Merge branch 'for-next/kspp' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.gitNotice: this object is not reachable from any branch.

Notice: this object is not reachable from any branch.

25 files changed, 757 insertions, 474 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 13d0edb699732..845b9e4a1bd08 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8568,8 +8568,6 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/har
 F:	include/linux/fortify-string.h
 F:	lib/fortify_kunit.c
 F:	lib/memcpy_kunit.c
-F:	lib/strcat_kunit.c
-F:	lib/strscpy_kunit.c
 F:	lib/test_fortify/*
 F:	scripts/test_fortify.sh
 K:	\b__NO_FORTIFY\b
@@ -22899,6 +22897,7 @@ F:	include/linux/ubsan.h
 F:	lib/Kconfig.ubsan
 F:	lib/test_ubsan.c
 F:	lib/ubsan.c
+F:	lib/ubsan.h
 F:	scripts/Makefile.ubsan
 K:	\bARCH_HAS_UBSAN\b
 
diff --git a/arch/arm64/configs/hardening.config b/arch/arm64/configs/hardening.config
index b0e7952089983..24179722927e1 100644
--- a/arch/arm64/configs/hardening.config
+++ b/arch/arm64/configs/hardening.config
@@ -5,6 +5,7 @@ CONFIG_ARM64_SW_TTBR0_PAN=y
 
 # Software Shadow Stack or PAC
 CONFIG_SHADOW_CALL_STACK=y
+CONFIG_UNWIND_PATCH_PAC_INTO_SCS=y
 
 # Pointer authentication (ARMv8.3 and later). If hardware actually supports
 # it, one can turn off CONFIG_STACKPROTECTOR_STRONG with this enabled.
diff --git a/arch/x86/configs/hardening.config b/arch/x86/configs/hardening.config
index 7b497f3b7bc3c..de319852a1e9d 100644
--- a/arch/x86/configs/hardening.config
+++ b/arch/x86/configs/hardening.config
@@ -10,5 +10,8 @@ CONFIG_INTEL_IOMMU_DEFAULT_ON=y
 CONFIG_INTEL_IOMMU_SVM=y
 CONFIG_AMD_IOMMU=y
 
+# Enforce CET Indirect Branch Tracking in the kernel.
+CONFIG_X86_KERNEL_IBT=y
+
 # Enable CET Shadow Stack for userspace.
 CONFIG_X86_USER_SHADOW_STACK=y
diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c
index 30cb4f64e7704..a0bcb0864ecd2 100644
--- a/drivers/message/fusion/mptsas.c
+++ b/drivers/message/fusion/mptsas.c
@@ -2965,17 +2965,13 @@ mptsas_exp_repmanufacture_info(MPT_ADAPTER *ioc,
 			goto out_free;
 
 		manufacture_reply = data_out + sizeof(struct rep_manu_request);
-		strscpy(edev->vendor_id, manufacture_reply->vendor_id,
-			sizeof(edev->vendor_id));
-		strscpy(edev->product_id, manufacture_reply->product_id,
-			sizeof(edev->product_id));
-		strscpy(edev->product_rev, manufacture_reply->product_rev,
-			sizeof(edev->product_rev));
+		memtostr(edev->vendor_id, manufacture_reply->vendor_id);
+		memtostr(edev->product_id, manufacture_reply->product_id);
+		memtostr(edev->product_rev, manufacture_reply->product_rev);
 		edev->level = manufacture_reply->sas_format;
 		if (manufacture_reply->sas_format) {
-			strscpy(edev->component_vendor_id,
-				manufacture_reply->component_vendor_id,
-				sizeof(edev->component_vendor_id));
+			memtostr(edev->component_vendor_id,
+				 manufacture_reply->component_vendor_id);
 			tmp = (u8 *)&manufacture_reply->component_id;
 			edev->component_id = tmp[0] << 8 | tmp[1];
 			edev->component_revision_id =
diff --git a/drivers/misc/lkdtm/Makefile b/drivers/misc/lkdtm/Makefile
index 95ef971b5e1cb..b28701138b4bc 100644
--- a/drivers/misc/lkdtm/Makefile
+++ b/drivers/misc/lkdtm/Makefile
@@ -19,7 +19,7 @@ KASAN_SANITIZE_rodata.o			:= n
 KCSAN_SANITIZE_rodata.o			:= n
 KCOV_INSTRUMENT_rodata.o		:= n
 OBJECT_FILES_NON_STANDARD_rodata.o	:= y
-CFLAGS_REMOVE_rodata.o			+= $(CC_FLAGS_LTO) $(RETHUNK_CFLAGS)
+CFLAGS_REMOVE_rodata.o			+= $(CC_FLAGS_LTO) $(RETHUNK_CFLAGS) $(CC_FLAGS_CFI)
 
 OBJCOPYFLAGS :=
 OBJCOPYFLAGS_rodata_objcopy.o	:= \
diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c
index b93404d656509..5b861dbff27e9 100644
--- a/drivers/misc/lkdtm/perms.c
+++ b/drivers/misc/lkdtm/perms.c
@@ -61,7 +61,7 @@ static void *setup_function_descriptor(func_desc_t *fdesc, void *dst)
 	return fdesc;
 }
 
-static noinline void execute_location(void *dst, bool write)
+static noinline __nocfi void execute_location(void *dst, bool write)
 {
 	void (*func)(void);
 	func_desc_t fdesc;
diff --git a/drivers/scsi/mpi3mr/mpi3mr_transport.c b/drivers/scsi/mpi3mr/mpi3mr_transport.c
index dabb91f0f75df..3caceddb864a7 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_transport.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_transport.c
@@ -211,17 +211,13 @@ static int mpi3mr_report_manufacture(struct mpi3mr_ioc *mrioc,
 		goto out;
 	}
 
-	strscpy(edev->vendor_id, manufacture_reply->vendor_id,
-	     SAS_EXPANDER_VENDOR_ID_LEN);
-	strscpy(edev->product_id, manufacture_reply->product_id,
-	     SAS_EXPANDER_PRODUCT_ID_LEN);
-	strscpy(edev->product_rev, manufacture_reply->product_rev,
-	     SAS_EXPANDER_PRODUCT_REV_LEN);
+	memtostr(edev->vendor_id, manufacture_reply->vendor_id);
+	memtostr(edev->product_id, manufacture_reply->product_id);
+	memtostr(edev->product_rev, manufacture_reply->product_rev);
 	edev->level = manufacture_reply->sas_format & 1;
 	if (edev->level) {
-		strscpy(edev->component_vendor_id,
-		    manufacture_reply->component_vendor_id,
-		     SAS_EXPANDER_COMPONENT_VENDOR_ID_LEN);
+		memtostr(edev->component_vendor_id,
+			 manufacture_reply->component_vendor_id);
 		tmp = (u8 *)&manufacture_reply->component_id;
 		edev->component_id = tmp[0] << 8 | tmp[1];
 		edev->component_revision_id =
diff --git a/drivers/scsi/qla2xxx/qla_mr.c b/drivers/scsi/qla2xxx/qla_mr.c
index 083f94e43fba0..82a7e21ddc838 100644
--- a/drivers/scsi/qla2xxx/qla_mr.c
+++ b/drivers/scsi/qla2xxx/qla_mr.c
@@ -1909,10 +1909,8 @@ qlafx00_fx_disc(scsi_qla_host_t *vha, fc_port_t *fcport, uint16_t fx_type)
 	if (fx_type == FXDISC_GET_CONFIG_INFO) {
 		struct config_info_data *pinfo =
 		    (struct config_info_data *) fdisc->u.fxiocb.rsp_addr;
-		strscpy(vha->hw->model_number, pinfo->model_num,
-			ARRAY_SIZE(vha->hw->model_number));
-		strscpy(vha->hw->model_desc, pinfo->model_description,
-			ARRAY_SIZE(vha->hw->model_desc));
+		memtostr(vha->hw->model_number, pinfo->model_num);
+		memtostr(vha->hw->model_desc, pinfo->model_description);
 		memcpy(&vha->hw->mr.symbolic_name, pinfo->symbolic_name,
 		    sizeof(vha->hw->mr.symbolic_name));
 		memcpy(&vha->hw->mr.serial_num, pinfo->serial_num,
diff --git a/drivers/virt/acrn/ioreq.c b/drivers/virt/acrn/ioreq.c
index 29e1ef1915fd2..e94358239a4b5 100644
--- a/drivers/virt/acrn/ioreq.c
+++ b/drivers/virt/acrn/ioreq.c
@@ -433,7 +433,7 @@ struct acrn_ioreq_client *acrn_ioreq_client_create(struct acrn_vm *vm,
 	client->priv = priv;
 	client->is_default = is_default;
 	if (name)
-		strncpy(client->name, name, sizeof(client->name) - 1);
+		strscpy(client->name, name);
 	rwlock_init(&client->range_lock);
 	INIT_LIST_HEAD(&client->range_list);
 	init_waitqueue_head(&client->wq);
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 2fe0f3af1a08e..d39a1a69feccd 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1606,9 +1606,7 @@ ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
 		goto out;
 	}
 	mutex_init(&tmp_tfm->key_tfm_mutex);
-	strncpy(tmp_tfm->cipher_name, cipher_name,
-		ECRYPTFS_MAX_CIPHER_NAME_SIZE);
-	tmp_tfm->cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
+	strscpy(tmp_tfm->cipher_name, cipher_name);
 	tmp_tfm->key_size = key_size;
 	rc = ecryptfs_process_key_cipher(&tmp_tfm->key_tfm,
 					 tmp_tfm->cipher_name,
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 2dc927ba067fe..577c563023144 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -256,11 +256,8 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 	substring_t args[MAX_OPT_ARGS];
 	int token;
 	char *sig_src;
-	char *cipher_name_dst;
 	char *cipher_name_src;
-	char *fn_cipher_name_dst;
 	char *fn_cipher_name_src;
-	char *fnek_dst;
 	char *fnek_src;
 	char *cipher_key_bytes_src;
 	char *fn_cipher_key_bytes_src;
@@ -293,12 +290,8 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 		case ecryptfs_opt_cipher:
 		case ecryptfs_opt_ecryptfs_cipher:
 			cipher_name_src = args[0].from;
-			cipher_name_dst =
-				mount_crypt_stat->
-				global_default_cipher_name;
-			strncpy(cipher_name_dst, cipher_name_src,
-				ECRYPTFS_MAX_CIPHER_NAME_SIZE);
-			cipher_name_dst[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
+			strscpy(mount_crypt_stat->global_default_cipher_name,
+				cipher_name_src);
 			cipher_name_set = 1;
 			break;
 		case ecryptfs_opt_ecryptfs_key_bytes:
@@ -326,11 +319,8 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 			break;
 		case ecryptfs_opt_fnek_sig:
 			fnek_src = args[0].from;
-			fnek_dst =
-				mount_crypt_stat->global_default_fnek_sig;
-			strncpy(fnek_dst, fnek_src, ECRYPTFS_SIG_SIZE_HEX);
-			mount_crypt_stat->global_default_fnek_sig[
-				ECRYPTFS_SIG_SIZE_HEX] = '\0';
+			strscpy(mount_crypt_stat->global_default_fnek_sig,
+				fnek_src);
 			rc = ecryptfs_add_global_auth_tok(
 				mount_crypt_stat,
 				mount_crypt_stat->global_default_fnek_sig,
@@ -348,12 +338,8 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options,
 			break;
 		case ecryptfs_opt_fn_cipher:
 			fn_cipher_name_src = args[0].from;
-			fn_cipher_name_dst =
-				mount_crypt_stat->global_default_fn_cipher_name;
-			strncpy(fn_cipher_name_dst, fn_cipher_name_src,
-				ECRYPTFS_MAX_CIPHER_NAME_SIZE);
-			mount_crypt_stat->global_default_fn_cipher_name[
-				ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
+			strscpy(mount_crypt_stat->global_default_fn_cipher_name,
+				fn_cipher_name_src);
 			fn_cipher_name_set = 1;
 			break;
 		case ecryptfs_opt_fn_cipher_key_bytes:
diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
index 9c9ff6b8c6f7e..5a400259ae74c 100644
--- a/fs/hfsplus/xattr.c
+++ b/fs/hfsplus/xattr.c
@@ -400,21 +400,19 @@ static int name_len(const char *xattr_name, int xattr_name_len)
 	return len;
 }
 
