Improve test coverage of strnlen function

Message ID 20210602161029.799090-1-skpgkp2@gmail.com
State New
Headers show
Series
  • Improve test coverage of strnlen function
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Commit Message

Szabolcs Nagy via Libc-alpha June 2, 2021, 4:10 p.m.
This patch covers the following condition:

Strings start with different alignments and end with less than 512 byte
length.
---
 string/test-strnlen.c | 4 ++++
 1 file changed, 4 insertions(+)

-- 
2.31.1

Comments

Szabolcs Nagy via Libc-alpha June 2, 2021, 5:26 p.m. | #1
On Wed, Jun 2, 2021 at 12:13 PM Sunil K Pandey via Libc-alpha
<libc-alpha@sourceware.org> wrote:
>

> This patch covers the following condition:

>

> Strings start with different alignments and end with less than 512 byte

> length.

> ---

>  string/test-strnlen.c | 4 ++++

>  1 file changed, 4 insertions(+)

>

> diff --git a/string/test-strnlen.c b/string/test-strnlen.c

> index d70faa26ab..20e645893a 100644

> --- a/string/test-strnlen.c

> +++ b/string/test-strnlen.c

> @@ -271,6 +271,10 @@ test_main (void)

>        do_test (1, 1 << i, 5000, BIG_CHAR);

>      }

>

> +  for (i = 1; i <= 127; i++)


I think it makes sense to either include 0 or 128 for alignments
as in some implementations (x86 avx2/evex for example)
that is a unique case.

> +    for (size_t length = i; length < 512; length++)

> +      do_test (i, length, 512, BIG_CHAR);


Might be strengthened a bit with additional test case
in inner loop:
do_test (getpagesize() - i, length, 512, BIG_CHAR);

> +

>    do_random_tests ();

>    do_page_tests ();

>    do_page_2_tests ();

> --

> 2.31.1

>
Szabolcs Nagy via Libc-alpha June 2, 2021, 5:33 p.m. | #2
On Wed, Jun 2, 2021 at 1:26 PM Noah Goldstein <goldstein.w.n@gmail.com> wrote:
>

> On Wed, Jun 2, 2021 at 12:13 PM Sunil K Pandey via Libc-alpha

> <libc-alpha@sourceware.org> wrote:

> >

> > This patch covers the following condition:

> >

> > Strings start with different alignments and end with less than 512 byte

> > length.

> > ---

> >  string/test-strnlen.c | 4 ++++

> >  1 file changed, 4 insertions(+)

> >

> > diff --git a/string/test-strnlen.c b/string/test-strnlen.c

> > index d70faa26ab..20e645893a 100644

> > --- a/string/test-strnlen.c

> > +++ b/string/test-strnlen.c

> > @@ -271,6 +271,10 @@ test_main (void)

> >        do_test (1, 1 << i, 5000, BIG_CHAR);

> >      }

> >

> > +  for (i = 1; i <= 127; i++)

>

> I think it makes sense to either include 0 or 128 for alignments

> as in some implementations (x86 avx2/evex for example)

> that is a unique case.

>

> > +    for (size_t length = i; length < 512; length++)

> > +      do_test (i, length, 512, BIG_CHAR);

I think it would also make sense to include multiple length.
Again in the x86_64 avx2/evex implementations for example
there are 4 cases for handling remaining length:
 [1,32], [33,64], [65,96], and [97, 128].

As well it might be useful to have tests for position of
null > length as well.

>

> Might be strengthened a bit with additional test case

> in inner loop:

> do_test (getpagesize() - i, length, 512, BIG_CHAR);

>

> > +

> >    do_random_tests ();

> >    do_page_tests ();

> >    do_page_2_tests ();

> > --

> > 2.31.1

> >
Szabolcs Nagy via Libc-alpha June 2, 2021, 8:57 p.m. | #3
On Wed, Jun 2, 2021 at 10:33 AM Noah Goldstein <goldstein.w.n@gmail.com>
wrote:

> On Wed, Jun 2, 2021 at 1:26 PM Noah Goldstein <goldstein.w.n@gmail.com>

> wrote:

> >

> > On Wed, Jun 2, 2021 at 12:13 PM Sunil K Pandey via Libc-alpha

> > <libc-alpha@sourceware.org> wrote:

> > >

> > > This patch covers the following condition:

> > >

> > > Strings start with different alignments and end with less than 512 byte

> > > length.

> > > ---

> > >  string/test-strnlen.c | 4 ++++

> > >  1 file changed, 4 insertions(+)

> > >

> > > diff --git a/string/test-strnlen.c b/string/test-strnlen.c

> > > index d70faa26ab..20e645893a 100644

> > > --- a/string/test-strnlen.c

> > > +++ b/string/test-strnlen.c

> > > @@ -271,6 +271,10 @@ test_main (void)

> > >        do_test (1, 1 << i, 5000, BIG_CHAR);

> > >      }

> > >

> > > +  for (i = 1; i <= 127; i++)

> >

> > I think it makes sense to either include 0 or 128 for alignments

> > as in some implementations (x86 avx2/evex for example)

> > that is a unique case.

> >

> > > +    for (size_t length = i; length < 512; length++)

> > > +      do_test (i, length, 512, BIG_CHAR);

> I think it would also make sense to include multiple length.

> Again in the x86_64 avx2/evex implementations for example

> there are 4 cases for handling remaining length:

>  [1,32], [33,64], [65,96], and [97, 128].

>

> As well it might be useful to have tests for position of

> null > length as well.

>

> >

> > Might be strengthened a bit with additional test case

> > in inner loop:

> > do_test (getpagesize() - i, length, 512, BIG_CHAR);

> >

> > > +

> > >    do_random_tests ();

> > >    do_page_tests ();

> > >    do_page_2_tests ();

> > > --

> > > 2.31.1

> > >

>

Sure, will submit a v2 patch which will incorporate all these cases.

Patch

diff --git a/string/test-strnlen.c b/string/test-strnlen.c
index d70faa26ab..20e645893a 100644
--- a/string/test-strnlen.c
+++ b/string/test-strnlen.c
@@ -271,6 +271,10 @@  test_main (void)
       do_test (1, 1 << i, 5000, BIG_CHAR);
     }
 
+  for (i = 1; i <= 127; i++)
+    for (size_t length = i; length < 512; length++)
+      do_test (i, length, 512, BIG_CHAR);
+
   do_random_tests ();
   do_page_tests ();
   do_page_2_tests ();