lib/test_string.c: avoid masking memset16/32/64 failures

If a memsetXX implementation is completely broken and fails in the first
iteration, when i, j, and k are all zero, the failure is masked as zero
is returned.  Failing in the first iteration is perhaps the most likely
failure, so this makes the tests pretty much useless.  Avoid the
situation by always setting a random unused bit in the result on
failure.

Link: http://lkml.kernel.org/r/20190506124634.6807-3-peda@axentia.se
Fixes: 03270c13c5 ("lib/string.c: add testcases for memset16/32/64")
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Peter Rosin 2019-07-16 16:27:18 -07:00 committed by Linus Torvalds
parent b09757104e
commit 33d6e0ff68

View File

@ -36,7 +36,7 @@ static __init int memset16_selftest(void)
fail:
kfree(p);
if (i < 256)
return (i << 24) | (j << 16) | k;
return (i << 24) | (j << 16) | k | 0x8000;
return 0;
}
@ -72,7 +72,7 @@ static __init int memset32_selftest(void)
fail:
kfree(p);
if (i < 256)
return (i << 24) | (j << 16) | k;
return (i << 24) | (j << 16) | k | 0x8000;
return 0;
}
@ -108,7 +108,7 @@ static __init int memset64_selftest(void)
fail:
kfree(p);
if (i < 256)
return (i << 24) | (j << 16) | k;
return (i << 24) | (j << 16) | k | 0x8000;
return 0;
}