x86: load new GDT after setting up boot cpu per-cpu area
Impact: sync 32 and 64-bit code
Merge load_gs_base() into switch_to_new_gdt(). Load the GDT and
per-cpu state for the boot cpu when its new area is set up.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 67e30c8..0c766b8 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -258,12 +258,17 @@
void switch_to_new_gdt(void)
{
struct desc_ptr gdt_descr;
+ int cpu = smp_processor_id();
- gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id());
+ gdt_descr.address = (long)get_cpu_gdt_table(cpu);
gdt_descr.size = GDT_SIZE - 1;
load_gdt(&gdt_descr);
+ /* Reload the per-cpu base */
#ifdef CONFIG_X86_32
- asm("mov %0, %%fs" : : "r" (__KERNEL_PERCPU) : "memory");
+ loadsegment(fs, __KERNEL_PERCPU);
+#else
+ loadsegment(gs, 0);
+ wrmsrl(MSR_GS_BASE, (unsigned long)per_cpu(irq_stack_union.gs_base, cpu));
#endif
}
@@ -968,10 +973,6 @@
struct task_struct *me;
int i;
- loadsegment(fs, 0);
- loadsegment(gs, 0);
- load_gs_base(cpu);
-
#ifdef CONFIG_NUMA
if (cpu != 0 && percpu_read(node_number) == 0 &&
cpu_to_node(cpu) != NUMA_NO_NODE)
@@ -993,6 +994,8 @@
*/
switch_to_new_gdt();
+ loadsegment(fs, 0);
+
load_idt((const struct desc_ptr *)&idt_descr);
memset(me->thread.tls_array, 0, GDT_ENTRY_TLS_ENTRIES * 8);
diff --git a/arch/x86/kernel/setup_percpu.c b/arch/x86/kernel/setup_percpu.c
index bcca3a7..4caa78d 100644
--- a/arch/x86/kernel/setup_percpu.c
+++ b/arch/x86/kernel/setup_percpu.c
@@ -113,13 +113,13 @@
per_cpu(x86_cpu_to_node_map, cpu) =
early_per_cpu_map(x86_cpu_to_node_map, cpu);
#endif
+#endif
/*
* Up to this point, the boot CPU has been using .data.init
- * area. Reload %gs offset for the boot CPU.
+ * area. Reload any changed state for the boot CPU.
*/
if (cpu == boot_cpu_id)
- load_gs_base(cpu);
-#endif
+ switch_to_new_gdt();
DBG("PERCPU: cpu %4d %p\n", cpu, ptr);
}