linux/arch/x86/kernel/smpcommon.c
Alex Nixon fc0091b3c8 x86: change init_gdt to update the gdt via write_gdt, rather than a direct write.
By writing directly, a memory access violation can occur whilst
hotplugging a CPU if the entry was previously marked read-only.

Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Cc: Jeremy Fitzhardinge <Jeremy.Fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-08-15 19:16:05 +02:00

30 lines
729 B
C

/*
* SMP stuff which is common to all sub-architectures.
*/
#include <linux/module.h>
#include <asm/smp.h>
#ifdef CONFIG_X86_32
DEFINE_PER_CPU(unsigned long, this_cpu_off);
EXPORT_PER_CPU_SYMBOL(this_cpu_off);
/*
* Initialize the CPU's GDT. This is either the boot CPU doing itself
* (still using the master per-cpu area), or a CPU doing it for a
* secondary which will soon come up.
*/
__cpuinit void init_gdt(int cpu)
{
struct desc_struct gdt;
pack_descriptor(&gdt, __per_cpu_offset[cpu], 0xFFFFF,
0x2 | DESCTYPE_S, 0x8);
gdt.s = 1;
write_gdt_entry(get_cpu_gdt_table(cpu),
GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
per_cpu(this_cpu_off, cpu) = __per_cpu_offset[cpu];
per_cpu(cpu_number, cpu) = cpu;
}
#endif