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-rw-r--r--include/linux/memfd.h23
-rw-r--r--include/linux/mm.h55
2 files changed, 11 insertions, 67 deletions
diff --git a/include/linux/memfd.h b/include/linux/memfd.h
index d437e3070850..246daadbfde8 100644
--- a/include/linux/memfd.h
+++ b/include/linux/memfd.h
@@ -7,7 +7,14 @@
#ifdef CONFIG_MEMFD_CREATE
extern long memfd_fcntl(struct file *file, unsigned int cmd, unsigned int arg);
struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx);
-unsigned int *memfd_file_seals_ptr(struct file *file);
+/*
+ * Check for any existing seals on mmap, return an error if access is denied due
+ * to sealing, or 0 otherwise.
+ *
+ * We also update VMA flags if appropriate by manipulating the VMA flags pointed
+ * to by vm_flags_ptr.
+ */
+int memfd_check_seals_mmap(struct file *file, unsigned long *vm_flags_ptr);
#else
static inline long memfd_fcntl(struct file *f, unsigned int c, unsigned int a)
{
@@ -17,19 +24,11 @@ static inline struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t idx)
{
return ERR_PTR(-EINVAL);
}
-
-static inline unsigned int *memfd_file_seals_ptr(struct file *file)
+static inline int memfd_check_seals_mmap(struct file *file,
+ unsigned long *vm_flags_ptr)
{
- return NULL;
+ return 0;
}
#endif
-/* Retrieve memfd seals associated with the file, if any. */
-static inline unsigned int memfd_file_seals(struct file *file)
-{
- unsigned int *sealsp = memfd_file_seals_ptr(file);
-
- return sealsp ? *sealsp : 0;
-}
-
#endif /* __LINUX_MEMFD_H */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a3a50c37603e..e7c54b9aac6d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -4102,61 +4102,6 @@ void mem_dump_obj(void *object);
static inline void mem_dump_obj(void *object) {}
#endif
-static inline bool is_write_sealed(int seals)
-{
- return seals & (F_SEAL_WRITE | F_SEAL_FUTURE_WRITE);
-}
-
-/**
- * is_readonly_sealed - Checks whether write-sealed but mapped read-only,
- * in which case writes should be disallowing moving
- * forwards.
- * @seals: the seals to check
- * @vm_flags: the VMA flags to check
- *
- * Returns whether readonly sealed, in which case writess should be disallowed
- * going forward.
- */
-static inline bool is_readonly_sealed(int seals, vm_flags_t vm_flags)
-{
- /*
- * Since an F_SEAL_[FUTURE_]WRITE sealed memfd can be mapped as
- * MAP_SHARED and read-only, take care to not allow mprotect to
- * revert protections on such mappings. Do this only for shared
- * mappings. For private mappings, don't need to mask
- * VM_MAYWRITE as we still want them to be COW-writable.
- */
- if (is_write_sealed(seals) &&
- ((vm_flags & (VM_SHARED | VM_WRITE)) == VM_SHARED))
- return true;
-
- return false;
-}
-
-/**
- * seal_check_write - Check for F_SEAL_WRITE or F_SEAL_FUTURE_WRITE flags and
- * handle them.
- * @seals: the seals to check
- * @vma: the vma to operate on
- *
- * Check whether F_SEAL_WRITE or F_SEAL_FUTURE_WRITE are set; if so, do proper
- * check/handling on the vma flags. Return 0 if check pass, or <0 for errors.
- */
-static inline int seal_check_write(int seals, struct vm_area_struct *vma)
-{
- if (!is_write_sealed(seals))
- return 0;
-
- /*
- * New PROT_WRITE and MAP_SHARED mmaps are not allowed when
- * write seals are active.
- */
- if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE))
- return -EPERM;
-
- return 0;
-}
-
#ifdef CONFIG_ANON_VMA_NAME
int madvise_set_anon_name(struct mm_struct *mm, unsigned long start,
unsigned long len_in,