2023-03-02 07:20:02

by Björn Töpel

[permalink] [raw]
Subject: [PATCH v3] lib/test_string.c: Add strncmp() tests

From: Palmer Dabbelt <[email protected]>

The RISC-V strncmp() fails on some inputs, see the linked thread for
more details. It turns out there were no strncmp() calls in the self
tests, this adds one.

Reported-by: Heiko Stübner <[email protected]>
Link: https://lore.kernel.org/all/2801162.88bMQJbFj6@diego/
Signed-off-by: Palmer Dabbelt <[email protected]>
Signed-off-by: Björn Töpel <[email protected]>
---
Change back to it's original form. Checkpatch still complains about
__initconst, but there's a patch addressing that [1].

[1] https://lore.kernel.org/all/[email protected]/

v2->v3: Removed the "checkpatch fix" patch
Added one more test

v1->v2: Added two more tests (pos/neg). (Andy)
Minor code style issues. (Andy)
Fixed checkpatch errors.
---
lib/test_string.c | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)

diff --git a/lib/test_string.c b/lib/test_string.c
index c5cb92fb710e..f18a34578f1f 100644
--- a/lib/test_string.c
+++ b/lib/test_string.c
@@ -207,6 +207,43 @@ static __init int strspn_selftest(void)
return 0;
}

+static __init int strncmp_selftest(void)
+{
+ size_t i;
+ static const struct strncmp_test {
+ const char *str_a;
+ const char *str_b;
+ unsigned long count;
+ unsigned long max_off;
+ int retval;
+ } tests[] __initconst = {
+ { "/dev/vda", "/dev/", 5, 4, 0 },
+ { "/dev/vda", "/dev/vdb", 5, 4, 0 },
+ { "00000000---11111", "00000000---11112", 12, 4, 0 },
+ { "/dev/vda", "/dev/vd\0", 8, 0, 97 },
+ { "ABC", "AB", 3, 0, 67 },
+ { "ABA", "ABZ", 3, 0, -25 },
+ { "ABC", "ABC", 3, 0, 0 },
+ };
+
+ for (i = 0; i < ARRAY_SIZE(tests); ++i) {
+ const struct strncmp_test *s = tests + i;
+ size_t off;
+
+ for (off = 0; off <= s->max_off; off++) {
+ int res = strncmp(s->str_a + off, s->str_b + off, s->count - off);
+
+ if (res == 0 && s->retval != 0)
+ return 0x1000 + 0x100*off + 0x10*i + 0x0;
+ if (res > 0 && s->retval <= 0)
+ return 0x1000 + 0x100*off + 0x10*i + 0x1;
+ if (res < 0 && s->retval >= 0)
+ return 0x1000 + 0x100*off + 0x10*i + 0x2;
+ }
+ }
+ return 0;
+}
+
static __exit void string_selftest_remove(void)
{
}
@@ -245,6 +282,11 @@ static __init int string_selftest_init(void)
if (subtest)
goto fail;

+ test = 7;
+ subtest = strncmp_selftest();
+ if (subtest)
+ goto fail;
+
pr_info("String selftests succeeded\n");
return 0;
fail:

base-commit: c0927a7a5391f7d8e593e5e50ead7505a23cadf9
--
2.37.2



2023-03-02 10:27:05

by Andy Shevchenko

[permalink] [raw]
Subject: Re: [PATCH v3] lib/test_string.c: Add strncmp() tests

On Thu, Mar 2, 2023 at 9:19 AM Björn Töpel <[email protected]> wrote:
>
> From: Palmer Dabbelt <[email protected]>
>
> The RISC-V strncmp() fails on some inputs, see the linked thread for
> more details. It turns out there were no strncmp() calls in the self
> tests, this adds one.

Thank you, it's good enough.

Reviewed-by: Andy Shevchenko <[email protected]>

> Reported-by: Heiko Stübner <[email protected]>
> Link: https://lore.kernel.org/all/2801162.88bMQJbFj6@diego/
> Signed-off-by: Palmer Dabbelt <[email protected]>
> Signed-off-by: Björn Töpel <[email protected]>
> ---
> Change back to it's original form. Checkpatch still complains about
> __initconst, but there's a patch addressing that [1].
>
> [1] https://lore.kernel.org/all/[email protected]/
>
> v2->v3: Removed the "checkpatch fix" patch
> Added one more test
>
> v1->v2: Added two more tests (pos/neg). (Andy)
> Minor code style issues. (Andy)
> Fixed checkpatch errors.
> ---
> lib/test_string.c | 42 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/lib/test_string.c b/lib/test_string.c
> index c5cb92fb710e..f18a34578f1f 100644
> --- a/lib/test_string.c
> +++ b/lib/test_string.c
> @@ -207,6 +207,43 @@ static __init int strspn_selftest(void)
> return 0;
> }
>
> +static __init int strncmp_selftest(void)
> +{
> + size_t i;
> + static const struct strncmp_test {
> + const char *str_a;
> + const char *str_b;
> + unsigned long count;
> + unsigned long max_off;
> + int retval;
> + } tests[] __initconst = {
> + { "/dev/vda", "/dev/", 5, 4, 0 },
> + { "/dev/vda", "/dev/vdb", 5, 4, 0 },
> + { "00000000---11111", "00000000---11112", 12, 4, 0 },
> + { "/dev/vda", "/dev/vd\0", 8, 0, 97 },
> + { "ABC", "AB", 3, 0, 67 },
> + { "ABA", "ABZ", 3, 0, -25 },
> + { "ABC", "ABC", 3, 0, 0 },
> + };
> +
> + for (i = 0; i < ARRAY_SIZE(tests); ++i) {
> + const struct strncmp_test *s = tests + i;
> + size_t off;
> +
> + for (off = 0; off <= s->max_off; off++) {
> + int res = strncmp(s->str_a + off, s->str_b + off, s->count - off);
> +
> + if (res == 0 && s->retval != 0)
> + return 0x1000 + 0x100*off + 0x10*i + 0x0;
> + if (res > 0 && s->retval <= 0)
> + return 0x1000 + 0x100*off + 0x10*i + 0x1;
> + if (res < 0 && s->retval >= 0)
> + return 0x1000 + 0x100*off + 0x10*i + 0x2;
> + }
> + }
> + return 0;
> +}
> +
> static __exit void string_selftest_remove(void)
> {
> }
> @@ -245,6 +282,11 @@ static __init int string_selftest_init(void)
> if (subtest)
> goto fail;
>
> + test = 7;
> + subtest = strncmp_selftest();
> + if (subtest)
> + goto fail;
> +
> pr_info("String selftests succeeded\n");
> return 0;
> fail:
>
> base-commit: c0927a7a5391f7d8e593e5e50ead7505a23cadf9
> --
> 2.37.2
>


--
With Best Regards,
Andy Shevchenko