On Mon, Apr 07, 2025 at 04:22:12PM -0700, Nathan Chancellor wrote:
A recent optimization change in LLVM [1] aims to transform certain loop idioms into calls to strlen() or wcslen(). This change transforms the first while loop in UniStrcat() into a call to wcslen(), breaking the build when UniStrcat() gets inlined into alloc_path_with_tree_prefix():
ld.lld: error: undefined symbol: wcslen
referenced by nls_ucs2_utils.h:54 (fs/smb/client/../../nls/nls_ucs2_utils.h:54) vmlinux.o:(alloc_path_with_tree_prefix) referenced by nls_ucs2_utils.h:54 (fs/smb/client/../../nls/nls_ucs2_utils.h:54) vmlinux.o:(alloc_path_with_tree_prefix)
Disable this optimization with '-fno-builtin-wcslen', which prevents the compiler from assuming that wcslen() is available in the kernel's C library
Cc: stable@vger.kernel.org Link: https://github.com/llvm/llvm-project/commit/9694844d7e36fd5e01011ab56b64f27b... [1] Signed-off-by: Nathan Chancellor nathan@kernel.org
Thanks for chasing this down. :)
Reviewed-by: Kees Cook kees@kernel.org
Since I have stuff queued for -rc2, do you want me to snag this too?