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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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![Vitaly Kuznetsov](/assets/img/avatar_default.png)
[ Upstream commit1f1fbc70c1
] With commitdc20b2d526
("x86/idt: Move interrupt gate initialization to IDT code") non assigned system vectors are also marked as used in 'used_vectors' (now 'system_vectors') bitmap. This makes checks in arch_show_interrupts() whether a particular system vector is allocated to always pass and e.g. 'Hyper-V reenlightenment interrupts' entry always shows up in /proc/interrupts. Another side effect of having all unassigned system vectors marked as used is that irq_matrix_debug_show() will wrongly count them among 'System' vectors. As it is now ensured that alloc_intr_gate() is not called after init, it is possible to leave unused entries in 'system_vectors' unset to fix these issues. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200428093824.1451532-4-vkuznets@redhat.com Signed-off-by: Sasha Levin <sashal@kernel.org>
371 lines
9.5 KiB
C
371 lines
9.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Interrupt descriptor table related code
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*/
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#include <linux/interrupt.h>
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#include <asm/traps.h>
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#include <asm/proto.h>
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#include <asm/desc.h>
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#include <asm/hw_irq.h>
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struct idt_data {
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unsigned int vector;
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unsigned int segment;
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struct idt_bits bits;
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const void *addr;
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};
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#define DPL0 0x0
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#define DPL3 0x3
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#define DEFAULT_STACK 0
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#define G(_vector, _addr, _ist, _type, _dpl, _segment) \
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{ \
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.vector = _vector, \
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.bits.ist = _ist, \
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.bits.type = _type, \
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.bits.dpl = _dpl, \
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.bits.p = 1, \
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.addr = _addr, \
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.segment = _segment, \
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}
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/* Interrupt gate */
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#define INTG(_vector, _addr) \
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G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL0, __KERNEL_CS)
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/* System interrupt gate */
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#define SYSG(_vector, _addr) \
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G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL3, __KERNEL_CS)
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/*
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* Interrupt gate with interrupt stack. The _ist index is the index in
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* the tss.ist[] array, but for the descriptor it needs to start at 1.
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*/
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#define ISTG(_vector, _addr, _ist) \
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G(_vector, _addr, _ist + 1, GATE_INTERRUPT, DPL0, __KERNEL_CS)
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/* Task gate */
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#define TSKG(_vector, _gdt) \
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G(_vector, NULL, DEFAULT_STACK, GATE_TASK, DPL0, _gdt << 3)
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/*
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* Early traps running on the DEFAULT_STACK because the other interrupt
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* stacks work only after cpu_init().
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*/
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static const __initconst struct idt_data early_idts[] = {
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INTG(X86_TRAP_DB, debug),
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SYSG(X86_TRAP_BP, int3),
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#ifdef CONFIG_X86_32
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INTG(X86_TRAP_PF, page_fault),
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#endif
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};
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/*
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* The default IDT entries which are set up in trap_init() before
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* cpu_init() is invoked. Interrupt stacks cannot be used at that point and
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* the traps which use them are reinitialized with IST after cpu_init() has
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* set up TSS.
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*/
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static const __initconst struct idt_data def_idts[] = {
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INTG(X86_TRAP_DE, divide_error),
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INTG(X86_TRAP_NMI, nmi),
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INTG(X86_TRAP_BR, bounds),
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INTG(X86_TRAP_UD, invalid_op),
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INTG(X86_TRAP_NM, device_not_available),
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INTG(X86_TRAP_OLD_MF, coprocessor_segment_overrun),
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INTG(X86_TRAP_TS, invalid_TSS),
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INTG(X86_TRAP_NP, segment_not_present),
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INTG(X86_TRAP_SS, stack_segment),
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INTG(X86_TRAP_GP, general_protection),
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INTG(X86_TRAP_SPURIOUS, spurious_interrupt_bug),
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INTG(X86_TRAP_MF, coprocessor_error),
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INTG(X86_TRAP_AC, alignment_check),
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INTG(X86_TRAP_XF, simd_coprocessor_error),
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#ifdef CONFIG_X86_32
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TSKG(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS),
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#else
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INTG(X86_TRAP_DF, double_fault),
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#endif
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INTG(X86_TRAP_DB, debug),
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#ifdef CONFIG_X86_MCE
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INTG(X86_TRAP_MC, &machine_check),
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#endif
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SYSG(X86_TRAP_OF, overflow),
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#if defined(CONFIG_IA32_EMULATION)
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SYSG(IA32_SYSCALL_VECTOR, entry_INT80_compat),
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#elif defined(CONFIG_X86_32)
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SYSG(IA32_SYSCALL_VECTOR, entry_INT80_32),
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#endif
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};
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/*
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* The APIC and SMP idt entries
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*/
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static const __initconst struct idt_data apic_idts[] = {
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#ifdef CONFIG_SMP
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INTG(RESCHEDULE_VECTOR, reschedule_interrupt),
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INTG(CALL_FUNCTION_VECTOR, call_function_interrupt),
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INTG(CALL_FUNCTION_SINGLE_VECTOR, call_function_single_interrupt),
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INTG(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt),
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INTG(REBOOT_VECTOR, reboot_interrupt),
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#endif
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#ifdef CONFIG_X86_THERMAL_VECTOR
