From 072de836f53be56a70cecf70b43ae43b7ce17376 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 10:08:36 +0000
Subject: [PATCH] mk-rootfs.sh
---
kernel/arch/x86/mm/cpu_entry_area.c | 133 +++++++++++++++++++++++++-------------------
1 files changed, 75 insertions(+), 58 deletions(-)
diff --git a/kernel/arch/x86/mm/cpu_entry_area.c b/kernel/arch/x86/mm/cpu_entry_area.c
index 076ebdc..6c2f1b7 100644
--- a/kernel/arch/x86/mm/cpu_entry_area.c
+++ b/kernel/arch/x86/mm/cpu_entry_area.c
@@ -4,21 +4,25 @@
#include <linux/percpu.h>
#include <linux/kallsyms.h>
#include <linux/kcore.h>
+#include <linux/pgtable.h>
#include <asm/cpu_entry_area.h>
-#include <asm/pgtable.h>
#include <asm/fixmap.h>
#include <asm/desc.h>
static DEFINE_PER_CPU_PAGE_ALIGNED(struct entry_stack_page, entry_stack_storage);
#ifdef CONFIG_X86_64
-static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks
- [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);
-static DEFINE_PER_CPU(struct kcore_list, kcore_entry_trampoline);
+static DEFINE_PER_CPU_PAGE_ALIGNED(struct exception_stacks, exception_stacks);
+DEFINE_PER_CPU(struct cea_exception_stacks*, cea_exception_stacks);
#endif
-struct cpu_entry_area *get_cpu_entry_area(int cpu)
+#ifdef CONFIG_X86_32
+DECLARE_PER_CPU_PAGE_ALIGNED(struct doublefault_stack, doublefault_stack);
+#endif
+
+/* Is called from entry code, so must be noinstr */
+noinstr struct cpu_entry_area *get_cpu_entry_area(int cpu)
{
unsigned long va = CPU_ENTRY_AREA_PER_CPU + cpu * CPU_ENTRY_AREA_SIZE;
BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0);
@@ -53,10 +57,10 @@
cea_set_pte(cea_vaddr, per_cpu_ptr_to_phys(ptr), prot);
}
-static void percpu_setup_debug_store(int cpu)
+static void __init percpu_setup_debug_store(unsigned int cpu)
{
#ifdef CONFIG_CPU_SUP_INTEL
- int npages;
+ unsigned int npages;
void *cea;
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
@@ -79,12 +83,56 @@
#endif
}
-/* Setup the fixmap mappings only once per-processor */
-static void __init setup_cpu_entry_area(int cpu)
-{
#ifdef CONFIG_X86_64
- extern char _entry_trampoline[];
+#define cea_map_stack(name) do { \
+ npages = sizeof(estacks->name## _stack) / PAGE_SIZE; \
+ cea_map_percpu_pages(cea->estacks.name## _stack, \
+ estacks->name## _stack, npages, PAGE_KERNEL); \
+ } while (0)
+
+static void __init percpu_setup_exception_stacks(unsigned int cpu)
+{
+ struct exception_stacks *estacks = per_cpu_ptr(&exception_stacks, cpu);
+ struct cpu_entry_area *cea = get_cpu_entry_area(cpu);
+ unsigned int npages;
+
+ BUILD_BUG_ON(sizeof(exception_stacks) % PAGE_SIZE != 0);
+
+ per_cpu(cea_exception_stacks, cpu) = &cea->estacks;
+
+ /*
+ * The exceptions stack mappings in the per cpu area are protected
+ * by guard pages so each stack must be mapped separately. DB2 is
+ * not mapped; it just exists to catch triple nesting of #DB.
