Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "The post-linux-next material.

  7 patches.

  Subsystems affected by this patch series (all mm): debug,
  slab-generic, migration, memcg, and kasan"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kasan: add kasan mode messages when kasan init
  mm: unexport {,un}lock_page_memcg
  mm: unexport folio_memcg_{,un}lock
  mm/migrate.c: remove MIGRATE_PFN_LOCKED
  mm: migrate: simplify the file-backed pages validation when migrating its mapping
  mm: allow only SLUB on PREEMPT_RT
  mm/page_owner.c: modify the type of argument "order" in some functions

Documentation/vm/hmm.rst

@@ -360,7 +360,7 @@ between device driver specific code and shared common code:
    system memory page, locks the page with ``lock_page()``, and fills in the
    ``dst`` array entry with::
 
-     dst[i] = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
+     dst[i] = migrate_pfn(page_to_pfn(dpage));
 
    Now that the driver knows that this page is being migrated, it can
    invalidate device private MMU mappings and copy device private memory

arch/arm64/mm/kasan_init.c

@@ -310,7 +310,7 @@ void __init kasan_init(void)
 	kasan_init_depth();
 #if defined(CONFIG_KASAN_GENERIC)
 	/* CONFIG_KASAN_SW_TAGS also requires kasan_init_sw_tags(). */
-	pr_info("KernelAddressSanitizer initialized\n");
+	pr_info("KernelAddressSanitizer initialized (generic)\n");
 #endif
 }
 

arch/powerpc/kvm/book3s_hv_uvmem.c

@@ -560,7 +560,7 @@ static int __kvmppc_svm_page_out(struct vm_area_struct *vma,
 				  gpa, 0, page_shift);
 
 	if (ret == U_SUCCESS)
-		*mig.dst = migrate_pfn(pfn) | MIGRATE_PFN_LOCKED;
+		*mig.dst = migrate_pfn(pfn);
 	else {
 		unlock_page(dpage);
 		__free_page(dpage);
@@ -774,7 +774,7 @@ static int kvmppc_svm_page_in(struct vm_area_struct *vma,
 		}
 	}
 
-	*mig.dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
+	*mig.dst = migrate_pfn(page_to_pfn(dpage));
 	migrate_vma_pages(&mig);
 out_finalize:
 	migrate_vma_finalize(&mig);

drivers/gpu/drm/amd/amdkfd/kfd_migrate.c

@@ -317,7 +317,6 @@ svm_migrate_copy_to_vram(struct amdgpu_device *adev, struct svm_range *prange,
 			migrate->dst[i] = svm_migrate_addr_to_pfn(adev, dst[i]);
 			svm_migrate_get_vram_page(prange, migrate->dst[i]);
 			migrate->dst[i] = migrate_pfn(migrate->dst[i]);
-			migrate->dst[i] |= MIGRATE_PFN_LOCKED;
 			src[i] = dma_map_page(dev, spage, 0, PAGE_SIZE,
 					      DMA_TO_DEVICE);
 			r = dma_mapping_error(dev, src[i]);
@@ -610,7 +609,6 @@ svm_migrate_copy_to_ram(struct amdgpu_device *adev, struct svm_range *prange,
 				     dst[i] >> PAGE_SHIFT, page_to_pfn(dpage));
 
 		migrate->dst[i] = migrate_pfn(page_to_pfn(dpage));
-		migrate->dst[i] |= MIGRATE_PFN_LOCKED;
 		j++;
 	}
 

drivers/gpu/drm/nouveau/nouveau_dmem.c

@@ -166,7 +166,7 @@ static vm_fault_t nouveau_dmem_fault_copy_one(struct nouveau_drm *drm,
 		goto error_dma_unmap;
 	mutex_unlock(&svmm->mutex);
 
-	args->dst[0] = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
+	args->dst[0] = migrate_pfn(page_to_pfn(dpage));
 	return 0;
 
 error_dma_unmap:
@@ -602,7 +602,7 @@ static unsigned long nouveau_dmem_migrate_copy_one(struct nouveau_drm *drm,
 		((paddr >> PAGE_SHIFT) << NVIF_VMM_PFNMAP_V0_ADDR_SHIFT);
 	if (src & MIGRATE_PFN_WRITE)
 		*pfn |= NVIF_VMM_PFNMAP_V0_W;
-	return migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
+	return migrate_pfn(page_to_pfn(dpage));
 
 out_dma_unmap:
 	dma_unmap_page(dev, *dma_addr, PAGE_SIZE, DMA_BIDIRECTIONAL);

include/linux/migrate.h

@@ -110,7 +110,6 @@ static inline int migrate_misplaced_page(struct page *page,
  */
 #define MIGRATE_PFN_VALID	(1UL << 0)
 #define MIGRATE_PFN_MIGRATE	(1UL << 1)
-#define MIGRATE_PFN_LOCKED	(1UL << 2)
 #define MIGRATE_PFN_WRITE	(1UL << 3)
 #define MIGRATE_PFN_SHIFT	6
 

include/linux/page_owner.h

@@ -8,24 +8,24 @@
 extern struct static_key_false page_owner_inited;
 extern struct page_ext_operations page_owner_ops;
 
-extern void __reset_page_owner(struct page *page, unsigned int order);
+extern void __reset_page_owner(struct page *page, unsigned short order);
 extern void __set_page_owner(struct page *page,
-			unsigned int order, gfp_t gfp_mask);
+			unsigned short order, gfp_t gfp_mask);
 extern void __split_page_owner(struct page *page, unsigned int nr);
 extern void __folio_copy_owner(struct folio *newfolio, struct folio *old);
 extern void __set_page_owner_migrate_reason(struct page *page, int reason);
 extern void __dump_page_owner(const struct page *page);
 extern void pagetypeinfo_showmixedcount_print(struct seq_file *m,
 					pg_data_t *pgdat, struct zone *zone);
 
