Commit-ID: 0c524f819683e9f1c165d571256a9023b56f1f0c
Gitweb: http://git.kernel.org/tip/0c524f819683e9f1c165d571256a9023b56f1f0c
Author: Thomas Gleixner <[email protected]>
AuthorDate: Sat, 29 Oct 2016 13:42:42 +0200
Committer: Thomas Gleixner <[email protected]>
CommitDate: Sat, 29 Oct 2016 13:58:07 +0200
x86/smpboot: Init apic mapping before usage
The recent changes, which forced the registration of the boot cpu on UP
systems, which do not have ACPI tables, have been fixed for systems w/o
local APIC, but left a wreckage for systems which have neither ACPI nor
mptables, but the CPU has an APIC, e.g. virtualbox.
The boot process crashes in prefill_possible_map() as it wants to register
the boot cpu, which needs to access the local apic, but the local APIC is
not yet mapped.
There is no reason why init_apic_mapping() can't be invoked before
prefill_possible_map(). So instead of playing another silly early mapping
game, as the ACPI/mptables code does, we just move init_apic_mapping()
before the call to prefill_possible_map().
In hindsight, I should have noticed that combination earlier.
Sorry for the churn (also in stable)!
Fixes: ff8560512b8d ("x86/boot/smp: Don't try to poke disabled/non-existent
APIC")
Reported-and-debugged-by: Michal Necasek <[email protected]>
Reported-and-tested-by: Wolfgang Bauer <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Borislav Petkov <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1610282114380.5053@nanos
Signed-off-by: Thomas Gleixner <[email protected]>
---
arch/x86/kernel/setup.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index bbfbca5..7be097e 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1221,11 +1221,16 @@ void __init setup_arch(char **cmdline_p)
*/
get_smp_config();
+ /*
+ * Systems w/o ACPI and mptables might not have it mapped the local
+ * APIC yet, but it prefill_possible_map() might need to access it.
+ */
+ init_apic_mappings();
+
prefill_possible_map();
init_cpu_to_node();
- init_apic_mappings();
io_apic_init_mappings();
kvm_guest_init();
