Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "7 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  kasan: add missing functions declarations to kasan.h
  kasan: consistently disable debugging features
  ipc/util.c: sysvipc_find_ipc() incorrectly updates position index
  userfaultfd: fix remap event with MREMAP_DONTUNMAP
  mm/gup: fix fixup_user_fault() on multiple retries
  epoll: call final ep_events_available() check under the lock
  mm, memcg: fix inconsistent oom event behavior

fs/eventpoll.c

@@ -1879,34 +1879,33 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
 		 * event delivery.
 		 */
 		init_wait(&wait);
-		write_lock_irq(&ep->lock);
-		__add_wait_queue_exclusive(&ep->wq, &wait);
-		write_unlock_irq(&ep->lock);
 
+		write_lock_irq(&ep->lock);
 		/*
-		 * We don't want to sleep if the ep_poll_callback() sends us
-		 * a wakeup in between. That's why we set the task state
-		 * to TASK_INTERRUPTIBLE before doing the checks.
+		 * Barrierless variant, waitqueue_active() is called under
+		 * the same lock on wakeup ep_poll_callback() side, so it
+		 * is safe to avoid an explicit barrier.
 		 */
-		set_current_state(TASK_INTERRUPTIBLE);
+		__set_current_state(TASK_INTERRUPTIBLE);
+
 		/*
-		 * Always short-circuit for fatal signals to allow
-		 * threads to make a timely exit without the chance of
-		 * finding more events available and fetching
-		 * repeatedly.
+		 * Do the final check under the lock. ep_scan_ready_list()
+		 * plays with two lists (->rdllist and ->ovflist) and there
+		 * is always a race when both lists are empty for short
+		 * period of time although events are pending, so lock is
+		 * important.
 		 */
-		if (fatal_signal_pending(current)) {
+		eavail = ep_events_available(ep);
+		if (!eavail) {
+			if (signal_pending(current))
 				res = -EINTR;
-			break;
+			else
+				__add_wait_queue_exclusive(&ep->wq, &wait);
 		}
+		write_unlock_irq(&ep->lock);
 
-		eavail = ep_events_available(ep);
-		if (eavail)
-			break;
-		if (signal_pending(current)) {
-			res = -EINTR;
+		if (eavail || res)
 			break;
-		}
 
 		if (!schedule_hrtimeout_range(to, slack, HRTIMER_MODE_ABS)) {
 			timed_out = 1;
@@ -1927,6 +1926,15 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
 	}
 
 send_events:
+	if (fatal_signal_pending(current)) {
+		/*
+		 * Always short-circuit for fatal signals to allow
+		 * threads to make a timely exit without the chance of
+		 * finding more events available and fetching
+		 * repeatedly.
+		 */
+		res = -EINTR;
+	}
 	/*
 	 * Try to transfer events to user space. In case we get 0 events and
 	 * there's still timeout left over, we go trying again in search of

include/linux/memcontrol.h

@@ -783,6 +783,8 @@ static inline void memcg_memory_event(struct mem_cgroup *memcg,
 		atomic_long_inc(&memcg->memory_events[event]);
 		cgroup_file_notify(&memcg->events_file);
 
+		if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
+			break;
 		if (cgrp_dfl_root.flags & CGRP_ROOT_MEMORY_LOCAL_EVENTS)
 			break;
 	} while ((memcg = parent_mem_cgroup(memcg)) &&

ipc/util.c

@@ -764,21 +764,21 @@ static struct kern_ipc_perm *sysvipc_find_ipc(struct ipc_ids *ids, loff_t pos,
 			total++;
 	}
 
-	*new_pos = pos + 1;
+	ipc = NULL;
 	if (total >= ids->in_use)
-		return NULL;
+		goto out;
 
 	for (; pos < ipc_mni; pos++) {
 		ipc = idr_find(&ids->ipcs_idr, pos);
 		if (ipc != NULL) {
 			rcu_read_lock();
 			ipc_lock_object(ipc);
-			return ipc;
+			break;
 		}
 	}
-
-	/* Out of range - return NULL to terminate iteration */
-	return NULL;
+out:
+	*new_pos = pos + 1;
+	return ipc;
 }
 
 static void *sysvipc_proc_next(struct seq_file *s, void *it, loff_t *pos)

mm/gup.c

@@ -1218,6 +1218,10 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
 	if (!vma_permits_fault(vma, fault_flags))
 		return -EFAULT;
 
+	if ((fault_flags & FAULT_FLAG_KILLABLE) &&
+	    fatal_signal_pending(current))
+		return -EINTR;
+
 	ret = handle_mm_fault(vma, address, fault_flags);
 	major |= ret & VM_FAULT_MAJOR;
 	if (ret & VM_FAULT_ERROR) {
@@ -1230,12 +1234,10 @@ int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
 
 	if (ret & VM_FAULT_RETRY) {
 		down_read(&mm->mmap_sem);
-		if (!(fault_flags & FAULT_FLAG_TRIED)) {
 		*unlocked = true;
 		fault_flags |= FAULT_FLAG_TRIED;
 		goto retry;
 	}
-	}
 
 	if (tsk) {
 		if (major)

mm/kasan/Makefile

 # SPDX-License-Identifier: GPL-2.0
 KASAN_SANITIZE := n
-UBSAN_SANITIZE_common.o := n
-UBSAN_SANITIZE_generic.o := n
-UBSAN_SANITIZE_generic_report.o := n
-UBSAN_SANITIZE_tags.o := n
+UBSAN_SANITIZE := n
 KCOV_INSTRUMENT := n
 
