drm: 32/64-bit DRM ioctl compatibility patch

The patch is against a 2.6.11 kernel tree.  I am running this with a
32-bit X server (compiled up from X.org CVS as of a couple of weeks
ago) and 32-bit DRI libraries and clients.  All the userland stuff is
identical to what I am using under a 32-bit kernel on my G4 powerbook
(which is a 32-bit machine of course).  I haven't tried compiling up a
64-bit X server or clients yet.

In the compatibility routines I have assumed that the kernel can
safely access user addresses after set_fs(KERNEL_DS).  That is, where
an ioctl argument structure contains pointers to other structures, and
those other structures are already compatible between the 32-bit and
64-bit ABIs (i.e. they only contain things like chars, shorts or
ints), I just check the address with access_ok() and then pass it
through to the 64-bit ioctl code.  I believe this approach may not
work on sparc64, but it does work on ppc64 and x86_64 at least.

One tricky area which may need to be revisited is the question of how
to handle the handles which we pass back to userspace to identify
mappings.  These handles are generated in the ADDMAP ioctl and then
passed in as the offset value to mmap.  However, offset values for
mmap seem to be generated in other ways as well, particularly for AGP
mappings.

The approach I have ended up with is to generate a fake 32-bit handle
only for _DRM_SHM mappings.  The handles for other mappings (AGP, REG,
FB) are physical addresses which are already limited to 32 bits, and
generating fake handles for them created all sorts of problems in the
mmap/nopage code.

This patch has been updated to use the new compatibility ioctls.

From: Paul Mackerras <paulus@samba.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 395 insertions, 0 deletions

