64/linux-xen/unwind_decoder.c  Wed Dec 28 15:19:56 2005 +0900
@@ -0,0 +1,459 @@
+/*
+ * Copyright (C) 2000 Hewlett-Packard Co
+ * Copyright (C) 2000 David Mosberger-Tang <davidm@xxxxxxxxxx>
+ *
+ * Generic IA-64 unwind info decoder.
+ *
+ * This file is used both by the Linux kernel and objdump.  Please keep
+ * the two copies of this file in sync.
+ *
+ * You need to customize the decoder by defining the following
+ * macros/constants before including this file:
+ *
+ *  Types:
+ *     unw_word        Unsigned integer type with at least 64 bits 
+ *
+ *  Register names:
+ *     UNW_REG_BSP
+ *     UNW_REG_BSPSTORE
+ *     UNW_REG_FPSR
+ *     UNW_REG_LC
+ *     UNW_REG_PFS
+ *     UNW_REG_PR
+ *     UNW_REG_RNAT
+ *     UNW_REG_PSP
+ *     UNW_REG_RP
+ *     UNW_REG_UNAT
+ *
+ *  Decoder action macros:
+ *     UNW_DEC_BAD_CODE(code)
+ *     UNW_DEC_ABI(fmt,abi,context,arg)
+ *     UNW_DEC_BR_GR(fmt,brmask,gr,arg)
+ *     UNW_DEC_BR_MEM(fmt,brmask,arg)
+ *     UNW_DEC_COPY_STATE(fmt,label,arg)
+ *     UNW_DEC_EPILOGUE(fmt,t,ecount,arg)
+ *     UNW_DEC_FRGR_MEM(fmt,grmask,frmask,arg)
+ *     UNW_DEC_FR_MEM(fmt,frmask,arg)
+ *     UNW_DEC_GR_GR(fmt,grmask,gr,arg)
+ *     UNW_DEC_GR_MEM(fmt,grmask,arg)
+ *     UNW_DEC_LABEL_STATE(fmt,label,arg)
+ *     UNW_DEC_MEM_STACK_F(fmt,t,size,arg)
+ *     UNW_DEC_MEM_STACK_V(fmt,t,arg)
+ *     UNW_DEC_PRIUNAT_GR(fmt,r,arg)
+ *     UNW_DEC_PRIUNAT_WHEN_GR(fmt,t,arg)
+ *     UNW_DEC_PRIUNAT_WHEN_MEM(fmt,t,arg)
+ *     UNW_DEC_PRIUNAT_WHEN_PSPREL(fmt,pspoff,arg)
+ *     UNW_DEC_PRIUNAT_WHEN_SPREL(fmt,spoff,arg)
+ *     UNW_DEC_PROLOGUE(fmt,body,rlen,arg)
+ *     UNW_DEC_PROLOGUE_GR(fmt,rlen,mask,grsave,arg)
+ *     UNW_DEC_REG_PSPREL(fmt,reg,pspoff,arg)
+ *     UNW_DEC_REG_REG(fmt,src,dst,arg)
+ *     UNW_DEC_REG_SPREL(fmt,reg,spoff,arg)
+ *     UNW_DEC_REG_WHEN(fmt,reg,t,arg)
+ *     UNW_DEC_RESTORE(fmt,t,abreg,arg)
+ *     UNW_DEC_RESTORE_P(fmt,qp,t,abreg,arg)
+ *     UNW_DEC_SPILL_BASE(fmt,pspoff,arg)
+ *     UNW_DEC_SPILL_MASK(fmt,imaskp,arg)
+ *     UNW_DEC_SPILL_PSPREL(fmt,t,abreg,pspoff,arg)
+ *     UNW_DEC_SPILL_PSPREL_P(fmt,qp,t,abreg,pspoff,arg)
+ *     UNW_DEC_SPILL_REG(fmt,t,abreg,x,ytreg,arg)
+ *     UNW_DEC_SPILL_REG_P(fmt,qp,t,abreg,x,ytreg,arg)
+ *     UNW_DEC_SPILL_SPREL(fmt,t,abreg,spoff,arg)
+ *     UNW_DEC_SPILL_SPREL_P(fmt,qp,t,abreg,pspoff,arg)
+ */
+
+static unw_word
+unw_decode_uleb128 (unsigned char **dpp)
+{
+  unsigned shift = 0;
+  unw_word byte, result = 0;
+  unsigned char *bp = *dpp;
+
+  while (1)
+    {
+      byte = *bp++;
+      result |= (byte & 0x7f) << shift;
+      if ((byte & 0x80) == 0)
+       break;
+      shift += 7;
+    }
+  *dpp = bp;
+  return result;
+}
+
+static unsigned char *
+unw_decode_x1 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unsigned char byte1, abreg;
+  unw_word t, off;
+
+  byte1 = *dp++;
+  t = unw_decode_uleb128 (&dp);
+  off = unw_decode_uleb128 (&dp);
+  abreg = (byte1 & 0x7f);
+  if (byte1 & 0x80)
+         UNW_DEC_SPILL_SPREL(X1, t, abreg, off, arg);
+  else
+         UNW_DEC_SPILL_PSPREL(X1, t, abreg, off, arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_x2 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unsigned char byte1, byte2, abreg, x, ytreg;
+  unw_word t;
+
+  byte1 = *dp++; byte2 = *dp++;
+  t = unw_decode_uleb128 (&dp);
