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-rw-r--r--arch/x86/kernel/idt.c344
1 files changed, 344 insertions, 0 deletions
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
new file mode 100644
index 000000000..f5a3374e6
--- /dev/null
+++ b/arch/x86/kernel/idt.c
@@ -0,0 +1,344 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Interrupt descriptor table related code
+ */
+#include <linux/interrupt.h>
+
+#include <asm/cpu_entry_area.h>
+#include <asm/set_memory.h>
+#include <asm/traps.h>
+#include <asm/proto.h>
+#include <asm/desc.h>
+#include <asm/hw_irq.h>
+#include <asm/idtentry.h>
+
+#define DPL0 0x0
+#define DPL3 0x3
+
+#define DEFAULT_STACK 0
+
+#define G(_vector, _addr, _ist, _type, _dpl, _segment) \
+ { \
+ .vector = _vector, \
+ .bits.ist = _ist, \
+ .bits.type = _type, \
+ .bits.dpl = _dpl, \
+ .bits.p = 1, \
+ .addr = _addr, \
+ .segment = _segment, \
+ }
+
+/* Interrupt gate */
+#define INTG(_vector, _addr) \
+ G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL0, __KERNEL_CS)
+
+/* System interrupt gate */
+#define SYSG(_vector, _addr) \
+ G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL3, __KERNEL_CS)
+
+#ifdef CONFIG_X86_64
+/*
+ * Interrupt gate with interrupt stack. The _ist index is the index in
+ * the tss.ist[] array, but for the descriptor it needs to start at 1.
+ */
+#define ISTG(_vector, _addr, _ist) \
+ G(_vector, _addr, _ist + 1, GATE_INTERRUPT, DPL0, __KERNEL_CS)
+#else
+#define ISTG(_vector, _addr, _ist) INTG(_vector, _addr)
+#endif
+
+/* Task gate */
+#define TSKG(_vector, _gdt) \
+ G(_vector, NULL, DEFAULT_STACK, GATE_TASK, DPL0, _gdt << 3)
+
+#define IDT_TABLE_SIZE (IDT_ENTRIES * sizeof(gate_desc))
+
+static bool idt_setup_done __initdata;
+
+/*
+ * Early traps running on the DEFAULT_STACK because the other interrupt
+ * stacks work only after cpu_init().
+ */
+static const __initconst struct idt_data early_idts[] = {
+ INTG(X86_TRAP_DB, asm_exc_debug),
+ SYSG(X86_TRAP_BP, asm_exc_int3),
+
+#ifdef CONFIG_X86_32
+ /*
+ * Not possible on 64-bit. See idt_setup_early_pf() for details.
+ */
+ INTG(X86_TRAP_PF, asm_exc_page_fault),
+#endif
+#ifdef CONFIG_INTEL_TDX_GUEST
+ INTG(X86_TRAP_VE, asm_exc_virtualization_exception),
+#endif
+};
+
+/*
+ * The default IDT entries which are set up in trap_init() before
+ * cpu_init() is invoked. Interrupt stacks cannot be used at that point and
+ * the traps which use them are reinitialized with IST after cpu_init() has
+ * set up TSS.
+ */
+static const __initconst struct idt_data def_idts[] = {
+ INTG(X86_TRAP_DE, asm_exc_divide_error),
+ ISTG(X86_TRAP_NMI, asm_exc_nmi, IST_INDEX_NMI),
+ INTG(X86_TRAP_BR, asm_exc_bounds),
+ INTG(X86_TRAP_UD, asm_exc_invalid_op),
+ INTG(X86_TRAP_NM, asm_exc_device_not_available),
+ INTG(X86_TRAP_OLD_MF, asm_exc_coproc_segment_overrun),
+ INTG(X86_TRAP_TS, asm_exc_invalid_tss),
+ INTG(X86_TRAP_NP, asm_exc_segment_not_present),
+ INTG(X86_TRAP_SS, asm_exc_stack_segment),
+ INTG(X86_TRAP_GP, asm_exc_general_protection),
+ INTG(X86_TRAP_SPURIOUS, asm_exc_spurious_interrupt_bug),
+ INTG(X86_TRAP_MF, asm_exc_coprocessor_error),
+ INTG(X86_TRAP_AC, asm_exc_alignment_check),
+ INTG(X86_TRAP_XF, asm_exc_simd_coprocessor_error),
+
+#ifdef CONFIG_X86_32
