diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2020-05-28 16:53:19 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2020-06-11 15:15:26 +0200 |
| commit | 00229a54300108502f68c8777faca2d13f805f1a (patch) | |
| tree | 5b676d21a17bbcc73c337fca26bb5c9cd50d28a7 /arch/x86/kernel/idt.c | |
| parent | 5a2bafca1b0675a126143eea3610143130347783 (diff) | |
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 <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200528145522.992376498@linutronix.de
Diffstat (limited to 'arch/x86/kernel/idt.c')
| -rw-r--r-- | arch/x86/kernel/idt.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c index b6e1a87f0822..902cdd006313 100644 --- a/arch/x86/kernel/idt.c +++ b/arch/x86/kernel/idt.c @@ -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; } |