summaryrefslogtreecommitdiff
path: root/mm/mmap.c
diff options
context:
space:
mode:
Diffstat (limited to 'mm/mmap.c')
-rw-r--r--mm/mmap.c222
1 files changed, 121 insertions, 101 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index d600404580b2..8f1000bc35df 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -182,7 +182,8 @@ static int check_brk_limits(unsigned long addr, unsigned long len)
if (IS_ERR_VALUE(mapped_addr))
return mapped_addr;
- return mlock_future_check(current->mm, current->mm->def_flags, len);
+ return mlock_future_ok(current->mm, current->mm->def_flags, len)
+ ? 0 : -EAGAIN;
}
static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *brkvma,
unsigned long addr, unsigned long request, unsigned long flags);
@@ -300,61 +301,40 @@ out:
}
#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
-extern void mt_validate(struct maple_tree *mt);
-extern void mt_dump(const struct maple_tree *mt);
-
-/* Validate the maple tree */
-static void validate_mm_mt(struct mm_struct *mm)
-{
- struct maple_tree *mt = &mm->mm_mt;
- struct vm_area_struct *vma_mt;
-
- MA_STATE(mas, mt, 0, 0);
-
- mt_validate(&mm->mm_mt);
- mas_for_each(&mas, vma_mt, ULONG_MAX) {
- if ((vma_mt->vm_start != mas.index) ||
- (vma_mt->vm_end - 1 != mas.last)) {
- pr_emerg("issue in %s\n", current->comm);
- dump_stack();
- dump_vma(vma_mt);
- pr_emerg("mt piv: %p %lu - %lu\n", vma_mt,
- mas.index, mas.last);
- pr_emerg("mt vma: %p %lu - %lu\n", vma_mt,
- vma_mt->vm_start, vma_mt->vm_end);
-
- mt_dump(mas.tree);
- if (vma_mt->vm_end != mas.last + 1) {
- pr_err("vma: %p vma_mt %lu-%lu\tmt %lu-%lu\n",
- mm, vma_mt->vm_start, vma_mt->vm_end,
- mas.index, mas.last);
- mt_dump(mas.tree);
- }
- VM_BUG_ON_MM(vma_mt->vm_end != mas.last + 1, mm);
- if (vma_mt->vm_start != mas.index) {
- pr_err("vma: %p vma_mt %p %lu - %lu doesn't match\n",
- mm, vma_mt, vma_mt->vm_start, vma_mt->vm_end);
- mt_dump(mas.tree);
- }
- VM_BUG_ON_MM(vma_mt->vm_start != mas.index, mm);
- }
- }
-}
-
static void validate_mm(struct mm_struct *mm)
{
int bug = 0;
int i = 0;
struct vm_area_struct *vma;
- MA_STATE(mas, &mm->mm_mt, 0, 0);
-
- validate_mm_mt(mm);
+ VMA_ITERATOR(vmi, mm, 0);
- mas_for_each(&mas, vma, ULONG_MAX) {
+ mt_validate(&mm->mm_mt);
+ for_each_vma(vmi, vma) {
#ifdef CONFIG_DEBUG_VM_RB
struct anon_vma *anon_vma = vma->anon_vma;
struct anon_vma_chain *avc;
+#endif
+ unsigned long vmi_start, vmi_end;
+ bool warn = 0;
+
+ vmi_start = vma_iter_addr(&vmi);
+ vmi_end = vma_iter_end(&vmi);
+ if (VM_WARN_ON_ONCE_MM(vma->vm_end != vmi_end, mm))
+ warn = 1;
+
+ if (VM_WARN_ON_ONCE_MM(vma->vm_start != vmi_start, mm))
+ warn = 1;
+ if (warn) {
+ pr_emerg("issue in %s\n", current->comm);
+ dump_stack();
+ dump_vma(vma);
+ pr_emerg("tree range: %px start %lx end %lx\n", vma,
+ vmi_start, vmi_end - 1);
+ vma_iter_dump_tree(&vmi);
+ }
+
+#ifdef CONFIG_DEBUG_VM_RB
if (anon_vma) {
anon_vma_lock_read(anon_vma);
list_for_each_entry(avc, &vma->anon_vma_chain, same_vma)
@@ -365,14 +345,13 @@ static void validate_mm(struct mm_struct *mm)
i++;
}
if (i != mm->map_count) {
- pr_emerg("map_count %d mas_for_each %d\n", mm->map_count, i);
+ pr_emerg("map_count %d vma iterator %d\n", mm->map_count, i);
bug = 1;
}
VM_BUG_ON_MM(bug, mm);
}
#else /* !CONFIG_DEBUG_VM_MAPLE_TREE */
-#define validate_mm_mt(root) do { } while (0)
#define validate_mm(mm) do { } while (0)
#endif /* CONFIG_DEBUG_VM_MAPLE_TREE */
@@ -1167,21 +1146,21 @@ static inline unsigned long round_hint_to_min(unsigned long hint)
return hint;
}
-int mlock_future_check(struct mm_struct *mm, unsigned long flags,
- unsigned long len)
+bool mlock_future_ok(struct mm_struct *mm, unsigned long flags,
+ unsigned long bytes)
{
- unsigned long locked, lock_limit;
+ unsigned long locked_pages, limit_pages;
- /* mlock MCL_FUTURE? */
- if (flags & VM_LOCKED) {
- locked = len >> PAGE_SHIFT;
- locked += mm->locked_vm;
- lock_limit = rlimit(RLIMIT_MEMLOCK);
- lock_limit >>= PAGE_SHIFT;
- if (locked > lock_limit && !capable(CAP_IPC_LOCK))
- return -EAGAIN;
- }
- return 0;
+ if (!(flags & VM_LOCKED) || capable(CAP_IPC_LOCK))
+ return true;
+
+ locked_pages = bytes >> PAGE_SHIFT;
+ locked_pages += mm->locked_vm;
+
+ limit_pages = rlimit(RLIMIT_MEMLOCK);
+ limit_pages >>= PAGE_SHIFT;
+
+ return locked_pages <= limit_pages;
}
static inline u64 file_mmap_size_max(struct file *file, struct inode *inode)
