Re: [PATCH v1] staging: r8188eu: an incorrect return value made the function always return fail

[Hans de Goede]

Hi Kate,

Good catch!

On 6/20/22 10:54, Kate Hsuan wrote:
> Since _SUCCESS (1) and _FAIL (0) are used to indicate the status of the
> functions. The previous commit 8ae7bf782eacad803f752c83a183393b0a67127b

This is the commit hash from one of the stable series backports, you
should always use the commit hash from Linus' master branch which is
f94b47c6bde6 and the format for referencing commits in a commit-message is:

commit <12 char hash> ("commit subject")

so in this case this should have been:

commit f94b47c6bde6 ("staging: r8188eu: add check for kzalloc")

Note that checkpatch.pl would have complained about the wrong format
(but not the wrong hash)

> fixed and prevented dereferencing a NULL pointer through checking the
> return pointer. The NULL pointer check work properly but the return
> values (-ENOMEM on fail and 0 on success). This work fixed the return
> values to make sure the caller function will return the correct status.
> 
> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2097526
> Signed-off-by: Kate Hsuan <hpa@xxxxxxxxxx>

This should have a fixes tag:

Fixes: f94b47c6bde6 ("staging: r8188eu: add check for kzalloc")

But while looking up the torvalds/master branch hash I noticed
someone alreayd beat you to it. Linus' master already has
a fix for this:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/staging/r8188eu?id=5b7419ae1d208cab1e2826d473d8dab045aa75c7

So this patch can be dropped since it is a duplicate.

Regards,

hans



> ---
>  drivers/staging/r8188eu/core/rtw_xmit.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c
> index f4e9f6102539..2f8720db21d9 100644
> --- a/drivers/staging/r8188eu/core/rtw_xmit.c
> +++ b/drivers/staging/r8188eu/core/rtw_xmit.c
> @@ -180,10 +180,8 @@ s32	_rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
>  	pxmitpriv->free_xmit_extbuf_cnt = num_xmit_extbuf;
>  
>  	res = rtw_alloc_hwxmits(padapter);
> -	if (res) {
> -		res = _FAIL;
> +	if (res == _FAIL)
>  		goto exit;
> -	}
>  
>  	rtw_init_hwxmits(pxmitpriv->hwxmits, pxmitpriv->hwxmit_entry);
>  
> @@ -1510,7 +1508,7 @@ int rtw_alloc_hwxmits(struct adapter *padapter)
>  
>  	pxmitpriv->hwxmits = kzalloc(sizeof(struct hw_xmit) * pxmitpriv->hwxmit_entry, GFP_KERNEL);
>  	if (!pxmitpriv->hwxmits)
> -		return -ENOMEM;
> +		return _FAIL;
>  
>  	hwxmits = pxmitpriv->hwxmits;
>  
> @@ -1528,7 +1526,7 @@ int rtw_alloc_hwxmits(struct adapter *padapter)
>  	} else {
>  	}
>  
> -	return 0;
> +	return _SUCCESS;
>  }
>  
>  void rtw_free_hwxmits(struct adapter *padapter)