From a51c7663f144606a5f08e772fa3e1e4f2277a614 Mon Sep 17 00:00:00 2001 From: Thomas Zimmermann Date: Mon, 20 Mar 2023 16:07:50 +0100 Subject: drm/fb-helper: Consolidate CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM 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 Reviewed-by: Javier Martinez Canillas Acked-by: Zack Rusin Tested-by: Sui Jingfeng Link: https://patchwork.freedesktop.org/patch/msgid/20230320150751.20399-8-tzimmermann@suse.de --- 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: -- cgit