+  abreg = (byte1 & 0x7f);
+  ytreg = byte2;
+  x = (byte1 >> 7) & 1;
+  if ((byte1 & 0x80) == 0 && ytreg == 0)
+    UNW_DEC_RESTORE(X2, t, abreg, arg);
+  else
+    UNW_DEC_SPILL_REG(X2, t, abreg, x, ytreg, arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_x3 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unsigned char byte1, byte2, abreg, qp;
+  unw_word t, off;
+
+  byte1 = *dp++; byte2 = *dp++;
+  t = unw_decode_uleb128 (&dp);
+  off = unw_decode_uleb128 (&dp);
+
+  qp = (byte1 & 0x3f);
+  abreg = (byte2 & 0x7f);
+
+  if (byte1 & 0x80)
+    UNW_DEC_SPILL_SPREL_P(X3, qp, t, abreg, off, arg);
+  else
+    UNW_DEC_SPILL_PSPREL_P(X3, qp, t, abreg, off, arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_x4 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unsigned char byte1, byte2, byte3, qp, abreg, x, ytreg;
+  unw_word t;
+
+  byte1 = *dp++; byte2 = *dp++; byte3 = *dp++;
+  t = unw_decode_uleb128 (&dp);
+
+  qp = (byte1 & 0x3f);
+  abreg = (byte2 & 0x7f);
+  x = (byte2 >> 7) & 1;
+  ytreg = byte3;
+
+  if ((byte2 & 0x80) == 0 && byte3 == 0)
+    UNW_DEC_RESTORE_P(X4, qp, t, abreg, arg);
+  else
+    UNW_DEC_SPILL_REG_P(X4, qp, t, abreg, x, ytreg, arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_r1 (unsigned char *dp, unsigned char code, void *arg)
+{
+  int body = (code & 0x20) != 0;
+  unw_word rlen;
+
+  rlen = (code & 0x1f);
+  UNW_DEC_PROLOGUE(R1, body, rlen, arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_r2 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unsigned char byte1, mask, grsave;
+  unw_word rlen;
+
+  byte1 = *dp++;
+
+  mask = ((code & 0x7) << 1) | ((byte1 >> 7) & 1);
+  grsave = (byte1 & 0x7f);
+  rlen = unw_decode_uleb128 (&dp);
+  UNW_DEC_PROLOGUE_GR(R2, rlen, mask, grsave, arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_r3 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unw_word rlen;
+
+  rlen = unw_decode_uleb128 (&dp);
+  UNW_DEC_PROLOGUE(R3, ((code & 0x3) == 1), rlen, arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_p1 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unsigned char brmask = (code & 0x1f);
+
+  UNW_DEC_BR_MEM(P1, brmask, arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_p2_p5 (unsigned char *dp, unsigned char code, void *arg)
+{
+  if ((code & 0x10) == 0)
+    {
+      unsigned char byte1 = *dp++;
+
+      UNW_DEC_BR_GR(P2, ((code & 0xf) << 1) | ((byte1 >> 7) & 1),
+                   (byte1 & 0x7f), arg);
+    }
+  else if ((code & 0x08) == 0)
+    {
+      unsigned char byte1 = *dp++, r, dst;
+
+      r = ((code & 0x7) << 1) | ((byte1 >> 7) & 1);
+      dst = (byte1 & 0x7f);
+      switch (r)
+       {
+       case 0: UNW_DEC_REG_GR(P3, UNW_REG_PSP, dst, arg); break;
+       case 1: UNW_DEC_REG_GR(P3, UNW_REG_RP, dst, arg); break;
+       case 2: UNW_DEC_REG_GR(P3, UNW_REG_PFS, dst, arg); break;
+       case 3: UNW_DEC_REG_GR(P3, UNW_REG_PR, dst, arg); break;
+       case 4: UNW_DEC_REG_GR(P3, UNW_REG_UNAT, dst, arg); break;
+       case 5: UNW_DEC_REG_GR(P3, UNW_REG_LC, dst, arg); break;
+       case 6: UNW_DEC_RP_BR(P3, dst, arg); break;
+       case 7: UNW_DEC_REG_GR(P3, UNW_REG_RNAT, dst, arg); break;
+       case 8: UNW_DEC_REG_GR(P3, UNW_REG_BSP, dst, arg); break;
+       case 9: UNW_DEC_REG_GR(P3, UNW_REG_BSPSTORE, dst, arg); break;
