Both rp_loc and pfs_loc can be in the register stack area _or_ they can
be in the memory stack area, the latter occurs when a struct pt_regs is
pushed. Correct the validation check on these fields to check for both
stack areas. Not allowing for memory stack locations means no
backtrace past ia64_leave_kernel, or any other code that uses
PT_REGS_UNWIND_INFO.
Signed-off-by: Keith Owens <kaos@xxxxxxx>
---
arch/ia64/kernel/unwind.c | 16 +++++++++++-----
1 file changed, 11 insertions(+), 5 deletions(-)
Index: linux/arch/ia64/kernel/unwind.c
===================================================================
--- linux.orig/arch/ia64/kernel/unwind.c
+++ linux/arch/ia64/kernel/unwind.c
@@ -1856,11 +1856,19 @@ find_save_locs (struct unw_frame_info *i
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)
{
unsigned long prev_ip, prev_sp, prev_bsp;
- unsigned long ip, pr, num_regs, rp_loc, pfs_loc;
+ unsigned long ip, pr, num_regs;
STAT(unsigned long start, flags;)
int retval;
@@ -1871,8 +1879,7 @@ unw_unwind (struct unw_frame_info *info)
prev_bsp = info->bsp;
/* validate the return IP pointer */
- rp_loc = (unsigned long) info->rp_loc;
- if ((rp_loc < info->regstk.limit) || (rp_loc > info->regstk.top)) {
+ 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);
@@ -1888,8 +1895,7 @@ unw_unwind (struct unw_frame_info *info)
}
/* validate the previous stack frame pointer */
- pfs_loc = (unsigned long) info->pfs_loc;
- if ((pfs_loc < info->regstk.limit) || (pfs_loc > info->regstk.top)) {
+ 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;
-
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