From 00229a54300108502f68c8777faca2d13f805f1a Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 28 May 2020 16:53:19 +0200 Subject: [PATCH] x86/idt: Cleanup trap_init() No point in having all the IDT cruft in trap_init(). Move it into the IDT code and fixup the comments. Signed-off-by: Thomas Gleixner Link: https://lkml.kernel.org/r/20200528145522.992376498@linutronix.de --- arch/x86/kernel/idt.c | 18 ++++++++++++++++++ arch/x86/kernel/traps.c | 9 --------- 2 files changed, 18 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index b6e1a87..902cdd0 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -4,6 +4,7 @@ */ #include +#include #include #include #include @@ -281,6 +282,19 @@ void __init idt_setup_ist_traps(void) } #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 */ @@ -307,6 +321,10 @@ void __init idt_setup_apic_and_irq_gates(void) set_intr_gate(i, entry); } #endif + /* Map IDT into CPU entry area and reload it. */ + idt_map_in_cea(); + load_idt(&idt_descr); + idt_setup_done = true; } diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 79af913..5566fe5 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -1056,15 +1056,6 @@ void __init trap_init(void) idt_setup_traps(); /* - * Set the IDT descriptor to a fixed read-only location, so that the - * "sidt" instruction will not leak the location of the kernel, and - * to defend the IDT against arbitrary memory write vulnerabilities. - * It will be reloaded in cpu_init() */ - cea_set_pte(CPU_ENTRY_AREA_RO_IDT_VADDR, __pa_symbol(idt_table), - PAGE_KERNEL_RO); - idt_descr.address = CPU_ENTRY_AREA_RO_IDT; - - /* * Should be a barrier for any external CPU state: */ cpu_init(); -- 2.7.4