Xen i386 xen-head.S fix sections mixup

Xen i386 xen-head.S fix sections mixup

xen-head.S does not come back to the data section, leaving the text section
as current section. It causes problems with a slightly enhanced DEBUG_RODATA
that supports CONFIG_HOTPLUG and bringing a CPU up after the text has been
marked read-only: reference to early_gdt_descr causes a page fault.

Updates:

- It should be using pushsection/popsection.
- Actually, the push/popsections around the ELFNOTEs are redundant; ELFNOTE()
  does its own push/popsection to put things into the appropriate .note* section
  anyway.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Acked-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/i386/xen/xen-head.S

@@ -7,20 +7,20 @@
 #include <asm/boot.h>
 #include <xen/interface/elfnote.h>
 
-	.section .init.text
+.pushsection .init.text
 ENTRY(startup_xen)
 	movl %esi,xen_start_info
 	cld
 	movl $(init_thread_union+THREAD_SIZE),%esp
 	jmp xen_start_kernel
+.popsection
 
-.pushsection ".bss.page_aligned"
+.pushsection .bss.page_aligned
 	.align PAGE_SIZE_asm
 ENTRY(hypercall_page)
 	.skip 0x1000
 .popsection
 
-	.section .text
 	ELFNOTE(Xen, XEN_ELFNOTE_GUEST_OS,       .asciz "linux")
 	ELFNOTE(Xen, XEN_ELFNOTE_GUEST_VERSION,  .asciz "2.6")
 	ELFNOTE(Xen, XEN_ELFNOTE_XEN_VERSION,    .asciz "xen-3.0")