On Wed, Nov 16, 2022 at 10:12:34AM +0530, Anshuman Khandual wrote:
> Planning to apply the following change after this patch.
>
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index 6552947ca7fa..cd8d96e1fa1a 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -562,14 +562,14 @@ bool __init arch_hugetlb_valid_size(unsigned long size)
>
> pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
> {
> - if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_2645198)) {
> - pte_t pte = READ_ONCE(*ptep);
> + if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_2645198) &&
> + cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
> /*
> * Break-before-make (BBM) is required for all user space mappings
> * when the permission changes from executable to non-executable
> * in cases where cpu is affected with errata #2645198.
> */
> - if (pte_user_exec(pte) && cpus_have_const_cap(ARM64_WORKAROUND_2645198))
> + if (pte_user_exec(READ_ONCE(*ptep)))
> return huge_ptep_clear_flush(vma, addr, ptep);
> }
> return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index c1fb0ce1473c..ec305ea3942c 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1705,14 +1705,14 @@ early_initcall(prevent_bootmem_remove_init);
>
> pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
> {
> - if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_2645198)) {
> - pte_t pte = READ_ONCE(*ptep);
> + if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_2645198) &&
> + cpus_have_const_cap(ARM64_WORKAROUND_2645198)) {
> /*
> * Break-before-make (BBM) is required for all user space mappings
> * when the permission changes from executable to non-executable
> * in cases where cpu is affected with errata #2645198.
> */
> - if (pte_user_exec(pte) && cpus_have_const_cap(ARM64_WORKAROUND_2645198))
> + if (pte_user_exec(READ_ONCE(*ptep)))
> return ptep_clear_flush(vma, addr, ptep);
> }
> return ptep_get_and_clear(vma->vm_mm, addr, ptep);
It looks fine to me. Thanks.
--
Catalin
