From e79d85c6c217221ea32354a5ac0587a7ccea02b9 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 23 May 2023 17:06:20 +0200 Subject: drm/fb-helper: Fix height, width, and accel_flags in fb_var Fbtest contains some very simple validation of the fbdev userspace API contract. When used with shmob-drm, it reports the following warnings and errors: height changed from 68 to 0 height was rounded down width changed from 111 to 0 width was rounded down accel_flags changed from 0 to 1 The first part happens because __fill_var() resets the physical dimensions of the first connector, as filled in by drm_setup_crtcs_fb(). Fix this by retaining the original values. The last part happens because __fill_var() forces the FB_ACCELF_TEXT flag on, while fbtest disables all acceleration on purpose, so it can draw safely to the frame buffer. Fix this by setting accel_flags to zero, as DRM does not implement any text console acceleration. Note that this issue can also be seen in the output of fbset, which reports "accel true". Fixes: ee4cce0a8f03a333 ("drm/fb-helper: fix input validation gaps in check_var") Signed-off-by: Geert Uytterhoeven Reviewed-by: Daniel Vetter Tested-by: Sui Jingfeng Signed-off-by: Thomas Zimmermann Link: https://patchwork.freedesktop.org/patch/msgid/57e6b334dae8148b1b8ae6ef308ce9a83810a850.1684854344.git.geert+renesas@glider.be --- drivers/gpu/drm/drm_fb_helper.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'drivers/gpu/drm/drm_fb_helper.c') diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index 6bb1b8b27d7a..fd27f1978635 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -1545,17 +1545,19 @@ static void drm_fb_helper_fill_pixel_fmt(struct fb_var_screeninfo *var, } } -static void __fill_var(struct fb_var_screeninfo *var, +static void __fill_var(struct fb_var_screeninfo *var, struct fb_info *info, struct drm_framebuffer *fb) { int i; var->xres_virtual = fb->width; var->yres_virtual = fb->height; - var->accel_flags = FB_ACCELF_TEXT; + var->accel_flags = 0; var->bits_per_pixel = drm_format_info_bpp(fb->format, 0); - var->height = var->width = 0; + var->height = info->var.height; + var->width = info->var.width; + var->left_margin = var->right_margin = 0; var->upper_margin = var->lower_margin = 0; var->hsync_len = var->vsync_len = 0; @@ -1618,7 +1620,7 @@ int drm_fb_helper_check_var(struct fb_var_screeninfo *var, return -EINVAL; } - __fill_var(var, fb); + __fill_var(var, info, fb); /* * fb_pan_display() validates this, but fb_set_par() doesn't and just @@ -2074,7 +2076,7 @@ static void drm_fb_helper_fill_var(struct fb_info *info, info->pseudo_palette = fb_helper->pseudo_palette; info->var.xoffset = 0; info->var.yoffset = 0; - __fill_var(&info->var, fb); + __fill_var(&info->var, info, fb); info->var.activate = FB_ACTIVATE_NOW; drm_fb_helper_fill_pixel_fmt(&info->var, format); -- cgit v1.2.3