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authorDheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>2023-06-17 02:52:36 +0530
committerBorislav Petkov (AMD) <bp@alien8.de>2023-06-19 20:59:40 +0200
commit85d38d5810e285d5aec7fb5283107d1da70c12a9 (patch)
tree7558ea94357c750ad4033bc2eafb8fb9dbe8d446
parentd082d48737c75d2b3cc1f972b8c8674c25131534 (diff)
x86/apic: Fix kernel panic when booting with intremap=off and x2apic_phys
When booting with "intremap=off" and "x2apic_phys" on the kernel command line, the physical x2APIC driver ends up being used even when x2APIC mode is disabled ("intremap=off" disables x2APIC mode). This happens because the first compound condition check in x2apic_phys_probe() is false due to x2apic_mode == 0 and so the following one returns true after default_acpi_madt_oem_check() having already selected the physical x2APIC driver. This results in the following panic: kernel BUG at arch/x86/kernel/apic/io_apic.c:2409! invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-rc2-ver4.1rc2 #2 Hardware name: Dell Inc. PowerEdge R6515/07PXPY, BIOS 2.3.6 07/06/2021 RIP: 0010:setup_IO_APIC+0x9c/0xaf0 Call Trace: <TASK> ? native_read_msr apic_intr_mode_init x86_late_time_init start_kernel x86_64_start_reservations x86_64_start_kernel secondary_startup_64_no_verify </TASK> which is: setup_IO_APIC: apic_printk(APIC_VERBOSE, "ENABLING IO-APIC IRQs\n"); for_each_ioapic(ioapic) BUG_ON(mp_irqdomain_create(ioapic)); Return 0 to denote that x2APIC has not been enabled when probing the physical x2APIC driver. [ bp: Massage commit message heavily. ] Fixes: 9ebd680bd029 ("x86, apic: Use probe routines to simplify apic selection") Signed-off-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Kishon Vijay Abraham I <kvijayab@amd.com> Reviewed-by: Vasant Hegde <vasant.hegde@amd.com> Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230616212236.1389-1-dheerajkumar.srivastava@amd.com
-rw-r--r--arch/x86/kernel/apic/x2apic_phys.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c
index 6bde05a86b4e..896bc41cb2ba 100644
--- a/arch/x86/kernel/apic/x2apic_phys.c
+++ b/arch/x86/kernel/apic/x2apic_phys.c
@@ -97,7 +97,10 @@ static void init_x2apic_ldr(void)
static int x2apic_phys_probe(void)
{
- if (x2apic_mode && (x2apic_phys || x2apic_fadt_phys()))
+ if (!x2apic_mode)
+ return 0;
+
+ if (x2apic_phys || x2apic_fadt_phys())
return 1;
return apic == &apic_x2apic_phys;