+       case 10: UNW_DEC_REG_GR(P3, UNW_REG_FPSR, dst, arg); break;
+       case 11: UNW_DEC_PRIUNAT_GR(P3, dst, arg); break;
+       default: UNW_DEC_BAD_CODE(r); break;
+       }
+    }
+  else if ((code & 0x7) == 0)
+    UNW_DEC_SPILL_MASK(P4, dp, arg);
+  else if ((code & 0x7) == 1)
+    {
+      unw_word grmask, frmask, byte1, byte2, byte3;
+
+      byte1 = *dp++; byte2 = *dp++; byte3 = *dp++;
+      grmask = ((byte1 >> 4) & 0xf);
+      frmask = ((byte1 & 0xf) << 16) | (byte2 << 8) | byte3;
+      UNW_DEC_FRGR_MEM(P5, grmask, frmask, arg);
+    }
+  else
+    UNW_DEC_BAD_CODE(code);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_p6 (unsigned char *dp, unsigned char code, void *arg)
+{
+  int gregs = (code & 0x10) != 0;
+  unsigned char mask = (code & 0x0f);
+
+  if (gregs)
+    UNW_DEC_GR_MEM(P6, mask, arg);
+  else
+    UNW_DEC_FR_MEM(P6, mask, arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_p7_p10 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unsigned char r, byte1, byte2;
+  unw_word t, size;
+
+  if ((code & 0x10) == 0)
+    {
+      r = (code & 0xf);
+      t = unw_decode_uleb128 (&dp);
+      switch (r)
+       {
+       case 0:
+         size = unw_decode_uleb128 (&dp);
+         UNW_DEC_MEM_STACK_F(P7, t, size, arg);
+         break;
+
+       case 1: UNW_DEC_MEM_STACK_V(P7, t, arg); break;
+       case 2: UNW_DEC_SPILL_BASE(P7, t, arg); break;
+       case 3: UNW_DEC_REG_SPREL(P7, UNW_REG_PSP, t, arg); break;
+       case 4: UNW_DEC_REG_WHEN(P7, UNW_REG_RP, t, arg); break;
+       case 5: UNW_DEC_REG_PSPREL(P7, UNW_REG_RP, t, arg); break;
+       case 6: UNW_DEC_REG_WHEN(P7, UNW_REG_PFS, t, arg); break;
+       case 7: UNW_DEC_REG_PSPREL(P7, UNW_REG_PFS, t, arg); break;
+       case 8: UNW_DEC_REG_WHEN(P7, UNW_REG_PR, t, arg); break;
+       case 9: UNW_DEC_REG_PSPREL(P7, UNW_REG_PR, t, arg); break;
+       case 10: UNW_DEC_REG_WHEN(P7, UNW_REG_LC, t, arg); break;
+       case 11: UNW_DEC_REG_PSPREL(P7, UNW_REG_LC, t, arg); break;
+       case 12: UNW_DEC_REG_WHEN(P7, UNW_REG_UNAT, t, arg); break;
+       case 13: UNW_DEC_REG_PSPREL(P7, UNW_REG_UNAT, t, arg); break;
+       case 14: UNW_DEC_REG_WHEN(P7, UNW_REG_FPSR, t, arg); break;
+       case 15: UNW_DEC_REG_PSPREL(P7, UNW_REG_FPSR, t, arg); break;
+       default: UNW_DEC_BAD_CODE(r); break;
+       }
+    }
+  else
+    {
+      switch (code & 0xf)
+       {
+       case 0x0: /* p8 */
+         {
+           r = *dp++;
+           t = unw_decode_uleb128 (&dp);
+           switch (r)
+             {
+             case  1: UNW_DEC_REG_SPREL(P8, UNW_REG_RP, t, arg); break;
+             case  2: UNW_DEC_REG_SPREL(P8, UNW_REG_PFS, t, arg); break;
+             case  3: UNW_DEC_REG_SPREL(P8, UNW_REG_PR, t, arg); break;
+             case  4: UNW_DEC_REG_SPREL(P8, UNW_REG_LC, t, arg); break;
+             case  5: UNW_DEC_REG_SPREL(P8, UNW_REG_UNAT, t, arg); break;
+             case  6: UNW_DEC_REG_SPREL(P8, UNW_REG_FPSR, t, arg); break;
+             case  7: UNW_DEC_REG_WHEN(P8, UNW_REG_BSP, t, arg); break;
+             case  8: UNW_DEC_REG_PSPREL(P8, UNW_REG_BSP, t, arg); break;
+             case  9: UNW_DEC_REG_SPREL(P8, UNW_REG_BSP, t, arg); break;
+             case 10: UNW_DEC_REG_WHEN(P8, UNW_REG_BSPSTORE, t, arg); break;
