2020-03-07 14:04:26

by xiaolong he

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

From: Leon He <[email protected]>

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 <[email protected]>
---
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


2020-03-13 17:18:15

by Shuah Khan

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

On 3/7/20 7:02 AM, Leon He wrote:
> From: Leon He <[email protected]>
>
> 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 <[email protected]>
> ---
> 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

2020-03-18 02:48:35

by xiaolong he

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

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

2020-08-26 17:49:53

by Ezequiel Garcia

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

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 <[email protected]> wrote:
>
> From: Leon He <[email protected]>
>
> 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 <[email protected]>
> ---
> 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
>