-static int copy_name(char *buffer, const char *xattr_name, int name_len)
+static ssize_t copy_name(char *buffer, const char *xattr_name, int name_len)
 {
-	int len = name_len;
-	int offset = 0;
+	ssize_t len;
 
-	if (!is_known_namespace(xattr_name)) {
-		memcpy(buffer, XATTR_MAC_OSX_PREFIX, XATTR_MAC_OSX_PREFIX_LEN);
-		offset += XATTR_MAC_OSX_PREFIX_LEN;
-		len += XATTR_MAC_OSX_PREFIX_LEN;
-	}
-
-	strncpy(buffer + offset, xattr_name, name_len);
-	memset(buffer + offset + name_len, 0, 1);
-	len += 1;
+	if (!is_known_namespace(xattr_name))
+		len = scnprintf(buffer, name_len + XATTR_MAC_OSX_PREFIX_LEN,
+				 "%s%s", XATTR_MAC_OSX_PREFIX, xattr_name);
+	else
+		len = strscpy(buffer, xattr_name, name_len + 1);
 
+	/* include NUL-byte in length for non-empty name */
+	if (len >= 0)
+		len++;
 	return len;
 }
 
diff --git a/fs/reiserfs/item_ops.c b/fs/reiserfs/item_ops.c
index 3a5a752d96c7b..5011c10287c65 100644
--- a/fs/reiserfs/item_ops.c
+++ b/fs/reiserfs/item_ops.c
@@ -389,16 +389,9 @@ static void direntry_print_item(struct item_head *ih, char *item)
 		name = item + deh_location(deh);
 		if (name[namelen - 1] == 0)
 			namelen = strlen(name);
-		namebuf[0] = '"';
-		if (namelen > sizeof(namebuf) - 3) {
-			strncpy(namebuf + 1, name, sizeof(namebuf) - 3);
-			namebuf[sizeof(namebuf) - 2] = '"';
-			namebuf[sizeof(namebuf) - 1] = 0;
-		} else {
-			memcpy(namebuf + 1, name, namelen);
-			namebuf[namelen + 1] = '"';
-			namebuf[namelen + 2] = 0;
-		}
+
+		scnprintf(namebuf, sizeof(namebuf), "\"%.*s\"",
+			  (int)sizeof(namebuf)-3, name);
 
 		printk("%d:  %-15s%-15d%-15d%-15lld%-15lld(%s)\n",
 		       i, namebuf,
diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h
index b24d62bad0b32..d658ae729a02a 100644
--- a/include/linux/fortify-string.h
+++ b/include/linux/fortify-string.h
@@ -15,10 +15,14 @@
 #define FORTIFY_REASON(func, write)	(FIELD_PREP(BIT(0), write) | \
 					 FIELD_PREP(GENMASK(7, 1), func))
 
+/* Overridden by KUnit tests. */
 #ifndef fortify_panic
 # define fortify_panic(func, write, avail, size, retfail)	\
 	 __fortify_panic(FORTIFY_REASON(func, write), avail, size)
 #endif
+#ifndef fortify_warn_once
+# define fortify_warn_once(x...)	WARN_ONCE(x)
+#endif
 
 #define FORTIFY_READ		 0
 #define FORTIFY_WRITE		 1
@@ -609,7 +613,7 @@ __FORTIFY_INLINE bool fortify_memcpy_chk(__kernel_size_t size,
 	const size_t __q_size = (q_size);				\
 	const size_t __p_size_field = (p_size_field);			\
 	const size_t __q_size_field = (q_size_field);			\
-	WARN_ONCE(fortify_memcpy_chk(__fortify_size, __p_size,		\
+	fortify_warn_once(fortify_memcpy_chk(__fortify_size, __p_size,	\
 				     __q_size, __p_size_field,		\
 				     __q_size_field, FORTIFY_FUNC_ ##op), \
 		  #op ": detected field-spanning write (size %zu) of single %s (size %zu)\n", \
@@ -734,7 +738,8 @@ __FORTIFY_INLINE void *kmemdup_noprof(const void * const POS0 p, size_t size, gf
 	if (__compiletime_lessthan(p_size, size))
 		__read_overflow();
 	if (p_size < size)
-		fortify_panic(FORTIFY_FUNC_kmemdup, FORTIFY_READ, p_size, size, NULL);
+		fortify_panic(FORTIFY_FUNC_kmemdup, FORTIFY_READ, p_size, size,
+			      __real_kmemdup(p, 0, gfp));
 	return __real_kmemdup(p, size, gfp);
 }
 #define kmemdup(...)	alloc_hooks(kmemdup_noprof(__VA_ARGS__))
diff --git a/include/linux/string.h b/include/linux/string.h
index 793c27ad7c0d2..60168aa2af075 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -14,8 +14,8 @@
 #include <uapi/linux/string.h>
 
 extern char *strndup_user(const char __user *, long);
-extern void *memdup_user(const void __user *, size_t);
-extern void *vmemdup_user(const void __user *, size_t);
+extern void *memdup_user(const void __user *, size_t) __realloc_size(2);
+extern void *vmemdup_user(const void __user *, size_t) __realloc_size(2);
 extern void *memdup_user_nul(const void __user *, size_t);
 
 /**
@@ -27,7 +27,8 @@ extern void *memdup_user_nul(const void __user *, size_t);
  * Return: an ERR_PTR() on failure. Result is physically
  * contiguous, to be freed by kfree().
  */
-static inline void *memdup_array_user(const void __user *src, size_t n, size_t size)
+static inline __realloc_size(2, 3)
+void *memdup_array_user(const void __user *src, size_t n, size_t size)
 {
 	size_t nbytes;
 
@@ -46,7 +47,8 @@ static inline void *memdup_array_user(const void __user *src, size_t n, size_t s
  * Return: an ERR_PTR() on failure. Result may be not
  * physically contiguous. Use kvfree() to free.
  */
-static inline void *vmemdup_array_user(const void __user *src, size_t n, size_t size)
+static inline __realloc_size(2, 3)
+void *vmemdup_array_user(const void __user *src, size_t n, size_t size)
 {
 	size_t nbytes;
 
@@ -287,7 +289,8 @@ extern void *kmemdup_noprof(const void *src, size_t len, gfp_t gfp) __realloc_si
 
 extern void *kvmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2);
 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
-extern void *kmemdup_array(const void *src, size_t element_size, size_t count, gfp_t gfp);
+extern void *kmemdup_array(const void *src, size_t element_size, size_t count, gfp_t gfp)
+		__realloc_size(2, 3);
 
 /* lib/argv_split.c */
 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
@@ -425,6 +428,55 @@ void memcpy_and_pad(void *dest, size_t dest_len, const void *src, size_t count,
 } while (0)
 
 /**
+ * memtostr - Copy a possibly non-NUL-term string to a NUL-term string
+ * @dest: Pointer to destination NUL-terminates string
+ * @src: Pointer to character array (likely marked as __nonstring)
+ *
+ * This is a replacement for strncpy() uses where the source is not
+ * a NUL-terminated string.
+ *
+ * Note that sizes of @dest and @src must be known at compile-time.
+ */
+#define memtostr(dest, src)	do {					\
+	const size_t _dest_len = __builtin_object_size(dest, 1);	\
+	const size_t _src_len = __builtin_object_size(src, 1);		\
+	const size_t _src_chars = strnlen(src, _src_len);		\
+	const size_t _copy_len = min(_dest_len - 1, _src_chars);	\
+									\
+	BUILD_BUG_ON(!__builtin_constant_p(_dest_len) ||		\
+		     !__builtin_constant_p(_src_len) ||			\
+		     _dest_len == 0 || _dest_len == (size_t)-1 ||	\
+		     _src_len == 0 || _src_len == (size_t)-1);		\
+	memcpy(dest, src, _copy_len);					\
+	dest[_copy_len] = '\0';						\
+} while (0)
+
+/**
+ * memtostr_pad - Copy a possibly non-NUL-term string to a NUL-term string
+ *                with NUL padding in the destination
+ * @dest: Pointer to destination NUL-terminates string
+ * @src: Pointer to character array (likely marked as __nonstring)
+ *
+ * This is a replacement for strncpy() uses where the source is not
+ * a NUL-terminated string.
+ *
+ * Note that sizes of @dest and @src must be known at compile-time.
+ */
+#define memtostr_pad(dest, src)		do {				\
+	const size_t _dest_len = __builtin_object_size(dest, 1);	\
+	const size_t _src_len = __builtin_object_size(src, 1);		\
+	const size_t _src_chars = strnlen(src, _src_len);		\
+	const size_t _copy_len = min(_dest_len - 1, _src_chars);	\
+									\
+	BUILD_BUG_ON(!__builtin_constant_p(_dest_len) ||		\
+		     !__builtin_constant_p(_src_len) ||			\
+		     _dest_len == 0 || _dest_len == (size_t)-1 ||	\
+		     _src_len == 0 || _src_len == (size_t)-1);		\
+	memcpy(dest, src, _copy_len);					\
+	memset(&dest[_copy_len], 0, _dest_len - _copy_len);		\
+} while (0)
+
+/**
  * memset_after - Set a value after a struct member to the end of a struct
  *
  * @obj: Address of target struct instance
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 3c5fd993bc7e3..6af29da8889eb 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -159,8 +159,7 @@ static int __init do_mount_root(const char *name, const char *fs,
 		if (!p)
 			return -ENOMEM;
 		data_page = page_address(p);
-		/* zero-pad. init_mount() will make sure it's terminated */
-		strncpy(data_page, data, PAGE_SIZE);
+		strscpy_pad(data_page, data, PAGE_SIZE);
 	}
 
