Commit 00229a54 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

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: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200528145522.992376498@linutronix.de
parent 5a2bafca

arch/x86/kernel/idt.c

+18 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 */

#include <linux/interrupt.h>



#include <asm/cpu_entry_area.h>

#include <asm/traps.h>

#include <asm/proto.h>

#include <asm/desc.h>
@@ -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;

}

arch/x86/kernel/traps.c

+0 −9
Original line number Diff line number Diff line
@@ -1055,15 +1055,6 @@ 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:

	 */

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