+             case 11: UNW_DEC_REG_PSPREL(P8, UNW_REG_BSPSTORE, t, arg); break;
+             case 12: UNW_DEC_REG_SPREL(P8, UNW_REG_BSPSTORE, t, arg); break;
+             case 13: UNW_DEC_REG_WHEN(P8, UNW_REG_RNAT, t, arg); break;
+             case 14: UNW_DEC_REG_PSPREL(P8, UNW_REG_RNAT, t, arg); break;
+             case 15: UNW_DEC_REG_SPREL(P8, UNW_REG_RNAT, t, arg); break;
+             case 16: UNW_DEC_PRIUNAT_WHEN_GR(P8, t, arg); break;
+             case 17: UNW_DEC_PRIUNAT_PSPREL(P8, t, arg); break;
+             case 18: UNW_DEC_PRIUNAT_SPREL(P8, t, arg); break;
+             case 19: UNW_DEC_PRIUNAT_WHEN_MEM(P8, t, arg); break;
+             default: UNW_DEC_BAD_CODE(r); break;
+           }
+         }
+         break;
+
+       case 0x1:
+         byte1 = *dp++; byte2 = *dp++;
+         UNW_DEC_GR_GR(P9, (byte1 & 0xf), (byte2 & 0x7f), arg);
+         break;
+
+       case 0xf: /* p10 */
+         byte1 = *dp++; byte2 = *dp++;
+         UNW_DEC_ABI(P10, byte1, byte2, arg);
+         break;
+
+       case 0x9:
+         return unw_decode_x1 (dp, code, arg);
+
+       case 0xa:
+         return unw_decode_x2 (dp, code, arg);
+
+       case 0xb:
+         return unw_decode_x3 (dp, code, arg);
+
+       case 0xc:
+         return unw_decode_x4 (dp, code, arg);
+
+       default:
+         UNW_DEC_BAD_CODE(code);
+         break;
+       }
+    }
+  return dp;
+}
+
+static unsigned char *
+unw_decode_b1 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unw_word label = (code & 0x1f);
+
+  if ((code & 0x20) != 0)
+    UNW_DEC_COPY_STATE(B1, label, arg);
+  else
+    UNW_DEC_LABEL_STATE(B1, label, arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_b2 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unw_word t;
+
+  t = unw_decode_uleb128 (&dp);
+  UNW_DEC_EPILOGUE(B2, t, (code & 0x1f), arg);
+  return dp;
+}
+
+static unsigned char *
+unw_decode_b3_x4 (unsigned char *dp, unsigned char code, void *arg)
+{
+  unw_word t, ecount, label;
+
+  if ((code & 0x10) == 0)
+    {
+      t = unw_decode_uleb128 (&dp);
+      ecount = unw_decode_uleb128 (&dp);
+      UNW_DEC_EPILOGUE(B3, t, ecount, arg);
+    }
+  else if ((code & 0x07) == 0)
+    {
+      label = unw_decode_uleb128 (&dp);
+      if ((code & 0x08) != 0)
+       UNW_DEC_COPY_STATE(B4, label, arg);
+      else
+       UNW_DEC_LABEL_STATE(B4, label, arg);
+    }
+  else
+    switch (code & 0x7)
+      {
+      case 1: return unw_decode_x1 (dp, code, arg);
+      case 2: return unw_decode_x2 (dp, code, arg);
+      case 3: return unw_decode_x3 (dp, code, arg);
+      case 4: return unw_decode_x4 (dp, code, arg);
+      default: UNW_DEC_BAD_CODE(code); break;
+      }
+  return dp;
+}
+
+typedef unsigned char *(*unw_decoder) (unsigned char *, unsigned char, void *);
+
+static unw_decoder unw_decode_table[2][8] =
+{
+  /* prologue table: */
+  {
+    unw_decode_r1,     /* 0 */
+    unw_decode_r1,
+    unw_decode_r2,
+    unw_decode_r3,
+    unw_decode_p1,     /* 4 */
+    unw_decode_p2_p5,
+    unw_decode_p6,
+    unw_decode_p7_p10
+  },
+  {
+    unw_decode_r1,     /* 0 */
+    unw_decode_r1,
+    unw_decode_r2,
+    unw_decode_r3,
+    unw_decode_b1,     /* 4 */
+    unw_decode_b1,
+    unw_decode_b2,
+    unw_decode_b3_x4
+  }
+};
+
+/*
+ * Decode one descriptor and return address of next descriptor.
