Commit 22c4e308 authored by Matt Mackall's avatar Matt Mackall Committed by Linus Torvalds
Browse files

[PATCH] tiny: Make x86 doublefault handling optional 



This adds configurable support for doublefault reporting on x86

add/remove: 0/3 grow/shrink: 0/1 up/down: 0/-13048 (-13048)
function                                     old     new   delta
cpu_init                                     846     786     -60
doublefault_fn                               188       -    -188
doublefault_stack                           4096       -   -4096
doublefault_tss                             8704       -   -8704

Signed-off-by: default avatarMatt Mackall <mpm@selenic.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 18e92b12

arch/i386/kernel/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -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

arch/i386/kernel/cpu/common.c

+2 −0
Original line number Diff line number Diff line
@@ -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");

init/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -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

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