x86: move stack_canary into irq_stack

Impact: x86_64 percpu area layout change, irq_stack now at the beginning

Now that the PDA is empty except for the stack canary, it can be removed.
The irqstack is moved to the start of the per-cpu section.  If the stack
protector is enabled, the canary overlaps the bottom 48 bytes of the irqstack.

tj: * updated subject
    * dropped asm relocation of irq_stack_ptr
    * updated comments a bit
    * rebased on top of stack canary changes

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 0 insertions, 4 deletions

diff --git a/arch/x86/kernel/asm-offsets_64.c b/arch/x86/kernel/asm-offsets_64.c
index 64c834a39aa8..94f9c8b39d20 100644
--- a/arch/x86/kernel/asm-offsets_64.c
+++ b/arch/x86/kernel/asm-offsets_64.c
@@ -48,10 +48,6 @@ int main(void)
 #endif
         BLANK();
 #undef ENTRY
-#define ENTRY(entry) DEFINE(pda_ ## entry, offsetof(struct x8664_pda, entry))
-        DEFINE(pda_size, sizeof(struct x8664_pda));
-        BLANK();
-#undef ENTRY
 #ifdef CONFIG_PARAVIRT
         BLANK();
         OFFSET(PARAVIRT_enabled, pv_info, paravirt_enabled);