diff --git a/arch/um/include/shared/user.h b/arch/um/include/shared/user.h
index 0347a190429cd..981e11d8e0254 100644
--- a/arch/um/include/shared/user.h
+++ b/arch/um/include/shared/user.h
@@ -50,7 +50,6 @@ static inline int printk(const char *fmt, ...)
 #endif
 
 extern int in_aton(char *str);
-extern size_t strlcpy(char *, const char *, size_t);
 extern size_t strlcat(char *, const char *, size_t);
 extern size_t strscpy(char *, const char *, size_t);
 
diff --git a/arch/um/os-Linux/umid.c b/arch/um/os-Linux/umid.c
index 7a1abb8299307..288c422bfa964 100644
--- a/arch/um/os-Linux/umid.c
+++ b/arch/um/os-Linux/umid.c
@@ -40,7 +40,7 @@ static int __init make_uml_dir(void)
 				__func__);
 			goto err;
 		}
-		strlcpy(dir, home, sizeof(dir));
+		strscpy(dir, home, sizeof(dir));
 		uml_dir++;
 	}
 	strlcat(dir, uml_dir, sizeof(dir));
@@ -243,7 +243,7 @@ int __init set_umid(char *name)
 	if (strlen(name) > UMID_LEN - 1)
 		return -E2BIG;
 
-	strlcpy(umid, name, sizeof(umid));
+	strscpy(umid, name, sizeof(umid));
 
 	return 0;
 }
@@ -262,7 +262,7 @@ static int __init make_umid(void)
 	make_uml_dir();
 
 	if (*umid == '\0') {
-		strlcpy(tmp, uml_dir, sizeof(tmp));
+		strscpy(tmp, uml_dir, sizeof(tmp));
 		strlcat(tmp, "XXXXXX", sizeof(tmp));
 		fd = mkstemp(tmp);
 		if (fd < 0) {
diff --git a/drivers/eisa/eisa-bus.c b/drivers/eisa/eisa-bus.c
index 713582cc27d1f..33f0ba11c6adf 100644
--- a/drivers/eisa/eisa-bus.c
+++ b/drivers/eisa/eisa-bus.c
@@ -60,7 +60,7 @@ static void __init eisa_name_device(struct eisa_device *edev)
 	int i;
 	for (i = 0; i < EISA_INFOS; i++) {
 		if (!strcmp(edev->id.sig, eisa_table[i].id.sig)) {
-			strlcpy(edev->pretty_name,
+			strscpy(edev->pretty_name,
 				eisa_table[i].name,
 				sizeof(edev->pretty_name));
 			return;
diff --git a/drivers/soc/fsl/qe/qe.c b/drivers/soc/fsl/qe/qe.c
index b3c226eb5292f..58746e570d14c 100644
--- a/drivers/soc/fsl/qe/qe.c
+++ b/drivers/soc/fsl/qe/qe.c
@@ -524,7 +524,7 @@ int qe_upload_firmware(const struct qe_firmware *firmware)
 	 * saved microcode information and put in the new.
 	 */
 	memset(&qe_firmware_info, 0, sizeof(qe_firmware_info));
-	strlcpy(qe_firmware_info.id, firmware->id, sizeof(qe_firmware_info.id));
+	strscpy(qe_firmware_info.id, firmware->id, sizeof(qe_firmware_info.id));
 	qe_firmware_info.extended_modes = be64_to_cpu(firmware->extended_modes);
 	memcpy(qe_firmware_info.vtraps, firmware->vtraps,
 		sizeof(firmware->vtraps));
@@ -599,7 +599,7 @@ struct qe_firmware_info *qe_get_firmware_info(void)
 	/* Copy the data into qe_firmware_info*/
 	sprop = of_get_property(fw, "id", NULL);
 	if (sprop)
-		strlcpy(qe_firmware_info.id, sprop,
+		strscpy(qe_firmware_info.id, sprop,
 			sizeof(qe_firmware_info.id));
 
 	of_property_read_u64(fw, "extended-modes",
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index bd023dd38ae6f..386ab580b839b 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -249,18 +249,19 @@ static inline void seq_show_option(struct seq_file *m, const char *name,
 
 /**
  * seq_show_option_n - display mount options with appropriate escapes
- *		       where @value must be a specific length.
+ *		       where @value must be a specific length (i.e.
+ *		       not NUL-terminated).
  * @m: the seq_file handle
  * @name: the mount option name
  * @value: the mount option name's value, cannot be NULL
- * @length: the length of @value to display
+ * @length: the exact length of @value to display, must be constant expression
  *
  * This is a macro since this uses "length" to define the size of the
  * stack buffer.
  */
 #define seq_show_option_n(m, name, value, length) {	\
 	char val_buf[length + 1];			\
-	strncpy(val_buf, value, length);		\
+	memcpy(val_buf, value, length);			\
 	val_buf[length] = '\0';				\
 	seq_show_option(m, name, val_buf);		\
 }
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 78ae7b6f90fdb..2554f5fc70dcd 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8249,7 +8249,7 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event)
 	unsigned int size;
 
 	memset(comm, 0, sizeof(comm));
-	strlcpy(comm, comm_event->task->comm, sizeof(comm));
+	strscpy(comm, comm_event->task->comm, sizeof(comm));
 	size = ALIGN(strlen(comm)+1, sizeof(u64));
 
 	comm_event->comm = comm;
@@ -8704,7 +8704,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
 	}
 
 cpy_name:
-	strlcpy(tmp, name, sizeof(tmp));
+	strscpy(tmp, name, sizeof(tmp));
 	name = tmp;
 got_name:
 	/*
@@ -9128,7 +9128,7 @@ void perf_event_ksymbol(u16 ksym_type, u64 addr, u32 len, bool unregister,
 	    ksym_type == PERF_RECORD_KSYMBOL_TYPE_UNKNOWN)
 		goto err;
 
-	strlcpy(name, sym, KSYM_NAME_LEN);
+	strscpy(name, sym, KSYM_NAME_LEN);
 	name_len = strlen(name) + 1;
 	while (!IS_ALIGNED(name_len, sizeof(u64)))
 		name[name_len++] = '\0';
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index efae7e0119565..59e21bfec188c 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan
@@ -13,7 +13,7 @@ menuconfig UBSAN
 if UBSAN
 
 config UBSAN_TRAP
-	bool "On Sanitizer warnings, abort the running kernel code"
+	bool "Abort on Sanitizer warnings (smaller kernel but less verbose)"
 	depends on !COMPILE_TEST
 	help
 	  Building kernels with Sanitizer features enabled tends to grow
@@ -26,6 +26,14 @@ config UBSAN_TRAP
 	  the system. For some system builders this is an acceptable
 	  trade-off.
 
+	  Also note that selecting Y will cause your kernel to Oops
+	  with an "illegal instruction" error with no further details
+	  when a UBSAN violation occurs. (Except on arm64, which will
+	  report which Sanitizer failed.) This may make it hard to
+	  determine whether an Oops was caused by UBSAN or to figure
+	  out the details of a UBSAN violation. It makes the kernel log
+	  output less useful for bug reports.
+
 config CC_HAS_UBSAN_BOUNDS_STRICT
 	def_bool $(cc-option,-fsanitize=bounds-strict)
 	help