fortify_test_known_sizes: EXPECTATION FAILED at lib/tests/fortify_kunit.c:90 (v7.0.2, ppc)

[Erhard Furtner <erhard_f@mailbox.org>]

Greetings!

Getting this on my G4 DP on kernel v7.0.2 and v7.1-rc1 at running 
fortify_kunit test:

[...]
KTAP version 1
1..1
     KTAP version 1
     # Subtest: fortify
     # module: fortify_kunit
     1..26
     # fortify_test_known_sizes: EXPECTATION FAILED at 
lib/tests/fortify_kunit.c:90
     Expected ({ char *__p = (char *)(stack); size_t __ret = 
(~(size_t)0); const size_t __p_size = 
__builtin_dynamic_object_size(stack, 1); if (__p_size != (~(size_t)0) && 
__builtin_constant_p(*__p)) { size_t __p_len = __p_size - 1; if 
(__builtin_constant_p(__p[__p_len]) && __p[__p_len] == '\0') __ret = 
__builtin_strlen(__p); } __ret; }) == 5, but
         ({ char *__p = (char *)(stack); size_t __ret = (~(size_t)0); 
const size_t __p_size = __builtin_dynamic_object_size(stack, 1); if 
(__p_size != (~(size_t)0) && __builtin_constant_p(*__p)) { size_t 
__p_len = __p_size - 1; if (__builtin_constant_p(__p[__p_len]) && 
__p[__p_len] == '\0') __ret = __builtin_strlen(__p); } __ret; }) == 
4294967295 (0xffffffff)
     not ok 1 fortify_test_known_sizes
     ok 2 fortify_test_control_flow_split
     ok 3 fortify_test_alloc_size_kmalloc_const
     ok 4 fortify_test_alloc_size_kmalloc_dynamic
     ok 5 fortify_test_alloc_size_vmalloc_const
     ok 6 fortify_test_alloc_size_vmalloc_dynamic
     ok 7 fortify_test_alloc_size_kvmalloc_const
     ok 8 fortify_test_alloc_size_kvmalloc_dynamic
     ok 9 fortify_test_alloc_size_devm_kmalloc_const
     ok 10 fortify_test_alloc_size_devm_kmalloc_dynamic
     ok 11 fortify_test_realloc_size
     ok 12 fortify_test_strlen
     ok 13 fortify_test_strnlen
     ok 14 fortify_test_strcpy
     ok 15 fortify_test_strncpy
     ok 16 fortify_test_strscpy
     ok 17 fortify_test_strcat
     ok 18 fortify_test_strncat
     ok 19 fortify_test_strlcat
     ok 20 fortify_test_memcpy
     ok 21 fortify_test_memmove
     ok 22 fortify_test_memscan
     ok 23 fortify_test_memchr
     ok 24 fortify_test_memchr_inv
     ok 25 fortify_test_memcmp
     ok 26 fortify_test_kmemdup
# fortify: pass:25 fail:1 skip:0 total:26
# Totals: pass:25 fail:1 skip:0 total:26


Suppose this may be a ppc/BE specific test failure as I don't get it on 
my Thinkpad T60 (x86).

Full dmesg and kernel .config available on request.

Greetings,
Erhard