diff --git a/drivers/char/drm/radeon_ioc32.c b/drivers/char/drm/radeon_ioc32.c
new file mode 100644
index 000000000000..bfe612215fb3
--- /dev/null
+++ b/drivers/char/drm/radeon_ioc32.c
@@ -0,0 +1,395 @@
+/**
+ * \file radeon_ioc32.c
+ *
+ * 32-bit ioctl compatibility routines for the Radeon DRM.
+ *
+ * \author Paul Mackerras <paulus@samba.org>
+ *
+ * Copyright (C) Paul Mackerras 2005
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+#include <linux/compat.h>
+#include <linux/ioctl32.h>
+
+#include "drmP.h"
+#include "drm.h"
+#include "radeon_drm.h"
+#include "radeon_drv.h"
+
+typedef struct drm_radeon_init32 {
+	int func;
+	u32 sarea_priv_offset;
+	int is_pci;
+	int cp_mode;
+	int gart_size;
+	int ring_size;
+	int usec_timeout;
+
+	unsigned int fb_bpp;
+	unsigned int front_offset, front_pitch;
+	unsigned int back_offset, back_pitch;
+	unsigned int depth_bpp;
+	unsigned int depth_offset, depth_pitch;
+
+	u32 fb_offset;
+	u32 mmio_offset;
+	u32 ring_offset;
+	u32 ring_rptr_offset;
+	u32 buffers_offset;
+	u32 gart_textures_offset;
+} drm_radeon_init32_t;
+
+static int compat_radeon_cp_init(struct file *file, unsigned int cmd,
+				 unsigned long arg)
+{
+	drm_radeon_init32_t init32;
+	drm_radeon_init_t __user *init;
+
+	if (copy_from_user(&init32, (void __user *)arg, sizeof(init32)))
+		return -EFAULT;
+
+	init = compat_alloc_user_space(sizeof(*init));
+	if (!access_ok(VERIFY_WRITE, init, sizeof(*init))
+	    || __put_user(init32.func, &init->func)
+	    || __put_user(init32.sarea_priv_offset, &init->sarea_priv_offset)
+	    || __put_user(init32.is_pci, &init->is_pci)
+	    || __put_user(init32.cp_mode, &init->cp_mode)
+	    || __put_user(init32.gart_size, &init->gart_size)
+	    || __put_user(init32.ring_size, &init->ring_size)
+	    || __put_user(init32.usec_timeout, &init->usec_timeout)
+	    || __put_user(init32.fb_bpp, &init->fb_bpp)
+	    || __put_user(init32.front_offset, &init->front_offset)
+	    || __put_user(init32.front_pitch, &init->front_pitch)
+	    || __put_user(init32.back_offset, &init->back_offset)
+	    || __put_user(init32.back_pitch, &init->back_pitch)
+	    || __put_user(init32.depth_bpp, &init->depth_bpp)
+	    || __put_user(init32.depth_offset, &init->depth_offset)
+	    || __put_user(init32.depth_pitch, &init->depth_pitch)
+	    || __put_user(init32.fb_offset, &init->fb_offset)
+	    || __put_user(init32.mmio_offset, &init->mmio_offset)
+	    || __put_user(init32.ring_offset, &init->ring_offset)
+	    || __put_user(init32.ring_rptr_offset, &init->ring_rptr_offset)
+	    || __put_user(init32.buffers_offset, &init->buffers_offset)
+	    || __put_user(init32.gart_textures_offset,
+			  &init->gart_textures_offset))
+		return -EFAULT;
+
+	return drm_ioctl(file->f_dentry->d_inode, file,
+			 DRM_IOCTL_RADEON_CP_INIT, (unsigned long) init);
+}
+
+typedef struct drm_radeon_clear32 {
+	unsigned int flags;
+	unsigned int clear_color;
+	unsigned int clear_depth;
+	unsigned int color_mask;
+	unsigned int depth_mask;   /* misnamed field:  should be stencil */
+	u32	     depth_boxes;
+} drm_radeon_clear32_t;
+
+static int compat_radeon_cp_clear(struct file *file, unsigned int cmd,
+				  unsigned long arg)
+{
+	drm_radeon_clear32_t clr32;
+	drm_radeon_clear_t __user *clr;
+
+	if (copy_from_user(&clr32, (void __user *)arg, sizeof(clr32)))
+		return -EFAULT;
+
+	clr = compat_alloc_user_space(sizeof(*clr));
+	if (!access_ok(VERIFY_WRITE, clr, sizeof(*clr))
+	    || __put_user(clr32.flags, &clr->flags)
+	    || __put_user(clr32.clear_color, &clr->clear_color)
+	    || __put_user(clr32.clear_depth, &clr->clear_depth)
+	    || __put_user(clr32.color_mask, &clr->color_mask)
+	    || __put_user(clr32.depth_mask, &clr->depth_mask)
+	    || __put_user((void __user *)(unsigned long)clr32.depth_boxes,
+			  &clr->depth_boxes))
+		return -EFAULT;
+
+	return drm_ioctl(file->f_dentry->d_inode, file,
+			 DRM_IOCTL_RADEON_CLEAR, (unsigned long) clr);
+}
+
+typedef struct drm_radeon_stipple32 {
+	u32 mask;
+} drm_radeon_stipple32_t;
+
