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charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 11/15/22 19:32, Catalin Marinas wrote: > On Sun, Nov 13, 2022 at 06:56:45AM +0530, Anshuman Khandual wrote: >> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c >> index 35e9a468d13e..6552947ca7fa 100644 >> --- a/arch/arm64/mm/hugetlbpage.c >> +++ b/arch/arm64/mm/hugetlbpage.c >> @@ -559,3 +559,24 @@ bool __init arch_hugetlb_valid_size(unsigned long size) >> { >> return __hugetlb_valid_size(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); > > Not sure whether the generated code would be any different but we should > probably add the check for the CPU capability in the 'if' condition > above, before the READ_ONCE (which expands to some asm volatile): Sure, will do. > > if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_2645198) && > cpus_have_const_cap(ARM64_WORKAROUND_2645198)) { > pte_t pte = ... > ... > } The local variable 'pte_t pte' can be dropped as well. > >> + /* >> + * 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)) >> + return huge_ptep_clear_flush(vma, addr, ptep); >> + } >> + return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep); >> +} >> + >> +void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, >> + pte_t old_pte, pte_t pte) >> +{ >> + set_huge_pte_at(vma->vm_mm, addr, ptep, pte); >> +} >> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c >> index 9a7c38965154..c1fb0ce1473c 100644 >> --- a/arch/arm64/mm/mmu.c >> +++ b/arch/arm64/mm/mmu.c >> @@ -1702,3 +1702,24 @@ static int __init prevent_bootmem_remove_init(void) >> } >> early_initcall(prevent_bootmem_remove_init); >> #endif >> + >> +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); >> + /* >> + * 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)) >> + return ptep_clear_flush(vma, addr, ptep); >> + } > > Same here. Sure, will do. > >> + return ptep_get_and_clear(vma->vm_mm, addr, ptep); >> +} >> + >> +void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, >> + pte_t old_pte, pte_t pte) >> +{ >> + __set_pte_at(vma->vm_mm, addr, ptep, pte); >> +} > 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); _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel