Re: [PATCH bpf-next v2 2/2] selftests/bpf: Test kfunc bpf_strcasecmp

[Viktor Malik]

On 9/2/25 09:55, Rong Tao wrote:
> From: Rong Tao <rongtao@xxxxxxxx>
> 
> Add testsuites for kfunc bpf_strcasecmp.
> 
> Signed-off-by: Rong Tao <rongtao@xxxxxxxx>
> ---
>  tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c | 6 ++++++
>  tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c | 1 +
>  tools/testing/selftests/bpf/progs/string_kfuncs_success.c  | 5 +++++
>  3 files changed, 12 insertions(+)
> 
> diff --git a/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c b/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c
> index 53af438bd998..99d72c68f76a 100644
> --- a/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c
> +++ b/tools/testing/selftests/bpf/progs/string_kfuncs_failure1.c
> @@ -31,6 +31,8 @@ char *invalid_kern_ptr = (char *)-1;
>  /* Passing NULL to string kfuncs (treated as a userspace ptr) */
>  SEC("syscall") __retval(USER_PTR_ERR) int test_strcmp_null1(void *ctx) { return bpf_strcmp(NULL, "hello"); }
>  SEC("syscall")  __retval(USER_PTR_ERR)int test_strcmp_null2(void *ctx) { return bpf_strcmp("hello", NULL); }
> +SEC("syscall") __retval(USER_PTR_ERR) int test_strcasecmp_null1(void *ctx) { return bpf_strcasecmp(NULL, "HELLO"); }
> +SEC("syscall")  __retval(USER_PTR_ERR)int test_strcasecmp_null2(void *ctx) { return bpf_strcasecmp("HELLO", NULL); }
>  SEC("syscall")  __retval(USER_PTR_ERR)int test_strchr_null(void *ctx) { return bpf_strchr(NULL, 'a'); }
>  SEC("syscall")  __retval(USER_PTR_ERR)int test_strchrnul_null(void *ctx) { return bpf_strchrnul(NULL, 'a'); }
>  SEC("syscall")  __retval(USER_PTR_ERR)int test_strnchr_null(void *ctx) { return bpf_strnchr(NULL, 1, 'a'); }
> @@ -49,6 +51,8 @@ SEC("syscall")  __retval(USER_PTR_ERR)int test_strnstr_null2(void *ctx) { return
>  /* Passing userspace ptr to string kfuncs */
>  SEC("syscall") __retval(USER_PTR_ERR) int test_strcmp_user_ptr1(void *ctx) { return bpf_strcmp(user_ptr, "hello"); }
>  SEC("syscall") __retval(USER_PTR_ERR) int test_strcmp_user_ptr2(void *ctx) { return bpf_strcmp("hello", user_ptr); }
> +SEC("syscall") __retval(USER_PTR_ERR) int test_strcasecmp_user_ptr1(void *ctx) { return bpf_strcasecmp(user_ptr, "HELLO"); }
> +SEC("syscall") __retval(USER_PTR_ERR) int test_strcasecmp_user_ptr2(void *ctx) { return bpf_strcasecmp("HELLO", user_ptr); }
>  SEC("syscall") __retval(USER_PTR_ERR) int test_strchr_user_ptr(void *ctx) { return bpf_strchr(user_ptr, 'a'); }
>  SEC("syscall") __retval(USER_PTR_ERR) int test_strchrnul_user_ptr(void *ctx) { return bpf_strchrnul(user_ptr, 'a'); }
>  SEC("syscall") __retval(USER_PTR_ERR) int test_strnchr_user_ptr(void *ctx) { return bpf_strnchr(user_ptr, 1, 'a'); }
> @@ -69,6 +73,8 @@ SEC("syscall") __retval(USER_PTR_ERR) int test_strnstr_user_ptr2(void *ctx) { re
>  /* Passing invalid kernel ptr to string kfuncs should always return -EFAULT */
>  SEC("syscall") __retval(-EFAULT) int test_strcmp_pagefault1(void *ctx) { return bpf_strcmp(invalid_kern_ptr, "hello"); }
>  SEC("syscall") __retval(-EFAULT) int test_strcmp_pagefault2(void *ctx) { return bpf_strcmp("hello", invalid_kern_ptr); }
> +SEC("syscall") __retval(-EFAULT) int test_strcasecmp_pagefault1(void *ctx) { return bpf_strcasecmp(invalid_kern_ptr, "HELLO"); }
> +SEC("syscall") __retval(-EFAULT) int test_strcasecmp_pagefault2(void *ctx) { return bpf_strcasecmp("HELLO", invalid_kern_ptr); }
>  SEC("syscall") __retval(-EFAULT) int test_strchr_pagefault(void *ctx) { return bpf_strchr(invalid_kern_ptr, 'a'); }
>  SEC("syscall") __retval(-EFAULT) int test_strchrnul_pagefault(void *ctx) { return bpf_strchrnul(invalid_kern_ptr, 'a'); }
>  SEC("syscall") __retval(-EFAULT) int test_strnchr_pagefault(void *ctx) { return bpf_strnchr(invalid_kern_ptr, 1, 'a'); }
> diff --git a/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c b/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c
> index 89fb4669b0e9..e41cc5601994 100644
> --- a/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c
> +++ b/tools/testing/selftests/bpf/progs/string_kfuncs_failure2.c
> @@ -7,6 +7,7 @@
>  char long_str[XATTR_SIZE_MAX + 1];
>  
>  SEC("syscall") int test_strcmp_too_long(void *ctx) { return bpf_strcmp(long_str, long_str); }
> +SEC("syscall") int test_strcasecmp_too_long(void *ctx) { return bpf_strcasecmp(long_str, long_str); }

