From 33d6e0ff68af74be0c846c8e042e84a9a1a0561e Mon Sep 17 00:00:00 2001 From: Peter Rosin Date: Tue, 16 Jul 2019 16:27:18 -0700 Subject: 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: 03270c13c5ff ("lib/string.c: add testcases for memset16/32/64") Signed-off-by: Peter Rosin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/test_string.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'lib/test_string.c') diff --git a/lib/test_string.c b/lib/test_string.c index bf8def01ed20..b5117ae59693 100644 --- a/lib/test_string.c +++ b/lib/test_string.c @@ -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; } -- cgit v1.2.3 From d1a5dc5e6accbeaabe59e3d55b47f15a8b19c2bd Mon Sep 17 00:00:00 2001 From: Peter Rosin Date: Tue, 16 Jul 2019 16:27:21 -0700 Subject: lib/test_string.c: add some testcases for strchr and strnchr Make sure that the trailing NUL is considered part of the string and can be found. Link: http://lkml.kernel.org/r/20190506124634.6807-4-peda@axentia.se Signed-off-by: Peter Rosin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/test_string.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 77 insertions(+) (limited to 'lib/test_string.c') diff --git a/lib/test_string.c b/lib/test_string.c index b5117ae59693..7b31f4a505bf 100644 --- a/lib/test_string.c +++ b/lib/test_string.c @@ -112,6 +112,73 @@ fail: return 0; } +static __init int strchr_selftest(void) +{ + const char *test_string = "abcdefghijkl"; + const char *empty_string = ""; + char *result; + int i; + + for (i = 0; i < strlen(test_string) + 1; i++) { + result = strchr(test_string, test_string[i]); + if (result - test_string != i) + return i + 'a'; + } + + result = strchr(empty_string, '\0'); + if (result != empty_string) + return 0x101; + + result = strchr(empty_string, 'a'); + if (result) + return 0x102; + + result = strchr(test_string, 'z'); + if (result) + return 0x103; + + return 0; +} + +static __init int strnchr_selftest(void) +{ + const char *test_string = "abcdefghijkl"; + const char *empty_string = ""; + char *result; + int i, j; + + for (i = 0; i < strlen(test_string) + 1; i++) { + for (j = 0; j < strlen(test_string) + 2; j++) { + result = strnchr(test_string, j, test_string[i]); + if (j <= i) { + if (!result) + continue; + return ((i + 'a') << 8) | j; + } + if (result - test_string != i) + return ((i + 'a') << 8) | j; + } + } + + result = strnchr(empty_string, 0, '\0'); + if (result) + return 0x10001; + + result = strnchr(empty_string, 1, '\0'); + if (result != empty_string) + return 0x10002; + + result = strnchr(empty_string, 1, 'a'); + if (result) + return 0x10003; + + result = strnchr(NULL, 0, '\0'); + if (result) + return 0x10004; + + return 0; +} + static __init int string_selftest_init(void) { int test, subtest; @@ -131,6 +198,16 @@ static __init int string_selftest_init(void) if (subtest) goto fail; + test = 4; + subtest = strchr_selftest(); + if (subtest) + goto fail; + + test = 5; + subtest = strnchr_selftest(); + if (subtest) + goto fail; + pr_info("String selftests succeeded\n"); return 0; fail: -- cgit v1.2.3