@@ -1293,7 +1272,7 @@ unsigned long do_mmap(struct file *file, unsigned long addr,
if (!can_do_mlock())
return -EPERM;
- if (mlock_future_check(mm, vm_flags, len))
+ if (!mlock_future_ok(mm, vm_flags, len))
return -EAGAIN;
if (file) {
@@ -1475,6 +1454,48 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
}
#endif /* __ARCH_WANT_SYS_OLD_MMAP */
+static bool vm_ops_needs_writenotify(const struct vm_operations_struct *vm_ops)
+{
+ return vm_ops && (vm_ops->page_mkwrite || vm_ops->pfn_mkwrite);
+}
+
+static bool vma_is_shared_writable(struct vm_area_struct *vma)
+{
+ return (vma->vm_flags & (VM_WRITE | VM_SHARED)) ==
+ (VM_WRITE | VM_SHARED);
+}
+
+static bool vma_fs_can_writeback(struct vm_area_struct *vma)
+{
+ /* No managed pages to writeback. */
+ if (vma->vm_flags & VM_PFNMAP)
+ return false;
+
+ return vma->vm_file && vma->vm_file->f_mapping &&
+ mapping_can_writeback(vma->vm_file->f_mapping);
+}
+
+/*
+ * Does this VMA require the underlying folios to have their dirty state
+ * tracked?
+ */
+bool vma_needs_dirty_tracking(struct vm_area_struct *vma)
+{
+ /* Only shared, writable VMAs require dirty tracking. */
+ if (!vma_is_shared_writable(vma))
+ return false;
+
+ /* Does the filesystem need to be notified? */
+ if (vm_ops_needs_writenotify(vma->vm_ops))
+ return true;
+
+ /*
+ * Even if the filesystem doesn't indicate a need for writenotify, if it
+ * can writeback, dirty tracking is still required.
+ */
+ return vma_fs_can_writeback(vma);
+}
+
/*
* Some shared mappings will want the pages marked read-only
* to track write events. If so, we'll downgrade vm_page_prot
@@ -1483,21 +1504,18 @@ SYSCALL_DEFINE1(old_mmap, struct mmap_arg_struct __user *, arg)
*/
int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot)
{
- vm_flags_t vm_flags = vma->vm_flags;
- const struct vm_operations_struct *vm_ops = vma->vm_ops;
-
/* If it was private or non-writable, the write bit is already clear */
- if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED)))
+ if (!vma_is_shared_writable(vma))
return 0;
/* The backer wishes to know when pages are first written to? */
- if (vm_ops && (vm_ops->page_mkwrite || vm_ops->pfn_mkwrite))
+ if (vm_ops_needs_writenotify(vma->vm_ops))
return 1;
/* The open routine did something to the protections that pgprot_modify
* won't preserve? */
if (pgprot_val(vm_page_prot) !=
- pgprot_val(vm_pgprot_modify(vm_page_prot, vm_flags)))
+ pgprot_val(vm_pgprot_modify(vm_page_prot, vma->vm_flags)))
return 0;
/*
@@ -1511,13 +1529,8 @@ int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot)
if (userfaultfd_wp(vma))
return 1;
- /* Specialty mapping? */
- if (vm_flags & VM_PFNMAP)
- return 0;
-
/* Can the mapping track the dirty pages? */
- return vma->vm_file && vma->vm_file->f_mapping &&
- mapping_can_writeback(vma->vm_file->f_mapping);
+ return vma_fs_can_writeback(vma);
}
/*
@@ -1911,7 +1924,7 @@ static int acct_stack_growth(struct vm_area_struct *vma,
return -ENOMEM;
/* mlock limit tests */
- if (mlock_future_check(mm, vma->vm_flags, grow << PAGE_SHIFT))
+ if (!mlock_future_ok(mm, vma->vm_flags, grow << PAGE_SHIFT))
return -ENOMEM;
/* Check to ensure the stack will not grow into a hugetlb-only region */
@@ -2234,7 +2247,7 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
struct vm_area_struct *new;
int err;
- validate_mm_mt(vma->vm_mm);
+ validate_mm(vma->vm_mm);
WARN_ON(vma->vm_start >= addr);
WARN_ON(vma->vm_end <= addr);
@@ -2292,7 +2305,7 @@ int __split_vma(struct vma_iterator *vmi, struct vm_area_struct *vma,
/* Success. */
if (new_below)
vma_next(vmi);
- validate_mm_mt(vma->vm_mm);
+ validate_mm(vma->vm_mm);
return 0;
out_free_mpol:
@@ -2301,7 +2314,7 @@ out_free_vmi:
vma_iter_free(vmi);
out_free_vma:
vm_area_free(new);
- validate_mm_mt(vma->vm_mm);
+ validate_mm(vma->vm_mm);
return err;
}
@@ -2394,28 +2407,32 @@ do_vmi_align_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
locked_vm += vma_pages(next);
count++;
+ if (unlikely(uf)) {
+ /*
+ * If userfaultfd_unmap_prep returns an error the vmas
+ * will remain split, but userland will get a
+ * highly unexpected error anyway. This is no
+ * different than the case where the first of the two
+ * __split_vma fails, but we don't undo the first
+ * split, despite we could. This is unlikely enough
+ * failure that it's not worth optimizing it for.