 	ret = init_mount(name, "/root", fs, flags, data_page);
diff --git a/kernel/configs/hardening.config b/kernel/configs/hardening.config
index 4b4cfcba31901..8a7ce7a6b3abf 100644
--- a/kernel/configs/hardening.config
+++ b/kernel/configs/hardening.config
@@ -23,6 +23,10 @@ CONFIG_SLAB_FREELIST_HARDENED=y
 CONFIG_SHUFFLE_PAGE_ALLOCATOR=y
 CONFIG_RANDOM_KMALLOC_CACHES=y
 
+# Sanity check userspace page table mappings.
+CONFIG_PAGE_TABLE_CHECK=y
+CONFIG_PAGE_TABLE_CHECK_ENFORCED=y
+
 # Randomize kernel stack offset on syscall entry.
 CONFIG_RANDOMIZE_KSTACK_OFFSET_DEFAULT=y
 
@@ -82,6 +86,10 @@ CONFIG_SECCOMP_FILTER=y
 # Provides some protections against SYN flooding.
 CONFIG_SYN_COOKIES=y
 
+# Enable Kernel Control Flow Integrity (currently Clang only).
+CONFIG_CFI_CLANG=y
+# CONFIG_CFI_PERMISSIVE is not set
+
 # Attack surface reduction: do not autoload TTY line disciplines.
 # CONFIG_LDISC_AUTOLOAD is not set
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 3856e2d7e7ff5..f4384fd60a769 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2804,16 +2804,6 @@ config HW_BREAKPOINT_KUNIT_TEST
 
 	  If unsure, say N.
 
-config STRCAT_KUNIT_TEST
-	tristate "Test strcat() family of functions at runtime" if !KUNIT_ALL_TESTS
-	depends on KUNIT
-	default KUNIT_ALL_TESTS
-
-config STRSCPY_KUNIT_TEST
-	tristate "Test strscpy*() family of functions at runtime" if !KUNIT_ALL_TESTS
-	depends on KUNIT
-	default KUNIT_ALL_TESTS
-
 config SIPHASH_KUNIT_TEST
 	tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
 	depends on KUNIT
diff --git a/lib/Makefile b/lib/Makefile
index ef4f4c66a52c1..573755b01bac8 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -387,8 +387,6 @@ CFLAGS_fortify_kunit.o += $(call cc-disable-warning, stringop-overread)
 CFLAGS_fortify_kunit.o += $(call cc-disable-warning, stringop-truncation)
 CFLAGS_fortify_kunit.o += $(DISABLE_STRUCTLEAK_PLUGIN)
 obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o
-obj-$(CONFIG_STRCAT_KUNIT_TEST) += strcat_kunit.o
-obj-$(CONFIG_STRSCPY_KUNIT_TEST) += strscpy_kunit.o
 obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o
 
 obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
diff --git a/lib/fortify_kunit.c b/lib/fortify_kunit.c
index 493ec02dd5b32..87b873108350c 100644
--- a/lib/fortify_kunit.c
+++ b/lib/fortify_kunit.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- * Runtime test cases for CONFIG_FORTIFY_SOURCE. For testing memcpy(),
- * see FORTIFY_MEM_* tests in LKDTM (drivers/misc/lkdtm/fortify.c).
+ * Runtime test cases for CONFIG_FORTIFY_SOURCE. For additional memcpy()
+ * testing see FORTIFY_MEM_* tests in LKDTM (drivers/misc/lkdtm/fortify.c).
  *
  * For corner cases with UBSAN, try testing with:
  *
@@ -15,14 +15,31 @@
  */
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+/* We don't need to fill dmesg with the fortify WARNs during testing. */
+#ifdef DEBUG
+# define FORTIFY_REPORT_KUNIT(x...) __fortify_report(x)
+# define FORTIFY_WARN_KUNIT(x...)   WARN_ONCE(x)
+#else
+# define FORTIFY_REPORT_KUNIT(x...) do { } while (0)
+# define FORTIFY_WARN_KUNIT(x...)   do { } while (0)
+#endif
+
 /* Redefine fortify_panic() to track failures. */
 void fortify_add_kunit_error(int write);
 #define fortify_panic(func, write, avail, size, retfail) do {		\
-	__fortify_report(FORTIFY_REASON(func, write), avail, size);	\
+	FORTIFY_REPORT_KUNIT(FORTIFY_REASON(func, write), avail, size);	\
 	fortify_add_kunit_error(write);					\
 	return (retfail);						\
 } while (0)
 
+/* Redefine fortify_warn_once() to track memcpy() failures. */
+#define fortify_warn_once(chk_func, x...) do {				\
+	bool __result = chk_func;					\
+	FORTIFY_WARN_KUNIT(__result, x);				\
+	if (__result)							\
+		fortify_add_kunit_error(1);				\
+} while (0)
+
 #include <kunit/device.h>
 #include <kunit/test.h>
 #include <kunit/test-bug.h>
@@ -64,7 +81,7 @@ void fortify_add_kunit_error(int write)
 	kunit_put_resource(resource);
 }
 
-static void known_sizes_test(struct kunit *test)
+static void fortify_test_known_sizes(struct kunit *test)
 {
 	KUNIT_EXPECT_EQ(test, __compiletime_strlen("88888888"), 8);
 	KUNIT_EXPECT_EQ(test, __compiletime_strlen(array_of_10), 10);
@@ -97,7 +114,7 @@ static noinline size_t want_minus_one(int pick)
 	return __compiletime_strlen(str);
 }
 
-static void control_flow_split_test(struct kunit *test)
+static void fortify_test_control_flow_split(struct kunit *test)
 {
 	KUNIT_EXPECT_EQ(test, want_minus_one(pick), SIZE_MAX);
 }
@@ -173,11 +190,11 @@ static volatile size_t unknown_size = 50;
 #endif
 
 #define DEFINE_ALLOC_SIZE_TEST_PAIR(allocator)				\
-static void alloc_size_##allocator##_const_test(struct kunit *test)	\
+static void fortify_test_alloc_size_##allocator##_const(struct kunit *test) \
 {									\
 	CONST_TEST_BODY(TEST_##allocator);				\
 }									\
-static void alloc_size_##allocator##_dynamic_test(struct kunit *test)	\
+static void fortify_test_alloc_size_##allocator##_dynamic(struct kunit *test) \
 {									\
 	DYNAMIC_TEST_BODY(TEST_##allocator);				\
 }
@@ -267,28 +284,28 @@ DEFINE_ALLOC_SIZE_TEST_PAIR(vmalloc)
 									\
 	checker((expected_pages) * PAGE_SIZE,				\
 		kvmalloc((alloc_pages) * PAGE_SIZE, gfp),		\
-		vfree(p));						\
+		kvfree(p));						\
 	checker((expected_pages) * PAGE_SIZE,				\
 		kvmalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \
-		vfree(p));						\
+		kvfree(p));						\
 	checker((expected_pages) * PAGE_SIZE,				\
 		kvzalloc((alloc_pages) * PAGE_SIZE, gfp),		\
-		vfree(p));						\
+		kvfree(p));						\
 	checker((expected_pages) * PAGE_SIZE,				\
 		kvzalloc_node((alloc_pages) * PAGE_SIZE, gfp, NUMA_NO_NODE), \
-		vfree(p));						\
+		kvfree(p));						\
 	checker((expected_pages) * PAGE_SIZE,				\
 		kvcalloc(1, (alloc_pages) * PAGE_SIZE, gfp),		\
-		vfree(p));						\
+		kvfree(p));						\
 	checker((expected_pages) * PAGE_SIZE,				\
 		kvcalloc((alloc_pages) * PAGE_SIZE, 1, gfp),		\
-		vfree(p));						\
+		kvfree(p));						\
 	checker((expected_pages) * PAGE_SIZE,				\
 		kvmalloc_array(1, (alloc_pages) * PAGE_SIZE, gfp),	\
-		vfree(p));						\
+		kvfree(p));						\
 	checker((expected_pages) * PAGE_SIZE,				\
 		kvmalloc_array((alloc_pages) * PAGE_SIZE, 1, gfp),	\
-		vfree(p));						\
+		kvfree(p));						\
 									\
 	prev_size = (expected_pages) * PAGE_SIZE;			\
 	orig = kvmalloc(prev_size, gfp);				\
@@ -346,6 +363,31 @@ DEFINE_ALLOC_SIZE_TEST_PAIR(kvmalloc)
 } while (0)
 DEFINE_ALLOC_SIZE_TEST_PAIR(devm_kmalloc)
 
+static const char * const test_phrases[] = {
+	"",
+	"Hello there",
+	"A longer string, just for variety",
+};
+
+#define TEST_realloc(checker)	do {					\
+	gfp_t gfp = GFP_KERNEL;						\
+	size_t len;							\
+	int idx;							\
+									\
+	for (idx = 0; idx < ARRAY_SIZE(test_phrases); idx++) {		\
+		len = strlen(test_phrases[idx]);			\
+		KUNIT_EXPECT_EQ(test, __builtin_constant_p(len), 0);	\
+		checker(len, kmemdup_array(test_phrases[idx], len, 1,	\
+					   gfp), kfree(p));		\
+		checker(len, kmemdup(test_phrases[idx], len, gfp),	\
+			kfree(p));					\
+	}								\
+} while (0)
+static void fortify_test_realloc_size(struct kunit *test)
+{
+	TEST_realloc(check_dynamic);
+}
+
 /*
  * We can't have an array at the end of a structure or else
  * builds without -fstrict-flex-arrays=3 will report them as
@@ -361,7 +403,7 @@ struct fortify_padding {
 /* Force compiler into not being able to resolve size at compile-time. */
 static volatile int unconst;
 
