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authorHidehiro Kawai <hidehiro.kawai.ez@hitachi.com>2016-10-11 23:54:23 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-12 01:06:32 +0300
commit0ee59413c967c35a6dd2dbdab605b4cd42025ee5 (patch)
treee3325918b5b8d40924eac2b3cc2f2a1f8467048a /arch/x86/kernel/smp.c
parent2b6b535d9158b822a45080b3d6d5b2993fd49e5a (diff)
downloadlinux-0ee59413c967c35a6dd2dbdab605b4cd42025ee5.tar.xz
x86/panic: replace smp_send_stop() with kdump friendly version in panic path
Daniel Walker reported problems which happens when crash_kexec_post_notifiers kernel option is enabled (https://lkml.org/lkml/2015/6/24/44). In that case, smp_send_stop() is called before entering kdump routines which assume other CPUs are still online. As the result, for x86, kdump routines fail to save other CPUs' registers and disable virtualization extensions. To fix this problem, call a new kdump friendly function, crash_smp_send_stop(), instead of the smp_send_stop() when crash_kexec_post_notifiers is enabled. crash_smp_send_stop() is a weak function, and it just call smp_send_stop(). Architecture codes should override it so that kdump can work appropriately. This patch only provides x86-specific version. For Xen's PV kernel, just keep the current behavior. NOTES: - Right solution would be to place crash_smp_send_stop() before __crash_kexec() invocation in all cases and remove smp_send_stop(), but we can't do that until all architectures implement own crash_smp_send_stop() - crash_smp_send_stop()-like work is still needed by machine_crash_shutdown() because crash_kexec() can be called without entering panic() Fixes: f06e5153f4ae (kernel/panic.c: add "crash_kexec_post_notifiers" option) Link: http://lkml.kernel.org/r/20160810080948.11028.15344.stgit@sysi4-13.yrl.intra.hitachi.co.jp Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Reported-by: Daniel Walker <dwalker@fifo99.com> Cc: Dave Young <dyoung@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Daniel Walker <dwalker@fifo99.com> Cc: Xunlei Pang <xpang@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Daney <david.daney@cavium.com> Cc: Aaro Koskinen <aaro.koskinen@iki.fi> Cc: "Steven J. Hill" <steven.hill@cavium.com> Cc: Corey Minyard <cminyard@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel/smp.c')
-rw-r--r--arch/x86/kernel/smp.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 658777cf3851..68f8cc222f25 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -32,6 +32,8 @@
#include <asm/nmi.h>
#include <asm/mce.h>
#include <asm/trace/irq_vectors.h>
+#include <asm/kexec.h>
+
/*
* Some notes on x86 processor bugs affecting SMP operation:
*
@@ -342,6 +344,9 @@ struct smp_ops smp_ops = {
.smp_cpus_done = native_smp_cpus_done,
.stop_other_cpus = native_stop_other_cpus,
+#if defined(CONFIG_KEXEC_CORE)
+ .crash_stop_other_cpus = kdump_nmi_shootdown_cpus,
+#endif
.smp_send_reschedule = native_smp_send_reschedule,
.cpu_up = native_cpu_up,