[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: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/arch/i386/kernel/Makefile b/arch/i386/kernel/Makefile
index 97f1e96..2239693 100644
--- a/arch/i386/kernel/Makefile
+++ b/arch/i386/kernel/Makefile
@@ -41,8 +41,6 @@
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
diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S
index 734be55..b322f72 100644
--- a/arch/i386/kernel/head.S
+++ b/arch/i386/kernel/head.S
@@ -513,10 +513,11 @@
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 @@
addl $4, (%esp)
jmp 1b
+
+unhandled_paravirt:
+ /* Nothing wanted us: we're screwed. */
+ ud2
#endif
/*
diff --git a/arch/i386/kernel/paravirt.c b/arch/i386/kernel/paravirt.c
index ebe8255..c156ecf 100644
--- a/arch/i386/kernel/paravirt.c
+++ b/arch/i386/kernel/paravirt.c
@@ -482,9 +482,6 @@
}
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,