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[IA64] Improve unwind checking.

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This patch adds some sanity checks to keep register and memory stack
pointers in the unw_frame_info structure within the tasks stack address
range.

Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Robin Holt 2007-05-18 13:46:23 -05:00 committed by Tony Luck
parent a8c8be08e0
commit e2e6fe7bb6
1 changed files with 14 additions and 7 deletions
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21
arch/ia64/kernel/unwind.c
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@ -1860,7 +1860,7 @@ int
unw_unwind (struct unw_frame_info *info)
{
unsigned long prev_ip, prev_sp, prev_bsp;
unsigned long ip, pr, num_regs;
unsigned long ip, pr, num_regs, rp_loc, pfs_loc;
STAT(unsigned long start, flags;)
int retval;
@ -1870,14 +1870,16 @@ 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 */
rp_loc = (unsigned long) info->rp_loc;
if ((rp_loc < info->regstk.limit) || (rp_loc > info->regstk.top)) {
/* 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 +1887,14 @@ unw_unwind (struct unw_frame_info *info)
return -1;
}
/* restore the cfm: */
if (!info->pfs_loc) {
/* validate the previous stack frame pointer */
pfs_loc = (unsigned long) info->pfs_loc;
if ((pfs_loc < info->regstk.limit) || (pfs_loc > info->regstk.top)) {
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 +1996,16 @@ 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;