+ */
+ cea_map_stack(DF);
+ cea_map_stack(NMI);
+ cea_map_stack(DB);
+ cea_map_stack(MCE);
+
+ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
+ if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) {
+ cea_map_stack(VC);
+ cea_map_stack(VC2);
+ }
+ }
+}
+#else
+static inline void percpu_setup_exception_stacks(unsigned int cpu)
+{
+ struct cpu_entry_area *cea = get_cpu_entry_area(cpu);
+
+ cea_map_percpu_pages(&cea->doublefault_stack,
+ &per_cpu(doublefault_stack, cpu), 1, PAGE_KERNEL);
+}
+#endif
+
+/* Setup the fixmap mappings only once per-processor */
+static void __init setup_cpu_entry_area(unsigned int cpu)
+{
+ struct cpu_entry_area *cea = get_cpu_entry_area(cpu);
+#ifdef CONFIG_X86_64
/* On 64-bit systems, we use a read-only fixmap GDT and TSS. */
pgprot_t gdt_prot = PAGE_KERNEL_RO;
pgprot_t tss_prot = PAGE_KERNEL_RO;
@@ -104,10 +152,9 @@
pgprot_t tss_prot = PAGE_KERNEL;
#endif
- cea_set_pte(&get_cpu_entry_area(cpu)->gdt, get_cpu_gdt_paddr(cpu),
- gdt_prot);
+ cea_set_pte(&cea->gdt, get_cpu_gdt_paddr(cpu), gdt_prot);
- cea_map_percpu_pages(&get_cpu_entry_area(cpu)->entry_stack_page,
+ cea_map_percpu_pages(&cea->entry_stack_page,
per_cpu_ptr(&entry_stack_storage, cpu), 1,
PAGE_KERNEL);
@@ -131,64 +178,34 @@
BUILD_BUG_ON((offsetof(struct tss_struct, x86_tss) ^
offsetofend(struct tss_struct, x86_tss)) & PAGE_MASK);
BUILD_BUG_ON(sizeof(struct tss_struct) % PAGE_SIZE != 0);
- cea_map_percpu_pages(&get_cpu_entry_area(cpu)->tss,
- &per_cpu(cpu_tss_rw, cpu),
+ /*
+ * VMX changes the host TR limit to 0x67 after a VM exit. This is
+ * okay, since 0x67 covers the size of struct x86_hw_tss. Make sure
+ * that this is correct.
+ */
+ BUILD_BUG_ON(offsetof(struct tss_struct, x86_tss) != 0);
+ BUILD_BUG_ON(sizeof(struct x86_hw_tss) != 0x68);
+
+ cea_map_percpu_pages(&cea->tss, &per_cpu(cpu_tss_rw, cpu),
sizeof(struct tss_struct) / PAGE_SIZE, tss_prot);
#ifdef CONFIG_X86_32
- per_cpu(cpu_entry_area, cpu) = get_cpu_entry_area(cpu);
+ per_cpu(cpu_entry_area, cpu) = cea;
#endif
-#ifdef CONFIG_X86_64
- BUILD_BUG_ON(sizeof(exception_stacks) % PAGE_SIZE != 0);
- BUILD_BUG_ON(sizeof(exception_stacks) !=
- sizeof(((struct cpu_entry_area *)0)->exception_stacks));
- cea_map_percpu_pages(&get_cpu_entry_area(cpu)->exception_stacks,
- &per_cpu(exception_stacks, cpu),
- sizeof(exception_stacks) / PAGE_SIZE, PAGE_KERNEL);
+ percpu_setup_exception_stacks(cpu);
- cea_set_pte(&get_cpu_entry_area(cpu)->entry_trampoline,
- __pa_symbol(_entry_trampoline), PAGE_KERNEL_RX);
- /*
- * The cpu_entry_area alias addresses are not in the kernel binary
- * so they do not show up in /proc/kcore normally. This adds entries
- * for them manually.
- */
- kclist_add_remap(&per_cpu(kcore_entry_trampoline, cpu),
- _entry_trampoline,
- &get_cpu_entry_area(cpu)->entry_trampoline, PAGE_SIZE);
-#endif
percpu_setup_debug_store(cpu);
}
-
-#ifdef CONFIG_X86_64
-int arch_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
- char *name)
-{
- unsigned int cpu, ncpu = 0;
-
- if (symnum >= num_possible_cpus())
- return -EINVAL;
-
- for_each_possible_cpu(cpu) {
- if (ncpu++ >= symnum)
- break;
- }
-
- *value = (unsigned long)&get_cpu_entry_area(cpu)->entry_trampoline;
- *type = 't';
- strlcpy(name, "__entry_SYSCALL_64_trampoline", KSYM_NAME_LEN);
-
- return 0;
-}
-#endif
static __init void setup_cpu_entry_area_ptes(void)
{
#ifdef CONFIG_X86_32
unsigned long start, end;
- BUILD_BUG_ON(CPU_ENTRY_AREA_PAGES * PAGE_SIZE < CPU_ENTRY_AREA_MAP_SIZE);
+ /* The +1 is for the readonly IDT: */
+ BUILD_BUG_ON((CPU_ENTRY_AREA_PAGES+1)*PAGE_SIZE != CPU_ENTRY_AREA_MAP_SIZE);
+ BUILD_BUG_ON(CPU_ENTRY_AREA_TOTAL_SIZE != CPU_ENTRY_AREA_MAP_SIZE);
BUG_ON(CPU_ENTRY_AREA_BASE & ~PMD_MASK);
start = CPU_ENTRY_AREA_BASE;
--
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