-static void strlen_test(struct kunit *test)
+static void fortify_test_strlen(struct kunit *test)
 {
 	struct fortify_padding pad = { };
 	int i, end = sizeof(pad.buf) - 1;
@@ -384,7 +426,7 @@ static void strlen_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
 }
 
-static void strnlen_test(struct kunit *test)
+static void fortify_test_strnlen(struct kunit *test)
 {
 	struct fortify_padding pad = { };
 	int i, end = sizeof(pad.buf) - 1;
@@ -422,7 +464,7 @@ static void strnlen_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
 }
 
-static void strcpy_test(struct kunit *test)
+static void fortify_test_strcpy(struct kunit *test)
 {
 	struct fortify_padding pad = { };
 	char src[sizeof(pad.buf) + 1] = { };
@@ -480,7 +522,7 @@ static void strcpy_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
 }
 
-static void strncpy_test(struct kunit *test)
+static void fortify_test_strncpy(struct kunit *test)
 {
 	struct fortify_padding pad = { };
 	char src[] = "Copy me fully into a small buffer and I will overflow!";
@@ -539,7 +581,7 @@ static void strncpy_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
 }
 
-static void strscpy_test(struct kunit *test)
+static void fortify_test_strscpy(struct kunit *test)
 {
 	struct fortify_padding pad = { };
 	char src[] = "Copy me fully into a small buffer and I will overflow!";
@@ -596,7 +638,7 @@ static void strscpy_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
 }
 
-static void strcat_test(struct kunit *test)
+static void fortify_test_strcat(struct kunit *test)
 {
 	struct fortify_padding pad = { };
 	char src[sizeof(pad.buf) / 2] = { };
@@ -653,7 +695,7 @@ static void strcat_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
 }
 
-static void strncat_test(struct kunit *test)
+static void fortify_test_strncat(struct kunit *test)
 {
 	struct fortify_padding pad = { };
 	char src[sizeof(pad.buf)] = { };
@@ -726,7 +768,7 @@ static void strncat_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
 }
 
-static void strlcat_test(struct kunit *test)
+static void fortify_test_strlcat(struct kunit *test)
 {
 	struct fortify_padding pad = { };
 	char src[sizeof(pad.buf)] = { };
@@ -811,7 +853,75 @@ static void strlcat_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);
 }
 
-static void memscan_test(struct kunit *test)
+/* Check for 0-sized arrays... */
+struct fortify_zero_sized {
+	unsigned long bytes_before;
+	char buf[0];
+	unsigned long bytes_after;
+};
+
+#define __fortify_test(memfunc)					\
+static void fortify_test_##memfunc(struct kunit *test)		\
+{								\
+	struct fortify_zero_sized zero = { };			\
+	struct fortify_padding pad = { };			\
+	char srcA[sizeof(pad.buf) + 2];				\
+	char srcB[sizeof(pad.buf) + 2];				\
+	size_t len = sizeof(pad.buf) + unconst;			\
+								\
+	memset(srcA, 'A', sizeof(srcA));			\
+	KUNIT_ASSERT_EQ(test, srcA[0], 'A');			\
+	memset(srcB, 'B', sizeof(srcB));			\
+	KUNIT_ASSERT_EQ(test, srcB[0], 'B');			\
+								\
+	memfunc(pad.buf, srcA, 0 + unconst);			\
+	KUNIT_EXPECT_EQ(test, pad.buf[0], '\0');		\
+	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);	\
+	KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);	\
+	memfunc(pad.buf + 1, srcB, 1 + unconst);		\
+	KUNIT_EXPECT_EQ(test, pad.buf[0], '\0');		\
+	KUNIT_EXPECT_EQ(test, pad.buf[1], 'B');			\
+	KUNIT_EXPECT_EQ(test, pad.buf[2], '\0');		\
+	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);	\
+	KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);	\
+	memfunc(pad.buf, srcA, 1 + unconst);			\
+	KUNIT_EXPECT_EQ(test, pad.buf[0], 'A');			\
+	KUNIT_EXPECT_EQ(test, pad.buf[1], 'B');			\
+	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);	\
+	KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);	\
+	memfunc(pad.buf, srcA, len - 1);			\
+	KUNIT_EXPECT_EQ(test, pad.buf[1], 'A');			\
+	KUNIT_EXPECT_EQ(test, pad.buf[len - 1], '\0');		\
+	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);	\
+	KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);	\
+	memfunc(pad.buf, srcA, len);				\
+	KUNIT_EXPECT_EQ(test, pad.buf[1], 'A');			\
+	KUNIT_EXPECT_EQ(test, pad.buf[len - 1], 'A');		\
+	KUNIT_EXPECT_EQ(test, pad.bytes_after, 0);		\
+	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);	\
+	KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);	\
+	memfunc(pad.buf, srcA, len + 1);			\
+	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);	\
+	KUNIT_EXPECT_EQ(test, fortify_write_overflows, 1);	\
+	memfunc(pad.buf + 1, srcB, len);			\
+	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);	\
+	KUNIT_EXPECT_EQ(test, fortify_write_overflows, 2);	\
+								\
+	/* Reset error counter. */				\
+	fortify_write_overflows = 0;				\
+	/* Copy nothing into nothing: no errors. */		\
+	memfunc(zero.buf, srcB, 0 + unconst);			\
+	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);	\
+	KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);	\
+	/* We currently explicitly ignore zero-sized dests. */	\
+	memfunc(zero.buf, srcB, 1 + unconst);			\
+	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 0);	\
+	KUNIT_EXPECT_EQ(test, fortify_write_overflows, 0);	\
+}
+__fortify_test(memcpy)
+__fortify_test(memmove)
+
+static void fortify_test_memscan(struct kunit *test)
 {
 	char haystack[] = "Where oh where is my memory range?";
 	char *mem = haystack + strlen("Where oh where is ");
@@ -830,7 +940,7 @@ static void memscan_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
 }
 
-static void memchr_test(struct kunit *test)
+static void fortify_test_memchr(struct kunit *test)
 {
 	char haystack[] = "Where oh where is my memory range?";
 	char *mem = haystack + strlen("Where oh where is ");
@@ -849,7 +959,7 @@ static void memchr_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
 }
 
-static void memchr_inv_test(struct kunit *test)
+static void fortify_test_memchr_inv(struct kunit *test)
 {
 	char haystack[] = "Where oh where is my memory range?";
 	char *mem = haystack + 1;
@@ -869,7 +979,7 @@ static void memchr_inv_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
 }
 
-static void memcmp_test(struct kunit *test)
+static void fortify_test_memcmp(struct kunit *test)
 {
 	char one[] = "My mind is going ...";
 	char two[] = "My mind is going ... I can feel it.";
@@ -891,7 +1001,7 @@ static void memcmp_test(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
 }
 
-static void kmemdup_test(struct kunit *test)
+static void fortify_test_kmemdup(struct kunit *test)
 {
 	char src[] = "I got Doom running on it!";
 	char *copy;
@@ -917,19 +1027,19 @@ static void kmemdup_test(struct kunit *test)
 
 	/* Out of bounds by 1 byte. */
 	copy = kmemdup(src, len + 1, GFP_KERNEL);
-	KUNIT_EXPECT_NULL(test, copy);
+	KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 1);
 	kfree(copy);
 
 	/* Way out of bounds. */
 	copy = kmemdup(src, len * 2, GFP_KERNEL);
-	KUNIT_EXPECT_NULL(test, copy);
+	KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 2);
 	kfree(copy);
 
 	/* Starting offset causing out of bounds. */
 	copy = kmemdup(src + 1, len, GFP_KERNEL);
-	KUNIT_EXPECT_NULL(test, copy);
+	KUNIT_EXPECT_PTR_EQ(test, copy, ZERO_SIZE_PTR);
 	KUNIT_EXPECT_EQ(test, fortify_read_overflows, 3);
 	kfree(copy);
 }
@@ -951,31 +1061,33 @@ static int fortify_test_init(struct kunit *test)
 }
 
 static struct kunit_case fortify_test_cases[] = {
-	KUNIT_CASE(known_sizes_test),
-	KUNIT_CASE(control_flow_split_test),
-	KUNIT_CASE(alloc_size_kmalloc_const_test),
-	KUNIT_CASE(alloc_size_kmalloc_dynamic_test),
-	KUNIT_CASE(alloc_size_vmalloc_const_test),
-	KUNIT_CASE(alloc_size_vmalloc_dynamic_test),
-	KUNIT_CASE(alloc_size_kvmalloc_const_test),
-	KUNIT_CASE(alloc_size_kvmalloc_dynamic_test),
-	KUNIT_CASE(alloc_size_devm_kmalloc_const_test),
-	KUNIT_CASE(alloc_size_devm_kmalloc_dynamic_test),
-	KUNIT_CASE(strlen_test),
-	KUNIT_CASE(strnlen_test),
-	KUNIT_CASE(strcpy_test),
-	KUNIT_CASE(strncpy_test),
-	KUNIT_CASE(strscpy_test),
-	KUNIT_CASE(strcat_test),
-	KUNIT_CASE(strncat_test),
-	KUNIT_CASE(strlcat_test),
+	KUNIT_CASE(fortify_test_known_sizes),
+	KUNIT_CASE(fortify_test_control_flow_split),
+	KUNIT_CASE(fortify_test_alloc_size_kmalloc_const),
+	KUNIT_CASE(fortify_test_alloc_size_kmalloc_dynamic),
+	KUNIT_CASE(fortify_test_alloc_size_vmalloc_const),
+	KUNIT_CASE(fortify_test_alloc_size_vmalloc_dynamic),
+	KUNIT_CASE(fortify_test_alloc_size_kvmalloc_const),
+	KUNIT_CASE(fortify_test_alloc_size_kvmalloc_dynamic),
+	KUNIT_CASE(fortify_test_alloc_size_devm_kmalloc_const),
+	KUNIT_CASE(fortify_test_alloc_size_devm_kmalloc_dynamic),
+	KUNIT_CASE(fortify_test_realloc_size),
+	KUNIT_CASE(fortify_test_strlen),
+	KUNIT_CASE(fortify_test_strnlen),
+	KUNIT_CASE(fortify_test_strcpy),
+	KUNIT_CASE(fortify_test_strncpy),
+	KUNIT_CASE(fortify_test_strscpy),
+	KUNIT_CASE(fortify_test_strcat),
+	KUNIT_CASE(fortify_test_strncat),
+	KUNIT_CASE(fortify_test_strlcat),
 	/* skip memset: performs bounds checking on whole structs */
-	/* skip memcpy: still using warn-and-overwrite instead of hard-fail */
-	KUNIT_CASE(memscan_test),
-	KUNIT_CASE(memchr_test),
-	KUNIT_CASE(memchr_inv_test),
-	KUNIT_CASE(memcmp_test),
-	KUNIT_CASE(kmemdup_test),
+	KUNIT_CASE(fortify_test_memcpy),
+	KUNIT_CASE(fortify_test_memmove),
+	KUNIT_CASE(fortify_test_memscan),
+	KUNIT_CASE(fortify_test_memchr),
+	KUNIT_CASE(fortify_test_memchr_inv),
+	KUNIT_CASE(fortify_test_memcmp),
+	KUNIT_CASE(fortify_test_kmemdup),
 	{}
 };
 
