From df8353792451c7650ee0163c40c3303c6952cf5a Mon Sep 17 00:00:00 2001
From: Pawel Wieczorkiewicz <wipawel@grsecurity.net>
Date: Fri, 24 Nov 2023 19:21:53 +0100
Subject: [PATCH] acpi,smp: always use APIC ID for CPU identifiers

Signed-off-by: Pawel Wieczorkiewicz <wipawel@grsecurity.net>
---
 common/acpi.c    | 20 +++++++++-----------
 common/percpu.c  |  4 ++--
 include/percpu.h |  2 +-
 3 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/common/acpi.c b/common/acpi.c
index 5d2a3d55..1cede225 100644
--- a/common/acpi.c
+++ b/common/acpi.c
@@ -248,16 +248,15 @@ static int process_madt_entries(void) {
             if (!enabled)
                 break;
 
-            cpu_t *cpu = get_cpu(madt_cpu->apic_proc_id)
-                             ?: add_cpu(madt_cpu->apic_proc_id, false, enabled);
+            cpu_t *cpu =
+                get_cpu(madt_cpu->apic_id) ?: add_cpu(madt_cpu->apic_id, false, enabled);
             cpu->flags.enabled = enabled;
 
             percpu_t *percpu = cpu->percpu;
-            percpu->cpu_id = madt_cpu->apic_proc_id;
-            percpu->apic_id = madt_cpu->apic_id;
+            percpu->acpi_id = madt_cpu->apic_proc_id;
 
-            printk("ACPI: [MADT] APIC Processor ID: %u, APIC ID: %u, Flags: %08x\n",
-                   cpu->id, percpu->apic_id, madt_cpu->flags);
+            printk("ACPI: [MADT] ACPI Processor ID: %u, APIC ID: %u, Flags: %08x\n",
+                   percpu->acpi_id, percpu->apic_id, madt_cpu->flags);
             break;
         }
         case ACPI_MADT_TYPE_IOAPIC: {
@@ -475,15 +474,14 @@ static void madt_parser(ACPI_SUBTABLE_HEADER *entry, void *arg) {
         if (!enabled)
             break;
 
-        cpu_t *cpu =
-            get_cpu(lapic->ProcessorId) ?: add_cpu(lapic->ProcessorId, false, enabled);
+        cpu_t *cpu = get_cpu(lapic->Id) ?: add_cpu(lapic->Id, false, enabled);
         cpu->flags.enabled = enabled;
 
         percpu_t *percpu = cpu->percpu;
-        percpu->apic_id = lapic->Id;
+        percpu->acpi_id = lapic->ProcessorId;
 
-        printk("ACPI: [MADT] APIC Processor ID: %u, APIC ID: %u, Flags: %08x\n", cpu->id,
-               percpu->apic_id, lapic->LapicFlags);
+        printk("ACPI: [MADT] ACPI Processor ID: %u, APIC ID: %u, Flags: %08x\n",
+               percpu->acpi_id, percpu->apic_id, lapic->LapicFlags);
         break;
     }
     case ACPI_MADT_TYPE_IO_APIC: {
diff --git a/common/percpu.c b/common/percpu.c
index cad7eeb3..df1f8b74 100644
--- a/common/percpu.c
+++ b/common/percpu.c
@@ -43,7 +43,7 @@ percpu_t *get_percpu_page(unsigned int cpu) {
     percpu_t *percpu;
 
     list_for_each_entry (percpu, &percpu_frames, list) {
-        if (percpu->cpu_id == cpu)
+        if (percpu->apic_id == cpu)
             return percpu;
     }
 
@@ -54,7 +54,7 @@ percpu_t *get_percpu_page(unsigned int cpu) {
     BUG_ON(!percpu);
     memset(percpu, 0, PAGE_SIZE);
 
-    percpu->cpu_id = cpu;
+    percpu->apic_id = cpu;
 
     list_add(&percpu->list, &percpu_frames);
     return percpu;
diff --git a/include/percpu.h b/include/percpu.h
index a61ea9e1..f6029ec5 100644
--- a/include/percpu.h
+++ b/include/percpu.h
@@ -34,7 +34,7 @@
 struct percpu {
     list_head_t list;
 
-    unsigned int cpu_id;
+    uint32_t acpi_id;
     uint32_t apic_id;
     uint32_t sapic_uid;
     uint8_t sapic_id;