Re: [PATCH] x86/mm: don't apply va_align to hugetlb mappings on AMD F15h

[Borislav Petkov]

On Sat, Sep 19, 2026 at 10:47:46AM +0200, Laurent Wandrebeck wrote:
> Here’s the « v2 » patch I used instead, on top of 7.3-rc3.
> Works without problem (several hours uptime).
> If this looks ok to you,

I can't complain about that too much, but let's see what Dave thinks.

Dave?
 
> diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
> index 776ae6fa7f2d..a54f930e2c9a 100644
> --- a/arch/x86/kernel/sys_x86_64.c
> +++ b/arch/x86/kernel/sys_x86_64.c
> @@ -28,7 +28,7 @@
>   */
>  static unsigned long get_align_mask(struct file *filp)
>  {
> -       if (filp && is_file_hugepages(filp))
> +       if (is_file_hugepages(filp))
>                 return huge_page_mask_align(filp);
>         /* handle 32- and 64-bit case with a single conditional */
>         if (va_align.flags < 0 || !(va_align.flags & (2 - mmap_is_ia32())))
> @@ -50,9 +50,13 @@ static unsigned long get_align_mask(struct file *filp)
>   * value before calling vm_unmapped_area() or ORed directly to the
>   * address.
>   */
> -static unsigned long get_align_bits(void)
> +static unsigned long get_align_bits(struct file *filp)
>  {
> -       return va_align.bits & get_align_mask(NULL);
> +       /* hugetlb mappings must stay on the huge page boundary. */
> +       if (is_file_hugepages(filp))
> +               return 0;
> +
> +       return va_align.bits & get_align_mask(filp);
>  }
>  
>  static int __init control_va_addr_alignment(char *str)
> @@ -157,7 +161,7 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len,
>         }
>         if (filp) {
>                 info.align_mask = get_align_mask(filp);
> -               info.align_offset += get_align_bits();
> +               info.align_offset += get_align_bits(filp);
>         }
>  
>         return vm_unmapped_area(&info);
> @@ -222,7 +226,7 @@ arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr0,
>  
>         if (filp) {
>                 info.align_mask = get_align_mask(filp);
> -               info.align_offset += get_align_bits();
> +               info.align_offset += get_align_bits(filp);
>         }
>         addr = vm_unmapped_area(&info);
>         if (!(addr & ~PAGE_MASK))
> 
> -- 
> Laurent Wandrebeck <l.wandrebeck@xxxxxxxxxxxxxxx>

-- 
Regards/Gruss,
    Boris.

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