From cf7df13d3c7c7f8a475c09ef49a5b72f7cfe3f4b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 30 Jun 2016 18:40:35 +0100 Subject: [PATCH] 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 Signed-off-by: Christoffer Dall --- arch/arm64/kvm/hyp/switch.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 437cfad5e3d8..81f21a2ab968 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -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, -- GitLab