Hi Matthew,
On 04.10.2024 16:17, Matthew Wilcox wrote:
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;
Thank you for reviewing! I am sending v4.
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.
--
Manas
