Re: [PATCH 19/34] x86, pkeys: optimize fault handling in access_error()

From: Thomas Gleixner
Date: Tue Dec 08 2015 - 13:15:46 EST


On Thu, 3 Dec 2015, Dave Hansen wrote:
> diff -puN arch/x86/mm/fault.c~pkeys-15-access_error arch/x86/mm/fault.c
> --- a/arch/x86/mm/fault.c~pkeys-15-access_error 2015-12-03 16:21:26.872727820 -0800
> +++ b/arch/x86/mm/fault.c 2015-12-03 16:21:26.876728002 -0800
> @@ -900,10 +900,16 @@ bad_area(struct pt_regs *regs, unsigned
> static inline bool bad_area_access_from_pkeys(unsigned long error_code,
> struct vm_area_struct *vma)
> {
> + /* This code is always called on the current mm */
> + int foreign = 0;

arch_vma_access_permitted takes a bool ....

> if (!boot_cpu_has(X86_FEATURE_OSPKE))
> return false;
> if (error_code & PF_PK)
> return true;
> + /* this checks permission keys on the VMA: */
> + if (!arch_vma_access_permitted(vma, (error_code & PF_WRITE), foreign))
> + return true;
> return false;
> }
>
> @@ -1091,6 +1097,8 @@ int show_unhandled_signals = 1;
> static inline int
> access_error(unsigned long error_code, struct vm_area_struct *vma)
> {
> + /* This is only called for the current mm, so: */
> + int foreign = 0;

Ditto.

Other than that: Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/