mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_PAGE,
0, src_vma, src_mm, addr, end);
mmu_notifier_invalidate_range_start(&range);
+ /*
+ * Disabling preemption is not needed for the write side, as
+ * the read side doesn't spin, but goes to the mmap_lock.
+ *
+ * Use the raw variant of the seqcount_t write API to avoid
+ * lockdep complaining about preemptibility.
+ */
+ mmap_assert_write_locked(src_mm);
+ raw_write_seqcount_begin(&src_mm->write_protect_seq);
}
ret = 0;
}
} while (dst_pgd++, src_pgd++, addr = next, addr != end);
- if (is_cow)
+ if (is_cow) {
+ raw_write_seqcount_end(&src_mm->write_protect_seq);
mmu_notifier_invalidate_range_end(&range);
+ }
return ret;
}
}
#endif /* __PAGETABLE_PMD_FOLDED */
-static int __follow_pte_pmd(struct mm_struct *mm, unsigned long address,
- struct mmu_notifier_range *range,
- pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp)
+int follow_pte(struct mm_struct *mm, unsigned long address,
+ struct mmu_notifier_range *range, pte_t **ptepp, pmd_t **pmdpp,
+ spinlock_t **ptlp)
{
pgd_t *pgd;
p4d_t *p4d;
return -EINVAL;
}
-static inline int follow_pte(struct mm_struct *mm, unsigned long address,
- pte_t **ptepp, spinlock_t **ptlp)
-{
- int res;
-
- /* (void) is needed to make gcc happy */
- (void) __cond_lock(*ptlp,
- !(res = __follow_pte_pmd(mm, address, NULL,
- ptepp, NULL, ptlp)));
- return res;
-}
-
-int follow_pte_pmd(struct mm_struct *mm, unsigned long address,
- struct mmu_notifier_range *range,
- pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp)
-{
- int res;
-
- /* (void) is needed to make gcc happy */
- (void) __cond_lock(*ptlp,
- !(res = __follow_pte_pmd(mm, address, range,
- ptepp, pmdpp, ptlp)));
- return res;
-}
-EXPORT_SYMBOL(follow_pte_pmd);
-
/**
* follow_pfn - look up PFN at a user virtual address
* @vma: memory mapping
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
return ret;
- ret = follow_pte(vma->vm_mm, address, &ptep, &ptl);
+ ret = follow_pte(vma->vm_mm, address, NULL, &ptep, NULL, &ptl);
if (ret)
return ret;
*pfn = pte_pfn(*ptep);
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP)))
goto out;
- if (follow_pte(vma->vm_mm, address, &ptep, &ptl))
+ if (follow_pte(vma->vm_mm, address, NULL, &ptep, NULL, &ptl))
goto out;
pte = *ptep;
#endif
/*
- * Access another process' address space as given in mm. If non-NULL, use the
- * given task for page fault accounting.
+ * Access another process' address space as given in mm.
*/
-int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
- unsigned long addr, void *buf, int len, unsigned int gup_flags)
+int __access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf,
+ int len, unsigned int gup_flags)
{
struct vm_area_struct *vma;
void *old_buf = buf;
int access_remote_vm(struct mm_struct *mm, unsigned long addr,
void *buf, int len, unsigned int gup_flags)
{
- return __access_remote_vm(NULL, mm, addr, buf, len, gup_flags);
+ return __access_remote_vm(mm, addr, buf, len, gup_flags);
}
/*
if (!mm)
return 0;
- ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags);
+ ret = __access_remote_vm(mm, addr, buf, len, gup_flags);
mmput(mm);