diff --git a/lib/memcpy_kunit.c b/lib/memcpy_kunit.c
index fd16e6ce53d1d..20ea9038c3fff 100644
--- a/lib/memcpy_kunit.c
+++ b/lib/memcpy_kunit.c
@@ -493,58 +493,6 @@ static void memmove_overlap_test(struct kunit *test)
 	}
 }
 
-static void strtomem_test(struct kunit *test)
-{
-	static const char input[sizeof(unsigned long)] = "hi";
-	static const char truncate[] = "this is too long";
-	struct {
-		unsigned long canary1;
-		unsigned char output[sizeof(unsigned long)] __nonstring;
-		unsigned long canary2;
-	} wrap;
-
-	memset(&wrap, 0xFF, sizeof(wrap));
-	KUNIT_EXPECT_EQ_MSG(test, wrap.canary1, ULONG_MAX,
-			    "bad initial canary value");
-	KUNIT_EXPECT_EQ_MSG(test, wrap.canary2, ULONG_MAX,
-			    "bad initial canary value");
-
-	/* Check unpadded copy leaves surroundings untouched. */
-	strtomem(wrap.output, input);
-	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
-	KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]);
-	KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]);
-	for (size_t i = 2; i < sizeof(wrap.output); i++)
-		KUNIT_EXPECT_EQ(test, wrap.output[i], 0xFF);
-	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
-
-	/* Check truncated copy leaves surroundings untouched. */
-	memset(&wrap, 0xFF, sizeof(wrap));
-	strtomem(wrap.output, truncate);
-	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
-	for (size_t i = 0; i < sizeof(wrap.output); i++)
-		KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]);
-	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
-
-	/* Check padded copy leaves only string padded. */
-	memset(&wrap, 0xFF, sizeof(wrap));
-	strtomem_pad(wrap.output, input, 0xAA);
-	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
-	KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]);
-	KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]);
-	for (size_t i = 2; i < sizeof(wrap.output); i++)
-		KUNIT_EXPECT_EQ(test, wrap.output[i], 0xAA);
-	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
-
-	/* Check truncated padded copy has no padding. */
-	memset(&wrap, 0xFF, sizeof(wrap));
-	strtomem(wrap.output, truncate);
-	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
-	for (size_t i = 0; i < sizeof(wrap.output); i++)
-		KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]);
-	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
-}
-
 static struct kunit_case memcpy_test_cases[] = {
 	KUNIT_CASE(memset_test),
 	KUNIT_CASE(memcpy_test),
@@ -552,7 +500,6 @@ static struct kunit_case memcpy_test_cases[] = {
 	KUNIT_CASE_SLOW(memmove_test),
 	KUNIT_CASE_SLOW(memmove_large_test),
 	KUNIT_CASE_SLOW(memmove_overlap_test),
-	KUNIT_CASE(strtomem_test),
 	{}
 };
 
diff --git a/lib/strcat_kunit.c b/lib/strcat_kunit.c
deleted file mode 100644
index e21be95514afa..0000000000000
--- a/lib/strcat_kunit.c
+++ /dev/null
@@ -1,104 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Kernel module for testing 'strcat' family of functions.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <kunit/test.h>
-#include <linux/string.h>
-
-static volatile int unconst;
-
-static void strcat_test(struct kunit *test)
-{
-	char dest[8];
-
-	/* Destination is terminated. */
-	memset(dest, 0, sizeof(dest));
-	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
-	/* Empty copy does nothing. */
-	KUNIT_EXPECT_TRUE(test, strcat(dest, "") == dest);
-	KUNIT_EXPECT_STREQ(test, dest, "");
-	/* 4 characters copied in, stops at %NUL. */
-	KUNIT_EXPECT_TRUE(test, strcat(dest, "four\000123") == dest);
-	KUNIT_EXPECT_STREQ(test, dest, "four");
-	KUNIT_EXPECT_EQ(test, dest[5], '\0');
-	/* 2 more characters copied in okay. */
-	KUNIT_EXPECT_TRUE(test, strcat(dest, "AB") == dest);
-	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
-}
-
-static void strncat_test(struct kunit *test)
-{
-	char dest[8];
-
-	/* Destination is terminated. */
-	memset(dest, 0, sizeof(dest));
-	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
-	/* Empty copy of size 0 does nothing. */
-	KUNIT_EXPECT_TRUE(test, strncat(dest, "", 0 + unconst) == dest);
-	KUNIT_EXPECT_STREQ(test, dest, "");
-	/* Empty copy of size 1 does nothing too. */
-	KUNIT_EXPECT_TRUE(test, strncat(dest, "", 1 + unconst) == dest);
-	KUNIT_EXPECT_STREQ(test, dest, "");
-	/* Copy of max 0 characters should do nothing. */
-	KUNIT_EXPECT_TRUE(test, strncat(dest, "asdf", 0 + unconst) == dest);
-	KUNIT_EXPECT_STREQ(test, dest, "");
-
-	/* 4 characters copied in, even if max is 8. */
-	KUNIT_EXPECT_TRUE(test, strncat(dest, "four\000123", 8 + unconst) == dest);
-	KUNIT_EXPECT_STREQ(test, dest, "four");
-	KUNIT_EXPECT_EQ(test, dest[5], '\0');
-	KUNIT_EXPECT_EQ(test, dest[6], '\0');
-	/* 2 characters copied in okay, 2 ignored. */
-	KUNIT_EXPECT_TRUE(test, strncat(dest, "ABCD", 2 + unconst) == dest);
-	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
-}
-
-static void strlcat_test(struct kunit *test)
-{
-	char dest[8] = "";
-	int len = sizeof(dest) + unconst;
-
-	/* Destination is terminated. */
-	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
-	/* Empty copy is size 0. */
-	KUNIT_EXPECT_EQ(test, strlcat(dest, "", len), 0);
-	KUNIT_EXPECT_STREQ(test, dest, "");
-	/* Size 1 should keep buffer terminated, report size of source only. */
-	KUNIT_EXPECT_EQ(test, strlcat(dest, "four", 1 + unconst), 4);
-	KUNIT_EXPECT_STREQ(test, dest, "");
-
-	/* 4 characters copied in. */
-	KUNIT_EXPECT_EQ(test, strlcat(dest, "four", len), 4);
-	KUNIT_EXPECT_STREQ(test, dest, "four");
-	/* 2 characters copied in okay, gets to 6 total. */
-	KUNIT_EXPECT_EQ(test, strlcat(dest, "AB", len), 6);
-	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
-	/* 2 characters ignored if max size (7) reached. */
-	KUNIT_EXPECT_EQ(test, strlcat(dest, "CD", 7 + unconst), 8);
-	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
-	/* 1 of 2 characters skipped, now at true max size. */
-	KUNIT_EXPECT_EQ(test, strlcat(dest, "EFG", len), 9);
-	KUNIT_EXPECT_STREQ(test, dest, "fourABE");
-	/* Everything else ignored, now at full size. */
-	KUNIT_EXPECT_EQ(test, strlcat(dest, "1234", len), 11);
-	KUNIT_EXPECT_STREQ(test, dest, "fourABE");
-}
-
-static struct kunit_case strcat_test_cases[] = {
-	KUNIT_CASE(strcat_test),
-	KUNIT_CASE(strncat_test),
-	KUNIT_CASE(strlcat_test),
-	{}
-};
-
-static struct kunit_suite strcat_test_suite = {
-	.name = "strcat",
-	.test_cases = strcat_test_cases,
-};
-
-kunit_test_suite(strcat_test_suite);
-
-MODULE_LICENSE("GPL");
diff --git a/lib/string_kunit.c b/lib/string_kunit.c
index eabf025cf77c9..2a812decf14bd 100644
--- a/lib/string_kunit.c
+++ b/lib/string_kunit.c
@@ -11,7 +11,13 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 
-static void test_memset16(struct kunit *test)
+#define STRCMP_LARGE_BUF_LEN 2048
+#define STRCMP_CHANGE_POINT 1337
+#define STRCMP_TEST_EXPECT_EQUAL(test, fn, ...) KUNIT_EXPECT_EQ(test, fn(__VA_ARGS__), 0)
+#define STRCMP_TEST_EXPECT_LOWER(test, fn, ...) KUNIT_EXPECT_LT(test, fn(__VA_ARGS__), 0)
+#define STRCMP_TEST_EXPECT_GREATER(test, fn, ...) KUNIT_EXPECT_GT(test, fn(__VA_ARGS__), 0)
+
+static void string_test_memset16(struct kunit *test)
 {
 	unsigned i, j, k;
 	u16 v, *p;
@@ -40,7 +46,7 @@ static void test_memset16(struct kunit *test)
 	}
 }
 
-static void test_memset32(struct kunit *test)
+static void string_test_memset32(struct kunit *test)
 {
 	unsigned i, j, k;
 	u32 v, *p;
@@ -69,7 +75,7 @@ static void test_memset32(struct kunit *test)
 	}
 }
 
-static void test_memset64(struct kunit *test)
+static void string_test_memset64(struct kunit *test)
 {
 	unsigned i, j, k;
 	u64 v, *p;
@@ -98,7 +104,7 @@ static void test_memset64(struct kunit *test)
 	}
 }
 
