• Hidehiro Kawai's avatar
    panic, x86: Fix re-entrance problem due to panic on NMI · 1717f209
    Hidehiro Kawai authored
    If panic on NMI happens just after panic() on the same CPU, panic() is
    recursively called. Kernel stalls, as a result, after failing to acquire
    panic_lock.
    
    To avoid this problem, don't call panic() in NMI context if we've
    already entered panic().
    
    For that, introduce nmi_panic() macro to reduce code duplication. In
    the case of panic on NMI, don't return from NMI handlers if another CPU
    already panicked.
    Signed-off-by: default avatarHidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
    Acked-by: default avatarMichal Hocko <mhocko@suse.com>
    Cc: Aaron Tomlin <atomlin@redhat.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: Baoquan He <bhe@redhat.com>
    Cc: Chris Metcalf <cmetcalf@ezchip.com>
    Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
    Cc: Don Zickus <dzickus@redhat.com>
    Cc: "Eric W. Biederman" <ebiederm@xmission.com>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: Gobinda Charan Maji <gobinda.cemk07@gmail.com>
    Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Cc: Ingo Molnar <mingo@kernel.org>
    Cc: Javi Merino <javi.merino@arm.com>
    Cc: Jonathan Corbet <corbet@lwn.net>
    Cc: kexec@lists.infradead.org
    Cc: linux-doc@vger.kernel.org
    Cc: lkml <linux-kernel@vger.kernel.org>
    Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
    Cc: Michal Nazarewicz <mina86@mina86.com>
    Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Prarit Bhargava <prarit@redhat.com>
    Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
    Cc: Rusty Russell <rusty@rustcorp.com.au>
    Cc: Seth Jennings <sjenning@redhat.com>
    Cc: Steven Rostedt <rostedt@goodmis.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: Ulrich Obergfell <uobergfe@redhat.com>
    Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
    Cc: Vivek Goyal <vgoyal@redhat.com>
    Link: http://lkml.kernel.org/r/20151210014626.25437.13302.stgit@softrs
    [ Cleanup comments, fixup formatting. ]
    Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    1717f209
watchdog.c 29 KB