Commit cf7df13d authored Jun 30, 2016 by Marc Zyngier Committed by Christoffer Dall Jul 03, 2016

arm64: KVM: Always reference __hyp_panic_string via its kernel VA



__hyp_panic_string is passed via the HYP panic code to the panic
function, and is being "upgraded" to a kernel address, as it is
referenced by the HYP code (in a PC-relative way).

This is a bit silly, and we'd be better off obtaining the kernel
address and not mess with it at all. This patch implements this
with a tiny bit of asm glue, by forcing the string pointer to be
read from the literal pool.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

parent 82a81bff

arch/arm64/kvm/hyp/switch.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -299,9 +299,16 @@ static const char __hyp_panic_string[] = "HYP panic:\nPS:%08llx PC:%016llx ESR:%

		static void __hyp_text __hyp_call_panic_nvhe(u64 spsr, u64 elr, u64 par)
		{
		unsigned long str_va = (unsigned long)__hyp_panic_string;
		unsigned long str_va;

		__hyp_do_panic(hyp_kern_va(str_va),
		/*
		* Force the panic string to be loaded from the literal pool,
		* making sure it is a kernel address and not a PC-relative
		* reference.
		*/
		asm volatile("ldr %0, =__hyp_panic_string" : "=r" (str_va));

		__hyp_do_panic(str_va,
		spsr, elr,
		read_sysreg(esr_el2), read_sysreg_el2(far),
		read_sysreg(hpfar_el2), par,