lkml.org 
[lkml]   [2016]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] dmascc: Return correct error codes
This change has been made with the goal that kernel functions should
return something more descriptive than -1 on failure.

A variable `err` has been introduced for storing error codes.

The return value of kzalloc on failure should return a -1 and not a
-ENOMEM. This was found using Coccinelle. A simplified version of
the semantic patch used is:

//<smpl>
@@
expression *e;
identifier l1;
@@

e = kzalloc(...);
if (e == NULL) {
...
goto l1;
}
l1:
...
return -1
+ -ENOMEM
;
//</smpl

Furthermore, set `err` to -ENOMEM on failure of alloc_netdev(), and to
-ENODEV on failure of register_netdev() and probe_irq_off().

The single call site only checks that the return value is not 0,
hence no change is required at the call site.

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
---
Not sure if -ENODEV is the right error code for probe_irq_off(irqs),
since there are few other examples with this function.

drivers/net/hamradio/dmascc.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hamradio/dmascc.c b/drivers/net/hamradio/dmascc.c
index c3d3777..e4137c1 100644
--- a/drivers/net/hamradio/dmascc.c
+++ b/drivers/net/hamradio/dmascc.c
@@ -451,7 +451,7 @@ static const struct net_device_ops scc_netdev_ops = {

static int __init setup_adapter(int card_base, int type, int n)
{
- int i, irq, chip;
+ int i, irq, chip, err;
struct scc_info *info;
struct net_device *dev;
struct scc_priv *priv;
@@ -463,14 +463,17 @@ static int __init setup_adapter(int card_base, int type, int n)

/* Initialize what is necessary for write_scc and write_scc_data */
info = kzalloc(sizeof(struct scc_info), GFP_KERNEL | GFP_DMA);
- if (!info)
+ if (!info) {
+ err = -ENOMEM;
goto out;
+ }

info->dev[0] = alloc_netdev(0, "", NET_NAME_UNKNOWN, dev_setup);
if (!info->dev[0]) {
printk(KERN_ERR "dmascc: "
"could not allocate memory for %s at %#3x\n",
hw[type].name, card_base);
+ err = -ENOMEM;
goto out1;
}

@@ -479,6 +482,7 @@ static int __init setup_adapter(int card_base, int type, int n)
printk(KERN_ERR "dmascc: "
"could not allocate memory for %s at %#3x\n",
hw[type].name, card_base);
+ err = -ENOMEM;
goto out2;
}
spin_lock_init(&info->register_lock);
@@ -549,6 +553,7 @@ static int __init setup_adapter(int card_base, int type, int n)
printk(KERN_ERR
"dmascc: could not find irq of %s at %#3x (irq=%d)\n",
hw[type].name, card_base, irq);
+ err = -ENODEV;
goto out3;
}

@@ -585,11 +590,13 @@ static int __init setup_adapter(int card_base, int type, int n)
if (register_netdev(info->dev[0])) {
printk(KERN_ERR "dmascc: could not register %s\n",
info->dev[0]->name);
+ err = -ENODEV;
goto out3;
}
if (register_netdev(info->dev[1])) {
printk(KERN_ERR "dmascc: could not register %s\n",
info->dev[1]->name);
+ err = -ENODEV;
goto out4;
}

@@ -612,7 +619,7 @@ static int __init setup_adapter(int card_base, int type, int n)
out1:
kfree(info);
out:
- return -1;
+ return err;
}


--
1.9.1
\
 
 \ /
  Last update: 2016-02-09 20:21    [W:0.057 / U:3.992 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site