Andy Shevchenko <[email protected]> writes: > On Tue, 2015-09-15 at 00:00 +0200, Rasmus Villemoes wrote: >> On Mon, Sep 14 2015, Vitaly Kuznetsov <[email protected]> wrote: >> > > Vitaly, thanks for the test cases. My comments below. > >> > +static __init void test_string_get_size_one(u64 size, u64 >> > blk_size, >> > + const enum >> > string_size_units units, >> > + const char >> > *exp_result) >> > +{ >> > + char buf[256]; >> > + >> > + string_get_size(size, blk_size, units, buf, sizeof(buf)); >> > + if (!strncmp(buf, exp_result, min(sizeof(buf), >> > strlen(exp_result)))) >> > + return; >> >> Nits: It probably makes sense to also test that string_get_size >> '\0'-terminates the buffer, so I'd spell this >> >> if (!memcmp(buf, exp_result, min(sizeof(buf), >> strlen(exp_result)+1))) >> >> With a generous stack buffer, that min() will always evaluate to the >> strlen(exp_result)+1. On that note: Maybe 256 is a bit excessive. I >> don't think this will run very deep in the kernel stack, but the code >> might >> get copy-pasted somewhere else. 16 should be plenty. > > Agree with Rasmus. > > And just to make a side note that useless use of min() since we have > strnlen() :-) > >> >> > + pr_warn("Test 'test_string_get_size_one' failed!\n"); >> > + pr_warn("string_get_size(size = %llu, blk_size = %llu, >> > units = %d\n", >> > + size, blk_size, units); >> >> [There's probably no pretty way of getting from units to a text >> representation, but it's slightly annoying to have to check the >> source >> for the enum definition to figure out what units=0 or units=1 means.] >> >> > + pr_warn("expected: %s, got %s\n", exp_result, buf); >> >> In case we failed to '\0'-terminate buf, we might want to print it >> with >> "%.*s", (int)sizeof(buf), buf. But maybe I'm just overly paranoid. > > I prefer to put '\0' at the position after we expected have an actual > '\0'. In this case we always be NULL terminated. I did this for hexdump > test cases.
Just to check I got your suggestions right: ... + if (!memcmp(buf, exp_result, strnlen(exp_result, sizeof(buf) - 1) + 1)) + return; + + /* NULL terminate buf right after the expected '\0' */ + buf[strnlen(exp_result, sizeof(buf) - 2) + 1] = '\0'; ... Alternatively, we could have avoided strnlen() by asserting strlen(exp_result) < sizeof(buf) - 1 at the very beginning. -- Vitaly -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