+ */
+static inline unsigned char *
+unw_decode (unsigned char *dp, int inside_body, void *arg)
+{
+  unw_decoder decoder;
+  unsigned char code;
+
+  code = *dp++;
+  decoder = unw_decode_table[inside_body][code >> 5];
+  dp = (*decoder) (dp, code, arg);
+  return dp;
+}
diff -r f218e6ba2653 -r df6a9e0d7e05 xen/arch/ia64/linux-xen/unwind_i.h
--- /dev/null   Thu Jan  1 00:00:00 1970 +0000
+++ b/xen/arch/ia64/linux-xen/unwind_i.h        Wed Dec 28 15:19:56 2005 +0900
@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2000, 2002-2003 Hewlett-Packard Co
+ *     David Mosberger-Tang <davidm@xxxxxxxxxx>
+ *
+ * Kernel unwind support.
+ */
+
+#define UNW_VER(x)             ((x) >> 48)
+#define UNW_FLAG_MASK          0x0000ffff00000000
+#define UNW_FLAG_OSMASK                0x0000f00000000000
+#define UNW_FLAG_EHANDLER(x)   ((x) & 0x0000000100000000L)
+#define UNW_FLAG_UHANDLER(x)   ((x) & 0x0000000200000000L)
+#define UNW_LENGTH(x)          ((x) & 0x00000000ffffffffL)
+
+enum unw_register_index {
+       /* primary unat: */
+       UNW_REG_PRI_UNAT_GR,
+       UNW_REG_PRI_UNAT_MEM,
+
+       /* register stack */
+       UNW_REG_BSP,                                    /* register stack 
pointer */
+       UNW_REG_BSPSTORE,
+       UNW_REG_PFS,                                    /* previous function 
state */
+       UNW_REG_RNAT,
+       /* memory stack */
+       UNW_REG_PSP,                                    /* previous memory 
stack pointer */
+       /* return pointer: */
+       UNW_REG_RP,
+
+       /* preserved registers: */
+       UNW_REG_R4, UNW_REG_R5, UNW_REG_R6, UNW_REG_R7,
+       UNW_REG_UNAT, UNW_REG_PR, UNW_REG_LC, UNW_REG_FPSR,
+       UNW_REG_B1, UNW_REG_B2, UNW_REG_B3, UNW_REG_B4, UNW_REG_B5,
+       UNW_REG_F2, UNW_REG_F3, UNW_REG_F4, UNW_REG_F5,
+       UNW_REG_F16, UNW_REG_F17, UNW_REG_F18, UNW_REG_F19,
+       UNW_REG_F20, UNW_REG_F21, UNW_REG_F22, UNW_REG_F23,
+       UNW_REG_F24, UNW_REG_F25, UNW_REG_F26, UNW_REG_F27,
+       UNW_REG_F28, UNW_REG_F29, UNW_REG_F30, UNW_REG_F31,
+       UNW_NUM_REGS
+};
+
+struct unw_info_block {
+       u64 header;
+       u64 desc[0];            /* unwind descriptors */
+       /* personality routine and language-specific data follow behind 
descriptors */
+};
+
+struct unw_table {
+       struct unw_table *next;         /* must be first member! */
+       const char *name;
+       unsigned long gp;               /* global pointer for this load-module 
*/
+       unsigned long segment_base;     /* base for offsets in the unwind table 
entries */
+       unsigned long start;
+       unsigned long end;
+       const struct unw_table_entry *array;
+       unsigned long length;
+};
+
+enum unw_where {
+       UNW_WHERE_NONE,                 /* register isn't saved at all */
+       UNW_WHERE_GR,                   /* register is saved in a general 
register */
+       UNW_WHERE_FR,                   /* register is saved in a 
floating-point register */
+       UNW_WHERE_BR,                   /* register is saved in a branch 
register */
+       UNW_WHERE_SPREL,                /* register is saved on memstack 
(sp-relative) */
+       UNW_WHERE_PSPREL,               /* register is saved on memstack 
(psp-relative) */
+       /*
+        * At the end of each prologue these locations get resolved to
+        * UNW_WHERE_PSPREL and UNW_WHERE_GR, respectively:
+        */
+       UNW_WHERE_SPILL_HOME,           /* register is saved in its spill home 
*/
+       UNW_WHERE_GR_SAVE               /* register is saved in next general 
