[PATCH] drm: kill more unused DRM macros

[PATCH] drm: kill more unused DRM macros

[Andres Salomon]

There are a few more macros in drmP.h that are unused; DRM_GET_PRIV_SAREA,
DRM_ARRAY_SIZE, and DRM_WAITCOUNT can go away completely.

Unfortunately, DRM_COPY is still used in one place, but we can at least
move it to where it's used.  It's an awful looking macro..

Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
---
 drivers/gpu/drm/drm_drv.c |   12 ++++++++++++
 include/drm/drmP.h        |   25 -------------------------
 2 files changed, 12 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index a75ca63..43297ca 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -366,6 +366,18 @@ module_init(drm_core_init);
 module_exit(drm_core_exit);
 
 /**
+ * Copy and IOCTL return string to user space
+ */
+#define DRM_COPY(name, value)                                         \
+	len = strlen(value);                                          \
+	if (len > name##_len) len = name##_len;                       \
+	name##_len = strlen(value);                                   \
+	if (len && name) {                                            \
+		if (copy_to_user(name, value, len))                   \
+			return -EFAULT;                               \
+	}
+
+/**
  * Get version information
  *
  * \param inode device inode.
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index af30da3..b2112f4 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -251,23 +251,10 @@ extern void drm_ut_debug_printk(unsigned int request_level,
 /** \name Internal types and structures */
 /*@{*/
 
-#define DRM_ARRAY_SIZE(x) ARRAY_SIZE(x)
-
 #define DRM_LEFTCOUNT(x) (((x)->rp + (x)->count - (x)->wp) % ((x)->count + 1))
 #define DRM_BUFCOUNT(x) ((x)->count - DRM_LEFTCOUNT(x))
-#define DRM_WAITCOUNT(dev,idx) DRM_BUFCOUNT(&dev->queuelist[idx]->waitlist)
 
 #define DRM_IF_VERSION(maj, min) (maj << 16 | min)
-/**
- * Get the private SAREA mapping.
- *
- * \param _dev DRM device.
- * \param _ctx context number.
- * \param _map output mapping.
- */
-#define DRM_GET_PRIV_SAREA(_dev, _ctx, _map) do {	\
-	(_map) = (_dev)->context_sareas[_ctx];		\
-} while(0)
 
 /**
  * Test that the hardware lock is held by the caller, returning otherwise.
@@ -287,18 +274,6 @@ do {										\
 } while (0)
 
 /**
- * Copy and IOCTL return string to user space
- */
-#define DRM_COPY( name, value )						\
-	len = strlen( value );						\
-	if ( len > name##_len ) len = name##_len;			\
-	name##_len = strlen( value );					\
-	if ( len && name ) {						\
-		if ( copy_to_user( name, value, len ) )			\
-			return -EFAULT;					\
-	}
-
-/**
  * Ioctl function type.
  *
  * \param inode device inode.
-- 
1.5.6.5

Re: [PATCH] drm: kill more unused DRM macros

[Andrew Morton]

On Mon, 19 Oct 2009 01:37:08 -0400 Andres Salomon <dilinger@collabora.co.uk> wrote:

> There are a few more macros in drmP.h that are unused; DRM_GET_PRIV_SAREA,
> DRM_ARRAY_SIZE, and DRM_WAITCOUNT can go away completely.
> 
> Unfortunately, DRM_COPY is still used in one place, but we can at least
> move it to where it's used.  It's an awful looking macro..

It would have been nice to fix the (valid) checkpatch warnings while
you were there.

[PATCH] drm: replace DRM_COPY macro w/ a function

[Andres Salomon]

On Mon, 2 Nov 2009 23:41:24 -0800
Andrew Morton <akpm@linux-foundation.org> wrote:

> On Mon, 19 Oct 2009 01:37:08 -0400 Andres Salomon
> <dilinger@collabora.co.uk> wrote:
> 
> > There are a few more macros in drmP.h that are unused;
> > DRM_GET_PRIV_SAREA, DRM_ARRAY_SIZE, and DRM_WAITCOUNT can go away
> > completely.
> > 
> > Unfortunately, DRM_COPY is still used in one place, but we can at
> > least move it to where it's used.  It's an awful looking macro..
> 
> It would have been nice to fix the (valid) checkpatch warnings while
> you were there.
> 

How about I do one better and replace the macro w/ a function?