+# Disable ftrace to avoid recursion.
 CFLAGS_REMOVE_common.o = $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_generic.o = $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_generic_report.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_init.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_quarantine.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_report.o = $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_tags.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_tags_report.o = $(CC_FLAGS_FTRACE)
 
 # Function splitter causes unnecessary splits in __asan_load1/__asan_store1
 # see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533
-
 CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
 CFLAGS_generic.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
 CFLAGS_generic_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
+CFLAGS_init.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
+CFLAGS_quarantine.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
+CFLAGS_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
 CFLAGS_tags.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
+CFLAGS_tags_report.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
 
 obj-$(CONFIG_KASAN) := common.o init.o report.o
 obj-$(CONFIG_KASAN_GENERIC) += generic.o generic_report.o quarantine.o

mm/kasan/kasan.h

@@ -212,8 +212,6 @@ static inline const void *arch_kasan_set_tag(const void *addr, u8 tag)
 asmlinkage void kasan_unpoison_task_stack_below(const void *watermark);
 void __asan_register_globals(struct kasan_global *globals, size_t size);
 void __asan_unregister_globals(struct kasan_global *globals, size_t size);
-void __asan_loadN(unsigned long addr, size_t size);
-void __asan_storeN(unsigned long addr, size_t size);
 void __asan_handle_no_return(void);
 void __asan_alloca_poison(unsigned long addr, size_t size);
 void __asan_allocas_unpoison(const void *stack_top, const void *stack_bottom);
@@ -228,6 +226,8 @@ void __asan_load8(unsigned long addr);
 void __asan_store8(unsigned long addr);
 void __asan_load16(unsigned long addr);
 void __asan_store16(unsigned long addr);
+void __asan_loadN(unsigned long addr, size_t size);
+void __asan_storeN(unsigned long addr, size_t size);
 
 void __asan_load1_noabort(unsigned long addr);
 void __asan_store1_noabort(unsigned long addr);
@@ -239,6 +239,21 @@ void __asan_load8_noabort(unsigned long addr);
 void __asan_store8_noabort(unsigned long addr);
 void __asan_load16_noabort(unsigned long addr);
 void __asan_store16_noabort(unsigned long addr);
+void __asan_loadN_noabort(unsigned long addr, size_t size);
+void __asan_storeN_noabort(unsigned long addr, size_t size);
+
+void __asan_report_load1_noabort(unsigned long addr);
+void __asan_report_store1_noabort(unsigned long addr);
+void __asan_report_load2_noabort(unsigned long addr);
+void __asan_report_store2_noabort(unsigned long addr);
+void __asan_report_load4_noabort(unsigned long addr);
+void __asan_report_store4_noabort(unsigned long addr);
+void __asan_report_load8_noabort(unsigned long addr);
+void __asan_report_store8_noabort(unsigned long addr);
+void __asan_report_load16_noabort(unsigned long addr);
+void __asan_report_store16_noabort(unsigned long addr);
+void __asan_report_load_n_noabort(unsigned long addr, size_t size);
+void __asan_report_store_n_noabort(unsigned long addr, size_t size);
 
 void __asan_set_shadow_00(const void *addr, size_t size);
 void __asan_set_shadow_f1(const void *addr, size_t size);
@@ -247,4 +262,19 @@ void __asan_set_shadow_f3(const void *addr, size_t size);
 void __asan_set_shadow_f5(const void *addr, size_t size);
 void __asan_set_shadow_f8(const void *addr, size_t size);
 
+void __hwasan_load1_noabort(unsigned long addr);
+void __hwasan_store1_noabort(unsigned long addr);
+void __hwasan_load2_noabort(unsigned long addr);
+void __hwasan_store2_noabort(unsigned long addr);
+void __hwasan_load4_noabort(unsigned long addr);
+void __hwasan_store4_noabort(unsigned long addr);
+void __hwasan_load8_noabort(unsigned long addr);
+void __hwasan_store8_noabort(unsigned long addr);
+void __hwasan_load16_noabort(unsigned long addr);
+void __hwasan_store16_noabort(unsigned long addr);
+void __hwasan_loadN_noabort(unsigned long addr, size_t size);
+void __hwasan_storeN_noabort(unsigned long addr, size_t size);
+
+void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size);
+
 #endif

mm/mremap.c

@@ -794,7 +794,7 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 	if (locked && new_len > old_len)
 		mm_populate(new_addr + old_len, new_len - old_len);
 	userfaultfd_unmap_complete(mm, &uf_unmap_early);
-	mremap_userfaultfd_complete(&uf, addr, new_addr, old_len);
+	mremap_userfaultfd_complete(&uf, addr, ret, old_len);
 	userfaultfd_unmap_complete(mm, &uf_unmap);
 	return ret;
 }