register */
+};
+
+#define UNW_WHEN_NEVER 0x7fffffff
+
+struct unw_reg_info {
+       unsigned long val;              /* save location: register number or 
offset */
+       enum unw_where where;           /* where the register gets saved */
+       int when;                       /* when the register gets saved */
+};
+
+struct unw_reg_state {
+       struct unw_reg_state *next;             /* next (outer) element on 
state stack */
+       struct unw_reg_info reg[UNW_NUM_REGS];  /* register save locations */
+};
+
+struct unw_labeled_state {
+       struct unw_labeled_state *next;         /* next labeled state (or NULL) 
*/
+       unsigned long label;                    /* label for this state */
+       struct unw_reg_state saved_state;
+};
+
+struct unw_state_record {
+       unsigned int first_region : 1;  /* is this the first region? */
+       unsigned int done : 1;          /* are we done scanning descriptors? */
+       unsigned int any_spills : 1;    /* got any register spills? */
+       unsigned int in_body : 1;       /* are we inside a body (as opposed to 
a prologue)? */
+       unsigned long flags;            /* see UNW_FLAG_* in unwind.h */
+
+       u8 *imask;                      /* imask of spill_mask record or NULL */
+       unsigned long pr_val;           /* predicate values */
+       unsigned long pr_mask;          /* predicate mask */
+       long spill_offset;              /* psp-relative offset for spill base */
+       int region_start;
+       int region_len;
+       int epilogue_start;
+       int epilogue_count;
+       int when_target;
+
+       u8 gr_save_loc;                 /* next general register to use for 
saving a register */
+       u8 return_link_reg;             /* branch register in which the return 
link is passed */
+
+       struct unw_labeled_state *labeled_states;       /* list of all labeled 
states */
+       struct unw_reg_state curr;      /* current state */
+};
+
+enum unw_nat_type {
+       UNW_NAT_NONE,           /* NaT not represented */
+       UNW_NAT_VAL,            /* NaT represented by NaT value (fp reg) */
+       UNW_NAT_MEMSTK,         /* NaT value is in unat word at offset OFF  */
+       UNW_NAT_REGSTK          /* NaT is in rnat */
+};
+
+enum unw_insn_opcode {
+       UNW_INSN_ADD,                   /* s[dst] += val */
+       UNW_INSN_ADD_PSP,               /* s[dst] = (s.psp + val) */
+       UNW_INSN_ADD_SP,                /* s[dst] = (s.sp + val) */
+       UNW_INSN_MOVE,                  /* s[dst] = s[val] */
+       UNW_INSN_MOVE2,                 /* s[dst] = s[val]; s[dst+1] = s[val+1] 
*/
+       UNW_INSN_MOVE_STACKED,          /* s[dst] = ia64_rse_skip(*s.bsp, val) 
*/
+       UNW_INSN_SETNAT_MEMSTK,         /* s[dst+1].nat.type = MEMSTK;
+                                          s[dst+1].nat.off = *s.pri_unat - 
s[dst] */
+       UNW_INSN_SETNAT_TYPE,           /* s[dst+1].nat.type = val */
+       UNW_INSN_LOAD,                  /* s[dst] = *s[val] */
+       UNW_INSN_MOVE_SCRATCH,          /* s[dst] = scratch reg "val" */
+       UNW_INSN_MOVE_CONST,            /* s[dst] = constant reg "val" */
+};
+
+struct unw_insn {
+       unsigned int opc        :  4;
+       unsigned int dst        :  9;
+       signed int val          : 19;
+};
+
+/*
+ * Preserved general static registers (r4-r7) give rise to two script
+ * instructions; everything else yields at most one instruction; at
+ * the end of the script, the psp gets popped, accounting for one more
+ * instruction.
