Tested-by: Sui Jingfeng<suijingfeng@xxxxxxxxxxx>
On 2023/3/20 23:07, Thomas Zimmermann wrote:
Consolidate all handling of CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM by
making the module parameter optional in drm_fb_helper.c.
Without the config option, modules can set smem_start in struct
fb_info for internal usage, but not export if to userspace. The
address can only be exported by enabling the option and setting
the module parameter. Also update the comment.
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Acked-by: Zack Rusin <zackr@xxxxxxxxxx>
---
drivers/gpu/drm/drm_fb_helper.c | 22 ++++++++--------------
drivers/gpu/drm/drm_fbdev_dma.c | 9 +--------
include/drm/drm_fb_helper.h | 9 ---------
3 files changed, 9 insertions(+), 31 deletions(-)
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index bb0b25209b3e..63ec95e86d0e 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -60,16 +60,17 @@ MODULE_PARM_DESC(drm_fbdev_overalloc,
* In order to keep user-space compatibility, we want in certain use-cases
* to keep leaking the fbdev physical address to the user-space program
* handling the fbdev buffer.
- * This is a bad habit essentially kept into closed source opengl driver
- * that should really be moved into open-source upstream projects instead
- * of using legacy physical addresses in user space to communicate with
- * other out-of-tree kernel modules.
+ *
+ * This is a bad habit, essentially kept to support closed-source OpenGL
+ * drivers that should really be moved into open-source upstream projects
+ * instead of using legacy physical addresses in user space to communicate
+ * with other out-of-tree kernel modules.
*
* This module_param *should* be removed as soon as possible and be
* considered as a broken and legacy behaviour from a modern fbdev device.
*/
-#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
static bool drm_leak_fbdev_smem;
+#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
module_param_unsafe(drm_leak_fbdev_smem, bool, 0600);
MODULE_PARM_DESC(drm_leak_fbdev_smem,
"Allow unsafe leaking fbdev physical smem address [default=false]");
@@ -1983,10 +1984,6 @@ static int drm_fb_helper_single_fb_probe(struct drm_fb_helper *fb_helper)
return ret;
}
-#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
- fb_helper->hint_leak_smem_start = drm_leak_fbdev_smem;
-#endif
-
/* push down into drivers */
ret = (*fb_helper->funcs->fb_probe)(fb_helper, &sizes);
if (ret < 0)
@@ -2185,11 +2182,8 @@ __drm_fb_helper_initial_config_and_unlock(struct drm_fb_helper *fb_helper)
info = fb_helper->info;
info->var.pixclock = 0;
- /* Shamelessly allow physical address leaking to userspace */
-#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
- if (!fb_helper->hint_leak_smem_start)
-#endif
- /* don't leak any physical addresses to userspace */
+
+ if (!drm_leak_fbdev_smem)
info->flags |= FBINFO_HIDE_SMEM_START;
/* Need to drop locks to avoid recursive deadlock in
diff --git a/drivers/gpu/drm/drm_fbdev_dma.c b/drivers/gpu/drm/drm_fbdev_dma.c
index cf553ac12a0f..728deffcc0d9 100644
--- a/drivers/gpu/drm/drm_fbdev_dma.c
+++ b/drivers/gpu/drm/drm_fbdev_dma.c
@@ -136,16 +136,9 @@ static int drm_fbdev_dma_helper_fb_probe(struct drm_fb_helper *fb_helper,
info->flags |= FBINFO_READS_FAST; /* signal caching */
info->screen_size = sizes->surface_height * fb->pitches[0];
info->screen_buffer = map.vaddr;
+ info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
info->fix.smem_len = info->screen_size;
-#if IS_ENABLED(CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM)
- /*
- * Shamelessly leak the physical address to user-space.
- */
- if (fb_helper->hint_leak_smem_start && !info->fix.smem_start)
- info->fix.smem_start = page_to_phys(virt_to_page(info->screen_buffer));
-#endif
-
return 0;
err_drm_client_buffer_vunmap:
diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index c5822ec2fdd1..72032c354a30 100644
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -195,15 +195,6 @@ struct drm_fb_helper {
*/
int preferred_bpp;
- /**
- * @hint_leak_smem_start:
- *
- * Hint to the fbdev emulation to store the framebuffer's physical
- * address in struct &fb_info.fix.smem_start. If the hint is unset,
- * the smem_start field should always be cleared to zero.
- */
- bool hint_leak_smem_start;
-
#ifdef CONFIG_FB_DEFERRED_IO
/**
* @fbdefio:
