From f7482771395535e1d216d0ad0891f4caed01d989 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 26 Oct 2021 07:39:24 +0200 Subject: [PATCH] powerpc/nohash: Fix __ptep_set_access_flags() and ptep_set_wrprotect() [ Upstream commit b1b93cb7e794e914787bf7d9936b57a149cdee4f ] Commit 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code") changed those two functions to use pte helpers to determine which bits to clear and which bits to set. This change was based on the assumption that bits to be set/cleared are always the same and can be determined by applying the pte manipulation helpers on __pte(0). But on platforms like book3e, the bits depend on whether the page is a user page or not. For the time being it more or less works because of _PAGE_EXEC being used for user pages only and exec right being set at all time on kernel page. But following patch will clean that and output of pte_mkexec() will depend on the page being a user or kernel page. Instead of trying to make an even more complicated helper where bits would become dependent on the final pte value, come back to a more static situation like before commit 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code"), by introducing an 8xx specific version of __ptep_set_access_flags() and ptep_set_wrprotect(). Fixes: 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/922bdab3a220781bae2360ff3dd5adb7fe4d34f1.1635226743.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin --- arch/powerpc/include/asm/nohash/32/pgtable.h | 17 ++++++++--------- arch/powerpc/include/asm/nohash/32/pte-8xx.h | 22 ++++++++++++++++++++++ 2 files changed, 30 insertions(+), 9 deletions(-) diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h index f06ae00..ac0a5ff 100644 --- a/arch/powerpc/include/asm/nohash/32/pgtable.h +++ b/arch/powerpc/include/asm/nohash/32/pgtable.h @@ -306,30 +306,29 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, } #define __HAVE_ARCH_PTEP_SET_WRPROTECT +#ifndef ptep_set_wrprotect static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { - unsigned long clr = ~pte_val(pte_wrprotect(__pte(~0))); - unsigned long set = pte_val(pte_wrprotect(__pte(0))); - - pte_update(mm, addr, ptep, clr, set, 0); + pte_update(mm, addr, ptep, _PAGE_RW, 0, 0); } +#endif +#ifndef __ptep_set_access_flags static inline void __ptep_set_access_flags(struct vm_area_struct *vma, pte_t *ptep, pte_t entry, unsigned long address, int psize) { - pte_t pte_set = pte_mkyoung(pte_mkdirty(pte_mkwrite(pte_mkexec(__pte(0))))); - pte_t pte_clr = pte_mkyoung(pte_mkdirty(pte_mkwrite(pte_mkexec(__pte(~0))))); - unsigned long set = pte_val(entry) & pte_val(pte_set); - unsigned long clr = ~pte_val(entry) & ~pte_val(pte_clr); + unsigned long set = pte_val(entry) & + (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC); int huge = psize > mmu_virtual_psize ? 1 : 0; - pte_update(vma->vm_mm, address, ptep, clr, set, huge); + pte_update(vma->vm_mm, address, ptep, 0, set, huge); flush_tlb_page(vma, address); } +#endif static inline int pte_young(pte_t pte) { diff --git a/arch/powerpc/include/asm/nohash/32/pte-8xx.h b/arch/powerpc/include/asm/nohash/32/pte-8xx.h index fcc48d5..1a89ebd 100644 --- a/arch/powerpc/include/asm/nohash/32/pte-8xx.h +++ b/arch/powerpc/include/asm/nohash/32/pte-8xx.h @@ -136,6 +136,28 @@ static inline pte_t pte_mkhuge(pte_t pte) #define pte_mkhuge pte_mkhuge +static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p, + unsigned long clr, unsigned long set, int huge); + +static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) +{ + pte_update(mm, addr, ptep, 0, _PAGE_RO, 0); +} +#define ptep_set_wrprotect ptep_set_wrprotect + +static inline void __ptep_set_access_flags(struct vm_area_struct *vma, pte_t *ptep, + pte_t entry, unsigned long address, int psize) +{ + unsigned long set = pte_val(entry) & (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_EXEC); + unsigned long clr = ~pte_val(entry) & _PAGE_RO; + int huge = psize > mmu_virtual_psize ? 1 : 0; + + pte_update(vma->vm_mm, address, ptep, clr, set, huge); + + flush_tlb_page(vma, address); +} +#define __ptep_set_access_flags __ptep_set_access_flags + static inline unsigned long pgd_leaf_size(pgd_t pgd) { if (pgd_val(pgd) & _PMD_PAGE_8M) -- 2.7.4