| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.19 49/49] x86/Xen: swap NX determination and GDT setup on BSP | Date | Mon, 24 May 2021 17:26:00 +0200 |
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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 @@ -1246,16 +1246,16 @@ 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);
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