>From 535091717408e4ec4974e8f309212f61aabd1880 Mon Sep 17 00:00:00 2001
From: Andres Salomon <dilinger@collabora.co.uk>
Date: Tue, 3 Nov 2009 15:03:52 -0500
Subject: [PATCH] drm: replace DRM_COPY macro w/ a function

Don't inline it; the compiler can figure it out.  Comments added that are
based upon my interpretation of the code.  Hopefully they're correct. :)

Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
---
 drivers/gpu/drm/drm_drv.c |   34 ++++++++++++++++++++++------------
 1 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 43297ca..ec0e3ae 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -368,14 +368,25 @@ module_exit(drm_core_exit);
 /**
  * Copy and IOCTL return string to user space
  */
-#define DRM_COPY(name, value)                                         \
-	len = strlen(value);                                          \
-	if (len > name##_len) len = name##_len;                       \
-	name##_len = strlen(value);                                   \
-	if (len && name) {                                            \
-		if (copy_to_user(name, value, len))                   \
-			return -EFAULT;                               \
-	}
+static int drm_copy_field(char *buf, size_t *buf_len, const char *value)
+{
+	int len;
+
+	/* don't overflow userbuf */
+	len = strlen(value);
+	if (len > *buf_len)
+		len = *buf_len;
+
+	/* let userspace know exact length of driver value (which could be
+	 * larger than the userspace-supplied buffer) */
+	*buf_len = strlen(value);
+
+	/* finally, try filling in the userbuf */
+	if (len && buf)
+		if (copy_to_user(buf, value, len))
+			return -EFAULT;
+	return 0;
+}
 
 /**
  * Get version information
@@ -392,14 +403,13 @@ static int drm_version(struct drm_device *dev, void *data,
 		       struct drm_file *file_priv)
 {
 	struct drm_version *version = data;
-	int len;
 
 	version->version_major = dev->driver->major;
 	version->version_minor = dev->driver->minor;
 	version->version_patchlevel = dev->driver->patchlevel;
-	DRM_COPY(version->name, dev->driver->name);
-	DRM_COPY(version->date, dev->driver->date);
-	DRM_COPY(version->desc, dev->driver->desc);
+	drm_copy_field(version->name, &version->name_len, dev->driver->name);
+	drm_copy_field(version->date, &version->date_len, dev->driver->date);
+	drm_copy_field(version->desc, &version->desc_len, dev->driver->desc);
 
 	return 0;
 }
-- 
1.5.6.5

[PATCH] drm: check return values in drm_version

[Andres Salomon]

On Tue, 3 Nov 2009 15:09:54 -0500
Andres Salomon <dilinger@collabora.co.uk> wrote:

> On Mon, 2 Nov 2009 23:41:24 -0800
> Andrew Morton <akpm@linux-foundation.org> wrote:
> 
> > On Mon, 19 Oct 2009 01:37:08 -0400 Andres Salomon
> > <dilinger@collabora.co.uk> wrote:
> > 
> > > There are a few more macros in drmP.h that are unused;
> > > DRM_GET_PRIV_SAREA, DRM_ARRAY_SIZE, and DRM_WAITCOUNT can go away
> > > completely.
> > > 
> > > Unfortunately, DRM_COPY is still used in one place, but we can at
> > > least move it to where it's used.  It's an awful looking macro..
> > 
> > It would have been nice to fix the (valid) checkpatch warnings while
> > you were there.
> > 
> 
> How about I do one better and replace the macro w/ a function?
> 
> 
> 
> From 535091717408e4ec4974e8f309212f61aabd1880 Mon Sep 17 00:00:00 2001
> From: Andres Salomon <dilinger@collabora.co.uk>
> Date: Tue, 3 Nov 2009 15:03:52 -0500
> Subject: [PATCH] drm: replace DRM_COPY macro w/ a function
> 
> Don't inline it; the compiler can figure it out.  Comments added that
> are based upon my interpretation of the code.  Hopefully they're
> correct. :)
> 

And here's one that actually checks the return values from
drm_copy_field.  This is separate from the pure cleanup patch(es)
as it changes behavior that userspace
sees, so it can be bisected and reverted apart from the others if
needed.



>From 041636a0e2b6d7ec5c4fdb8f495682d6928b73bf Mon Sep 17 00:00:00 2001
From: Andres Salomon <dilinger@collabora.co.uk>
Date: Tue, 3 Nov 2009 15:15:51 -0500
Subject: [PATCH] drm: check return values in drm_version

In drm_version, actually check the results from function calls so that
we're not potentially passing garbage back to userspace.

Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
---
 drivers/gpu/drm/drm_drv.c |   16 +++++++++++-----
 1 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index ec0e3ae..5bd3f94 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -403,15 +403,21 @@ static int drm_version(struct drm_device *dev, void *data,
 		       struct drm_file *file_priv)
 {
 	struct drm_version *version = data;
+	int err;
 
 	version->version_major = dev->driver->major;
 	version->version_minor = dev->driver->minor;
 	version->version_patchlevel = dev->driver->patchlevel;
-	drm_copy_field(version->name, &version->name_len, dev->driver->name);
-	drm_copy_field(version->date, &version->date_len, dev->driver->date);
-	drm_copy_field(version->desc, &version->desc_len, dev->driver->desc);
-
-	return 0;
+	err = drm_copy_field(version->name, &version->name_len,
+			dev->driver->name);
+	if (!err)
+		err = drm_copy_field(version->date, &version->date_len,
+				dev->driver->date);
+	if (!err)
+		err = drm_copy_field(version->desc, &version->desc_len,
+				dev->driver->desc);
+
+	return err;
 }
 
 /**
-- 
1.5.6.5