+ */
+ error = userfaultfd_unmap_prep(next, start, end, uf);
+
+ if (error)
+ goto userfaultfd_error;
+ }
#ifdef CONFIG_DEBUG_VM_MAPLE_TREE
BUG_ON(next->vm_start < start);
BUG_ON(next->vm_start > end);
#endif
}
- next = vma_next(vmi);
- if (unlikely(uf)) {
- /*
- * If userfaultfd_unmap_prep returns an error the vmas
- * will remain split, but userland will get a
- * highly unexpected error anyway. This is no
- * different than the case where the first of the two
- * __split_vma fails, but we don't undo the first
- * split, despite we could. This is unlikely enough
- * failure that it's not worth optimizing it for.
- */
- error = userfaultfd_unmap_prep(mm, start, end, uf);
+ if (vma_iter_end(vmi) > end)
+ next = vma_iter_load(vmi);
- if (error)
- goto userfaultfd_error;
- }
+ if (!next)
+ next = vma_next(vmi);
#if defined(CONFIG_DEBUG_VM_MAPLE_TREE)
/* Make sure no VMAs are about to be lost. */
@@ -2620,6 +2637,9 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
}
cannot_expand:
+ if (prev)
+ vma_iter_next_range(&vmi);
+
/*
* Determine the object being mapped and call the appropriate
* specific mapper. the address has already been validated, but
@@ -2933,7 +2953,7 @@ int do_vma_munmap(struct vma_iterator *vmi, struct vm_area_struct *vma,
arch_unmap(mm, start, end);
ret = do_vmi_align_munmap(vmi, vma, mm, start, end, uf, downgrade);
- validate_mm_mt(mm);
+ validate_mm(mm);
return ret;
}
@@ -2955,7 +2975,7 @@ static int do_brk_flags(struct vma_iterator *vmi, struct vm_area_struct *vma,
struct mm_struct *mm = current->mm;
struct vma_prepare vp;
- validate_mm_mt(mm);
+ validate_mm(mm);
/*
* Check against address space limits by the changed size
* Note: This happens *after* clearing old mappings in some code paths.
@@ -3196,7 +3216,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
bool faulted_in_anon_vma = true;
VMA_ITERATOR(vmi, mm, addr);
- validate_mm_mt(mm);
+ validate_mm(mm);
/*
* If anonymous vma has not yet been faulted, update new pgoff
* to match new location, to increase its chance of merging.
@@ -3255,7 +3275,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
goto out_vma_link;
*need_rmap_locks = false;
}
- validate_mm_mt(mm);
+ validate_mm(mm);
return new_vma;
out_vma_link:
@@ -3271,7 +3291,7 @@ out_free_mempol:
out_free_vma:
vm_area_free(new_vma);
out:
- validate_mm_mt(mm);
+ validate_mm(mm);
return NULL;
}
@@ -3408,7 +3428,7 @@ static struct vm_area_struct *__install_special_mapping(
int ret;
struct vm_area_struct *vma;
- validate_mm_mt(mm);
+ validate_mm(mm);
vma = vm_area_alloc(mm);
if (unlikely(vma == NULL))
return ERR_PTR(-ENOMEM);
@@ -3431,12 +3451,12 @@ static struct vm_area_struct *__install_special_mapping(
perf_event_mmap(vma);
- validate_mm_mt(mm);
+ validate_mm(mm);
return vma;
out:
vm_area_free(vma);
- validate_mm_mt(mm);
+ validate_mm(mm);
return ERR_PTR(ret);
}