x86, espfix: Make espfix64 a Kconfig option, fix UML

commit 197725de65477bc8509b41388157c1a2283542bb upstream.

Make espfix64 a hidden Kconfig option.  This fixes the x86-64 UML
build which had broken due to the non-existence of init_espfix_bsp()
in UML: since UML uses its own Kconfig, this option does not appear in
the UML build.

This also makes it possible to make support for 16-bit segments a
configuration option, for the people who want to minimize the size of
the kernel.

Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Richard Weinberger <richard@nod.at>
Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 9dc1a24d41b83c0a6db22fb82a438f817c4d8078..b423c245595f7c908b77722ce05807accd06dd8a 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -978,6 +978,10 @@ config VM86
          XFree86 to initialize some video cards via BIOS. Disabling this
          option saves about 6k.
 
+config X86_ESPFIX64
+       def_bool y
+       depends on X86_64
+
 config TOSHIBA
        tristate "Toshiba Laptop support"
        depends on X86_32

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index d5c94c90716be7f4bdd235d693e96eff8b34d2f3..32f114091e97ef23cb1249674a6c4311cb8be167 100644 (file)
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -29,7 +29,7 @@ obj-$(CONFIG_X86_64)  += sys_x86_64.o x8664_ksyms_64.o
 obj-y                  += syscall_$(BITS).o
 obj-$(CONFIG_X86_64)   += vsyscall_64.o
 obj-$(CONFIG_X86_64)   += vsyscall_emu_64.o
-obj-$(CONFIG_X86_64)   += espfix_64.o
+obj-$(CONFIG_X86_ESPFIX64)     += espfix_64.o
 obj-y                  += bootflag.o e820.o
 obj-y                  += pci-dma.o quirks.o topology.o kdebugfs.o
 obj-y                  += alternative.o i8253.o pci-nommu.o hw_breakpoint.o

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index a7340d7d6d062d6b8554ea39d09d3ae60bfe9ef9..42c26a485533d8a42e3eb6b07f0800a5d98af86d 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -267,7 +267,7 @@ static void notrace start_secondary(void *unused)
        /*
         * Enable the espfix hack for this CPU
         */
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_X86_ESPFIX64
        init_espfix_ap();
 #endif
 

diff --git a/init/main.c b/init/main.c
index 8e35b39b5a802da3313afc636be4c2c70b9db966..18122186526630afbcd6230aeabfb7c5757a0c94 100644 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -610,7 +610,7 @@ asmlinkage void __init start_kernel(void)
        if (efi_enabled(EFI_RUNTIME_SERVICES))
                efi_enter_virtual_mode();
 #endif
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_X86_ESPFIX64
        /* Should be run before the first non-init thread is created */
        init_espfix_bsp();
 #endif