2008-12-21 15:39:34

by Julia Lawall

Subject: [PATCH 7/13] drivers/net/wan: Remove redundant test

From: Julia Lawall <[email protected]>

arg is checked not to be NULL a few lines before.

A simplified version of the semantic patch that makes this change is as
follows: (http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r exists@
local idexpression x;
expression E;
position p1,p2;
@@

if (x@p1 == NULL || ...) { ... when forall
return ...; }
... when != \(x=E\|x--\|x++\|--x\|++x\|x-=E\|x+=E\|x|=E\|x&=E\|&x\)
(
x@p2 == NULL
|
x@p2 != NULL
)

// another path to the test that is not through p1?
@s exists@
local idexpression r.x;
position r.p1,r.p2;
@@

... when != x@p1
(
x@p2 == NULL
|
x@p2 != NULL
)

@fix depends on !s@
position r.p1,r.p2;
expression x,E;
statement S1,S2;
@@

(
- if ((x@p2 != NULL) || ...)
S1
|
- if ((x@p2 == NULL) && ...) S1
|
- BUG_ON(x@p2 == NULL);
)
// </smpl>

Signed-off-by: Julia Lawall <[email protected]>

---
drivers/net/wan/pc300_drv.c | 5 ++---
1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wan/pc300_drv.c b/drivers/net/wan/pc300_drv.c
index d67957a..c23fde0 100644
--- a/drivers/net/wan/pc300_drv.c
+++ b/drivers/net/wan/pc300_drv.c
@@ -2718,9 +2718,8 @@ static int cpc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
}
pc300patrntst.num_errors =
falc_pattern_test_error(card, ch);
- if (!arg
- || copy_to_user(arg, &pc300patrntst,
- sizeof (pc300patterntst_t)))
+ if (copy_to_user(arg, &pc300patrntst,
+ sizeof(pc300patterntst_t)))
return -EINVAL;
} else {
falc_pattern_test(card, ch, pc300patrntst.patrntst_on);

2008-12-22 00:18:35

by Krzysztof Halasa

Subject: Re: [PATCH 7/13] drivers/net/wan: Remove redundant test

Julia Lawall <[email protected]> writes:

> arg is checked not to be NULL a few lines before.
>
> A simplified version of the semantic patch that makes this change is as
> follows: (http://www.emn.fr/x-info/coccinelle/)

> ---
> drivers/net/wan/pc300_drv.c | 5 ++---

Impressive. Thanks.
--
Krzysztof Halasa

2008-12-26 02:05:01

by David Miller

Subject: Re: [PATCH 7/13] drivers/net/wan: Remove redundant test

From: Julia Lawall <[email protected]>
Date: Sun, 21 Dec 2008 16:39:15 +0100 (CET)

> arg is checked not to be NULL a few lines before.

Applied.