On Tue, Apr 02, 2013 at 02:25:12PM +0100, Marc Zyngier wrote: > We're about to move to a init procedure where we rely on the > fact that the init code fits in a single page. Make sure we > align the idmap text on a page boundary, and that the code is > not bigger than a single page. > > Signed-off-by: Marc Zyngier <[email protected]> > --- > arch/arm/kernel/vmlinux.lds.S | 2 +- > arch/arm/kvm/init.S | 7 +++++++ > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S > index b571484..d9dd265 100644 > --- a/arch/arm/kernel/vmlinux.lds.S > +++ b/arch/arm/kernel/vmlinux.lds.S > @@ -20,7 +20,7 @@ > VMLINUX_SYMBOL(__idmap_text_start) = .; \ > *(.idmap.text) \ > VMLINUX_SYMBOL(__idmap_text_end) = .; \ > - ALIGN_FUNCTION(); \ > + . = ALIGN(PAGE_SIZE); \ > VMLINUX_SYMBOL(__hyp_idmap_text_start) = .; \ > *(.hyp.idmap.text) \ > VMLINUX_SYMBOL(__hyp_idmap_text_end) = .; > diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S > index 9f37a79..35a463f 100644 > --- a/arch/arm/kvm/init.S > +++ b/arch/arm/kvm/init.S > @@ -111,4 +111,11 @@ __do_hyp_init: > .globl __kvm_hyp_init_end > __kvm_hyp_init_end: > > + /* > + * The above code *must* fit in a single page for the trampoline > + * madness to work. Whoever decides to change it must make sure > + * we map the right amount of memory for the trampoline to work. > + * The line below ensures any breakage will get noticed. > + */ > + .org __kvm_hyp_init + PAGE_SIZE > .popsection
What effect does this have on the size of the kernel image? I'd expect the idmap code to be pretty small, so aligning to a page might be overkill a lot of the time. Will -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
