From facaa3e3c813848e6b49ee37a42a3688832e63cd Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 28 Aug 2017 08:47:59 +0200 Subject: [PATCH] x86/idt: Hide set_intr_gate() set_intr_gate() is an internal function of the IDT code. The only user left is the KVM code which replaces the pagefault handler eventually. Provide an explicit update_intr_gate() function and make set_intr_gate() static. While at it replace the magic number 14 in the KVM code with the proper trap define. Signed-off-by: Thomas Gleixner Acked-by: Paolo Bonzini Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20170828064959.663008004@linutronix.de Signed-off-by: Ingo Molnar --- arch/x86/include/asm/desc.h | 2 +- arch/x86/kernel/idt.c | 33 ++++++++++++++++++++------------- arch/x86/kernel/kvm.c | 2 +- 3 files changed, 22 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h index 33f84f29a724..1a2ba368da39 100644 --- a/arch/x86/include/asm/desc.h +++ b/arch/x86/include/asm/desc.h @@ -390,7 +390,7 @@ static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit) desc->limit1 = (limit >> 16) & 0xf; } -void set_intr_gate(unsigned int n, const void *addr); +void update_intr_gate(unsigned int n, const void *addr); void alloc_intr_gate(unsigned int n, const void *addr); extern unsigned long used_vectors[]; diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index b609eac3d73c..61b490c69250 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -225,6 +225,22 @@ idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size, bool sy } } +static void set_intr_gate(unsigned int n, const void *addr) +{ + struct idt_data data; + + BUG_ON(n > 0xFF); + + memset(&data, 0, sizeof(data)); + data.vector = n; + data.addr = addr; + data.segment = __KERNEL_CS; + data.bits.type = GATE_INTERRUPT; + data.bits.p = 1; + + idt_setup_from_table(idt_table, &data, 1, false); +} + /** * idt_setup_early_traps - Initialize the idt table with early traps * @@ -336,20 +352,11 @@ void idt_invalidate(void *addr) load_idt(&idt); } -void set_intr_gate(unsigned int n, const void *addr) +void __init update_intr_gate(unsigned int n, const void *addr) { - struct idt_data data; - - BUG_ON(n > 0xFF); - - memset(&data, 0, sizeof(data)); - data.vector = n; - data.addr = addr; - data.segment = __KERNEL_CS; - data.bits.type = GATE_INTERRUPT; - data.bits.p = 1; - - idt_setup_from_table(idt_table, &data, 1, false); + if (WARN_ON_ONCE(!test_bit(n, used_vectors))) + return; + set_intr_gate(n, addr); } void alloc_intr_gate(unsigned int n, const void *addr) diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 6ed9242b5fa7..874827b0d7ca 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -455,7 +455,7 @@ static int kvm_cpu_down_prepare(unsigned int cpu) static void __init kvm_apf_trap_init(void) { - set_intr_gate(14, async_page_fault); + update_intr_gate(X86_TRAP_PF, async_page_fault); } void __init kvm_guest_init(void) -- 2.20.1