Commit 992af681 authored by Rusty Russell's avatar Rusty Russell Committed by Andi Kleen
Browse files

[PATCH] i386: paravirt unhandled fallthrough 



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: default avatarRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
parent 9af3cf05

arch/i386/kernel/Makefile

+0 −2
Original line number Diff line number Diff line
@@ -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

arch/i386/kernel/head.S

+6 −1
Original line number Diff line number Diff line
@@ -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



/*

arch/i386/kernel/paravirt.c

+0 −3
Original line number Diff line number Diff line
@@ -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,

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