+ */
+#define UNW_MAX_SCRIPT_LEN     (UNW_NUM_REGS + 5)
+
+struct unw_script {
+       unsigned long ip;               /* ip this script is for */
+       unsigned long pr_mask;          /* mask of predicates script depends on 
*/
+       unsigned long pr_val;           /* predicate values this script is for 
*/
+       rwlock_t lock;
+       unsigned int flags;             /* see UNW_FLAG_* in unwind.h */
+       unsigned short lru_chain;       /* used for least-recently-used chain */
+       unsigned short coll_chain;      /* used for hash collisions */
+       unsigned short hint;            /* hint for next script to try (or -1) 
*/
+       unsigned short count;           /* number of instructions in script */
+       struct unw_insn insn[UNW_MAX_SCRIPT_LEN];
+};
diff -r f218e6ba2653 -r df6a9e0d7e05 xen/include/asm-ia64/linux-xen/asm/unwind.h
--- /dev/null   Thu Jan  1 00:00:00 1970 +0000
+++ b/xen/include/asm-ia64/linux-xen/asm/unwind.h       Wed Dec 28 15:19:56 
2005 +0900
@@ -0,0 +1,233 @@
+#ifndef _ASM_IA64_UNWIND_H
+#define _ASM_IA64_UNWIND_H
+
+/*
+ * Copyright (C) 1999-2000, 2003 Hewlett-Packard Co
+ *     David Mosberger-Tang <davidm@xxxxxxxxxx>
+ *
+ * A simple API for unwinding kernel stacks.  This is used for
+ * debugging and error reporting purposes.  The kernel doesn't need
+ * full-blown stack unwinding with all the bells and whitles, so there
+ * is not much point in implementing the full IA-64 unwind API (though
+ * it would of course be possible to implement the kernel API on top
+ * of it).
+ */
+
+struct task_struct;    /* forward declaration */
+struct switch_stack;   /* forward declaration */
+
+enum unw_application_register {
+       UNW_AR_BSP,
+       UNW_AR_BSPSTORE,
+       UNW_AR_PFS,
+       UNW_AR_RNAT,
+       UNW_AR_UNAT,
+       UNW_AR_LC,
+       UNW_AR_EC,
+       UNW_AR_FPSR,
+       UNW_AR_RSC,
+       UNW_AR_CCV,
+       UNW_AR_CSD,
+       UNW_AR_SSD
+};
+
+/*
+ * The following declarations are private to the unwind
+ * implementation:
+ */
+
+struct unw_stack {
+       unsigned long limit;
+       unsigned long top;
+};
+
+#define UNW_FLAG_INTERRUPT_FRAME       (1UL << 0)
+
+/*
+ * No user of this module should every access this structure directly
+ * as it is subject to change.  It is declared here solely so we can
+ * use automatic variables.
+ */
+struct unw_frame_info {
+       struct unw_stack regstk;
+       struct unw_stack memstk;
+       unsigned int flags;
+       short hint;
+       short prev_script;
+
+       /* current frame info: */
+       unsigned long bsp;              /* backing store pointer value */
+       unsigned long sp;               /* stack pointer value */
+       unsigned long psp;              /* previous sp value */
+       unsigned long ip;               /* instruction pointer value */
+       unsigned long pr;               /* current predicate values */
+       unsigned long *cfm_loc;         /* cfm save location (or NULL) */
+       unsigned long pt;               /* struct pt_regs location */
+
+       struct task_struct *task;
+       struct switch_stack *sw;
+
+       /* preserved state: */
+       unsigned long *bsp_loc;         /* previous bsp save location */
+       unsigned long *bspstore_loc;
+       unsigned long *pfs_loc;
+       unsigned long *rnat_loc;
+       unsigned long *rp_loc;
+       unsigned long *pri_unat_loc;
+       unsigned long *unat_loc;
+       unsigned long *pr_loc;
+       unsigned long *lc_loc;
+       unsigned long *fpsr_loc;
+       struct unw_ireg {
+               unsigned long *loc;
+               struct unw_ireg_nat {
+                       long type : 3;                  /* enum unw_nat_type */
+                       signed long off : 61;           /* NaT word is at 
loc+nat.off */
+               } nat;
+       } r4, r5, r6, r7;
+       unsigned long *b1_loc, *b2_loc, *b3_loc, *b4_loc, *b5_loc;
+       struct ia64_fpreg *f2_loc, *f3_loc, *f4_loc, *f5_loc, *fr_loc[16];
+};
+
+/*
+ * The official API follows below:
+ */
+
+struct unw_table_entry {
+       u64 start_offset;
+       u64 end_offset;
+       u64 info_offset;
+};
+
+/*
+ * Initialize unwind support.
