update samsungs opensource release to SM-A155F_14_A155FXXS5BYC2, everything else is already compatible to *C2

Author: Your Name

Kernel/kernel-5.10/drivers/media/usb/uvc/uvc_driver.c

@@ -661,7 +661,7 @@ static int uvc_parse_format(struct uvc_device *dev,
 	/* Parse the frame descriptors. Only uncompressed, MJPEG and frame
 	 * based formats have frame descriptors.
 	 */
-	while (buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
+	while (ftype && buflen > 2 && buffer[1] == USB_DT_CS_INTERFACE &&
 	       buffer[2] == ftype && buffer[2] != UVC_VS_UNDEFINED) {
 		frame = &format->frame[format->nframes];
 		if (ftype != UVC_VS_FRAME_FRAME_BASED)

Kernel/kernel-5.10/mm/mremap.c

@@ -210,44 +210,12 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
 		drop_rmap_locks(vma);
 }
 
-#ifdef CONFIG_SPECULATIVE_PAGE_FAULT
-static inline bool trylock_vma_ref_count(struct vm_area_struct *vma)
-{
-	/*
-	 * If we have the only reference, swap the refcount to -1. This
-	 * will prevent other concurrent references by get_vma() for SPFs.
-	 */
-	return atomic_cmpxchg_acquire(&vma->vm_ref_count, 1, -1) == 1;
-}
-
-/*
- * Restore the VMA reference count to 1 after a fast mremap.
- */
-static inline void unlock_vma_ref_count(struct vm_area_struct *vma)
-{
-	int old = atomic_xchg_release(&vma->vm_ref_count, 1);
-
-	/*
-	 * This should only be called after a corresponding,
-	 * successful trylock_vma_ref_count().
-	 */
-	VM_BUG_ON_VMA(old != -1, vma);
-}
-#else	/* !CONFIG_SPECULATIVE_PAGE_FAULT */
-static inline bool trylock_vma_ref_count(struct vm_area_struct *vma)
-{
-	return true;
-}
-static inline void unlock_vma_ref_count(struct vm_area_struct *vma)
-{
-}
-#endif	/* CONFIG_SPECULATIVE_PAGE_FAULT */
-
 #ifdef CONFIG_HAVE_MOVE_PMD
 static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
 		  unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd)
 {
-	spinlock_t *old_ptl, *new_ptl;
+	spinlock_t *old_ptl, *new_ptl, *old_pte_ptl;
+
 	struct mm_struct *mm = vma->vm_mm;
 	pmd_t pmd;
 
@@ -277,14 +245,6 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
 	if (WARN_ON_ONCE(!pmd_none(*new_pmd)))
 		return false;
 
-	/*
-	 * We hold both exclusive mmap_lock and rmap_lock at this point and
-	 * cannot block. If we cannot immediately take exclusive ownership
-	 * of the VMA fallback to the move_ptes().
-	 */
-	if (!trylock_vma_ref_count(vma))
-		return false;
-
 	/*
 	 * We don't have to worry about the ordering of src and dst
 	 * ptlocks because exclusive mmap_lock prevents deadlock.
@@ -294,6 +254,24 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
 	if (new_ptl != old_ptl)
 		spin_lock_nested(new_ptl, SINGLE_DEPTH_NESTING);
 
+	/*
+	 * If SPF is enabled, take the ptl lock on the source page table
+	 * page, to prevent the entire pmd from being moved under a
+	 * concurrent SPF.
+	 *
+	 * There is no need to take the destination ptl lock since, mremap
+	 * has already created a hole at the destination and freed the
+	 * corresponding page tables in the process.
+	 *
+	 * NOTE: If USE_SPLIT_PTE_PTLOCKS is false, then the old_ptl, new_ptl,
+	 * and the old_pte_ptl; are all the same lock (mm->page_table_lock).
+	 * Check that the locks are different to avoid a deadlock.
+	 */
+	old_pte_ptl = pte_lockptr(mm, old_pmd);
+	if (IS_ENABLED(CONFIG_SPECULATIVE_PAGE_FAULT) && old_pte_ptl != old_ptl)
+		spin_lock(old_pte_ptl);
+
+
 	/* Clear the pmd */
 	pmd = *old_pmd;
 	pmd_clear(old_pmd);
@@ -303,11 +281,13 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
 	/* Set the new pmd */
 	set_pmd_at(mm, new_addr, new_pmd, pmd);
 	flush_tlb_range(vma, old_addr, old_addr + PMD_SIZE);
+
+	if (IS_ENABLED(CONFIG_SPECULATIVE_PAGE_FAULT) && old_pte_ptl != old_ptl)
+		spin_unlock(old_pte_ptl);
 	if (new_ptl != old_ptl)
 		spin_unlock(new_ptl);
 	spin_unlock(old_ptl);
 
-	unlock_vma_ref_count(vma);
 	return true;
 }
 #else
@@ -319,7 +299,8 @@ static inline bool move_normal_pmd(struct vm_area_struct *vma,
 }
 #endif
 
-#ifdef CONFIG_HAVE_MOVE_PUD
+#if CONFIG_PGTABLE_LEVELS > 2 && defined(CONFIG_HAVE_MOVE_PUD) && \
+		!defined(CONFIG_SPECULATIVE_PAGE_FAULT)
 static bool move_normal_pud(struct vm_area_struct *vma, unsigned long old_addr,
 		  unsigned long new_addr, pud_t *old_pud, pud_t *new_pud)
 {
@@ -334,14 +315,6 @@ static bool move_normal_pud(struct vm_area_struct *vma, unsigned long old_addr,
 	if (WARN_ON_ONCE(!pud_none(*new_pud)))
 		return false;
 
-	/*
-	 * We hold both exclusive mmap_lock and rmap_lock at this point and
-	 * cannot block. If we cannot immediately take exclusive ownership
-	 * of the VMA fallback to the move_ptes().
-	 */
-	if (!trylock_vma_ref_count(vma))
-		return false;
-
 	/*
 	 * We don't have to worry about the ordering of src and dst
 	 * ptlocks because exclusive mmap_lock prevents deadlock.
@@ -364,7 +337,6 @@ static bool move_normal_pud(struct vm_area_struct *vma, unsigned long old_addr,
 		spin_unlock(new_ptl);
 	spin_unlock(old_ptl);
 
-	unlock_vma_ref_count(vma);
 	return true;
 }
 #else