From 9172b5c4a778da1f855b2e3780b1afabb3cfd523 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Thu, 30 Sep 2021 14:16:15 +0200 Subject: xen/x86: prevent PVH type from getting clobbered Like xen_start_flags, xen_domain_type gets set before .bss gets cleared. Hence this variable also needs to be prevented from getting put in .bss, which is possible because XEN_NATIVE is an enumerator evaluating to zero. Any use prior to init_hvm_pv_info() setting the variable again would lead to wrong decisions; one such case is xenboot_console_setup() when called as a result of "earlyprintk=xen". Use __ro_after_init as more applicable than either __section(".data") or __read_mostly. Signed-off-by: Jan Beulich Reviewed-by: Juergen Gross Link: https://lore.kernel.org/r/d301677b-6f22-5ae6-bd36-458e1f323d0b@suse.com Signed-off-by: Juergen Gross --- arch/x86/xen/enlighten.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'arch/x86') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index c79bd0af2e8c..f252faf5028f 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -52,9 +52,6 @@ DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); DEFINE_PER_CPU(uint32_t, xen_vcpu_id); EXPORT_PER_CPU_SYMBOL(xen_vcpu_id); -enum xen_domain_type xen_domain_type = XEN_NATIVE; -EXPORT_SYMBOL_GPL(xen_domain_type); - unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START; EXPORT_SYMBOL(machine_to_phys_mapping); unsigned long machine_to_phys_nr; @@ -69,9 +66,11 @@ __read_mostly int xen_have_vector_callback; EXPORT_SYMBOL_GPL(xen_have_vector_callback); /* - * NB: needs to live in .data because it's used by xen_prepare_pvh which runs - * before clearing the bss. + * NB: These need to live in .data or alike because they're used by + * xen_prepare_pvh() which runs before clearing the bss. */ +enum xen_domain_type __ro_after_init xen_domain_type = XEN_NATIVE; +EXPORT_SYMBOL_GPL(xen_domain_type); uint32_t xen_start_flags __section(".data") = 0; EXPORT_SYMBOL(xen_start_flags); -- cgit