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Commit fc8b8a60 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Ingo Molnar
Browse files

x86, 64-bit: use write_gdt_entry in vsyscall_set_cpu 



Use write_gdt_entry to generate the special vgetcpu descriptor in the
vsyscall page.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: xen-devel <xen-devel@lists.xensource.com>
Cc: Stephen Tweedie <sct@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent ada85708

arch/x86/kernel/vsyscall_64.c

+6 −6
Original line number Diff line number Diff line
@@ -249,7 +249,7 @@ static ctl_table kernel_root_table2[] = { 
   doesn't violate that. We'll find out if it does. */

static void __cpuinit vsyscall_set_cpu(int cpu)

{

	unsigned long *d;

	unsigned long d;

	unsigned long node = 0;

#ifdef CONFIG_NUMA

	node = cpu_to_node(cpu);
@@ -260,11 +260,11 @@ static void __cpuinit vsyscall_set_cpu(int cpu) 
	/* Store cpu number in limit so that it can be loaded quickly

	   in user space in vgetcpu.

	   12 bits for the CPU and 8 bits for the node. */

	d = (unsigned long *)(get_cpu_gdt_table(cpu) + GDT_ENTRY_PER_CPU);

	*d = 0x0f40000000000ULL;

	*d |= cpu;

	*d |= (node & 0xf) << 12;

	*d |= (node >> 4) << 48;

	d = 0x0f40000000000ULL;

	d |= cpu;

	d |= (node & 0xf) << 12;

	d |= (node >> 4) << 48;

	write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S);

}



static void __cpuinit cpu_vsyscall_init(void *arg)