[PATCH 00/11] fix error return code

[PATCH 00/11] fix error return code

[Julia Lawall]

The complate semantic patch that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@ok exists@
identifier f,ret,i;
expression e;
constant c;
@@

// identify a function that returns a negative return value at least once.
f(...) {
... when any
(
return -c@i;
|
ret = -c@i;
... when != ret = e
return ret;
|
if (ret < 0) { ... return ret; }
)
... when any
}

@r exists@
identifier ret,ok.f,fn;
expression e1,e2,e3,e4,e5,e6,x;
statement S,S1;
position p1,p2,p3;
@@

// identify a case where the return variable is set to a non-negative value
// and then returned in error-handling code
f(...) {
... when any
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != \(ret = e1\|ret++\|ret--\|ret+=e1\|ret-=e1\)
    when != &ret
    when any
(
 if (<+... ret = e5 ...+>) S1
|
 if (<+... &ret ...+>) S1
|
if@p2(<+...x = fn(...)...+>)
 {
  ... when != ret = e6
      when forall
 return@p3 ret;
}
|
break;
|
x = fn(...)
... when != \(ret = e4\|ret++\|ret--\|ret+=e4\|ret-=e4\)
    when != &ret
(
 if (<+... ret = e3 ...+>) S
|
 if (<+... &ret ...+>) S
|
if@p2(<+...\(x != 0\|x < 0\|x == NULL\|IS_ERR(x)\)...+>)
 {
  ... when != ret = e2
      when forall
 return@p3 ret;
}
)
)
... when any
}

@printer depends on r@
position p;
identifier ok.f,pr;
constant char [] c;
@@

f(...) { <...pr@p(...,c,...)...> }

@bad0 exists@
identifier r.ret,ok.f,g != {ERR_PTR,IS_ERR};
position p != printer.p;
@@

f(...) { ... when any
g@p(...,ret,...)
... when any
 }

@bad depends on !bad0 exists@
position r.p1,r.p2;
statement S1,S2;
identifier r.ret;
expression e1;
@@

// ignore the above if there is some path where the variable is set to
// something else
(
if@p1 (\(ret < 0\|ret != 0\)) S1
|
ret@p1 = 0
)
... when any
 \(ret = e1\|ret++\|ret--\|ret+=e1\|ret-=e1\|&ret\)
... when any
if@p2(...) S2

@bad1 depends on !bad0 && !bad exists@
position r.p2;
statement S2;
identifier r.ret;
expression e1;
constant c;
@@

ret = -c
... when != \(ret = e1\|ret++\|ret--\|ret+=e1\|ret-=e1\)
    when != &ret
    when any
if@p2(...) S2

@bad2 depends on !bad0 && !bad && !bad1 exists@
position r.p1,r.p2;
identifier r.ret;
expression e1;
statement S2;
constant c;
@@

// likewise ignore it if there has been an intervening return
ret@p1 = 0
... when != if (...) { ... ret = e1 ... return ret; }
    when != if (...) { ... return -c; }
    when any
if@p2(...) S2

@script:python depends on !bad0 && !bad && !bad1 && !bad2@
p1 << r.p1;
p2 << r.p2;
p3 << r.p3;
@@

cocci.print_main("",p1)
cocci.print_secs("",p2)
cocci.print_secs("",p3)
// </smpl>

[PATCH 03/11] net: davinci_emac: fix error return code

[Julia Lawall]

Propagate error code on failure.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 drivers/net/ethernet/ti/davinci_emac.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
index aeebc0a..a21c77b 100644
--- a/drivers/net/ethernet/ti/davinci_emac.c
+++ b/drivers/net/ethernet/ti/davinci_emac.c
@@ -2004,8 +2004,10 @@ static int davinci_emac_probe(struct platform_device *pdev)
 	if (res_ctrl) {
 		priv->ctrl_base =
 			devm_ioremap_resource(&pdev->dev, res_ctrl);
-		if (IS_ERR(priv->ctrl_base))
+		if (IS_ERR(priv->ctrl_base)) {
+			rc = PTR_ERR(priv->ctrl_base);
 			goto no_pdata;
+		}
 	} else {
 		priv->ctrl_base = priv->remap_addr + pdata->ctrl_mod_reg_offset;
 	}

