[PATCH] Staging: lustre: Use kmemdup() instead of kzalloc and memcpy

[PATCH] Staging: lustre: Use kmemdup() instead of kzalloc and memcpy

[Shreeya Patel]

Replace calls to kzalloc or kmalloc followed by a memcpy with
a direct call to kmemdup to shorten the code.

The Coccinelle semantic patch used to make this change is as follows:
@@
expression from,to,size,flag;
statement S;
@@

-  to = \(kmalloc\|kzalloc\)(size,flag);
+  to = kmemdup(from,size,flag);
   if (to==NULL || ...) S
-  memcpy(to, from, size);

Signed-off-by: Shreeya Patel <shreeya.patel23498@gmail.com>
---
 drivers/staging/lustre/lnet/lnet/api-ni.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/lustre/lnet/lnet/api-ni.c b/drivers/staging/lustre/lnet/lnet/api-ni.c
index f9ed697..36ea14e 100644
--- a/drivers/staging/lustre/lnet/lnet/api-ni.c
+++ b/drivers/staging/lustre/lnet/lnet/api-ni.c
@@ -1271,15 +1271,14 @@ lnet_startup_lndni(struct lnet_ni *ni, struct lnet_ioctl_config_data *conf)
 		lnd_tunables = (struct lnet_ioctl_config_lnd_tunables *)conf->cfg_bulk;
 
 	if (lnd_tunables) {
-		ni->ni_lnd_tunables = kzalloc(sizeof(*ni->ni_lnd_tunables),
+		ni->ni_lnd_tunables = kmemdup(lnd_tunables,
+					      sizeof(*ni->ni_lnd_tunables),
 					      GFP_NOFS);
 		if (!ni->ni_lnd_tunables) {
 			mutex_unlock(&the_lnet.ln_lnd_mutex);
 			rc = -ENOMEM;
 			goto failed0;
 		}
-		memcpy(ni->ni_lnd_tunables, lnd_tunables,
-		       sizeof(*ni->ni_lnd_tunables));
 	}
 
 	/*
-- 
2.7.4

Re: [PATCH] Staging: lustre: Use kmemdup() instead of kzalloc and memcpy

[Greg KH]

On Sun, Jun 17, 2018 at 04:46:55PM +0530, Shreeya Patel wrote:
> Replace calls to kzalloc or kmalloc followed by a memcpy with
> a direct call to kmemdup to shorten the code.
> 
> The Coccinelle semantic patch used to make this change is as follows:
> @@
> expression from,to,size,flag;
> statement S;
> @@
> 
> -  to = \(kmalloc\|kzalloc\)(size,flag);
> +  to = kmemdup(from,size,flag);
>    if (to==NULL || ...) S
> -  memcpy(to, from, size);
> 
> Signed-off-by: Shreeya Patel <shreeya.patel23498@gmail.com>
> ---
>  drivers/staging/lustre/lnet/lnet/api-ni.c | 5 ++---

Always work off of the latest kernel tree.  Ideally linux-next or the
staging.git staging-next tree.  Worse case, Linus's tree.  But never off
of an old kernel tree, that will only cause you to duplicate work that
others have done :(

Please resync against 4.18-rc1 and see why I say this when trying to
apply your patch...

thanks,

greg k-h