-static void test_strchr(struct kunit *test)
+static void string_test_strchr(struct kunit *test)
 {
 	const char *test_string = "abcdefghijkl";
 	const char *empty_string = "";
@@ -121,7 +127,7 @@ static void test_strchr(struct kunit *test)
 	KUNIT_ASSERT_NULL(test, result);
 }
 
-static void test_strnchr(struct kunit *test)
+static void string_test_strnchr(struct kunit *test)
 {
 	const char *test_string = "abcdefghijkl";
 	const char *empty_string = "";
@@ -154,7 +160,7 @@ static void test_strnchr(struct kunit *test)
 	KUNIT_ASSERT_NULL(test, result);
 }
 
-static void test_strspn(struct kunit *test)
+static void string_test_strspn(struct kunit *test)
 {
 	static const struct strspn_test {
 		const char str[16];
@@ -179,13 +185,444 @@ static void test_strspn(struct kunit *test)
 	}
 }
 
+static char strcmp_buffer1[STRCMP_LARGE_BUF_LEN];
+static char strcmp_buffer2[STRCMP_LARGE_BUF_LEN];
+
+static void strcmp_fill_buffers(char fill1, char fill2)
+{
+	memset(strcmp_buffer1, fill1, STRCMP_LARGE_BUF_LEN);
+	memset(strcmp_buffer2, fill2, STRCMP_LARGE_BUF_LEN);
+	strcmp_buffer1[STRCMP_LARGE_BUF_LEN - 1] = 0;
+	strcmp_buffer2[STRCMP_LARGE_BUF_LEN - 1] = 0;
+}
+
+static void string_test_strcmp(struct kunit *test)
+{
+	/* Equal strings */
+	STRCMP_TEST_EXPECT_EQUAL(test, strcmp, "Hello, Kernel!", "Hello, Kernel!");
+	/* First string is lexicographically less than the second */
+	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Hello, KUnit!", "Hello, Kernel!");
+	/* First string is lexicographically larger than the second */
+	STRCMP_TEST_EXPECT_GREATER(test, strcmp, "Hello, Kernel!", "Hello, KUnit!");
+	/* Empty string is always lexicographically less than any non-empty string */
+	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "", "Non-empty string");
+	/* Two empty strings should be equal */
+	STRCMP_TEST_EXPECT_EQUAL(test, strcmp, "", "");
+	/* Compare two strings which have only one char difference */
+	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Abacaba", "Abadaba");
+	/* Compare two strings which have the same prefix*/
+	STRCMP_TEST_EXPECT_LOWER(test, strcmp, "Just a string", "Just a string and something else");
+}
+
+static void string_test_strcmp_long_strings(struct kunit *test)
+{
+	strcmp_fill_buffers('B', 'B');
+	STRCMP_TEST_EXPECT_EQUAL(test, strcmp, strcmp_buffer1, strcmp_buffer2);
+
+	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'A';
+	STRCMP_TEST_EXPECT_LOWER(test, strcmp, strcmp_buffer1, strcmp_buffer2);
+
+	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
+	STRCMP_TEST_EXPECT_GREATER(test, strcmp, strcmp_buffer1, strcmp_buffer2);
+}
+
+static void string_test_strncmp(struct kunit *test)
+{
+	/* Equal strings */
+	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Hello, KUnit!", "Hello, KUnit!", 13);
+	/* First string is lexicographically less than the second */
+	STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Hello, KUnit!", "Hello, Kernel!", 13);
+	/* Result is always 'equal' when count = 0 */
+	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Hello, Kernel!", "Hello, KUnit!", 0);
+	/* Strings with common prefix are equal if count = length of prefix */
+	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Abacaba", "Abadaba", 3);
+	/* Strings with common prefix are not equal when count = length of prefix + 1 */
+	STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Abacaba", "Abadaba", 4);
+	/* If one string is a prefix of another, the shorter string is lexicographically smaller */
+	STRCMP_TEST_EXPECT_LOWER(test, strncmp, "Just a string", "Just a string and something else",
+				 strlen("Just a string and something else"));
+	/*
+	 * If one string is a prefix of another, and we check first length
+	 * of prefix chars, the result is 'equal'
+	 */
+	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, "Just a string", "Just a string and something else",
+				 strlen("Just a string"));
+}
+
+static void string_test_strncmp_long_strings(struct kunit *test)
+{
+	strcmp_fill_buffers('B', 'B');
+	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, strcmp_buffer1,
+				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
+
+	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'A';
+	STRCMP_TEST_EXPECT_LOWER(test, strncmp, strcmp_buffer1,
+				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
+
+	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
+	STRCMP_TEST_EXPECT_GREATER(test, strncmp, strcmp_buffer1,
+				   strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
+	/* the strings are equal up to STRCMP_CHANGE_POINT */
+	STRCMP_TEST_EXPECT_EQUAL(test, strncmp, strcmp_buffer1,
+				 strcmp_buffer2, STRCMP_CHANGE_POINT);
+	STRCMP_TEST_EXPECT_GREATER(test, strncmp, strcmp_buffer1,
+				   strcmp_buffer2, STRCMP_CHANGE_POINT + 1);
+}
+
+static void string_test_strcasecmp(struct kunit *test)
+{
+	/* Same strings in different case should be equal */
+	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "Hello, Kernel!", "HeLLO, KErNeL!");
+	/* Empty strings should be equal */
+	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "", "");
+	/* Despite ascii code for 'a' is larger than ascii code for 'B', 'a' < 'B' */
+	STRCMP_TEST_EXPECT_LOWER(test, strcasecmp, "a", "B");
+	STRCMP_TEST_EXPECT_GREATER(test, strcasecmp, "B", "a");
+	/* Special symbols and numbers should be processed correctly */
+	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, "-+**.1230ghTTT~^", "-+**.1230Ghttt~^");
+}
+
+static void string_test_strcasecmp_long_strings(struct kunit *test)
+{
+	strcmp_fill_buffers('b', 'B');
+	STRCMP_TEST_EXPECT_EQUAL(test, strcasecmp, strcmp_buffer1, strcmp_buffer2);
+
+	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'a';
+	STRCMP_TEST_EXPECT_LOWER(test, strcasecmp, strcmp_buffer1, strcmp_buffer2);
+
+	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
+	STRCMP_TEST_EXPECT_GREATER(test, strcasecmp, strcmp_buffer1, strcmp_buffer2);
+}
+
+static void string_test_strncasecmp(struct kunit *test)
+{
+	/* Same strings in different case should be equal */
+	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "AbAcAbA", "Abacaba", strlen("Abacaba"));
+	/* strncasecmp should check 'count' chars only */
+	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "AbaCaBa", "abaCaDa", 5);
+	STRCMP_TEST_EXPECT_LOWER(test, strncasecmp, "a", "B", 1);
+	STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, "B", "a", 1);
+	/* Result is always 'equal' when count = 0 */
+	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, "Abacaba", "Not abacaba", 0);
+}
+
+static void string_test_strncasecmp_long_strings(struct kunit *test)
+{
+	strcmp_fill_buffers('b', 'B');
+	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, strcmp_buffer1,
+				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
+
+	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'a';
+	STRCMP_TEST_EXPECT_LOWER(test, strncasecmp, strcmp_buffer1,
+				 strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
+
+	strcmp_buffer1[STRCMP_CHANGE_POINT] = 'C';
+	STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, strcmp_buffer1,
+				   strcmp_buffer2, STRCMP_LARGE_BUF_LEN);
+
+	STRCMP_TEST_EXPECT_EQUAL(test, strncasecmp, strcmp_buffer1,
+				 strcmp_buffer2, STRCMP_CHANGE_POINT);
+	STRCMP_TEST_EXPECT_GREATER(test, strncasecmp, strcmp_buffer1,
+				   strcmp_buffer2, STRCMP_CHANGE_POINT + 1);
+}
+
+/**
+ * strscpy_check() - Run a specific test case.
+ * @test: KUnit test context pointer
+ * @src: Source string, argument to strscpy_pad()
+ * @count: Size of destination buffer, argument to strscpy_pad()
+ * @expected: Expected return value from call to strscpy_pad()
+ * @chars: Number of characters from the src string expected to be
+ *         written to the dst buffer.
+ * @terminator: 1 if there should be a terminating null byte 0 otherwise.
+ * @pad: Number of pad characters expected (in the tail of dst buffer).
+ *       (@pad does not include the null terminator byte.)
+ *
+ * Calls strscpy_pad() and verifies the return value and state of the
+ * destination buffer after the call returns.
+ */
+static void strscpy_check(struct kunit *test, char *src, int count,
+			  int expected, int chars, int terminator, int pad)
+{
+	int nr_bytes_poison;
+	int max_expected;
+	int max_count;
+	int written;
+	char buf[6];
+	int index, i;
+	const char POISON = 'z';
+
+	KUNIT_ASSERT_TRUE_MSG(test, src != NULL,
+			      "null source string not supported");
+
+	memset(buf, POISON, sizeof(buf));
+	/* Future proofing test suite, validate args */
+	max_count = sizeof(buf) - 2; /* Space for null and to verify overflow */
+	max_expected = count - 1;    /* Space for the null */
+
+	KUNIT_ASSERT_LE_MSG(test, count, max_count,
+		"count (%d) is too big (%d) ... aborting", count, max_count);
+	KUNIT_EXPECT_LE_MSG(test, expected, max_expected,
+		"expected (%d) is bigger than can possibly be returned (%d)",
+		expected, max_expected);
+
+	written = strscpy_pad(buf, src, count);
+	KUNIT_ASSERT_EQ(test, written, expected);
+
+	if (count && written == -E2BIG) {
+		KUNIT_ASSERT_EQ_MSG(test, 0, strncmp(buf, src, count - 1),
+			"buffer state invalid for -E2BIG");
+		KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0',
+			"too big string is not null terminated correctly");
+	}
+
+	for (i = 0; i < chars; i++)
+		KUNIT_ASSERT_EQ_MSG(test, buf[i], src[i],
+			"buf[i]==%c != src[i]==%c", buf[i], src[i]);
+
+	if (terminator)
+		KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0',
