2023-05-05 06:31:42

by ye.xingchen

Subject: [PATCH] iommufd/selftest: Use fdget() and fdput()

From: Ye Xingchen <[email protected]>

convert the fget()/fput() uses to fdget()/fdput().

Signed-off-by: Ye Xingchen <[email protected]>
---
drivers/iommu/iommufd/selftest.c | 11 +++++------
1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 74c2076105d4..d3512fa673a5 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -583,17 +583,16 @@ static const struct file_operations iommfd_test_staccess_fops;

static struct selftest_access *iommufd_access_get(int fd)
{
- struct file *file;
+ struct fd f = fdget(fd);

- file = fget(fd);
- if (!file)
+ if (!f.file)
return ERR_PTR(-EBADFD);

- if (file->f_op != &iommfd_test_staccess_fops) {
- fput(file);
+ if (f.file->f_op != &iommfd_test_staccess_fops) {
+ fdput(f);
return ERR_PTR(-EBADFD);
}
- return file->private_data;
+ return f.file->private_data;
}

static void iommufd_test_access_unmap(void *data, unsigned long iova,
--
2.25.1

2023-05-05 12:10:12

by Jason Gunthorpe

Subject: Re: [PATCH] iommufd/selftest: Use fdget() and fdput()

On Fri, May 05, 2023 at 02:12:39PM +0800, [email protected] wrote:
> From: Ye Xingchen <[email protected]>
>
> convert the fget()/fput() uses to fdget()/fdput().
>
> Signed-off-by: Ye Xingchen <[email protected]>
> ---
> drivers/iommu/iommufd/selftest.c | 11 +++++------
> 1 file changed, 5 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
> index 74c2076105d4..d3512fa673a5 100644
> --- a/drivers/iommu/iommufd/selftest.c
> +++ b/drivers/iommu/iommufd/selftest.c
> @@ -583,17 +583,16 @@ static const struct file_operations iommfd_test_staccess_fops;
>
> static struct selftest_access *iommufd_access_get(int fd)
> {
> - struct file *file;
> + struct fd f = fdget(fd);
>
> - file = fget(fd);
> - if (!file)
> + if (!f.file)
> return ERR_PTR(-EBADFD);

Why are you doing these conversions? This is wrong, fdget has to be
paired with fdput(), since the struct fd doesn't leave the stack frame
it cannot be correct.

I see your other patches have the same problem.

Jason