This is not sufficient, you also need to update
prog_tests/string_kfuncs.c so that the test case is actually triggered.

Viktor

>  SEC("syscall") int test_strchr_too_long(void *ctx) { return bpf_strchr(long_str, 'b'); }
>  SEC("syscall") int test_strchrnul_too_long(void *ctx) { return bpf_strchrnul(long_str, 'b'); }
>  SEC("syscall") int test_strnchr_too_long(void *ctx) { return bpf_strnchr(long_str, sizeof(long_str), 'b'); }
> diff --git a/tools/testing/selftests/bpf/progs/string_kfuncs_success.c b/tools/testing/selftests/bpf/progs/string_kfuncs_success.c
> index 46697f381878..67830456637b 100644
> --- a/tools/testing/selftests/bpf/progs/string_kfuncs_success.c
> +++ b/tools/testing/selftests/bpf/progs/string_kfuncs_success.c
> @@ -12,6 +12,11 @@ char str[] = "hello world";
>  /* Functional tests */
>  __test(0) int test_strcmp_eq(void *ctx) { return bpf_strcmp(str, "hello world"); }
>  __test(1) int test_strcmp_neq(void *ctx) { return bpf_strcmp(str, "hello"); }
> +__test(0) int test_strcasecmp_eq1(void *ctx) { return bpf_strcasecmp(str, "hello world"); }
> +__test(0) int test_strcasecmp_eq2(void *ctx) { return bpf_strcasecmp(str, "HELLO WORLD"); }
> +__test(0) int test_strcasecmp_eq3(void *ctx) { return bpf_strcasecmp(str, "HELLO world"); }
> +__test(1) int test_strcasecmp_neq1(void *ctx) { return bpf_strcasecmp(str, "hello"); }
> +__test(1) int test_strcasecmp_neq2(void *ctx) { return bpf_strcasecmp(str, "HELLO"); }
>  __test(1) int test_strchr_found(void *ctx) { return bpf_strchr(str, 'e'); }
>  __test(11) int test_strchr_null(void *ctx) { return bpf_strchr(str, '\0'); }
>  __test(-ENOENT) int test_strchr_notfound(void *ctx) { return bpf_strchr(str, 'x'); }