[PATCH] ath9k: Fix write callback of 'debug' which configures debug mask

[PATCH] ath9k: Fix write callback of 'debug' which configures debug mask

[Vasanthakumar Thiagarajan]

Handle error condition on copy_from_user() properly and
make sure a NUL terminated char[] is sent to strict_strtoul()
for proper conversion.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
---
 drivers/net/wireless/ath/ath9k/debug.c |   22 ++++++++++++++--------
 1 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index a42d631..6d20725 100644
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -49,8 +49,9 @@ static ssize_t read_file_debug(struct file *file, char __user *user_buf,
 {
 	struct ath_softc *sc = file->private_data;
 	char buf[32];
-	unsigned int len = 0;
-	len += snprintf(buf, sizeof(buf), "0x%08x\n", sc->debug.debug_mask);
+	unsigned int len;
+
+	len = snprintf(buf, sizeof(buf), "0x%08x\n", sc->debug.debug_mask);
 	return simple_read_from_buffer(user_buf, count, ppos, buf, len);
 }
 
@@ -60,12 +61,17 @@ static ssize_t write_file_debug(struct file *file, const char __user *user_buf,
 	struct ath_softc *sc = file->private_data;
 	unsigned long mask;
 	char buf[32];
-	if (copy_from_user(buf, user_buf, (sizeof(buf) - 1) < count ?
-		(sizeof(buf) - 1) : count))
-		return 0;
-	buf[sizeof(buf)-1] = 0;
-	if (strict_strtoul(buf, 0, &mask) == 0)
-		sc->debug.debug_mask = mask;
+	ssize_t len;
+
+	len = min(count, sizeof(buf) - 1);
+	if (copy_from_user(buf, user_buf, len))
+		return -EINVAL;
+
+	buf[len] = '\0';
+	if (strict_strtoul(buf, 0, &mask))
+		return -EINVAL;
+
+	sc->debug.debug_mask = mask;
 	return count;
 }
 
-- 
1.5.5.1

[PATCH] ath9k: Remove modparam 'debug'

[Vasanthakumar Thiagarajan]

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
---
 drivers/net/wireless/ath/ath9k/Kconfig |    4 ++--
 drivers/net/wireless/ath/ath9k/debug.c |    5 +----
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/Kconfig b/drivers/net/wireless/ath/ath9k/Kconfig
index 0ed1ac3..a5ab53f 100644
--- a/drivers/net/wireless/ath/ath9k/Kconfig
+++ b/drivers/net/wireless/ath/ath9k/Kconfig
@@ -17,8 +17,8 @@ config ATH9K_DEBUG
 	depends on ATH9K
 	---help---
 	  Say Y, if you need ath9k to display debug messages.
-	  Pass the debug mask as a module parameter:
+	  Pass the debug mask through debugfs interface:
 
-	  modprobe ath9k debug=0x00002000
+	  echo <debug mask> > /<debugfsroot>/ath9k/phyX/debug
 
 	  Look in ath9k/core.h for possible debug masks
diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index 6d20725..a4c0c7a 100644
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -18,9 +18,6 @@
 
 #include "ath9k.h"
 
-static unsigned int ath9k_debug = DBG_DEFAULT;
-module_param_named(debug, ath9k_debug, uint, 0);
-
 static struct dentry *ath9k_debugfs_root;
 
 void DPRINTF(struct ath_softc *sc, int dbg_mask, const char *fmt, ...)
@@ -489,7 +486,7 @@ static const struct file_operations fops_wiphy = {
 
 int ath9k_init_debug(struct ath_softc *sc)
 {
-	sc->debug.debug_mask = ath9k_debug;
+	sc->debug.debug_mask = DBG_DEFAULT;
 
 	if (!ath9k_debugfs_root)
 		return -ENOENT;
-- 
1.5.5.1

Re: [PATCH] ath9k: Remove modparam 'debug'

[Luis R. Rodriguez]

On Tue, Jun 02, 2009 at 06:58:56AM -0700, Vasanth Thiagarajan wrote:
> -         modprobe ath9k debug=0x00002000
> +         echo <debug mask> > /<debugfsroot>/ath9k/phyX/debug

This means no debugging available during module init which does seem
useful to keep.

  Luis

Re: [PATCH] ath9k: Remove modparam 'debug'

[Vasanthakumar Thiagarajan]

On Tue, Jun 02, 2009 at 10:13:38PM +0530, Luis Rodriguez wrote:
> On Tue, Jun 02, 2009 at 06:58:56AM -0700, Vasanth Thiagarajan wrote:
> > -         modprobe ath9k debug=0x00002000
> > +         echo <debug mask> > /<debugfsroot>/ath9k/phyX/debug
> 
> This means no debugging available during module init which does seem
> useful to keep.

Thats true,let's keep it, thanks.

Vasanth

Re: [PATCH] ath9k: Remove modparam 'debug'

[Vasanthakumar Thiagarajan]

On Tue, Jun 02, 2009 at 07:28:56PM +0530, Vasanth Thiagarajan wrote:

John,

> Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
> ---
>  drivers/net/wireless/ath/ath9k/Kconfig |    4 ++--
>  drivers/net/wireless/ath/ath9k/debug.c |    5 +----
>  2 files changed, 3 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath9k/Kconfig b/drivers/net/wireless/ath/ath9k/Kconfig
> index 0ed1ac3..a5ab53f 100644
> --- a/drivers/net/wireless/ath/ath9k/Kconfig
> +++ b/drivers/net/wireless/ath/ath9k/Kconfig
> @@ -17,8 +17,8 @@ config ATH9K_DEBUG
>         depends on ATH9K
>         ---help---
>           Say Y, if you need ath9k to display debug messages.
> -         Pass the debug mask as a module parameter:
> +         Pass the debug mask through debugfs interface:
> 
> -         modprobe ath9k debug=0x00002000
> +         echo <debug mask> > /<debugfsroot>/ath9k/phyX/debug
> 
>           Look in ath9k/core.h for possible debug masks
> diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
> index 6d20725..a4c0c7a 100644
> --- a/drivers/net/wireless/ath/ath9k/debug.c
> +++ b/drivers/net/wireless/ath/ath9k/debug.c
> @@ -18,9 +18,6 @@
> 
>  #include "ath9k.h"
> 
> -static unsigned int ath9k_debug = DBG_DEFAULT;
> -module_param_named(debug, ath9k_debug, uint, 0);
> -
>  static struct dentry *ath9k_debugfs_root;
> 
>  void DPRINTF(struct ath_softc *sc, int dbg_mask, const char *fmt, ...)
> @@ -489,7 +486,7 @@ static const struct file_operations fops_wiphy = {
> 
>  int ath9k_init_debug(struct ath_softc *sc)
>  {
> -       sc->debug.debug_mask = ath9k_debug;
> +       sc->debug.debug_mask = DBG_DEFAULT;
> 
>         if (!ath9k_debugfs_root)
>                 return -ENOENT;
> --
> 1.5.5.1
> 
> --
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Please ignore this patch as we will miss debug information during
device attach time if we remove the option to pass debug mask as 
modparam. thanks.


Vasanth