Pull acpi-debug into release branch

[linux-2.6-omap-h63xx.git] / arch / ia64 / kernel / unwind.c

diff --git a/arch/ia64/kernel/unwind.c b/arch/ia64/kernel/unwind.c
index fe1426266b9bf3092191c83183e174e746a58684..c1bdb5131814c8f9f24e01cc51eae54e4df35666 100644 (file)
--- a/arch/ia64/kernel/unwind.c
+++ b/arch/ia64/kernel/unwind.c
@@ -2,7 +2,7 @@
  * Copyright (C) 1999-2004 Hewlett-Packard Co
  *     David Mosberger-Tang <davidm@hpl.hp.com>
  * Copyright (C) 2003 Fenghua Yu <fenghua.yu@intel.com>
- *     - Change pt_regs_off() to make it less dependant on pt_regs structure.
+ *     - Change pt_regs_off() to make it less dependent on pt_regs structure.
  */
 /*
  * This file implements call frame unwind support for the Linux
@@ -1856,6 +1856,14 @@ find_save_locs (struct unw_frame_info *info)
        return 0;
 }
 
+static int
+unw_valid(const struct unw_frame_info *info, unsigned long* p)
+{
+       unsigned long loc = (unsigned long)p;
+       return (loc >= info->regstk.limit && loc < info->regstk.top) ||
+              (loc >= info->memstk.top && loc < info->memstk.limit);
+}
+
 int
 unw_unwind (struct unw_frame_info *info)
 {
@@ -1870,14 +1878,15 @@ unw_unwind (struct unw_frame_info *info)
        prev_sp = info->sp;
        prev_bsp = info->bsp;
 
-       /* restore the ip */
-       if (!info->rp_loc) {
+       /* validate the return IP pointer */
+       if (!unw_valid(info, 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;
        }
+       /* restore the ip */
        ip = info->ip = *info->rp_loc;
        if (ip < GATE_ADDR) {
                UNW_DPRINT(2, "unwind.%s: reached user-space (ip=0x%lx)\n", __FUNCTION__, ip);
@@ -1885,12 +1894,13 @@ unw_unwind (struct unw_frame_info *info)
                return -1;
        }
 
-       /* restore the cfm: */
-       if (!info->pfs_loc) {
+       /* validate the previous stack frame pointer */
+       if (!unw_valid(info, 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;
        }
+       /* restore the cfm: */
        info->cfm_loc = info->pfs_loc;
 
        /* restore the bsp: */
@@ -1992,13 +2002,16 @@ init_frame_info (struct unw_frame_info *info, struct task_struct *t,
        memset(info, 0, sizeof(*info));
 
        rbslimit = (unsigned long) t + IA64_RBS_OFFSET;
+       stklimit = (unsigned long) t + IA64_STK_OFFSET;
+
        rbstop   = sw->ar_bspstore;
-       if (rbstop - (unsigned long) t >= IA64_STK_OFFSET)
+       if (rbstop > stklimit || rbstop < rbslimit)
                rbstop = rbslimit;
 
-       stklimit = (unsigned long) t + IA64_STK_OFFSET;
        if (stktop <= rbstop)
                stktop = rbstop;
+       if (stktop > stklimit)
+               stktop = stklimit;
 
        info->regstk.limit = rbslimit;
        info->regstk.top   = rbstop;