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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index af88b27..0c152c8 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -957,6 +957,10 @@ 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 0fde293..111eb35 100644 (file)
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -27,7 +27,7 @@ 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 9f009cc..fe86275 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -267,7 +267,7 @@ notrace static void __cpuinit 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 6001365..2132ffd 100644 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -606,7 +606,7 @@ 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