+			"string is not null terminated correctly");
+
+	for (i = 0; i < pad; i++) {
+		index = chars + terminator + i;
+		KUNIT_ASSERT_EQ_MSG(test, buf[index], '\0',
+			"padding missing at index: %d", i);
+	}
+
+	nr_bytes_poison = sizeof(buf) - chars - terminator - pad;
+	for (i = 0; i < nr_bytes_poison; i++) {
+		index = sizeof(buf) - 1 - i; /* Check from the end back */
+		KUNIT_ASSERT_EQ_MSG(test, buf[index], POISON,
+			"poison value missing at index: %d", i);
+	}
+}
+
+static void string_test_strscpy(struct kunit *test)
+{
+	char dest[8];
+
+	/*
+	 * strscpy_check() uses a destination buffer of size 6 and needs at
+	 * least 2 characters spare (one for null and one to check for
+	 * overflow).  This means we should only call tc() with
+	 * strings up to a maximum of 4 characters long and 'count'
+	 * should not exceed 4.  To test with longer strings increase
+	 * the buffer size in tc().
+	 */
+
+	/* strscpy_check(test, src, count, expected, chars, terminator, pad) */
+	strscpy_check(test, "a", 0, -E2BIG, 0, 0, 0);
+	strscpy_check(test, "",  0, -E2BIG, 0, 0, 0);
+
+	strscpy_check(test, "a", 1, -E2BIG, 0, 1, 0);
+	strscpy_check(test, "",  1, 0,	 0, 1, 0);
+
+	strscpy_check(test, "ab", 2, -E2BIG, 1, 1, 0);
+	strscpy_check(test, "a",  2, 1,	  1, 1, 0);
+	strscpy_check(test, "",   2, 0,	  0, 1, 1);
+
+	strscpy_check(test, "abc", 3, -E2BIG, 2, 1, 0);
+	strscpy_check(test, "ab",  3, 2,	   2, 1, 0);
+	strscpy_check(test, "a",   3, 1,	   1, 1, 1);
+	strscpy_check(test, "",    3, 0,	   0, 1, 2);
+
+	strscpy_check(test, "abcd", 4, -E2BIG, 3, 1, 0);
+	strscpy_check(test, "abc",  4, 3,	    3, 1, 0);
+	strscpy_check(test, "ab",   4, 2,	    2, 1, 1);
+	strscpy_check(test, "a",    4, 1,	    1, 1, 2);
+	strscpy_check(test, "",     4, 0,	    0, 1, 3);
+
+	/* Compile-time-known source strings. */
+	KUNIT_EXPECT_EQ(test, strscpy(dest, "", ARRAY_SIZE(dest)), 0);
+	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 3), 0);
+	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 1), 0);
+	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 0), -E2BIG);
+	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", ARRAY_SIZE(dest)), 5);
+	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 3), -E2BIG);
+	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 1), -E2BIG);
+	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 0), -E2BIG);
+	KUNIT_EXPECT_EQ(test, strscpy(dest, "This is too long", ARRAY_SIZE(dest)), -E2BIG);
+}
+
+static volatile int unconst;
+
+static void string_test_strcat(struct kunit *test)
+{
+	char dest[8];
+
+	/* Destination is terminated. */
+	memset(dest, 0, sizeof(dest));
+	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
+	/* Empty copy does nothing. */
+	KUNIT_EXPECT_TRUE(test, strcat(dest, "") == dest);
+	KUNIT_EXPECT_STREQ(test, dest, "");
+	/* 4 characters copied in, stops at %NUL. */
+	KUNIT_EXPECT_TRUE(test, strcat(dest, "four\000123") == dest);
+	KUNIT_EXPECT_STREQ(test, dest, "four");
+	KUNIT_EXPECT_EQ(test, dest[5], '\0');
+	/* 2 more characters copied in okay. */
+	KUNIT_EXPECT_TRUE(test, strcat(dest, "AB") == dest);
+	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
+}
+
+static void string_test_strncat(struct kunit *test)
+{
+	char dest[8];
+
+	/* Destination is terminated. */
+	memset(dest, 0, sizeof(dest));
+	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
+	/* Empty copy of size 0 does nothing. */
+	KUNIT_EXPECT_TRUE(test, strncat(dest, "", 0 + unconst) == dest);
+	KUNIT_EXPECT_STREQ(test, dest, "");
+	/* Empty copy of size 1 does nothing too. */
+	KUNIT_EXPECT_TRUE(test, strncat(dest, "", 1 + unconst) == dest);
+	KUNIT_EXPECT_STREQ(test, dest, "");
+	/* Copy of max 0 characters should do nothing. */
+	KUNIT_EXPECT_TRUE(test, strncat(dest, "asdf", 0 + unconst) == dest);
+	KUNIT_EXPECT_STREQ(test, dest, "");
+
+	/* 4 characters copied in, even if max is 8. */
+	KUNIT_EXPECT_TRUE(test, strncat(dest, "four\000123", 8 + unconst) == dest);
+	KUNIT_EXPECT_STREQ(test, dest, "four");
+	KUNIT_EXPECT_EQ(test, dest[5], '\0');
+	KUNIT_EXPECT_EQ(test, dest[6], '\0');
+	/* 2 characters copied in okay, 2 ignored. */
+	KUNIT_EXPECT_TRUE(test, strncat(dest, "ABCD", 2 + unconst) == dest);
+	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
+}
+
+static void string_test_strlcat(struct kunit *test)
+{
+	char dest[8] = "";
+	int len = sizeof(dest) + unconst;
+
+	/* Destination is terminated. */
+	KUNIT_EXPECT_EQ(test, strlen(dest), 0);
+	/* Empty copy is size 0. */
+	KUNIT_EXPECT_EQ(test, strlcat(dest, "", len), 0);
+	KUNIT_EXPECT_STREQ(test, dest, "");
+	/* Size 1 should keep buffer terminated, report size of source only. */
+	KUNIT_EXPECT_EQ(test, strlcat(dest, "four", 1 + unconst), 4);
+	KUNIT_EXPECT_STREQ(test, dest, "");
+
+	/* 4 characters copied in. */
+	KUNIT_EXPECT_EQ(test, strlcat(dest, "four", len), 4);
+	KUNIT_EXPECT_STREQ(test, dest, "four");
+	/* 2 characters copied in okay, gets to 6 total. */
+	KUNIT_EXPECT_EQ(test, strlcat(dest, "AB", len), 6);
+	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
+	/* 2 characters ignored if max size (7) reached. */
+	KUNIT_EXPECT_EQ(test, strlcat(dest, "CD", 7 + unconst), 8);
+	KUNIT_EXPECT_STREQ(test, dest, "fourAB");
+	/* 1 of 2 characters skipped, now at true max size. */
+	KUNIT_EXPECT_EQ(test, strlcat(dest, "EFG", len), 9);
+	KUNIT_EXPECT_STREQ(test, dest, "fourABE");
+	/* Everything else ignored, now at full size. */
+	KUNIT_EXPECT_EQ(test, strlcat(dest, "1234", len), 11);
+	KUNIT_EXPECT_STREQ(test, dest, "fourABE");
+}
+
+static void string_test_strtomem(struct kunit *test)
+{
+	static const char input[sizeof(unsigned long)] = "hi";
+	static const char truncate[] = "this is too long";
+	struct {
+		unsigned long canary1;
+		unsigned char output[sizeof(unsigned long)] __nonstring;
+		unsigned long canary2;
+	} wrap;
+
+	memset(&wrap, 0xFF, sizeof(wrap));
+	KUNIT_EXPECT_EQ_MSG(test, wrap.canary1, ULONG_MAX,
+			    "bad initial canary value");
+	KUNIT_EXPECT_EQ_MSG(test, wrap.canary2, ULONG_MAX,
+			    "bad initial canary value");
+
+	/* Check unpadded copy leaves surroundings untouched. */
+	strtomem(wrap.output, input);
+	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
+	KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]);
+	KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]);
+	for (size_t i = 2; i < sizeof(wrap.output); i++)
+		KUNIT_EXPECT_EQ(test, wrap.output[i], 0xFF);
+	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
+
+	/* Check truncated copy leaves surroundings untouched. */
+	memset(&wrap, 0xFF, sizeof(wrap));
+	strtomem(wrap.output, truncate);
+	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
+	for (size_t i = 0; i < sizeof(wrap.output); i++)
+		KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]);
+	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
+
+	/* Check padded copy leaves only string padded. */
+	memset(&wrap, 0xFF, sizeof(wrap));
+	strtomem_pad(wrap.output, input, 0xAA);
+	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
+	KUNIT_EXPECT_EQ(test, wrap.output[0], input[0]);
+	KUNIT_EXPECT_EQ(test, wrap.output[1], input[1]);
+	for (size_t i = 2; i < sizeof(wrap.output); i++)
+		KUNIT_EXPECT_EQ(test, wrap.output[i], 0xAA);
+	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
+
+	/* Check truncated padded copy has no padding. */
+	memset(&wrap, 0xFF, sizeof(wrap));
+	strtomem(wrap.output, truncate);
+	KUNIT_EXPECT_EQ(test, wrap.canary1, ULONG_MAX);
+	for (size_t i = 0; i < sizeof(wrap.output); i++)
+		KUNIT_EXPECT_EQ(test, wrap.output[i], truncate[i]);
+	KUNIT_EXPECT_EQ(test, wrap.canary2, ULONG_MAX);
+}
+
+
+static void string_test_memtostr(struct kunit *test)
+{
+	char nonstring[7] = { 'a', 'b', 'c', 'd', 'e', 'f', 'g' };
+	char nonstring_small[3] = { 'a', 'b', 'c' };
+	char dest[sizeof(nonstring) + 1];
+
+	/* Copy in a non-NUL-terminated string into exactly right-sized dest. */
+	KUNIT_EXPECT_EQ(test, sizeof(dest), sizeof(nonstring) + 1);
+	memset(dest, 'X', sizeof(dest));
+	memtostr(dest, nonstring);
+	KUNIT_EXPECT_STREQ(test, dest, "abcdefg");
+	memset(dest, 'X', sizeof(dest));
+	memtostr(dest, nonstring_small);
+	KUNIT_EXPECT_STREQ(test, dest, "abc");
+	KUNIT_EXPECT_EQ(test, dest[7], 'X');
+
+	memset(dest, 'X', sizeof(dest));
+	memtostr_pad(dest, nonstring);
+	KUNIT_EXPECT_STREQ(test, dest, "abcdefg");
+	memset(dest, 'X', sizeof(dest));
+	memtostr_pad(dest, nonstring_small);
+	KUNIT_EXPECT_STREQ(test, dest, "abc");
+	KUNIT_EXPECT_EQ(test, dest[7], '\0');
+}
+
 static struct kunit_case string_test_cases[] = {
-	KUNIT_CASE(test_memset16),
-	KUNIT_CASE(test_memset32),
-	KUNIT_CASE(test_memset64),
-	KUNIT_CASE(test_strchr),
-	KUNIT_CASE(test_strnchr),
-	KUNIT_CASE(test_strspn),
+	KUNIT_CASE(string_test_memset16),
+	KUNIT_CASE(string_test_memset32),
+	KUNIT_CASE(string_test_memset64),
+	KUNIT_CASE(string_test_strchr),
+	KUNIT_CASE(string_test_strnchr),
+	KUNIT_CASE(string_test_strspn),
+	KUNIT_CASE(string_test_strcmp),
+	KUNIT_CASE(string_test_strcmp_long_strings),
+	KUNIT_CASE(string_test_strncmp),
+	KUNIT_CASE(string_test_strncmp_long_strings),
+	KUNIT_CASE(string_test_strcasecmp),
+	KUNIT_CASE(string_test_strcasecmp_long_strings),
+	KUNIT_CASE(string_test_strncasecmp),
+	KUNIT_CASE(string_test_strncasecmp_long_strings),
+	KUNIT_CASE(string_test_strscpy),
+	KUNIT_CASE(string_test_strcat),
+	KUNIT_CASE(string_test_strncat),
+	KUNIT_CASE(string_test_strlcat),
+	KUNIT_CASE(string_test_strtomem),
+	KUNIT_CASE(string_test_memtostr),
 	{}
 };
 
