The code currently issues the user a warning unconditionally:
WARNING: CPU: 0 PID: 0 at /arch/x86/kernel/apic/apic.c:2129
register_lapic_address+0x3d/0x50
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 6.6.62-rt31-yocto-preempt-rt #1
RIP: 0010:register_lapic_address+0x3d/0x50
Call Trace:
<TASK>
? show_regs+0x69/0x80
? __warn+0x8e/0x160
? register_lapic_address+0x3d/0x50
? report_bug+0x171/0x1a0
? early_fixup_exception+0xb8/0xd0
? do_early_exception+0x1f/0x60
? early_idt_handler_common+0x2f/0x40
? register_lapic_address+0x3d/0x50
? register_lapic_address+0x9/0x50
? x86_dtb_init+0xdc/0x2f0
? __pfx_acpi_parse_lapic+0x10/0x10
setup_arch+0x8e1/0xd70
start_kernel+0x66/0x6e0
x86_64_start_reservations+0x1c/0x30
x86_64_start_kernel+0xce/0xe0
secondary_startup_64_no_verify+0x18a/0x18b
</TASK>
This warning may lead users to believe they have a early kernel panic,
or major issue stemming from BIOS. This can be avoided unless the
kernel is being passed a non-default value for LAPIC address.
Fixes: 81287ad65da5b8 ("x86/apic: Sanitize APIC address setup")
Signed-off-by: Eric Schikschneit <eric.schikschneit@novatechautomation.com>
---
arch/x86/kernel/apic/apic.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index d73ba5a7b623..e71cc6f776fe 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2078,7 +2078,9 @@ static __init void apic_set_fixmap(bool read_apic)
void __init register_lapic_address(unsigned long address)
{
/* This should only happen once */
- WARN_ON_ONCE(mp_lapic_addr);
+ if (address != APIC_DEFAULT_PHYS_BASE)
+ WARN_ON_ONCE(mp_lapic_addr);
+
mp_lapic_addr = address;
if (!x2apic_mode)
--
2.43.0