5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefano Stabellini <sstabellini@xxxxxxxxxx> [ Upstream commit 7bf9a6b46549852a37e6d07e52c601c3c706b562 ] xen_vcpu_info is a percpu area than needs to be mapped by Xen. Currently, it could cross a page boundary resulting in Xen being unable to map it: [ 0.567318] kernel BUG at arch/arm64/xen/../../arm/xen/enlighten.c:164! [ 0.574002] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Fix the issue by using __alloc_percpu and requesting alignment for the memory allocation. Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxx> Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2311221501340.2053963@ubuntu-linux-20-04-desktop Fixes: 24d5373dda7c ("arm/xen: Use alloc_percpu rather than __alloc_percpu") Reviewed-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/arm/xen/enlighten.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 57dfc13b27529..c4d1cac0fe32d 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -354,7 +354,8 @@ static int __init xen_guest_init(void) * for secondary CPUs as they are brought up. * For uniformity we use VCPUOP_register_vcpu_info even on cpu0. */ - xen_vcpu_info = alloc_percpu(struct vcpu_info); + xen_vcpu_info = __alloc_percpu(sizeof(struct vcpu_info), + 1 << fls(sizeof(struct vcpu_info) - 1)); if (xen_vcpu_info == NULL) return -ENOMEM; -- 2.42.0