+static int compat_radeon_cp_stipple(struct file *file, unsigned int cmd,
+				    unsigned long arg)
+{
+	drm_radeon_stipple32_t __user *argp = (void __user *) arg;
+	drm_radeon_stipple_t __user *request;
+	u32 mask;
+
+	if (get_user(mask, &argp->mask))
+		return -EFAULT;
+
+	request = compat_alloc_user_space(sizeof(*request));
+	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	    || __put_user((unsigned int __user *)(unsigned long) mask,
+			  &request->mask))
+		return -EFAULT;
+
+	return drm_ioctl(file->f_dentry->d_inode, file,
+			 DRM_IOCTL_RADEON_STIPPLE, (unsigned long) request);
+}
+
+typedef struct drm_radeon_tex_image32 {
+	unsigned int x, y;		/* Blit coordinates */
+	unsigned int width, height;
+	u32 data;
+} drm_radeon_tex_image32_t;
+
+typedef struct drm_radeon_texture32 {
+	unsigned int offset;
+	int pitch;
+	int format;
+	int width;			/* Texture image coordinates */
+	int height;
+	u32 image;
+} drm_radeon_texture32_t;
+
+static int compat_radeon_cp_texture(struct file *file, unsigned int cmd,
+				    unsigned long arg)
+{
+	drm_radeon_texture32_t req32;
+	drm_radeon_texture_t __user *request;
+	drm_radeon_tex_image32_t img32;
+	drm_radeon_tex_image_t __user *image;
+
+	if (copy_from_user(&req32, (void __user *) arg, sizeof(req32)))
+		return -EFAULT;
+	if (req32.image == 0)
+		return -EINVAL;
+	if (copy_from_user(&img32, (void __user *)(unsigned long)req32.image,
+			   sizeof(img32)))
+		return -EFAULT;
+
+	request = compat_alloc_user_space(sizeof(*request) + sizeof(*image));
+	if (!access_ok(VERIFY_WRITE, request,
+		       sizeof(*request) + sizeof(*image)))
+		return -EFAULT;
+	image = (drm_radeon_tex_image_t __user *) (request + 1);
+
+	if (__put_user(req32.offset, &request->offset)
+	    || __put_user(req32.pitch, &request->pitch)
+	    || __put_user(req32.format, &request->format)
+	    || __put_user(req32.width, &request->width)
+	    || __put_user(req32.height, &request->height)
+	    || __put_user(image, &request->image)
+	    || __put_user(img32.x, &image->x)
+	    || __put_user(img32.y, &image->y)
+	    || __put_user(img32.width, &image->width)
+	    || __put_user(img32.height, &image->height)
+	    || __put_user((const void __user *)(unsigned long)img32.data,
+			  &image->data))
+		return -EFAULT;
+
+	return drm_ioctl(file->f_dentry->d_inode, file,
+			 DRM_IOCTL_RADEON_TEXTURE, (unsigned long) request);
+}
+
+typedef struct drm_radeon_vertex2_32 {
+	int idx;			/* Index of vertex buffer */
+	int discard;			/* Client finished with buffer? */
+	int nr_states;
+	u32 state;
+	int nr_prims;
+	u32 prim;
+} drm_radeon_vertex2_32_t;
+
+static int compat_radeon_cp_vertex2(struct file *file, unsigned int cmd,
+				    unsigned long arg)
+{
+	drm_radeon_vertex2_32_t req32;
+	drm_radeon_vertex2_t __user *request;
+
+	if (copy_from_user(&req32, (void __user *) arg, sizeof(req32)))
+		return -EFAULT;
+
+	request = compat_alloc_user_space(sizeof(*request));
+	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	    || __put_user(req32.idx, &request->idx)
+	    || __put_user(req32.discard, &request->discard)
+	    || __put_user(req32.nr_states, &request->nr_states)
+	    || __put_user((void __user *)(unsigned long)req32.state,
+			  &request->state)
+	    || __put_user(req32.nr_prims, &request->nr_prims)
+	    || __put_user((void __user *)(unsigned long)req32.prim,
+			  &request->prim))
+		return -EFAULT;
+
+	return drm_ioctl(file->f_dentry->d_inode, file,
+			 DRM_IOCTL_RADEON_VERTEX2, (unsigned long) request);
+}
+
+typedef struct drm_radeon_cmd_buffer32 {
+	int bufsz;
+	u32 buf;
+	int nbox;
+	u32 boxes;
+} drm_radeon_cmd_buffer32_t;
+
+static int compat_radeon_cp_cmdbuf(struct file *file, unsigned int cmd,
+				   unsigned long arg)
+{
+	drm_radeon_cmd_buffer32_t req32;
+	drm_radeon_cmd_buffer_t __user *request;
+
+	if (copy_from_user(&req32, (void __user *) arg, sizeof(req32)))
+		return -EFAULT;
+
+	request = compat_alloc_user_space(sizeof(*request));
+	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	    || __put_user(req32.bufsz, &request->bufsz)
