Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "28 patches.

  Subsystems affected by this series: mm (memblock, pagealloc, hugetlb,
  highmem, kfence, oom-kill, madvise, kasan, userfaultfd, memcg, and
  zram), core-kernel, kconfig, fork, binfmt, MAINTAINERS, kbuild, and
  ia64"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (28 commits)
  zram: fix broken page writeback
  zram: fix return value on writeback_store
  mm/memcg: set memcg when splitting page
  mm/memcg: rename mem_cgroup_split_huge_fixup to split_page_memcg and add nr_pages argument
  ia64: fix ptrace(PTRACE_SYSCALL_INFO_EXIT) sign
  ia64: fix ia64_syscall_get_set_arguments() for break-based syscalls
  mm/userfaultfd: fix memory corruption due to writeprotect
  kasan: fix KASAN_STACK dependency for HW_TAGS
  kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC
  mm/madvise: replace ptrace attach requirement for process_madvise
  include/linux/sched/mm.h: use rcu_dereference in in_vfork()
  kfence: fix reports if constant function prefixes exist
  kfence, slab: fix cache_alloc_debugcheck_after() for bulk allocations
  kfence: fix printk format for ptrdiff_t
  linux/compiler-clang.h: define HAVE_BUILTIN_BSWAP*
  MAINTAINERS: exclude uapi directories in API/ABI section
  binfmt_misc: fix possible deadlock in bm_register_write
  mm/highmem.c: fix zero_user_segments() with start > end
  hugetlb: do early cow when page pinned on src mm
  mm: use is_cow_mapping() across tree where proper
  ...

MAINTAINERS

@@ -261,8 +261,8 @@ ABI/API
 L:	linux-api@vger.kernel.org
 F:	include/linux/syscalls.h
 F:	kernel/sys_ni.c
-F:	include/uapi/
-F:	arch/*/include/uapi/
+X:	include/uapi/
+X:	arch/*/include/uapi/
 
 ABIT UGURU 1,2 HARDWARE MONITOR DRIVER
 M:	Hans de Goede <hdegoede@redhat.com>

arch/ia64/include/asm/syscall.h

@@ -32,7 +32,7 @@ static inline void syscall_rollback(struct task_struct *task,
 static inline long syscall_get_error(struct task_struct *task,
 				     struct pt_regs *regs)
 {
-	return regs->r10 == -1 ? regs->r8:0;
+	return regs->r10 == -1 ? -regs->r8:0;
 }
 
 static inline long syscall_get_return_value(struct task_struct *task,

arch/ia64/kernel/ptrace.c

@@ -2013,27 +2013,39 @@ static void syscall_get_set_args_cb(struct unw_frame_info *info, void *data)
 {
 	struct syscall_get_set_args *args = data;
 	struct pt_regs *pt = args->regs;
-	unsigned long *krbs, cfm, ndirty;
+	unsigned long *krbs, cfm, ndirty, nlocals, nouts;
 	int i, count;
 
 	if (unw_unwind_to_user(info) < 0)
 		return;
 
+	/*
+	 * We get here via a few paths:
+	 * - break instruction: cfm is shared with caller.
+	 *   syscall args are in out= regs, locals are non-empty.
+	 * - epsinstruction: cfm is set by br.call
+	 *   locals don't exist.
+	 *
+	 * For both cases argguments are reachable in cfm.sof - cfm.sol.
+	 * CFM: [ ... | sor: 17..14 | sol : 13..7 | sof : 6..0 ]
+	 */
 	cfm = pt->cr_ifs;
+	nlocals = (cfm >> 7) & 0x7f; /* aka sol */
+	nouts = (cfm & 0x7f) - nlocals; /* aka sof - sol */
 	krbs = (unsigned long *)info->task + IA64_RBS_OFFSET/8;
 	ndirty = ia64_rse_num_regs(krbs, krbs + (pt->loadrs >> 19));
 
 	count = 0;
 	if (in_syscall(pt))
-		count = min_t(int, args->n, cfm & 0x7f);
+		count = min_t(int, args->n, nouts);
 