diff --git a/lib/strscpy_kunit.c b/lib/strscpy_kunit.c
deleted file mode 100644
index a6b6344354ed5..0000000000000
--- a/lib/strscpy_kunit.c
+++ /dev/null
@@ -1,142 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * Kernel module for testing 'strscpy' family of functions.
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <kunit/test.h>
-#include <linux/string.h>
-
-/*
- * tc() - Run a specific test case.
- * @src: Source string, argument to strscpy_pad()
- * @count: Size of destination buffer, argument to strscpy_pad()
- * @expected: Expected return value from call to strscpy_pad()
- * @terminator: 1 if there should be a terminating null byte 0 otherwise.
- * @chars: Number of characters from the src string expected to be
- *         written to the dst buffer.
- * @pad: Number of pad characters expected (in the tail of dst buffer).
- *       (@pad does not include the null terminator byte.)
- *
- * Calls strscpy_pad() and verifies the return value and state of the
- * destination buffer after the call returns.
- */
-static void tc(struct kunit *test, char *src, int count, int expected,
-	       int chars, int terminator, int pad)
-{
-	int nr_bytes_poison;
-	int max_expected;
-	int max_count;
-	int written;
-	char buf[6];
-	int index, i;
-	const char POISON = 'z';
-
-	KUNIT_ASSERT_TRUE_MSG(test, src != NULL,
-			      "null source string not supported");
-
-	memset(buf, POISON, sizeof(buf));
-	/* Future proofing test suite, validate args */
-	max_count = sizeof(buf) - 2; /* Space for null and to verify overflow */
-	max_expected = count - 1;    /* Space for the null */
-
-	KUNIT_ASSERT_LE_MSG(test, count, max_count,
-		"count (%d) is too big (%d) ... aborting", count, max_count);
-	KUNIT_EXPECT_LE_MSG(test, expected, max_expected,
-		"expected (%d) is bigger than can possibly be returned (%d)",
-		expected, max_expected);
-
-	written = strscpy_pad(buf, src, count);
-	KUNIT_ASSERT_EQ(test, written, expected);
-
-	if (count && written == -E2BIG) {
-		KUNIT_ASSERT_EQ_MSG(test, 0, strncmp(buf, src, count - 1),
-			"buffer state invalid for -E2BIG");
-		KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0',
-			"too big string is not null terminated correctly");
-	}
-
-	for (i = 0; i < chars; i++)
-		KUNIT_ASSERT_EQ_MSG(test, buf[i], src[i],
-			"buf[i]==%c != src[i]==%c", buf[i], src[i]);
-
-	if (terminator)
-		KUNIT_ASSERT_EQ_MSG(test, buf[count - 1], '\0',
-			"string is not null terminated correctly");
-
-	for (i = 0; i < pad; i++) {
-		index = chars + terminator + i;
-		KUNIT_ASSERT_EQ_MSG(test, buf[index], '\0',
-			"padding missing at index: %d", i);
-	}
-
-	nr_bytes_poison = sizeof(buf) - chars - terminator - pad;
-	for (i = 0; i < nr_bytes_poison; i++) {
-		index = sizeof(buf) - 1 - i; /* Check from the end back */
-		KUNIT_ASSERT_EQ_MSG(test, buf[index], POISON,
-			"poison value missing at index: %d", i);
-	}
-}
-
-static void strscpy_test(struct kunit *test)
-{
-	char dest[8];
-
-	/*
-	 * tc() uses a destination buffer of size 6 and needs at
-	 * least 2 characters spare (one for null and one to check for
-	 * overflow).  This means we should only call tc() with
-	 * strings up to a maximum of 4 characters long and 'count'
-	 * should not exceed 4.  To test with longer strings increase
-	 * the buffer size in tc().
-	 */
-
-	/* tc(test, src, count, expected, chars, terminator, pad) */
-	tc(test, "a", 0, -E2BIG, 0, 0, 0);
-	tc(test, "",  0, -E2BIG, 0, 0, 0);
-
-	tc(test, "a", 1, -E2BIG, 0, 1, 0);
-	tc(test, "",  1, 0,	 0, 1, 0);
-
-	tc(test, "ab", 2, -E2BIG, 1, 1, 0);
-	tc(test, "a",  2, 1,	  1, 1, 0);
-	tc(test, "",   2, 0,	  0, 1, 1);
-
-	tc(test, "abc", 3, -E2BIG, 2, 1, 0);
-	tc(test, "ab",  3, 2,	   2, 1, 0);
-	tc(test, "a",   3, 1,	   1, 1, 1);
-	tc(test, "",    3, 0,	   0, 1, 2);
-
-	tc(test, "abcd", 4, -E2BIG, 3, 1, 0);
-	tc(test, "abc",  4, 3,	    3, 1, 0);
-	tc(test, "ab",   4, 2,	    2, 1, 1);
-	tc(test, "a",    4, 1,	    1, 1, 2);
-	tc(test, "",     4, 0,	    0, 1, 3);
-
-	/* Compile-time-known source strings. */
-	KUNIT_EXPECT_EQ(test, strscpy(dest, "", ARRAY_SIZE(dest)), 0);
-	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 3), 0);
-	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 1), 0);
-	KUNIT_EXPECT_EQ(test, strscpy(dest, "", 0), -E2BIG);
-	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", ARRAY_SIZE(dest)), 5);
-	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 3), -E2BIG);
-	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 1), -E2BIG);
-	KUNIT_EXPECT_EQ(test, strscpy(dest, "Fixed", 0), -E2BIG);
-	KUNIT_EXPECT_EQ(test, strscpy(dest, "This is too long", ARRAY_SIZE(dest)), -E2BIG);
-}
-
-static struct kunit_case strscpy_test_cases[] = {
-	KUNIT_CASE(strscpy_test),
-	{}
-};
-
-static struct kunit_suite strscpy_test_suite = {
-	.name = "strscpy",
-	.test_cases = strscpy_test_cases,
-};
-
-kunit_test_suite(strscpy_test_suite);
-
-MODULE_AUTHOR("Tobin C. Harding <tobin@kernel.org>");
-MODULE_LICENSE("GPL");
diff --git a/lib/ubsan.h b/lib/ubsan.h
index 0abbbac8700d1..07e37d4429b4b 100644
--- a/lib/ubsan.h
+++ b/lib/ubsan.h
@@ -43,7 +43,7 @@ enum {
 struct type_descriptor {
 	u16 type_kind;
 	u16 type_info;
-	char type_name[1];
+	char type_name[];
 };
 
 struct source_location {
@@ -124,19 +124,32 @@ typedef s64 s_max;
 typedef u64 u_max;
 #endif
 
-void __ubsan_handle_add_overflow(void *data, void *lhs, void *rhs);
-void __ubsan_handle_sub_overflow(void *data, void *lhs, void *rhs);
-void __ubsan_handle_mul_overflow(void *data, void *lhs, void *rhs);
-void __ubsan_handle_negate_overflow(void *_data, void *old_val);
-void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs);
-void __ubsan_handle_type_mismatch(struct type_mismatch_data *data, void *ptr);
-void __ubsan_handle_type_mismatch_v1(void *_data, void *ptr);
-void __ubsan_handle_out_of_bounds(void *_data, void *index);
-void __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs);
-void __ubsan_handle_builtin_unreachable(void *_data);
-void __ubsan_handle_load_invalid_value(void *_data, void *val);
-void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
-					 unsigned long align,
-					 unsigned long offset);
+/*
+ * When generating Runtime Calls, Clang doesn't respect the -mregparm=3
+ * option used on i386: https://github.com/llvm/llvm-project/issues/89670
+ * Fix this for earlier Clang versions by forcing the calling convention
+ * to use non-register arguments.
+ */
+#if defined(CONFIG_X86_32) && \
+    defined(CONFIG_CC_IS_CLANG) && CONFIG_CLANG_VERSION < 190000
+# define ubsan_linkage asmlinkage
+#else
+# define ubsan_linkage
+#endif
+
+void ubsan_linkage __ubsan_handle_add_overflow(void *data, void *lhs, void *rhs);
+void ubsan_linkage __ubsan_handle_sub_overflow(void *data, void *lhs, void *rhs);
+void ubsan_linkage __ubsan_handle_mul_overflow(void *data, void *lhs, void *rhs);
+void ubsan_linkage __ubsan_handle_negate_overflow(void *_data, void *old_val);
+void ubsan_linkage __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs);
+void ubsan_linkage __ubsan_handle_type_mismatch(struct type_mismatch_data *data, void *ptr);
+void ubsan_linkage __ubsan_handle_type_mismatch_v1(void *_data, void *ptr);
+void ubsan_linkage __ubsan_handle_out_of_bounds(void *_data, void *index);
+void ubsan_linkage __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs);
+void ubsan_linkage __ubsan_handle_builtin_unreachable(void *_data);
+void ubsan_linkage __ubsan_handle_load_invalid_value(void *_data, void *val);
+void ubsan_linkage __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
+						       unsigned long align,
+						       unsigned long offset);
 
 #endif