korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-12 05:48:39 +08:00
Code Issues Packages Projects Releases Wiki Activity

[IA64] Tighten up unw_unwind_to_user check

Browse Source 
Detect user space by the unwind frame with predicate PRED_USER_STACK
set, instead of a user space IP.  Tighten up the last ditch check for
running off the top of the kernel stack.

Based on a suggestion by David Mosberger, reworked to fit the current
tree.  This survives my stress test which used to break 2.6.9 kernels.
Unlike 2.6.11, the stress test now unwinds to the correct point, so
gdb can get the user space registers.

Signed-off-by: Keith Owens <kaos@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This commit is contained in:
Keith Owens 2005-04-25 11:45:26 -07:00 committed by Tony Luck
parent 8297511530
commit e8d1cb2f28
1 changed files with 18 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
arch/ia64/kernel/unwind.c
View File

@ -1943,23 +1943,30 @@ EXPORT_SYMBOL(unw_unwind);
int
unw_unwind_to_user (struct unw_frame_info *info)
{
unsigned long ip, sp;
unsigned long ip, sp, pr = 0;
while (unw_unwind(info) >= 0) {
if (unw_get_rp(info, &ip) < 0) {
unw_get_ip(info, &ip);
UNW_DPRINT(0, "unwind.%s: failed to read return pointer (ip=0x%lx)\n",
__FUNCTION__, ip);
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_sp(info, &sp);
if (sp >= (unsigned long)info->task + IA64_STK_OFFSET)
break;
if (ip < FIXADDR_USER_END)
return 0;
}
unw_get_ip(info, &ip);
UNW_DPRINT(0, "unwind.%s: failed to unwind to user-level (ip=0x%lx)\n", __FUNCTION__, 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);