+	    || __put_user((void __user *)(unsigned long)req32.buf,
+			  &request->buf)
+	    || __put_user(req32.nbox, &request->nbox)
+	    || __put_user((void __user *)(unsigned long)req32.boxes,
+			  &request->boxes))
+		return -EFAULT;
+
+	return drm_ioctl(file->f_dentry->d_inode, file,
+			 DRM_IOCTL_RADEON_CMDBUF, (unsigned long) request);
+}
+
+typedef struct drm_radeon_getparam32 {
+	int param;
+	u32 value;
+} drm_radeon_getparam32_t;
+
+static int compat_radeon_cp_getparam(struct file *file, unsigned int cmd,
+				     unsigned long arg)
+{
+	drm_radeon_getparam32_t req32;
+	drm_radeon_getparam_t __user *request;
+
+	if (copy_from_user(&req32, (void __user *) arg, sizeof(req32)))
+		return -EFAULT;
+
+	request = compat_alloc_user_space(sizeof(*request));
+	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	    || __put_user(req32.param, &request->param)
+	    || __put_user((void __user *)(unsigned long)req32.value,
+			  &request->value))
+		return -EFAULT;
+
+	return drm_ioctl(file->f_dentry->d_inode, file,
+			 DRM_IOCTL_RADEON_GETPARAM, (unsigned long) request);
+}
+
+typedef struct drm_radeon_mem_alloc32 {
+	int region;
+	int alignment;
+	int size;
+	u32 region_offset;	/* offset from start of fb or GART */
+} drm_radeon_mem_alloc32_t;
+
+static int compat_radeon_mem_alloc(struct file *file, unsigned int cmd,
+				   unsigned long arg)
+{
+	drm_radeon_mem_alloc32_t req32;
+	drm_radeon_mem_alloc_t __user *request;
+
+	if (copy_from_user(&req32, (void __user *) arg, sizeof(req32)))
+		return -EFAULT;
+
+	request = compat_alloc_user_space(sizeof(*request));
+	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	    || __put_user(req32.region, &request->region)
+	    || __put_user(req32.alignment, &request->alignment)
+	    || __put_user(req32.size, &request->size)
+	    || __put_user((int __user *)(unsigned long)req32.region_offset,
+			  &request->region_offset))
+		return -EFAULT;
+
+	return drm_ioctl(file->f_dentry->d_inode, file,
+			 DRM_IOCTL_RADEON_ALLOC, (unsigned long) request);
+}
+
+typedef struct drm_radeon_irq_emit32 {
+	u32 irq_seq;
+} drm_radeon_irq_emit32_t;
+
+static int compat_radeon_irq_emit(struct file *file, unsigned int cmd,
+				  unsigned long arg)
+{
+	drm_radeon_irq_emit32_t req32;
+	drm_radeon_irq_emit_t __user *request;
+
+	if (copy_from_user(&req32, (void __user *) arg, sizeof(req32)))
+		return -EFAULT;
+
+	request = compat_alloc_user_space(sizeof(*request));
+	if (!access_ok(VERIFY_WRITE, request, sizeof(*request))
+	    || __put_user((int __user *)(unsigned long)req32.irq_seq,
+			  &request->irq_seq))
+		return -EFAULT;
+
+	return drm_ioctl(file->f_dentry->d_inode, file,
+			 DRM_IOCTL_RADEON_IRQ_EMIT, (unsigned long) request);
+}
+
+drm_ioctl_compat_t *radeon_compat_ioctls[] = {
+	[DRM_RADEON_CP_INIT] = compat_radeon_cp_init,
+	[DRM_RADEON_CLEAR] = compat_radeon_cp_clear,
+	[DRM_RADEON_STIPPLE] = compat_radeon_cp_stipple,
+	[DRM_RADEON_TEXTURE] = compat_radeon_cp_texture,
+	[DRM_RADEON_VERTEX2] = compat_radeon_cp_vertex2,
+	[DRM_RADEON_CMDBUF] = compat_radeon_cp_cmdbuf,
+	[DRM_RADEON_GETPARAM] = compat_radeon_cp_getparam,
+	[DRM_RADEON_ALLOC] = compat_radeon_mem_alloc,
+	[DRM_RADEON_IRQ_EMIT] = compat_radeon_irq_emit,
+};
+
+/**
+ * Called whenever a 32-bit process running under a 64-bit kernel
+ * performs an ioctl on /dev/dri/card<n>.
+ *
+ * \param filp file pointer.
+ * \param cmd command.
+ * \param arg user argument.
+ * \return zero on success or negative number on failure.
+ */
+long radeon_compat_ioctl(struct file *filp, unsigned int cmd,
+			 unsigned long arg)
+{
+	unsigned int nr = DRM_IOCTL_NR(cmd);
+	drm_ioctl_compat_t *fn = NULL;
+	int ret;
+
+	if (nr < DRM_COMMAND_BASE)
+		return drm_compat_ioctl(filp, cmd, arg);
+
+	if (nr < DRM_COMMAND_BASE + DRM_ARRAY_SIZE(radeon_compat_ioctls))
+		fn = radeon_compat_ioctls[nr - DRM_COMMAND_BASE];
+
+	lock_kernel();		/* XXX for now */
+	if (fn != NULL)
+		ret = (*fn)(filp, cmd, arg);
+	else
+		ret = drm_ioctl(filp->f_dentry->d_inode, filp, cmd, arg);
+	unlock_kernel();
+
+	return ret;
+}