x86-64: Handle PC-relative relocations on per-CPU data

This is in preparation of using RIP-relative addressing in many of the
per-CPU accesses.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/5458A15A0200007800044A9A@mail.emea.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c
index 57ab74d..644abd7 100644
--- a/arch/x86/boot/compressed/misc.c
+++ b/arch/x86/boot/compressed/misc.c
@@ -260,7 +260,7 @@
 
 	/*
 	 * Process relocations: 32 bit relocations first then 64 bit after.
-	 * Two sets of binary relocations are added to the end of the kernel
+	 * Three sets of binary relocations are added to the end of the kernel
 	 * before compression. Each relocation table entry is the kernel
 	 * address of the location which needs to be updated stored as a
 	 * 32-bit value which is sign extended to 64 bits.
@@ -270,6 +270,8 @@
 	 * kernel bits...
 	 * 0 - zero terminator for 64 bit relocations
 	 * 64 bit relocation repeated
+	 * 0 - zero terminator for inverse 32 bit relocations
+	 * 32 bit inverse relocation repeated
 	 * 0 - zero terminator for 32 bit relocations
 	 * 32 bit relocation repeated
 	 *
@@ -286,6 +288,16 @@
 		*(uint32_t *)ptr += delta;
 	}
 #ifdef CONFIG_X86_64
+	while (*--reloc) {
+		long extended = *reloc;
+		extended += map;
+
+		ptr = (unsigned long)extended;
+		if (ptr < min_addr || ptr > max_addr)
+			error("inverse 32-bit relocation outside of kernel!\n");
+
+		*(int32_t *)ptr -= delta;
+	}
 	for (reloc--; *reloc; reloc--) {
 		long extended = *reloc;
 		extended += map;