From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kirill Korotaev Date: Mon, 19 Mar 2007 10:49:04 +0000 Subject: [IA64] unwind did not work for processes born with CLONE_STOPPED Message-Id: <45FE6E34.3070207@sw.ru> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org [IA64] unwind did not work for processes born with CLONE_STOPPED Minor problem for mainstream. Big problem for CPT, because all the stopped/traced processes are born in this state, hence they cannot be checkpointed again due to failing unwind. The problem was identified as assumption in kernel unwind library that top level frame is different of syscall frame. It is the case unless process was born with CLONE_STOPPED. Author: Alexey Kuznetsov Signed-Off-By: Alexey Kuznetsov Signed-Off-By: Kirill Korotaev --- a/arch/ia64/kernel/unwind.c +++ b/arch/ia64/kernel/unwind.c @@ -60,6 +60,7 @@ #ifdef UNW_DEBUG # define UNW_DEBUG_ON(n) unw_debug_level >= n /* Do not code a printk level, not all debug lines end in newline */ # define UNW_DPRINT(n, ...) if (UNW_DEBUG_ON(n)) printk(__VA_ARGS__) +# undef inline # define inline #else /* !UNW_DEBUG */ # define UNW_DEBUG_ON(n) 0 @@ -1943,9 +1944,9 @@ EXPORT_SYMBOL(unw_unwind); int unw_unwind_to_user (struct unw_frame_info *info) { - unsigned long ip, sp, pr = 0; + unsigned long ip, sp, pr = info->pr; - while (unw_unwind(info) >= 0) { + do { unw_get_sp(info, &sp); if ((long)((unsigned long)info->task + IA64_STK_OFFSET - sp) < IA64_PT_REGS_SIZE) { @@ -1963,7 +1964,7 @@ unw_unwind_to_user (struct unw_frame_inf __FUNCTION__, ip); return -1; } - } + } while (unw_unwind(info) >= 0); unw_get_ip(info, &ip); UNW_DPRINT(0, "unwind.%s: failed to unwind to user-level (ip=0x%lx)\n", __FUNCTION__, ip);