+	/* Iterate over outs. */
 	for (i = 0; i < count; i++) {
+		int j = ndirty + nlocals + i + args->i;
 		if (args->rw)
-			*ia64_rse_skip_regs(krbs, ndirty + i + args->i) =
-				args->args[i];
+			*ia64_rse_skip_regs(krbs, j) = args->args[i];
 		else
-			args->args[i] = *ia64_rse_skip_regs(krbs,
-				ndirty + i + args->i);
+			args->args[i] = *ia64_rse_skip_regs(krbs, j);
 	}
 
 	if (!args->rw) {

drivers/block/zram/zram_drv.c

@@ -627,7 +627,7 @@ static ssize_t writeback_store(struct device *dev,
 	struct bio_vec bio_vec;
 	struct page *page;
 	ssize_t ret = len;
-	int mode;
+	int mode, err;
 	unsigned long blk_idx = 0;
 
 	if (sysfs_streq(buf, "idle"))
@@ -638,8 +638,8 @@ static ssize_t writeback_store(struct device *dev,
 		if (strncmp(buf, PAGE_WB_SIG, sizeof(PAGE_WB_SIG) - 1))
 			return -EINVAL;
 
-		ret = kstrtol(buf + sizeof(PAGE_WB_SIG) - 1, 10, &index);
-		if (ret || index >= nr_pages)
+		if (kstrtol(buf + sizeof(PAGE_WB_SIG) - 1, 10, &index) ||
+				index >= nr_pages)
 			return -EINVAL;
 
 		nr_pages = 1;
@@ -663,7 +663,7 @@ static ssize_t writeback_store(struct device *dev,
 		goto release_init_lock;
 	}
 
-	while (nr_pages--) {
+	for (; nr_pages != 0; index++, nr_pages--) {
 		struct bio_vec bvec;
 
 		bvec.bv_page = page;
@@ -728,12 +728,17 @@ static ssize_t writeback_store(struct device *dev,
 		 * XXX: A single page IO would be inefficient for write
 		 * but it would be not bad as starter.
 		 */
-		ret = submit_bio_wait(&bio);
-		if (ret) {
+		err = submit_bio_wait(&bio);
+		if (err) {
 			zram_slot_lock(zram, index);
 			zram_clear_flag(zram, index, ZRAM_UNDER_WB);
 			zram_clear_flag(zram, index, ZRAM_IDLE);
 			zram_slot_unlock(zram, index);
+			/*
+			 * Return last IO error unless every IO were
+			 * not suceeded.
+			 */
+			ret = err;
 			continue;
 		}
 

drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c

@@ -500,8 +500,6 @@ vm_fault_t vmw_bo_vm_huge_fault(struct vm_fault *vmf,
 	vm_fault_t ret;
 	pgoff_t fault_page_size;
 	bool write = vmf->flags & FAULT_FLAG_WRITE;
-	bool is_cow_mapping =
-		(vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
 
 	switch (pe_size) {
 	case PE_SIZE_PMD:
@@ -518,7 +516,7 @@ vm_fault_t vmw_bo_vm_huge_fault(struct vm_fault *vmf,
 	}
 
 	/* Always do write dirty-tracking and COW on PTE level. */
-	if (write && (READ_ONCE(vbo->dirty) || is_cow_mapping))
+	if (write && (READ_ONCE(vbo->dirty) || is_cow_mapping(vma->vm_flags)))
 		return VM_FAULT_FALLBACK;
 
 	ret = ttm_bo_vm_reserve(bo, vmf);

drivers/gpu/drm/vmwgfx/vmwgfx_ttm_glue.c

@@ -49,7 +49,7 @@ int vmw_mmap(struct file *filp, struct vm_area_struct *vma)
 	vma->vm_ops = &vmw_vm_ops;
 
