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x86/idt: Cleanup trap_init()

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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 <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200528145522.992376498@linutronix.de
This commit is contained in:
Thomas Gleixner 2020-05-28 16:53:19 +02:00
parent 5a2bafca1b
commit 00229a5430
2 changed files with 18 additions and 9 deletions
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18
arch/x86/kernel/idt.c
View File

@ -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;
}

9
arch/x86/kernel/traps.c
View File

@ -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:
*/