x86: use linker to offset symbols by __per_cpu_load

Impact: cleanup and bug fix

Use the linker to create symbols for certain per-cpu variables
that are offset by __per_cpu_load.  This allows the removal of
the runtime fixup of the GDT pointer, which fixes a bug with
resume reported by Jiri Slaby.

Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 5 deletions

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 0f73ea423089..41b0de6df873 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -902,12 +902,8 @@ struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };
 
 DEFINE_PER_CPU_FIRST(union irq_stack_union,
                      irq_stack_union) __aligned(PAGE_SIZE);
-#ifdef CONFIG_SMP
-DEFINE_PER_CPU(char *, irq_stack_ptr);  /* will be set during per cpu init */
-#else
 DEFINE_PER_CPU(char *, irq_stack_ptr) =
-        per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
-#endif
+        init_per_cpu_var(irq_stack_union.irq_stack) + IRQ_STACK_SIZE - 64;
 
 DEFINE_PER_CPU(unsigned long, kernel_stack) =
         (unsigned long)&init_thread_union - KERNEL_STACK_OFFSET + THREAD_SIZE;