On Fri, Oct 04, 2024 at 07:15:48PM +0530, Manas via B4 Relay wrote:
> +++ b/mm/memory.c
> @@ -6346,10 +6346,10 @@ static inline void pfnmap_args_setup(struct follow_pfnmap_args *args,
> static inline void pfnmap_lockdep_assert(struct vm_area_struct *vma)
> {
> #ifdef CONFIG_LOCKDEP
> - struct address_space *mapping = vma->vm_file->f_mapping;
> + struct address_space *mapping = vma->vm_file ? vma->vm_file->f_mapping : NULL;
Overly long and complex line. Much simpler to write:
struct address_space *mapping = NULL;
if (vma->vm_file)
mapping = vma->vm_file->f_mapping;
> if (mapping)
> - lockdep_assert(lockdep_is_held(&vma->vm_file->f_mapping->i_mmap_rwsem) ||
> + lockdep_assert(lockdep_is_held(&mapping->i_mmap_rwsem) ||
> lockdep_is_held(&vma->vm_mm->mmap_lock));
> else
> lockdep_assert(lockdep_is_held(&vma->vm_mm->mmap_lock));
This one should have been lockdep_assert_held(&vma->vm_mm->mmap_lock).
I'm not sure that the previous one is correct. The
lockdep_assert_held() macro is pretty careful about checking
LOCK_STATE_NOT_HELD to avoid the LOCK_STATE_UNKNOWN possibility.
But I'll leave that for Peter to fix.
