From 22c4e3084eb8b88288a622a57d8b35c450a439f2 Mon Sep 17 00:00:00 2001 From: Matt Mackall Date: Sun, 8 Jan 2006 01:05:24 -0800 Subject: [PATCH] [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: Matt Mackall Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/Makefile | 3 ++- arch/i386/kernel/cpu/common.c | 2 ++ init/Kconfig | 9 +++++++++ 3 files changed, 13 insertions(+), 1 deletion(-) diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile index f10de0f2c5..4f40589e17 100644 --- a/arch/i386/kernel/Makefile +++ b/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/arch/i386/kernel/cpu/common.c b/arch/i386/kernel/cpu/common.c index cca655688f..170400879f 100644 --- a/arch/i386/kernel/cpu/common.c +++ b/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/init/Kconfig b/init/Kconfig index 0c9932f9f0..0eb65f2ad8 100644 --- a/init/Kconfig +++ b/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 -- 2.39.5