apply_to_page_range() takes an address range, and if any parts of it are not covered by the existing page table hierarchy, it allocates memory to fill them in. In some use cases, this is not what we want - we want to be able to operate exclusively on PTEs that are already in the tables. Add apply_to_existing_page_range() for this. Adjust the walker functions for apply_to_page_range to take 'create', which switches them between the old and new modes. This will be used in KASAN vmalloc. [akpm@linux-foundation.org: reduce code duplication] [akpm@linux-foundation.org: s/apply_to_existing_pages/apply_to_existing_page_range/] [akpm@linux-foundation.org: initialize __apply_to_page_range::err] Link: http://lkml.kernel.org/r/20191205140407.1874-1-dja@axtens.net Signed-off-by: Daniel Axtens <dja@axtens.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Daniel Axtens <dja@axtens.net> Cc: Qian Cai <cai@lca.pw> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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| @@ -2621,6 +2621,9 @@ static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags) · 2620 unmodified lines | |||
| 2621 | typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data); | 2621 | typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data); |
| 2622 | extern int apply_to_page_range(struct mm_struct *mm, unsigned long address, | 2622 | extern int apply_to_page_range(struct mm_struct *mm, unsigned long address, |
| 2623 | unsigned long size, pte_fn_t fn, void *data); | 2623 | unsigned long size, pte_fn_t fn, void *data); |
| 2624 | extern int apply_to_existing_page_range(struct mm_struct *mm, | ||
| 2625 | unsigned long address, unsigned long size, | ||
| 2626 | pte_fn_t fn, void *data); | ||
| 2624 | 2627 | ||
| 2625 | #ifdef CONFIG_PAGE_POISONING | 2628 | #ifdef CONFIG_PAGE_POISONING |
| 2626 | extern bool page_poisoning_enabled(void); | 2629 | extern bool page_poisoning_enabled(void); |