summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/idt.c
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2020-05-28 16:53:19 +0200
committerThomas Gleixner <tglx@linutronix.de>2020-06-11 15:15:26 +0200
commit00229a54300108502f68c8777faca2d13f805f1a (patch)
tree5b676d21a17bbcc73c337fca26bb5c9cd50d28a7 /arch/x86/kernel/idt.c
parent5a2bafca1b0675a126143eea3610143130347783 (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.c18
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;
}