-static inline void reset_page_owner(struct page *page, unsigned int order)
+static inline void reset_page_owner(struct page *page, unsigned short order)
 {
 	if (static_branch_unlikely(&page_owner_inited))
 		__reset_page_owner(page, order);
 }
 
 static inline void set_page_owner(struct page *page,
-			unsigned int order, gfp_t gfp_mask)
+			unsigned short order, gfp_t gfp_mask)
 {
 	if (static_branch_unlikely(&page_owner_inited))
 		__set_page_owner(page, order, gfp_mask);
@@ -52,15 +52,15 @@ static inline void dump_page_owner(const struct page *page)
 		__dump_page_owner(page);
 }
 #else
-static inline void reset_page_owner(struct page *page, unsigned int order)
+static inline void reset_page_owner(struct page *page, unsigned short order)
 {
 }
 static inline void set_page_owner(struct page *page,
 			unsigned int order, gfp_t gfp_mask)
 {
 }
 static inline void split_page_owner(struct page *page,
-			unsigned int order)
+			unsigned short order)
 {
 }
 static inline void folio_copy_owner(struct folio *newfolio, struct folio *folio)

init/Kconfig

@@ -1896,6 +1896,7 @@ choice
 
 config SLAB
 	bool "SLAB"
+	depends on !PREEMPT_RT
 	select HAVE_HARDENED_USERCOPY_ALLOCATOR
 	help
 	  The regular slab allocator that is established and known to work
@@ -1916,6 +1917,7 @@ config SLUB
 config SLOB
 	depends on EXPERT
 	bool "SLOB (Simple Allocator)"
+	depends on !PREEMPT_RT
 	help
 	   SLOB replaces the stock allocator with a drastically simpler
 	   allocator. SLOB is generally more space efficient but

lib/test_hmm.c

@@ -613,8 +613,7 @@ static void dmirror_migrate_alloc_and_copy(struct migrate_vma *args,
 		 */
 		rpage->zone_device_data = dmirror;
 
-		*dst = migrate_pfn(page_to_pfn(dpage)) |
-			    MIGRATE_PFN_LOCKED;
+		*dst = migrate_pfn(page_to_pfn(dpage));
 		if ((*src & MIGRATE_PFN_WRITE) ||
 		    (!spage && args->vma->vm_flags & VM_WRITE))
 			*dst |= MIGRATE_PFN_WRITE;
@@ -1137,7 +1136,7 @@ static vm_fault_t dmirror_devmem_fault_alloc_and_copy(struct migrate_vma *args,
 		lock_page(dpage);
 		xa_erase(&dmirror->pt, addr >> PAGE_SHIFT);
 		copy_highpage(dpage, spage);
-		*dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
+		*dst = migrate_pfn(page_to_pfn(dpage));
 		if (*src & MIGRATE_PFN_WRITE)
 			*dst |= MIGRATE_PFN_WRITE;
 	}

mm/kasan/hw_tags.c

@@ -106,6 +106,16 @@ static int __init early_kasan_flag_stacktrace(char *arg)
 }
 early_param("kasan.stacktrace", early_kasan_flag_stacktrace);
 
+static inline const char *kasan_mode_info(void)
+{
+	if (kasan_mode == KASAN_MODE_ASYNC)
+		return "async";
+	else if (kasan_mode == KASAN_MODE_ASYMM)
+		return "asymm";
+	else
+		return "sync";
+}
+
 /* kasan_init_hw_tags_cpu() is called for each CPU. */
 void kasan_init_hw_tags_cpu(void)
 {
@@ -177,7 +187,9 @@ void __init kasan_init_hw_tags(void)
 		break;
 	}
 
-	pr_info("KernelAddressSanitizer initialized\n");
+	pr_info("KernelAddressSanitizer initialized (hw-tags, mode=%s, stacktrace=%s)\n",
+		kasan_mode_info(),
+		kasan_stack_collection_enabled() ? "on" : "off");
 }
 
 void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags)

mm/kasan/sw_tags.c

@@ -42,7 +42,7 @@ void __init kasan_init_sw_tags(void)
 	for_each_possible_cpu(cpu)
 		per_cpu(prng_state, cpu) = (u32)get_cycles();
 
-	pr_info("KernelAddressSanitizer initialized\n");
+	pr_info("KernelAddressSanitizer initialized (sw-tags)\n");
 }
 
 /*

mm/memcontrol.c

@@ -2058,13 +2058,11 @@ void folio_memcg_lock(struct folio *folio)
 	memcg->move_lock_task = current;
 	memcg->move_lock_flags = flags;
 }
-EXPORT_SYMBOL(folio_memcg_lock);
 
 void lock_page_memcg(struct page *page)
 {
 	folio_memcg_lock(page_folio(page));
 }
-EXPORT_SYMBOL(lock_page_memcg);
 
 static void __folio_memcg_unlock(struct mem_cgroup *memcg)
 {
@@ -2092,13 +2090,11 @@ void folio_memcg_unlock(struct folio *folio)
 {
 	__folio_memcg_unlock(folio_memcg(folio));
 }
-EXPORT_SYMBOL(folio_memcg_unlock);
 
 void unlock_page_memcg(struct page *page)
 {
 	folio_memcg_unlock(page_folio(page));
 }
-EXPORT_SYMBOL(unlock_page_memcg);
 
 struct obj_stock {
 #ifdef CONFIG_MEMCG_KMEM