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authorCliff Wickman <cpw@sgi.com>2010-07-20 18:09:05 -0500
committerH. Peter Anvin <hpa@linux.intel.com>2010-07-21 11:33:27 -0700
commit5edd19af18a36a4e22c570b1b969179e0ca1fe4c (patch)
treead4c52f24218c1358d8e8ea51d2ce23a20c37d68 /arch/x86/kernel/crash.c
parent93a7ca0c3ebe5d931126f1fb732cb9c4518383d4 (diff)
x86, UV: Make kdump avoid stack dumps
UV NMI callback's should not write stack dumps when a kdump is to be written. When invoking the crash kernel to write a dump, kdump_nmi_shootdown_cpus() uses NMI's to get all the cpu's to save their register context and halt. But the NMI interrupt handler runs a callback list. This patch sets a flag to prevent any of those callbacks from interfering with the halt of the cpu. For UV, which currently has the only callback to which this is relevant, the uv_handle_nmi() callback should not do dumping of stacks. The 'in_crash_kexec' flag is defined as an extern in kdebug.h firstly because x2apic_uv_x.c includes it. Secondly because some future callback might need the flag to know that it should not enter the debugger. (Such a scenario was in fact present in the 2.6.32 kernel, SuSE distribution, where a call to kdb needed to be avoided.) Signed-off-by: Cliff Wickman <cpw@sgi.com> LKML-Reference: <E1ObLvt-0005UZ-Va@eag09.americas.sgi.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/crash.c')
-rw-r--r--arch/x86/kernel/crash.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index ebd4c51d096..764c7c2b181 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -28,6 +28,8 @@
#include <asm/reboot.h>
#include <asm/virtext.h>
+int in_crash_kexec;
+
#if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC)
static void kdump_nmi_callback(int cpu, struct die_args *args)
@@ -61,6 +63,7 @@ static void kdump_nmi_callback(int cpu, struct die_args *args)
static void kdump_nmi_shootdown_cpus(void)
{
+ in_crash_kexec = 1;
nmi_shootdown_cpus(kdump_nmi_callback);
disable_local_APIC();