[PATCH v3 02/16] drm/fb-helper: keep the .gamma_store updated in drm_fb_helper_setcmap

From: Peter Rosin
Date: Tue Jul 04 2017 - 06:36:36 EST


I think the gamma_store can end up invalid on error. But the way I read
it, that can happen in drm_mode_gamma_set_ioctl as well, so why should
this pesky legacy fbdev stuff be any better?

Signed-off-by: Peter Rosin <peda@xxxxxxxxxx>
---
drivers/gpu/drm/drm_fb_helper.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 9c76b8c..41fd9e0 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -1339,6 +1339,7 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
const struct drm_crtc_helper_funcs *crtc_funcs;
u16 *red, *green, *blue, *transp;
struct drm_crtc *crtc;
+ u16 *r, *g, *b;
int i, j, rc = 0;
int start;

@@ -1367,6 +1368,24 @@ int drm_fb_helper_setcmap(struct fb_cmap *cmap, struct fb_info *info)
transp = cmap->transp;
start = cmap->start;

+ if (!crtc->gamma_size) {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ if (cmap->start + cmap->len > crtc->gamma_size) {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ r = crtc->gamma_store;
+ g = r + crtc->gamma_size;
+ b = g + crtc->gamma_size;
+
+ memcpy(r + cmap->start, cmap->red, cmap->len * sizeof(*r));
+ memcpy(g + cmap->start, cmap->green, cmap->len * sizeof(*g));
+ memcpy(b + cmap->start, cmap->blue, cmap->len * sizeof(*b));
+
for (j = 0; j < cmap->len; j++) {
u16 hred, hgreen, hblue, htransp = 0xffff;

--
2.1.4