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authorKeith Owens <kaos@sgi.com>2007-06-26 16:25:22 +1000
committerTony Luck <tony.luck@intel.com>2007-06-26 13:33:10 -0700
commit66fa9b107e259d01929fe647796b3021d3a83c4a (patch)
tree6fe7bde9c86a4d5dffae53ab815b34362eb19571 /arch/ia64
parent9be26f4c4b138c425598bd3cc50411bd87fce287 (diff)
downloadlinux-2.6.34-ux500-66fa9b107e259d01929fe647796b3021d3a83c4a.tar.gz
[IA64] Correct unwind validation code
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@sgi.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64')
-rw-r--r--arch/ia64/kernel/unwind.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/arch/ia64/kernel/unwind.c b/arch/ia64/kernel/unwind.c
index b0b08b5f3ec..c1bdb513181 100644
--- a/arch/ia64/kernel/unwind.c
+++ b/arch/ia64/kernel/unwind.c
@@ -1856,11 +1856,19 @@ 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)
{
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;