From edf955647269422e387732870d04fc15933a25ea Mon Sep 17 00:00:00 2001 From: Alexandre Ghiti Date: Wed, 13 Dec 2023 21:30:01 +0100 Subject: riscv: Use accessors to page table entries instead of direct dereference As very well explained in commit 20a004e7b017 ("arm64: mm: Use READ_ONCE/WRITE_ONCE when accessing page tables"), an architecture whose page table walker can modify the PTE in parallel must use READ_ONCE()/WRITE_ONCE() macro to avoid any compiler transformation. So apply that to riscv which is such architecture. Signed-off-by: Alexandre Ghiti Acked-by: Anup Patel Link: https://lore.kernel.org/r/20231213203001.179237-5-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/pageattr.c | 44 ++++++++++++++++++++++---------------------- 1 file changed, 22 insertions(+), 22 deletions(-) (limited to 'arch/riscv/mm/pageattr.c') diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c index fc5fc4f785c4..0b5e38e018c8 100644 --- a/arch/riscv/mm/pageattr.c +++ b/arch/riscv/mm/pageattr.c @@ -29,7 +29,7 @@ static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk) static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr, unsigned long next, struct mm_walk *walk) { - p4d_t val = READ_ONCE(*p4d); + p4d_t val = p4dp_get(p4d); if (p4d_leaf(val)) { val = __p4d(set_pageattr_masks(p4d_val(val), walk)); @@ -42,7 +42,7 @@ static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr, static int pageattr_pud_entry(pud_t *pud, unsigned long addr, unsigned long next, struct mm_walk *walk) { - pud_t val = READ_ONCE(*pud); + pud_t val = pudp_get(pud); if (pud_leaf(val)) { val = __pud(set_pageattr_masks(pud_val(val), walk)); @@ -55,7 +55,7 @@ static int pageattr_pud_entry(pud_t *pud, unsigned long addr, static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long next, struct mm_walk *walk) { - pmd_t val = READ_ONCE(*pmd); + pmd_t val = pmdp_get(pmd); if (pmd_leaf(val)) { val = __pmd(set_pageattr_masks(pmd_val(val), walk)); @@ -68,7 +68,7 @@ static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr, static int pageattr_pte_entry(pte_t *pte, unsigned long addr, unsigned long next, struct mm_walk *walk) { - pte_t val = READ_ONCE(*pte); + pte_t val = ptep_get(pte); val = __pte(set_pageattr_masks(pte_val(val), walk)); set_pte(pte, val); @@ -108,10 +108,10 @@ static int __split_linear_mapping_pmd(pud_t *pudp, vaddr <= (vaddr & PMD_MASK) && end >= next) continue; - if (pmd_leaf(*pmdp)) { + if (pmd_leaf(pmdp_get(pmdp))) { struct page *pte_page; - unsigned long pfn = _pmd_pfn(*pmdp); - pgprot_t prot = __pgprot(pmd_val(*pmdp) & ~_PAGE_PFN_MASK); + unsigned long pfn = _pmd_pfn(pmdp_get(pmdp)); + pgprot_t prot = __pgprot(pmd_val(pmdp_get(pmdp)) & ~_PAGE_PFN_MASK); pte_t *ptep_new; int i; @@ -148,10 +148,10 @@ static int __split_linear_mapping_pud(p4d_t *p4dp, vaddr <= (vaddr & PUD_MASK) && end >= next) continue; - if (pud_leaf(*pudp)) { + if (pud_leaf(pudp_get(pudp))) { struct page *pmd_page; - unsigned long pfn = _pud_pfn(*pudp); - pgprot_t prot = __pgprot(pud_val(*pudp) & ~_PAGE_PFN_MASK); + unsigned long pfn = _pud_pfn(pudp_get(pudp)); + pgprot_t prot = __pgprot(pud_val(pudp_get(pudp)) & ~_PAGE_PFN_MASK); pmd_t *pmdp_new; int i; @@ -197,10 +197,10 @@ static int __split_linear_mapping_p4d(pgd_t *pgdp, vaddr <= (vaddr & P4D_MASK) && end >= next) continue; - if (p4d_leaf(*p4dp)) { + if (p4d_leaf(p4dp_get(p4dp))) { struct page *pud_page; - unsigned long pfn = _p4d_pfn(*p4dp); - pgprot_t prot = __pgprot(p4d_val(*p4dp) & ~_PAGE_PFN_MASK); + unsigned long pfn = _p4d_pfn(p4dp_get(p4dp)); + pgprot_t prot = __pgprot(p4d_val(p4dp_get(p4dp)) & ~_PAGE_PFN_MASK); pud_t *pudp_new; int i; @@ -406,29 +406,29 @@ bool kernel_page_present(struct page *page) pte_t *pte; pgd = pgd_offset_k(addr); - if (!pgd_present(*pgd)) + if (!pgd_present(pgdp_get(pgd))) return false; - if (pgd_leaf(*pgd)) + if (pgd_leaf(pgdp_get(pgd))) return true; p4d = p4d_offset(pgd, addr); - if (!p4d_present(*p4d)) + if (!p4d_present(p4dp_get(p4d))) return false; - if (p4d_leaf(*p4d)) + if (p4d_leaf(p4dp_get(p4d))) return true; pud = pud_offset(p4d, addr); - if (!pud_present(*pud)) + if (!pud_present(pudp_get(pud))) return false; - if (pud_leaf(*pud)) + if (pud_leaf(pudp_get(pud))) return true; pmd = pmd_offset(pud, addr); - if (!pmd_present(*pmd)) + if (!pmd_present(pmdp_get(pmd))) return false; - if (pmd_leaf(*pmd)) + if (pmd_leaf(pmdp_get(pmd))) return true; pte = pte_offset_kernel(pmd, addr); - return pte_present(*pte); + return pte_present(ptep_get(pte)); } -- cgit v1.2.3