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INTG(THERMAL_APIC_VECTOR, thermal_interrupt),
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#endif
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#ifdef CONFIG_X86_MCE_THRESHOLD
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INTG(THRESHOLD_APIC_VECTOR, threshold_interrupt),
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#endif
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#ifdef CONFIG_X86_MCE_AMD
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INTG(DEFERRED_ERROR_VECTOR, deferred_error_interrupt),
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#endif
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#ifdef CONFIG_X86_LOCAL_APIC
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INTG(LOCAL_TIMER_VECTOR, apic_timer_interrupt),
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INTG(X86_PLATFORM_IPI_VECTOR, x86_platform_ipi),
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# ifdef CONFIG_HAVE_KVM
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INTG(POSTED_INTR_VECTOR, kvm_posted_intr_ipi),
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INTG(POSTED_INTR_WAKEUP_VECTOR, kvm_posted_intr_wakeup_ipi),
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INTG(POSTED_INTR_NESTED_VECTOR, kvm_posted_intr_nested_ipi),
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# endif
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# ifdef CONFIG_IRQ_WORK
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INTG(IRQ_WORK_VECTOR, irq_work_interrupt),
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# endif
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#ifdef CONFIG_X86_UV
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INTG(UV_BAU_MESSAGE, uv_bau_message_intr1),
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#endif
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INTG(SPURIOUS_APIC_VECTOR, spurious_interrupt),
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INTG(ERROR_APIC_VECTOR, error_interrupt),
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#endif
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};
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#ifdef CONFIG_X86_64
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/*
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* Early traps running on the DEFAULT_STACK because the other interrupt
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* stacks work only after cpu_init().
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*/
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static const __initconst struct idt_data early_pf_idts[] = {
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INTG(X86_TRAP_PF, page_fault),
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};
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/*
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* Override for the debug_idt. Same as the default, but with interrupt
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* stack set to DEFAULT_STACK (0). Required for NMI trap handling.
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*/
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static const __initconst struct idt_data dbg_idts[] = {
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INTG(X86_TRAP_DB, debug),
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};
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#endif
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/* Must be page-aligned because the real IDT is used in a fixmap. */
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gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;
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struct desc_ptr idt_descr __ro_after_init = {
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.size = (IDT_ENTRIES * 2 * sizeof(unsigned long)) - 1,
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.address = (unsigned long) idt_table,
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};
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#ifdef CONFIG_X86_64
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/* No need to be aligned, but done to keep all IDTs defined the same way. */
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gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss;
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/*
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* The exceptions which use Interrupt stacks. They are setup after
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* cpu_init() when the TSS has been initialized.
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*/
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static const __initconst struct idt_data ist_idts[] = {
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ISTG(X86_TRAP_DB, debug, IST_INDEX_DB),
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ISTG(X86_TRAP_NMI, nmi, IST_INDEX_NMI),
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ISTG(X86_TRAP_DF, double_fault, IST_INDEX_DF),
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#ifdef CONFIG_X86_MCE
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ISTG(X86_TRAP_MC, &machine_check, IST_INDEX_MCE),
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#endif
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};
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/*
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* Override for the debug_idt. Same as the default, but with interrupt
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* stack set to DEFAULT_STACK (0). Required for NMI trap handling.
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*/
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const struct desc_ptr debug_idt_descr = {
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.size = IDT_ENTRIES * 16 - 1,
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.address = (unsigned long) debug_idt_table,
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};
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#endif
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static inline void idt_init_desc(gate_desc *gate, const struct idt_data *d)
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{
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unsigned long addr = (unsigned long) d->addr;
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gate->offset_low = (u16) addr;
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gate->segment = (u16) d->segment;
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gate->bits = d->bits;
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gate->offset_middle = (u16) (addr >> 16);
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#ifdef CONFIG_X86_64
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gate->offset_high = (u32) (addr >> 32);
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gate->reserved = 0;
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#endif
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}
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static void
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idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size, bool sys)
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{
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gate_desc desc;
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for (; size > 0; t++, size--) {
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idt_init_desc(&desc, t);
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write_idt_entry(idt, t->vector, &desc);
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if (sys)
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set_bit(t->vector, system_vectors);
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}
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}
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static void set_intr_gate(unsigned int n, const void *addr)
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{
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struct idt_data data;
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BUG_ON(n > 0xFF);
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memset(&data, 0, sizeof(data));
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data.vector = n;
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data.addr = addr;
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data.segment = __KERNEL_CS;
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data.bits.type = GATE_INTERRUPT;
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data.bits.p = 1;
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idt_setup_from_table(idt_table, &data, 1, false);
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}
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/**
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* idt_setup_early_traps - Initialize the idt table with early traps
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*
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* On X8664 these traps do not use interrupt stacks as they can't work
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* before cpu_init() is invoked and sets up TSS. The IST variants are
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* installed after that.
