Messages in this thread Patch in this message | | | From | Chih-En Lin <> | Subject | [PATCH v4 12/14] fs/proc: Support COW PTE with clear_refs_write | Date | Tue, 7 Feb 2023 11:51:37 +0800 |
| |
Before clearing the entry in COW-ed PTE, break COW PTE first.
Signed-off-by: Chih-En Lin <shiyn.lin@gmail.com> --- fs/proc/task_mmu.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index af1c49ae11b1..94958422aede 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1196,6 +1196,11 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr, if (pmd_trans_unstable(pmd)) return 0; + /* Only break COW when we modify the soft-dirty bit. */ + if (cp->type == CLEAR_REFS_SOFT_DIRTY && + break_cow_pte(vma, pmd, addr)) + return 0; + pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); for (; addr != end; pte++, addr += PAGE_SIZE) { ptent = *pte; -- 2.34.1
| |