From e8d1cb2f280aa53e1c75c8b5fcbf80b3481d0caa Mon Sep 17 00:00:00 2001 From: Keith Owens Date: Mon, 25 Apr 2005 11:45:26 -0700 Subject: [IA64] Tighten up unw_unwind_to_user check 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 Signed-off-by: Tony Luck --- arch/ia64/kernel/unwind.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) (limited to 'arch/ia64') diff --git a/arch/ia64/kernel/unwind.c b/arch/ia64/kernel/unwind.c index d494ff647cac..2776a074c6f1 100644 --- a/arch/ia64/kernel/unwind.c +++ b/arch/ia64/kernel/unwind.c @@ -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); - return -1; - } unw_get_sp(info, &sp); - if (sp >= (unsigned long)info->task + IA64_STK_OFFSET) + 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 (ip < FIXADDR_USER_END) + } + 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_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); -- cgit v1.2.3