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*/
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void __init idt_setup_early_traps(void)
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{
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idt_setup_from_table(idt_table, early_idts, ARRAY_SIZE(early_idts),
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true);
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load_idt(&idt_descr);
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}
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/**
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* idt_setup_traps - Initialize the idt table with default traps
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*/
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void __init idt_setup_traps(void)
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{
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idt_setup_from_table(idt_table, def_idts, ARRAY_SIZE(def_idts), true);
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}
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#ifdef CONFIG_X86_64
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/**
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* idt_setup_early_pf - Initialize the idt table with early pagefault handler
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*
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* On X8664 this does not use interrupt stacks as they can't work before
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* cpu_init() is invoked and sets up TSS. The IST variant is installed
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* after that.
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*
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* FIXME: Why is 32bit and 64bit installing the PF handler at different
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* places in the early setup code?
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*/
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void __init idt_setup_early_pf(void)
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{
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idt_setup_from_table(idt_table, early_pf_idts,
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ARRAY_SIZE(early_pf_idts), true);
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}
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/**
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* idt_setup_ist_traps - Initialize the idt table with traps using IST
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*/
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void __init idt_setup_ist_traps(void)
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{
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idt_setup_from_table(idt_table, ist_idts, ARRAY_SIZE(ist_idts), true);
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}
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/**
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* idt_setup_debugidt_traps - Initialize the debug idt table with debug traps
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*/
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void __init idt_setup_debugidt_traps(void)
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{
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memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16);
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idt_setup_from_table(debug_idt_table, dbg_idts, ARRAY_SIZE(dbg_idts), false);
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}
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#endif
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/**
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* idt_setup_apic_and_irq_gates - Setup APIC/SMP and normal interrupt gates
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*/
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void __init idt_setup_apic_and_irq_gates(void)
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{
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int i = FIRST_EXTERNAL_VECTOR;
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void *entry;
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idt_setup_from_table(idt_table, apic_idts, ARRAY_SIZE(apic_idts), true);
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for_each_clear_bit_from(i, system_vectors, FIRST_SYSTEM_VECTOR) {
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entry = irq_entries_start + 8 * (i - FIRST_EXTERNAL_VECTOR);
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set_intr_gate(i, entry);
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}
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#ifdef CONFIG_X86_LOCAL_APIC
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for_each_clear_bit_from(i, system_vectors, NR_VECTORS) {
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/*
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* Don't set the non assigned system vectors in the
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* system_vectors bitmap. Otherwise they show up in
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* /proc/interrupts.
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*/
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entry = spurious_entries_start + 8 * (i - FIRST_SYSTEM_VECTOR);
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set_intr_gate(i, entry);
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}
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#endif
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}
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/**
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* idt_setup_early_handler - Initializes the idt table with early handlers
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*/
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void __init idt_setup_early_handler(void)
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{
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int i;
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for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
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set_intr_gate(i, early_idt_handler_array[i]);
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#ifdef CONFIG_X86_32
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for ( ; i < NR_VECTORS; i++)
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set_intr_gate(i, early_ignore_irq);
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#endif
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load_idt(&idt_descr);
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}
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/**
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* idt_invalidate - Invalidate interrupt descriptor table
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* @addr: The virtual address of the 'invalid' IDT
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*/
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void idt_invalidate(void *addr)
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{
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struct desc_ptr idt = { .address = (unsigned long) addr, .size = 0 };
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load_idt(&idt);
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}
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void __init update_intr_gate(unsigned int n, const void *addr)
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{
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if (WARN_ON_ONCE(!test_bit(n, system_vectors)))
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return;
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set_intr_gate(n, addr);
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}
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void alloc_intr_gate(unsigned int n, const void *addr)
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{
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BUG_ON(n < FIRST_SYSTEM_VECTOR);
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if (!test_and_set_bit(n, system_vectors))
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set_intr_gate(n, addr);
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}
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