Re: [Minios-devel] [UNIKRAFT PATCH 2/3] lib/vfscore: Return error when trying to close standard file descriptors

[Sharan Santhanam <sharan.santhanam@xxxxxxxxx>]

Hello,

Please find the comments inline.

Thanks & Regards

Sharan

On 9/2/19 3:22 PM, Costin Lupu wrote:
> Some applications may want to close the standard file descriptors (stdin,
> stdout, stderr), that is perfectly normal. The underlying platform should return
> an error if such request is not allowed, instead of crashing.
>
> Signed-off-by: Costin Lupu <costin.lupu@xxxxxxxxx>
> ---
>   lib/vfscore/fd.c                   | 7 +++++--
>   lib/vfscore/include/vfscore/file.h | 2 +-
>   lib/vfscore/main.c                 | 8 +++++---
>   3 files changed, 11 insertions(+), 6 deletions(-)
>
> diff --git a/lib/vfscore/fd.c b/lib/vfscore/fd.c
> index e09dd54c..f1a268c4 100644
> --- a/lib/vfscore/fd.c
> +++ b/lib/vfscore/fd.c
> @@ -73,14 +73,15 @@ exit:
>         return ret;
>   }
>   
> -void vfscore_put_fd(int fd)
> +int vfscore_put_fd(int fd)
>   {
>         struct vfscore_file *fp;
>         unsigned long flags;
>   
>   	UK_ASSERT(fd < (int) FDTABLE_MAX_FILES);
>         /* Currently it is not allowed to free std(in|out|err) */
> -       UK_ASSERT(fd > 2);
> +       if (fd <= 2)
> +               return -EINVAL;
Maybe we could return -EBUSY?
>   
>   	flags = ukplat_lcpu_save_irqf();
>         uk_bitmap_clear(fdtable.bitmap, fd, 1);
> @@ -94,6 +95,8 @@ void vfscore_put_fd(int fd)
>          */
>         if (fp)
>                 fdrop(fp);
> +
> +       return 0;
>   }
>   
>   int vfscore_install_fd(int fd, struct vfscore_file *file)
> diff --git a/lib/vfscore/include/vfscore/file.h 
> b/lib/vfscore/include/vfscore/file.h
> index 51f0791a..05434dfe 100644
> --- a/lib/vfscore/include/vfscore/file.h
> +++ b/lib/vfscore/include/vfscore/file.h
> @@ -62,7 +62,7 @@ struct vfscore_file {
>   };
>   
>   int vfscore_alloc_fd(void);
> -void vfscore_put_fd(int fd);
> +int vfscore_put_fd(int fd);
>   int vfscore_install_fd(int fd, struct vfscore_file *file);
>   struct vfscore_file *vfscore_get_file(int fd);
>   void vfscore_put_file(struct vfscore_file *file);
> diff --git a/lib/vfscore/main.c b/lib/vfscore/main.c
> index be055b78..4498811d 100644
> --- a/lib/vfscore/main.c
> +++ b/lib/vfscore/main.c
> @@ -205,15 +205,17 @@ UK_TRACEPOINT(trace_vfs_close_err, "%d", int);
>   int fdclose(int fd)
>   {
>         struct vfscore_file *fp;
> +       int error;
>   
>   	fp = vfscore_get_file(fd);
>         if (!fp)
>                 return EBADF;
>   
> -	vfscore_put_fd(fd);
> -       fdrop(fp);
> +       error = vfscore_put_fd(fd);
> +       if (!error)
> +               fdrop(fp);
>   
> -	return 0;
> +       return error;
>   }
>   
>   int close(int fd)
_______________________________________________
Minios-devel mailing list
Minios-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/minios-devel