From: Jan Beulich jbeulich@suse.com
commit ae897fda4f507e4b239f0bdfd578b3688ca96fb4 upstream.
xen_setup_gdt(), via xen_load_gdt_boot(), wants to adjust page tables. For this to work when NX is not available, x86_configure_nx() needs to be called first.
[jgross] Note that this is a revert of 36104cb9012a82e73 ("x86/xen: Delay get_cpu_cap until stack canary is established"), which is possible now that we no longer support running as PV guest in 32-bit mode.
Cc: <stable.vger.kernel.org> # 5.9 Fixes: 36104cb9012a82e73 ("x86/xen: Delay get_cpu_cap until stack canary is established") Reported-by: Olaf Hering olaf@aepfle.de Signed-off-by: Jan Beulich jbeulich@suse.com Reviewed-by: Juergen Gross jgross@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
Link: https://lore.kernel.org/r/12a866b0-9e89-59f7-ebeb-a2a6cec0987a@suse.com Signed-off-by: Juergen Gross jgross@suse.com --- arch/x86/xen/enlighten_pv.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -1276,16 +1276,16 @@ asmlinkage __visible void __init xen_sta /* Get mfn list */ xen_build_dynamic_phys_to_machine();
+ /* Work out if we support NX */ + get_cpu_cap(&boot_cpu_data); + x86_configure_nx(); + /* * Set up kernel GDT and segment registers, mainly so that * -fstack-protector code can be executed. */ xen_setup_gdt(0);
- /* Work out if we support NX */ - get_cpu_cap(&boot_cpu_data); - x86_configure_nx(); - /* Determine virtual and physical address sizes */ get_cpu_address_sizes(&boot_cpu_data);