+ */
+extern void unw_init (void);
+
+extern void *unw_add_unwind_table (const char *name, unsigned long 
segment_base, unsigned long gp,
+                                  const void *table_start, const void 
*table_end);
+
+extern void unw_remove_unwind_table (void *handle);
+
+/*
+ * Prepare to unwind blocked task t.
+ */
+extern void unw_init_from_blocked_task (struct unw_frame_info *info, struct 
task_struct *t);
+
+extern void unw_init_frame_info (struct unw_frame_info *info, struct 
task_struct *t,
+                                struct switch_stack *sw);
+
+/*
+ * Prepare to unwind the currently running thread.
+ */
+extern void unw_init_running (void (*callback)(struct unw_frame_info *info, 
void *arg), void *arg);
+
+/*
+ * Unwind to previous to frame.  Returns 0 if successful, negative
+ * number in case of an error.
+ */
+extern int unw_unwind (struct unw_frame_info *info);
+
+/*
+ * Unwind until the return pointer is in user-land (or until an error
+ * occurs).  Returns 0 if successful, negative number in case of
+ * error.
+ */
+extern int unw_unwind_to_user (struct unw_frame_info *info);
+
+#define unw_is_intr_frame(info)        (((info)->flags & 
UNW_FLAG_INTERRUPT_FRAME) != 0)
+
+static inline int
+unw_get_ip (struct unw_frame_info *info, unsigned long *valp)
+{
+       *valp = (info)->ip;
+       return 0;
+}
+
+static inline int
+unw_get_sp (struct unw_frame_info *info, unsigned long *valp)
+{
+       *valp = (info)->sp;
+       return 0;
+}
+
+static inline int
+unw_get_psp (struct unw_frame_info *info, unsigned long *valp)
+{
+       *valp = (info)->psp;
+       return 0;
+}
+
+static inline int
+unw_get_bsp (struct unw_frame_info *info, unsigned long *valp)
+{
+       *valp = (info)->bsp;
+       return 0;
+}
+
+static inline int
+unw_get_cfm (struct unw_frame_info *info, unsigned long *valp)
+{
+       *valp = *(info)->cfm_loc;
+       return 0;
+}
+
+static inline int
+unw_set_cfm (struct unw_frame_info *info, unsigned long val)
+{
+       *(info)->cfm_loc = val;
+       return 0;
+}
+
+static inline int
+unw_get_rp (struct unw_frame_info *info, unsigned long *val)
+{
+       if (!info->rp_loc)
+               return -1;
+       *val = *info->rp_loc;
+       return 0;
+}
+
+extern int unw_access_gr (struct unw_frame_info *, int, unsigned long *, char 
*, int);
+extern int unw_access_br (struct unw_frame_info *, int, unsigned long *, int);
+extern int unw_access_fr (struct unw_frame_info *, int, struct ia64_fpreg *, 
int);
+extern int unw_access_ar (struct unw_frame_info *, int, unsigned long *, int);
+extern int unw_access_pr (struct unw_frame_info *, unsigned long *, int);
+
+static inline int
+unw_set_gr (struct unw_frame_info *i, int n, unsigned long v, char nat)
+{
+       return unw_access_gr(i, n, &v, &nat, 1);
+}
+
+static inline int
+unw_set_br (struct unw_frame_info *i, int n, unsigned long v)
+{
+       return unw_access_br(i, n, &v, 1);
+}
+
+static inline int
+unw_set_fr (struct unw_frame_info *i, int n, struct ia64_fpreg v)
+{
+       return unw_access_fr(i, n, &v, 1);
+}
+
+static inline int
+unw_set_ar (struct unw_frame_info *i, int n, unsigned long v)
+{
+       return unw_access_ar(i, n, &v, 1);
+}
+
+static inline int
+unw_set_pr (struct unw_frame_info *i, unsigned long v)
+{
+       return unw_access_pr(i, &v, 1);
+}
+
+#define unw_get_gr(i,n,v,nat)  unw_access_gr(i,n,v,nat,0)
+#define unw_get_br(i,n,v)      unw_access_br(i,n,v,0)
+#define unw_get_fr(i,n,v)      unw_access_fr(i,n,v,0)
+#define unw_get_ar(i,n,v)      unw_access_ar(i,n,v,0)
+#define unw_get_pr(i,v)                unw_access_pr(i,v,0)
+
+#endif /* _ASM_UNWIND_H */

-- 
yamahata

_______________________________________________
Xen-ia64-devel mailing list
Xen-ia64-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-ia64-devel

<Prev in Thread] Current Thread [Next in Thread>
  • [Xen-ia64-devel] [PATCH] [1/6] panic stack trace: import stack unwind files from Linux, Isaku Yamahata <=