 	/* Use VM_PFNMAP rather than VM_MIXEDMAP if not a COW mapping */
-	if ((vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) != VM_MAYWRITE)
+	if (!is_cow_mapping(vma->vm_flags))
 		vma->vm_flags = (vma->vm_flags & ~VM_MIXEDMAP) | VM_PFNMAP;
 
 	return 0;

fs/binfmt_misc.c

@@ -649,12 +649,24 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer,
 	struct super_block *sb = file_inode(file)->i_sb;
 	struct dentry *root = sb->s_root, *dentry;
 	int err = 0;
+	struct file *f = NULL;
 
 	e = create_entry(buffer, count);
 
 	if (IS_ERR(e))
 		return PTR_ERR(e);
 
+	if (e->flags & MISC_FMT_OPEN_FILE) {
+		f = open_exec(e->interpreter);
+		if (IS_ERR(f)) {
+			pr_notice("register: failed to install interpreter file %s\n",
+				 e->interpreter);
+			kfree(e);
+			return PTR_ERR(f);
+		}
+		e->interp_file = f;
+	}
+
 	inode_lock(d_inode(root));
 	dentry = lookup_one_len(e->name, root, strlen(e->name));
 	err = PTR_ERR(dentry);
@@ -678,21 +690,6 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer,
 		goto out2;
 	}
 
-	if (e->flags & MISC_FMT_OPEN_FILE) {
-		struct file *f;
-
-		f = open_exec(e->interpreter);
-		if (IS_ERR(f)) {
-			err = PTR_ERR(f);
-			pr_notice("register: failed to install interpreter file %s\n", e->interpreter);
-			simple_release_fs(&bm_mnt, &entry_count);
-			iput(inode);
-			inode = NULL;
-			goto out2;
-		}
-		e->interp_file = f;
-	}
-
 	e->dentry = dget(dentry);
 	inode->i_private = e;
 	inode->i_fop = &bm_entry_operations;
@@ -709,6 +706,8 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer,
 	inode_unlock(d_inode(root));
 
 	if (err) {
+		if (f)
+			filp_close(f, NULL);
 		kfree(e);
 		return err;
 	}

fs/proc/task_mmu.c

@@ -1036,8 +1036,6 @@ struct clear_refs_private {
 
 #ifdef CONFIG_MEM_SOFT_DIRTY
 
-#define is_cow_mapping(flags) (((flags) & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE)
-
 static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
 {
 	struct page *page;

include/linux/compiler-clang.h

@@ -31,6 +31,12 @@
 #define __no_sanitize_thread
 #endif
 
+#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
+#define __HAVE_BUILTIN_BSWAP32__
+#define __HAVE_BUILTIN_BSWAP64__
+#define __HAVE_BUILTIN_BSWAP16__
+#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
+
 #if __has_feature(undefined_behavior_sanitizer)
 /* GCC does not have __SANITIZE_UNDEFINED__ */
 #define __no_sanitize_undefined \

include/linux/memblock.h

@@ -460,7 +460,7 @@ static inline void memblock_free_late(phys_addr_t base, phys_addr_t size)
 /*
  * Set the allocation direction to bottom-up or top-down.
  */
-static inline void memblock_set_bottom_up(bool enable)
+static inline __init void memblock_set_bottom_up(bool enable)
 {
 	memblock.bottom_up = enable;
 }
@@ -470,7 +470,7 @@ static inline void memblock_set_bottom_up(bool enable)
  * if this is true, that said, memblock will allocate memory
  * in bottom-up direction.
  */
-static inline bool memblock_bottom_up(void)
+static inline __init bool memblock_bottom_up(void)
 {
 	return memblock.bottom_up;
 }

include/linux/memcontrol.h

@@ -1061,9 +1061,7 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm,
 	rcu_read_unlock();
 }
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-void mem_cgroup_split_huge_fixup(struct page *head);
-#endif
+void split_page_memcg(struct page *head, unsigned int nr);
 
 #else /* CONFIG_MEMCG */
 
@@ -1400,7 +1398,7 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
 	return 0;
 }
 
