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authorAndi Kleen <ak@suse.de>2006-09-26 10:52:34 +0200
committerAndi Kleen <andi@basil.nowhere.org>2006-09-26 10:52:34 +0200
commitb7f5e3c7742d5332b78b831131f43fc3630e6322 (patch)
tree4334c97a3a8e2ac409444ecb2d7844d3a63e4118 /arch
parent3fa7c794fe4dc127f7fac3fad4d13628e68f89ce (diff)
[PATCH] Don't access the APIC in safe_smp_processor_id when it is not mapped yet
Lockdep can call the dwarf2 unwinder early, and the dwarf2 code uses safe_smp_processor_id which tries to access the local APIC page. But that doesn't work before the APIC code has set up its fixmap. Check for this case and always return boot cpu then. Cc: jbeulich@novell.com Cc: mingo@elte.hu Signed-off-by: Andi Kleen <ak@suse.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86_64/kernel/apic.c2
-rw-r--r--arch/x86_64/kernel/smp.c2
2 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index b95d1e378b9..6472e321cad 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -38,6 +38,7 @@
#include <asm/timex.h>
#include <asm/apic.h>
+int apic_mapped;
int apic_verbosity;
int apic_runs_main_timer;
int apic_calibrate_pmtmr __initdata;
@@ -600,6 +601,7 @@ void __init init_apic_mappings(void)
apic_phys = mp_lapic_addr;
set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
+ apic_mapped = 1;
apic_printk(APIC_VERBOSE,"mapped APIC to %16lx (%16lx)\n", APIC_BASE, apic_phys);
/*
diff --git a/arch/x86_64/kernel/smp.c b/arch/x86_64/kernel/smp.c
index 06af6ca6012..2df988bbf31 100644
--- a/arch/x86_64/kernel/smp.c
+++ b/arch/x86_64/kernel/smp.c
@@ -526,7 +526,7 @@ int safe_smp_processor_id(void)
{
unsigned apicid, i;
- if (disable_apic)
+ if (disable_apic || !apic_mapped)
return 0;
apicid = hard_smp_processor_id();