From: "David Hildenbrand (Arm)" Let's define (pgd|p4d|pud)_leaf(), hard-coding it to "false". Note that we missed to define pud_leaf() before, allowing architectures to unknowingly overwrite it. Still use static inline functions (type checking), and while at it, just use "bool" as a return value. We can now drop the arm64 custom variant that did that. As it documents: Note: reusing the original pointer means that we may dereference the same (live) page-table entry multiple times. This is safe because it is still only loaded once in the context of each level and the CPU guarantees same-address read-after-read ordering. We now have the same situation. Don't document that, as we will be removing the double read next. Signed-off-by: David Hildenbrand (Arm) --- arch/arm64/include/asm/pgtable.h | 23 ----------------------- include/asm-generic/pgtable-nop4d.h | 2 ++ include/asm-generic/pgtable-nopmd.h | 3 ++- include/asm-generic/pgtable-nopud.h | 2 ++ 4 files changed, 6 insertions(+), 24 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index a2681d755358..6185fc291fd7 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -1188,29 +1188,6 @@ static inline bool pgtable_l5_enabled(void) { return false; } #define p4d_clear_fixmap() #define p4d_offset_kimg(dir,addr) ((p4d_t *)dir) - -static inline -p4d_t *p4d_offset_lockless_folded(pgd_t *pgdp, pgd_t pgd, unsigned long addr) -{ - /* - * With runtime folding of the pud, pud_offset_lockless() passes - * the 'pgd_t *' we return here to p4d_to_folded_pud(), which - * will offset the pointer assuming that it points into - * a page-table page. However, the fast GUP path passes us a - * pgd_t allocated on the stack and so we must use the original - * pointer in 'pgdp' to construct the p4d pointer instead of - * using the generic p4d_offset_lockless() implementation. - * - * Note: reusing the original pointer means that we may - * dereference the same (live) page-table entry multiple times. - * This is safe because it is still only loaded once in the - * context of each level and the CPU guarantees same-address - * read-after-read ordering. - */ - return p4d_offset(pgdp, addr); -} -#define p4d_offset_lockless p4d_offset_lockless_folded - #endif /* CONFIG_PGTABLE_LEVELS > 4 */ #define pgd_ERROR(e) \ diff --git a/include/asm-generic/pgtable-nop4d.h b/include/asm-generic/pgtable-nop4d.h index 89c21f84cffb..c6a5a43899b5 100644 --- a/include/asm-generic/pgtable-nop4d.h +++ b/include/asm-generic/pgtable-nop4d.h @@ -22,6 +22,8 @@ static inline int pgd_none(pgd_t pgd) { return 0; } static inline int pgd_bad(pgd_t pgd) { return 0; } static inline int pgd_present(pgd_t pgd) { return 1; } static inline void pgd_clear(pgd_t *pgd) { } +static inline bool pgd_leaf(pgd_t pgd) { return false; } +#define pgd_leaf pgd_leaf #define p4d_ERROR(p4d) (pgd_ERROR((p4d).pgd)) #define pgd_populate(mm, pgd, p4d) do { } while (0) diff --git a/include/asm-generic/pgtable-nopmd.h b/include/asm-generic/pgtable-nopmd.h index 36b6490ed180..dbd38b4c3a05 100644 --- a/include/asm-generic/pgtable-nopmd.h +++ b/include/asm-generic/pgtable-nopmd.h @@ -31,7 +31,8 @@ static inline int pud_none(pud_t pud) { return 0; } static inline int pud_bad(pud_t pud) { return 0; } static inline int pud_present(pud_t pud) { return 1; } static inline int pud_user(pud_t pud) { return 0; } -static inline int pud_leaf(pud_t pud) { return 0; } +static inline bool pud_leaf(pud_t pud) { return false; } +#define pud_leaf pud_leaf static inline void pud_clear(pud_t *pud) { } #define pmd_ERROR(pmd) (pud_ERROR((pmd).pud)) diff --git a/include/asm-generic/pgtable-nopud.h b/include/asm-generic/pgtable-nopud.h index 356cbfbaab24..6c9bca78047c 100644 --- a/include/asm-generic/pgtable-nopud.h +++ b/include/asm-generic/pgtable-nopud.h @@ -29,6 +29,8 @@ static inline int p4d_none(p4d_t p4d) { return 0; } static inline int p4d_bad(p4d_t p4d) { return 0; } static inline int p4d_present(p4d_t p4d) { return 1; } static inline void p4d_clear(p4d_t *p4d) { } +static inline bool p4d_leaf(p4d_t p4d) { return false; } +#define p4d_leaf p4d_leaf #define pud_ERROR(pud) (p4d_ERROR((pud).p4d)) #define p4d_populate(mm, p4d, pud) do { } while (0) -- 2.43.0