[v2] dma-buf: heaps: bugfix for selftest failure

[v2] dma-buf: heaps: bugfix for selftest failure

[Leon He]

From: Leon He <leon.he@unisoc.com>

There are two errors in the dmabuf-heap selftest:
1. The 'char name[5]' was not initialized to zero, which will cause
   strcmp(name, "vgem") failed in check_vgem().
2. The return value of test_alloc_errors() should be reversed, other-
   wise the while loop in main() will be broken.

Signed-off-by: Leon He <leon.he@unisoc.com>
---
 tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
index cd5e1f6..836b185 100644
--- a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
+++ b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
@@ -22,7 +22,7 @@
 static int check_vgem(int fd)
 {
 	drm_version_t version = { 0 };
-	char name[5];
+	char name[5] = { 0 };
 	int ret;
 
 	version.name_len = 4;
@@ -357,7 +357,7 @@ static int test_alloc_errors(char *heap_name)
 	if (heap_fd >= 0)
 		close(heap_fd);
 
-	return ret;
+	return !ret;
 }
 
 int main(void)
-- 
2.7.4

Re: [v2] dma-buf: heaps: bugfix for selftest failure

[shuah]

On 3/7/20 7:02 AM, Leon He wrote:
> From: Leon He <leon.he@unisoc.com>
> 
> There are two errors in the dmabuf-heap selftest:
> 1. The 'char name[5]' was not initialized to zero, which will cause
>     strcmp(name, "vgem") failed in check_vgem().
> 2. The return value of test_alloc_errors() should be reversed, other-
>     wise the while loop in main() will be broken.
> 
> Signed-off-by: Leon He <leon.he@unisoc.com>
> ---
>   tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> index cd5e1f6..836b185 100644
> --- a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> +++ b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> @@ -22,7 +22,7 @@
>   static int check_vgem(int fd)
>   {
>   	drm_version_t version = { 0 };
> -	char name[5];
> +	char name[5] = { 0 };
>   	int ret;
>   
>   	version.name_len = 4;

Please see my comment on v1 for this.

> @@ -357,7 +357,7 @@ static int test_alloc_errors(char *heap_name)
>   	if (heap_fd >= 0)
>   		close(heap_fd);
>   
> -	return ret;
> +	return !ret;

This change doesn't make sense. Initializing ret to 0 is a better
way to go.

thanks,
-- Shuah

Re: [v2] dma-buf: heaps: bugfix for selftest failure

[xiaolong he]

Dear Shuah:

> > @@ -357,7 +357,7 @@ static int test_alloc_errors(char *heap_name)
> >       if (heap_fd >= 0)
> >               close(heap_fd);
> >
> > -     return ret;
> > +     return !ret;
>
> This change doesn't make sense. Initializing ret to 0 is a better
> way to go.
>

I don't agree with you about this comment. Initializing ret to 0 can
not solve this problem.
Because the ret value will be override by the following
dmabuf_heap_alloc() calls.

static int test_alloc_errors(char *heap_name)
{
        int ret;

        ret = dmabuf_heap_alloc(...);
        ...
        ret = dmabuf_heap_alloc(...);
        ...
        ret = dmabuf_heap_alloc_fdflags(...);
        ...

        return ret;
}

The purpose for test_alloc_errors() is to pass some invalid parameters
to dmabuf_heap_alloc()
and wish it return some errors. So -1 is what we expect from
test_alloc_errors(). But the code
in main() will break the loop when the ret value is -1. So I reversed
the return value in test_alloc_errors().

int main(void)
{
        while(...) {
                ...
                ret = test_alloc_errors(dir->d_name);
                if (ret)
                        break;
        }
}

thanks,
-- Leon

Re: [v2] dma-buf: heaps: bugfix for selftest failure

[Ezequiel Garcia]

Hi Leon, Shuah,

Thanks for the fix. I had this issue pending to fix,
but have been lazy about it, I appreciate you are taking care of it!

On Sat, 7 Mar 2020 at 11:03, Leon He <hexiaolong2008@gmail.com> wrote:
>
> From: Leon He <leon.he@unisoc.com>
>
> There are two errors in the dmabuf-heap selftest:
> 1. The 'char name[5]' was not initialized to zero, which will cause
>    strcmp(name, "vgem") failed in check_vgem().
> 2. The return value of test_alloc_errors() should be reversed, other-
>    wise the while loop in main() will be broken.
>
> Signed-off-by: Leon He <leon.he@unisoc.com>
> ---
>  tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> index cd5e1f6..836b185 100644
> --- a/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> +++ b/tools/testing/selftests/dmabuf-heaps/dmabuf-heap.c
> @@ -22,7 +22,7 @@
>  static int check_vgem(int fd)
>  {
>         drm_version_t version = { 0 };
> -       char name[5];
> +       char name[5] = { 0 };
>         int ret;
>

As Shuah already mentioned, I think we want to use strncmp
to be on the safe side.

>         version.name_len = 4;
> @@ -357,7 +357,7 @@ static int test_alloc_errors(char *heap_name)
>         if (heap_fd >= 0)
>                 close(heap_fd);
>
> -       return ret;
> +       return !ret;

I agree with Shuah, this change makes no sense, just drop it.

I think the fact this test was broken and nobody noticed
uncovers the fact that the test isn't being run.

Any reason why this test isn't a regular TARGET?
Or any idea how we can make sure this is run by CIs
and any other testing system?

Thanks!
Ezequiel

>  }
>
>  int main(void)
> --
> 2.7.4
>