[PATCH 5.15 178/913] drm/fb-helper: Mark screen buffers in system memory with FBINFO_VIRTFB

[PATCH 5.15 178/913] drm/fb-helper: Mark screen buffers in system memory with FBINFO_VIRTFB

[Greg Kroah-Hartman]

From: Thomas Zimmermann <tzimmermann@suse.de>

commit cd9f7f7ac5932129fe81b4c7559cfcb226ec7c5c upstream.

Mark screen buffers in system memory with FBINFO_VIRTFB. Otherwise, fbdev
deferred I/O marks mmap'ed areas of system memory with VM_IO. (There's an
inverse relationship between the two flags.)

For shadow buffers, also set the FBINFO_READS_FAST hint.

v3:
	* change FB_ to FBINFO_ in commit description
v2:
	* updated commit description (Daniel)
	* added Fixes tag

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: d536540f304c ("drm/fb-helper: Add generic fbdev emulation .fb_probe function")
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v4.19+
Link: https://patchwork.freedesktop.org/patch/msgid/20220201115305.9333-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/drm_fb_helper.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2346,6 +2346,7 @@ static int drm_fb_helper_generic_probe(s
 	fbi->fbops = &drm_fbdev_fb_ops;
 	fbi->screen_size = fb->height * fb->pitches[0];
 	fbi->fix.smem_len = fbi->screen_size;
+	fbi->flags = FBINFO_DEFAULT;
 
 	drm_fb_helper_fill_info(fbi, fb_helper, sizes);
 
@@ -2353,19 +2354,21 @@ static int drm_fb_helper_generic_probe(s
 		fbi->screen_buffer = vzalloc(fbi->screen_size);
 		if (!fbi->screen_buffer)
 			return -ENOMEM;
+		fbi->flags |= FBINFO_VIRTFB | FBINFO_READS_FAST;
 
 		fbi->fbdefio = &drm_fbdev_defio;
-
 		fb_deferred_io_init(fbi);
 	} else {
 		/* buffer is mapped for HW framebuffer */
 		ret = drm_client_buffer_vmap(fb_helper->buffer, &map);
 		if (ret)
 			return ret;
-		if (map.is_iomem)
+		if (map.is_iomem) {
 			fbi->screen_base = map.vaddr_iomem;
-		else
+		} else {
 			fbi->screen_buffer = map.vaddr;
+			fbi->flags |= FBINFO_VIRTFB;
+		}
 
 		/*
 		 * Shamelessly leak the physical address to user-space. As

[PATCH 5.15 737/913] video: fbdev: nvidiafb: Use strscpy() to prevent buffer overflow

[Greg Kroah-Hartman]

From: Tim Gardner <tim.gardner@canonical.com>

[ Upstream commit 37a1a2e6eeeb101285cd34e12e48a881524701aa ]

Coverity complains of a possible buffer overflow. However,
given the 'static' scope of nvidia_setup_i2c_bus() it looks
like that can't happen after examiniing the call sites.

CID 19036 (#1 of 1): Copy into fixed size buffer (STRING_OVERFLOW)
1. fixed_size_dest: You might overrun the 48-character fixed-size string
  chan->adapter.name by copying name without checking the length.
2. parameter_as_source: Note: This defect has an elevated risk because the
  source argument is a parameter of the current function.
 89        strcpy(chan->adapter.name, name);

Fix this warning by using strscpy() which will silence the warning and
prevent any future buffer overflows should the names used to identify the
channel become much longer.

Cc: Antonino Daplas <adaplas@gmail.com>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/video/fbdev/nvidia/nv_i2c.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/nvidia/nv_i2c.c b/drivers/video/fbdev/nvidia/nv_i2c.c
index d7994a173245..0b48965a6420 100644
--- a/drivers/video/fbdev/nvidia/nv_i2c.c
+++ b/drivers/video/fbdev/nvidia/nv_i2c.c
@@ -86,7 +86,7 @@ static int nvidia_setup_i2c_bus(struct nvidia_i2c_chan *chan, const char *name,
 {
 	int rc;
 
-	strcpy(chan->adapter.name, name);
+	strscpy(chan->adapter.name, name, sizeof(chan->adapter.name));
 	chan->adapter.owner = THIS_MODULE;
 	chan->adapter.class = i2c_class;
 	chan->adapter.algo_data = &chan->algo;
-- 
2.34.1

[PATCH 5.15 783/913] drm/dp: Fix off-by-one in register cache size

[Greg Kroah-Hartman]

From: Kees Cook <keescook@chromium.org>

commit d4da1f27396fb1dde079447a3612f4f512caed07 upstream.

The pcon_dsc_dpcd array holds 13 registers (0x92 through 0x9E). Fix the
math to calculate the max size. Found from a -Warray-bounds build:

drivers/gpu/drm/drm_dp_helper.c: In function 'drm_dp_pcon_dsc_bpp_incr':
drivers/gpu/drm/drm_dp_helper.c:3130:28: error: array subscript 12 is outside array bounds of 'const u8[12]' {aka 'const unsigned char[12]'} [-Werror=array-bounds]
 3130 |         buf = pcon_dsc_dpcd[DP_PCON_DSC_BPP_INCR - DP_PCON_DSC_ENCODER];
      |               ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/drm_dp_helper.c:3126:39: note: while referencing 'pcon_dsc_dpcd'
 3126 | int drm_dp_pcon_dsc_bpp_incr(const u8 pcon_dsc_dpcd[DP_PCON_DSC_ENCODER_CAP_SIZE])
      |                              ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: dri-devel@lists.freedesktop.org
Fixes: e2e16da398d9 ("drm/dp_helper: Add support for Configuring DSC for HDMI2.1 Pcon")
Cc: stable@vger.kernel.org
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/lkml/20211214001849.GA62559@embeddedor/
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220105173310.2420598-1-keescook@chromium.org
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220225035610.2552144-2-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/drm/drm_dp_helper.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -455,7 +455,7 @@ struct drm_panel;
 # define DP_FEC_BIT_ERROR_COUNT_CAP	    (1 << 3)
 
 /* DP-HDMI2.1 PCON DSC ENCODER SUPPORT */
-#define DP_PCON_DSC_ENCODER_CAP_SIZE        0xC	/* 0x9E - 0x92 */
+#define DP_PCON_DSC_ENCODER_CAP_SIZE        0xD	/* 0x92 through 0x9E */
 #define DP_PCON_DSC_ENCODER                 0x092
 # define DP_PCON_DSC_ENCODER_SUPPORTED      (1 << 0)
 # define DP_PCON_DSC_PPS_ENC_OVERRIDE       (1 << 1)