[PATCH 05/11] mlxsw: fix error return code

[Julia Lawall]

Return a negative error code on failure.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 drivers/net/ethernet/mellanox/mlxsw/pci.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/pci.c b/drivers/net/ethernet/mellanox/mlxsw/pci.c
index a34f474..045f98f 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/pci.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/pci.c
@@ -1726,6 +1726,7 @@ static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 						mlxsw_pci_dbg_root);
 	if (!mlxsw_pci->dbg_dir) {
 		dev_err(&pdev->dev, "Failed to create debugfs dir\n");
+		err = -ENOMEM;
 		goto err_dbg_create_dir;
 	}
 

[PATCH 10/11] ah6: fix error return code

[Julia Lawall]

Return a negative error code on failure.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret; expression e1,e2;
@@
(
if (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
 net/ipv6/ah6.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/ah6.c b/net/ipv6/ah6.c
index ed7d4e3..0630a4d 100644
--- a/net/ipv6/ah6.c
+++ b/net/ipv6/ah6.c
@@ -577,8 +577,10 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
 
 	work_iph = ah_alloc_tmp(ahash, nfrags + sglists, hdr_len +
 				ahp->icv_trunc_len + seqhi_len);
-	if (!work_iph)
+	if (!work_iph) {
+		err = -ENOMEM;
 		goto out;
+	}
 
 	auth_data = ah_tmp_auth((u8 *)work_iph, hdr_len);
 	seqhi = (__be32 *)(auth_data + ahp->icv_trunc_len);

Re: [PATCH 05/11] mlxsw: fix error return code

[Jiri Pirko]

Sun, Aug 23, 2015 at 02:11:16AM CEST, Julia.Lawall@lip6.fr wrote:
>Return a negative error code on failure.
>
>A simplified version of the semantic match that finds this problem is as
>follows: (http://coccinelle.lip6.fr/)
>
>// <smpl>
>@@
>identifier ret; expression e1,e2;
>@@
>(
>if (\(ret < 0\|ret != 0\))
> { ... return ret; }
>|
>ret = 0
>)
>... when != ret = e1
>    when != &ret
>*if(...)
>{
>  ... when != ret = e2
>      when forall
> return ret;
>}
>// </smpl>
>
>Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

Acked-by: Jiri Pirko <jiri@mellanox.com>

Re: [PATCH 10/11] ah6: fix error return code

[Herbert Xu]

On Sun, Aug 23, 2015 at 02:11:21AM +0200, Julia Lawall wrote:
> Return a negative error code on failure.
> 
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @@
> identifier ret; expression e1,e2;
> @@
> (
> if (\(ret < 0\|ret != 0\))
>  { ... return ret; }
> |
> ret = 0
> )
> ... when != ret = e1
>     when != &ret
> *if(...)
> {
>   ... when != ret = e2
>       when forall
>  return ret;
> }
> // </smpl>
> 
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

This problem exists in net/ipv4/ah4.c too, right?

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH 10/11] ah6: fix error return code

[David Miller]

From: Julia Lawall <Julia.Lawall@lip6.fr>
Date: Sun, 23 Aug 2015 02:11:21 +0200

> Return a negative error code on failure.
> 
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
 ...
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

Applied and as noticed by Herbert Xu I fixed up the net/ipv4/ah4.c case
as well.

Re: [PATCH 05/11] mlxsw: fix error return code

[David Miller]

From: Julia Lawall <Julia.Lawall@lip6.fr>
Date: Sun, 23 Aug 2015 02:11:16 +0200

> Return a negative error code on failure.
> 
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
 ...
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

Applied.

Re: [PATCH 03/11] net: davinci_emac: fix error return code

[David Miller]

From: Julia Lawall <Julia.Lawall@lip6.fr>
Date: Sun, 23 Aug 2015 02:11:14 +0200

> Propagate error code on failure.
> 
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
 ...
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

Applied.