+ TSKG(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS),
+#else
+ ISTG(X86_TRAP_DF, asm_exc_double_fault, IST_INDEX_DF),
+#endif
+ ISTG(X86_TRAP_DB, asm_exc_debug, IST_INDEX_DB),
+
+#ifdef CONFIG_X86_MCE
+ ISTG(X86_TRAP_MC, asm_exc_machine_check, IST_INDEX_MCE),
+#endif
+
+#ifdef CONFIG_X86_KERNEL_IBT
+ INTG(X86_TRAP_CP, asm_exc_control_protection),
+#endif
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+ ISTG(X86_TRAP_VC, asm_exc_vmm_communication, IST_INDEX_VC),
+#endif
+
+ SYSG(X86_TRAP_OF, asm_exc_overflow),
+#if defined(CONFIG_IA32_EMULATION)
+ SYSG(IA32_SYSCALL_VECTOR, asm_int80_emulation),
+#elif defined(CONFIG_X86_32)
+ SYSG(IA32_SYSCALL_VECTOR, entry_INT80_32),
+#endif
+};
+
+/*
+ * The APIC and SMP idt entries
+ */
+static const __initconst struct idt_data apic_idts[] = {
+#ifdef CONFIG_SMP
+ INTG(RESCHEDULE_VECTOR, asm_sysvec_reschedule_ipi),
+ INTG(CALL_FUNCTION_VECTOR, asm_sysvec_call_function),
+ INTG(CALL_FUNCTION_SINGLE_VECTOR, asm_sysvec_call_function_single),
+ INTG(IRQ_MOVE_CLEANUP_VECTOR, asm_sysvec_irq_move_cleanup),
+ INTG(REBOOT_VECTOR, asm_sysvec_reboot),
+#endif
+
+#ifdef CONFIG_X86_THERMAL_VECTOR
+ INTG(THERMAL_APIC_VECTOR, asm_sysvec_thermal),
+#endif
+
+#ifdef CONFIG_X86_MCE_THRESHOLD
+ INTG(THRESHOLD_APIC_VECTOR, asm_sysvec_threshold),
+#endif
+
+#ifdef CONFIG_X86_MCE_AMD
+ INTG(DEFERRED_ERROR_VECTOR, asm_sysvec_deferred_error),
+#endif
+
+#ifdef CONFIG_X86_LOCAL_APIC
+ INTG(LOCAL_TIMER_VECTOR, asm_sysvec_apic_timer_interrupt),
+ INTG(X86_PLATFORM_IPI_VECTOR, asm_sysvec_x86_platform_ipi),
+# ifdef CONFIG_HAVE_KVM
+ INTG(POSTED_INTR_VECTOR, asm_sysvec_kvm_posted_intr_ipi),
+ INTG(POSTED_INTR_WAKEUP_VECTOR, asm_sysvec_kvm_posted_intr_wakeup_ipi),
+ INTG(POSTED_INTR_NESTED_VECTOR, asm_sysvec_kvm_posted_intr_nested_ipi),
+# endif
+# ifdef CONFIG_IRQ_WORK
+ INTG(IRQ_WORK_VECTOR, asm_sysvec_irq_work),
+# endif
+ INTG(SPURIOUS_APIC_VECTOR, asm_sysvec_spurious_apic_interrupt),
+ INTG(ERROR_APIC_VECTOR, asm_sysvec_error_interrupt),
+#endif
+};
+
+/* Must be page-aligned because the real IDT is used in the cpu entry area */
+static gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;
+
+static struct desc_ptr idt_descr __ro_after_init = {
+ .size = IDT_TABLE_SIZE - 1,
+ .address = (unsigned long) idt_table,
+};
+
+void load_current_idt(void)
+{
+ lockdep_assert_irqs_disabled();
+ load_idt(&idt_descr);
+}
+
+#ifdef CONFIG_X86_F00F_BUG
+bool idt_is_f00f_address(unsigned long address)
+{
+ return ((address - idt_descr.address) >> 3) == 6;
+}
+#endif
+
+static __init void
+idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size, bool sys)
+{
+ gate_desc desc;
+
+ for (; size > 0; t++, size--) {
+ idt_init_desc(&desc, t);
+ write_idt_entry(idt, t->vector, &desc);
+ if (sys)
+ set_bit(t->vector, system_vectors);
+ }
+}
+
+static __init void set_intr_gate(unsigned int n, const void *addr)
+{
+ struct idt_data data;
+
+ init_idt_data(&data, n, addr);
+
+ idt_setup_from_table(idt_table, &data, 1, false);
+}
+
+/**
+ * idt_setup_early_traps - Initialize the idt table with early traps
+ *
+ * On X8664 these traps do not use interrupt stacks as they can't work
+ * before cpu_init() is invoked and sets up TSS. The IST variants are
+ * installed after that.
