Booting an x86_32 SMP kernel via kdump fails if the boot CPU has local
APIC ID != 0, with a panic:
Boot APIC ID in local APIC unexpected (1 vs 0)
MP_processor_info() sets boot_cpu_physical_apicid to 0 based on the
mptable. But this variable needs to be set to 1 later on to reflect the
actual local APIC ID. (Setting it to 1 right off the bat causes
generic_processor_info() to complain about an "apic version mismatch",
which I don't understand.)
This change restores the apic_64.c logic, which existed prior to the
merge with apic_32.c, and allows the kdump kernel to boot.
Signed-off-by: Ed Swierk <[email protected]>
---
arch/x86/kernel/apic/apic.c | 3 +--
1 files changed, 1 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index f287092..b45c764 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1563,8 +1563,7 @@ void __init init_apic_mappings(void)
* Fetch the APIC ID of the BSP in case we have a
* default configuration (or the MP table is broken).
*/
- if (boot_cpu_physical_apicid == -1U)
- boot_cpu_physical_apicid = read_apic_id();
+ boot_cpu_physical_apicid = read_apic_id();
}
/*