-static inline void mem_cgroup_split_huge_fixup(struct page *head)
+static inline void split_page_memcg(struct page *head, unsigned int nr)
 {
 }
 

include/linux/mm.h

@@ -1300,6 +1300,27 @@ static inline bool page_maybe_dma_pinned(struct page *page)
 		GUP_PIN_COUNTING_BIAS;
 }
 
+static inline bool is_cow_mapping(vm_flags_t flags)
+{
+	return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
+}
+
+/*
+ * This should most likely only be called during fork() to see whether we
+ * should break the cow immediately for a page on the src mm.
+ */
+static inline bool page_needs_cow_for_dma(struct vm_area_struct *vma,
+					  struct page *page)
+{
+	if (!is_cow_mapping(vma->vm_flags))
+		return false;
+
+	if (!atomic_read(&vma->vm_mm->has_pinned))
+		return false;
+
+	return page_maybe_dma_pinned(page);
+}
+
 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 #define SECTION_IN_PAGE_FLAGS
 #endif

include/linux/mm_types.h

@@ -23,6 +23,7 @@
 #endif
 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
 
+#define INIT_PASID	0
 
 struct address_space;
 struct mem_cgroup;

include/linux/sched/mm.h

@@ -140,7 +140,8 @@ static inline bool in_vfork(struct task_struct *tsk)
 	 * another oom-unkillable task does this it should blame itself.
 	 */
 	rcu_read_lock();
-	ret = tsk->vfork_done && tsk->real_parent->mm == tsk->mm;
+	ret = tsk->vfork_done &&
+			rcu_dereference(tsk->real_parent)->mm == tsk->mm;
 	rcu_read_unlock();
 
 	return ret;

include/linux/stop_machine.h

@@ -128,7 +128,7 @@ int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data,
 				   const struct cpumask *cpus);
 #else	/* CONFIG_SMP || CONFIG_HOTPLUG_CPU */
 
-static inline int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data,
+static __always_inline int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data,
 					  const struct cpumask *cpus)
 {
 	unsigned long flags;
@@ -139,14 +139,15 @@ static inline int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data,
 	return ret;
 }
 
-static inline int stop_machine(cpu_stop_fn_t fn, void *data,
-			       const struct cpumask *cpus)
+static __always_inline int
+stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus)
 {
 	return stop_machine_cpuslocked(fn, data, cpus);
 }
 
-static inline int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data,
-						 const struct cpumask *cpus)
+static __always_inline int
+stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data,
+			       const struct cpumask *cpus)
 {
 	return stop_machine(fn, data, cpus);
 }

init/Kconfig

@@ -119,8 +119,7 @@ config INIT_ENV_ARG_LIMIT
 
 config COMPILE_TEST
 	bool "Compile also drivers which will not load"
-	depends on !UML && !S390
-	default n
+	depends on HAS_IOMEM
 	help
 	  Some drivers can be compiled on a different platform than they are
 	  intended to be run on. Despite they cannot be loaded there (or even

kernel/fork.c

@@ -994,6 +994,13 @@ static void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
 #endif
 }
 
+static void mm_init_pasid(struct mm_struct *mm)
+{
+#ifdef CONFIG_IOMMU_SUPPORT
+	mm->pasid = INIT_PASID;
+#endif
+}
+
 static void mm_init_uprobes_state(struct mm_struct *mm)
 {
 #ifdef CONFIG_UPROBES
@@ -1024,6 +1031,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p,
 	mm_init_cpumask(mm);
 	mm_init_aio(mm);
 	mm_init_owner(mm, p);
+	mm_init_pasid(mm);
 	RCU_INIT_POINTER(mm->exe_file, NULL);
 	mmu_notifier_subscriptions_init(mm);
 	init_tlb_flush_pending(mm);

lib/Kconfig.kasan

@@ -156,6 +156,7 @@ config KASAN_STACK_ENABLE
 
 config KASAN_STACK
 	int
+	depends on KASAN_GENERIC || KASAN_SW_TAGS
 	default 1 if KASAN_STACK_ENABLE || CC_IS_GCC
 	default 0