Messages in this thread Patch in this message | | | From | Kees Cook <> | Subject | [PATCH] lib/test_string.c: Add test for strlen() | Date | Sun, 30 Jan 2022 10:36:53 -0800 |
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Add a simple test for strlen() functionality, including using it as a constant expression.
Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Peter Rosin <peda@axentia.se> Signed-off-by: Kees Cook <keescook@chromium.org> --- I'll be taking this as part of my Clang FORTIFY_SOURCE series. --- lib/test_string.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+)
diff --git a/lib/test_string.c b/lib/test_string.c index 9dfd6f52de92..59994f552c48 100644 --- a/lib/test_string.c +++ b/lib/test_string.c @@ -179,6 +179,38 @@ static __init int strnchr_selftest(void) return 0; } +/* + * Unlike many other string functions, strlen() can be used in + * static initializers when string lengths are known at compile + * time. (i.e. Under these conditions, strlen() is a constant + * expression.) Make sure it can be used this way. + */ +static const int strlen_ce = strlen("tada, a constant expression"); + +static __init int strlen_selftest(void) +{ + /* String length ruler: 123456789012345 */ + static const char normal[] = "I am normal"; + static const char *ptr = "where do I go?"; + static const char trailing[] = "hidden NULLs\0\0\0"; + static const char leading[] = "\0\0hidden text"; + + if (strlen(normal) != 11) + return 0x100001; + if (strlen(ptr++) != 14) + return 0x100002; + if (strlen(ptr++) != 13) + return 0x100003; + if (strlen(trailing) != 12) + return 0x100004; + if (strlen(leading) != 0) + return 0x100005; + if (strlen_ce != 27) + return 0x100006; + + return 0; +} + static __exit void string_selftest_remove(void) { } @@ -212,6 +244,11 @@ static __init int string_selftest_init(void) if (subtest) goto fail; + test = 5; + subtest = strlen_selftest(); + if (subtest) + goto fail; + pr_info("String selftests succeeded\n"); return 0; fail: -- 2.30.2
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