From 10a4f6657b2437bb8a76e2796e0072ec47cea4ae Mon Sep 17 00:00:00 2001
From: Matt Mackall <mpm@selenic.com>
Date: Sun, 8 Jan 2006 01:05:24 -0800
Subject: [PATCH] --- yaml --- r: 17047 b: refs/heads/master c:
 22c4e3084eb8b88288a622a57d8b35c450a439f2 h: refs/heads/master i:   17045:
 f59de15ddc812f0e00145f205e6fde70502cc2a5   17043:
 1f4315cc50c35ae652d301b8ae87ad972e1b46f2   17039:
 3a17548b25641096e2c1f15009c96bf3cae7f83b v: v3

---
 [refs]                              | 2 +-
 trunk/arch/i386/kernel/Makefile     | 3 ++-
 trunk/arch/i386/kernel/cpu/common.c | 2 ++
 trunk/init/Kconfig                  | 9 +++++++++
 4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index 522842a87bd4..3eee02317aa0 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 18e92b12e83bef077a31ba6871f1aec3621b69e3
+refs/heads/master: 22c4e3084eb8b88288a622a57d8b35c450a439f2
diff --git a/trunk/arch/i386/kernel/Makefile b/trunk/arch/i386/kernel/Makefile
index f10de0f2c5e6..4f40589e179c 100644
--- a/trunk/arch/i386/kernel/Makefile
+++ b/trunk/arch/i386/kernel/Makefile
@@ -7,7 +7,7 @@ extra-y := head.o init_task.o vmlinux.lds
 obj-y	:= process.o semaphore.o signal.o entry.o traps.o irq.o vm86.o \
 		ptrace.o time.o ioport.o ldt.o setup.o i8259.o sys_i386.o \
 		pci-dma.o i386_ksyms.o i387.o dmi_scan.o bootflag.o \
-		doublefault.o quirks.o i8237.o
+		quirks.o i8237.o
 
 obj-y				+= cpu/
 obj-y				+= timers/
@@ -33,6 +33,7 @@ obj-y				+= sysenter.o vsyscall.o
 obj-$(CONFIG_ACPI_SRAT) 	+= srat.o
 obj-$(CONFIG_HPET_TIMER) 	+= time_hpet.o
 obj-$(CONFIG_EFI) 		+= efi.o efi_stub.o
+obj-$(CONFIG_DOUBLEFAULT) 	+= doublefault.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o
 
 EXTRA_AFLAGS   := -traditional
diff --git a/trunk/arch/i386/kernel/cpu/common.c b/trunk/arch/i386/kernel/cpu/common.c
index cca655688ffc..170400879f44 100644
--- a/trunk/arch/i386/kernel/cpu/common.c
+++ b/trunk/arch/i386/kernel/cpu/common.c
@@ -609,8 +609,10 @@ void __devinit cpu_init(void)
 	load_TR_desc();
 	load_LDT(&init_mm.context);
 
+#ifdef CONFIG_DOUBLEFAULT
 	/* Set up doublefault TSS pointer in the GDT */
 	__set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, &doublefault_tss);
+#endif
 
 	/* Clear %fs and %gs. */
 	asm volatile ("xorl %eax, %eax; movl %eax, %fs; movl %eax, %gs");
diff --git a/trunk/init/Kconfig b/trunk/init/Kconfig
index 0c9932f9f06b..0eb65f2ad8c9 100644
--- a/trunk/init/Kconfig
+++ b/trunk/init/Kconfig
@@ -309,6 +309,15 @@ config BUG
           option for embedded systems with no facilities for reporting errors.
           Just say Y.
 
+config DOUBLEFAULT
+	depends X86
+	default y if X86
+	bool "Enable doublefault exception handler" if EMBEDDED
+	help
+          This option allows trapping of rare doublefault exceptions that
+          would otherwise cause a system to silently reboot. Disabling this
+          option saves about 4k.
+
 config BASE_FULL
 	default y
 	bool "Enable full-sized data structures for core" if EMBEDDED