Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | [PATCH x86 for review III] [25/29] i386: paravirt unhandled fallthrough | Date | Mon, 12 Feb 2007 17:51:46 +0100 (CET) |
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From: Rusty Russell <rusty@rustcorp.com.au> The current code simply calls "start_kernel" directly if we're under a hypervisor and no paravirt_ops backend wants us, because paravirt.c registers that as a backend.
This was always a vain hope; start_kernel won't get far without setup. It's also impossible for paravirt_ops backends which don't sit in the arch/i386/kernel directory: they can't link before paravirt.o anyway.
Keep it simple: if we pass all the registered paravirt probes, BUG().
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andi Kleen <ak@suse.de>
--- arch/i386/kernel/Makefile | 2 -- arch/i386/kernel/head.S | 7 ++++++- arch/i386/kernel/paravirt.c | 3 --- 3 files changed, 6 insertions(+), 6 deletions(-)
Index: linux/arch/i386/kernel/Makefile =================================================================== --- linux.orig/arch/i386/kernel/Makefile +++ linux/arch/i386/kernel/Makefile @@ -41,8 +41,6 @@ obj-$(CONFIG_HPET_TIMER) += hpet.o obj-$(CONFIG_K8_NB) += k8.o obj-$(CONFIG_VMI) += vmi.o vmitime.o - -# Make sure this is linked after any other paravirt_ops structs: see head.S obj-$(CONFIG_PARAVIRT) += paravirt.o EXTRA_AFLAGS := -traditional Index: linux/arch/i386/kernel/head.S =================================================================== --- linux.orig/arch/i386/kernel/head.S +++ linux/arch/i386/kernel/head.S @@ -513,10 +513,11 @@ startup_paravirt: pushl %ecx pushl %eax - /* paravirt.o is last in link, and that probe fn never returns */ pushl $__start_paravirtprobe 1: movl 0(%esp), %eax + cmpl $__stop_paravirtprobe, %eax + je unhandled_paravirt pushl (%eax) movl 8(%esp), %eax call *(%esp) @@ -528,6 +529,10 @@ startup_paravirt: addl $4, (%esp) jmp 1b + +unhandled_paravirt: + /* Nothing wanted us: we're screwed. */ + ud2 #endif /* Index: linux/arch/i386/kernel/paravirt.c =================================================================== --- linux.orig/arch/i386/kernel/paravirt.c +++ linux/arch/i386/kernel/paravirt.c @@ -482,9 +482,6 @@ static int __init print_banner(void) } core_initcall(print_banner); -/* We simply declare start_kernel to be the paravirt probe of last resort. */ -paravirt_probe(start_kernel); - struct paravirt_ops paravirt_ops = { .name = "bare hardware", .paravirt_enabled = 0, - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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