+ */
+void __init idt_setup_early_traps(void)
+{
+ idt_setup_from_table(idt_table, early_idts, ARRAY_SIZE(early_idts),
+ true);
+ load_idt(&idt_descr);
+}
+
+/**
+ * idt_setup_traps - Initialize the idt table with default traps
+ */
+void __init idt_setup_traps(void)
+{
+ idt_setup_from_table(idt_table, def_idts, ARRAY_SIZE(def_idts), true);
+}
+
+#ifdef CONFIG_X86_64
+/*
+ * Early traps running on the DEFAULT_STACK because the other interrupt
+ * stacks work only after cpu_init().
+ */
+static const __initconst struct idt_data early_pf_idts[] = {
+ INTG(X86_TRAP_PF, asm_exc_page_fault),
+};
+
+/**
+ * idt_setup_early_pf - Initialize the idt table with early pagefault handler
+ *
+ * On X8664 this does not use interrupt stacks as they can't work before
+ * cpu_init() is invoked and sets up TSS. The IST variant is installed
+ * after that.
+ *
+ * Note, that X86_64 cannot install the real #PF handler in
+ * idt_setup_early_traps() because the memory initialization needs the #PF
+ * handler from the early_idt_handler_array to initialize the early page
+ * tables.
+ */
+void __init idt_setup_early_pf(void)
+{
+ idt_setup_from_table(idt_table, early_pf_idts,
+ ARRAY_SIZE(early_pf_idts), true);
+}
+#endif
+
+static void __init idt_map_in_cea(void)
+{
+ /*
+ * Set the IDT descriptor to a fixed read-only location in the cpu
+ * entry area, so that the "sidt" instruction will not leak the
+ * location of the kernel, and to defend the IDT against arbitrary
+ * memory write vulnerabilities.
+ */
+ cea_set_pte(CPU_ENTRY_AREA_RO_IDT_VADDR, __pa_symbol(idt_table),
+ PAGE_KERNEL_RO);
+ idt_descr.address = CPU_ENTRY_AREA_RO_IDT;
+}
+
+/**
+ * idt_setup_apic_and_irq_gates - Setup APIC/SMP and normal interrupt gates
+ */
+void __init idt_setup_apic_and_irq_gates(void)
+{
+ int i = FIRST_EXTERNAL_VECTOR;
+ void *entry;
+
+ idt_setup_from_table(idt_table, apic_idts, ARRAY_SIZE(apic_idts), true);
+
+ for_each_clear_bit_from(i, system_vectors, FIRST_SYSTEM_VECTOR) {
+ entry = irq_entries_start + IDT_ALIGN * (i - FIRST_EXTERNAL_VECTOR);
+ set_intr_gate(i, entry);
+ }
+
+#ifdef CONFIG_X86_LOCAL_APIC
+ for_each_clear_bit_from(i, system_vectors, NR_VECTORS) {
+ /*
+ * Don't set the non assigned system vectors in the
+ * system_vectors bitmap. Otherwise they show up in
+ * /proc/interrupts.
+ */
+ entry = spurious_entries_start + IDT_ALIGN * (i - FIRST_SYSTEM_VECTOR);
+ set_intr_gate(i, entry);
+ }
+#endif
+ /* Map IDT into CPU entry area and reload it. */
+ idt_map_in_cea();
+ load_idt(&idt_descr);
+
+ /* Make the IDT table read only */
+ set_memory_ro((unsigned long)&idt_table, 1);
+
+ idt_setup_done = true;
+}
+
+/**
+ * idt_setup_early_handler - Initializes the idt table with early handlers
+ */
+void __init idt_setup_early_handler(void)
+{
+ int i;
+
+ for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
+ set_intr_gate(i, early_idt_handler_array[i]);
+#ifdef CONFIG_X86_32
+ for ( ; i < NR_VECTORS; i++)
+ set_intr_gate(i, early_ignore_irq);
+#endif
+ load_idt(&idt_descr);
+}
+
+/**
+ * idt_invalidate - Invalidate interrupt descriptor table
+ */
+void idt_invalidate(void)
+{
+ static const struct desc_ptr idt = { .address = 0, .size = 0 };
+
+ load_idt(&idt);
+}
+
+void __init alloc_intr_gate(unsigned int n, const void *addr)
+{
+ if (WARN_ON(n < FIRST_SYSTEM_VECTOR))
+ return;
+
+ if (WARN_ON(idt_setup_done))
+ return;
+
+ if (!WARN_ON(test_and_set_bit(n, system_vectors)))
+ set_intr_gate(n, addr);
+}