From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793210589; b=iLDyqPKb0mSUfe6FS7jMsDoIn1qQAwJsLpOw+0F9j4iNuIEUXg5NNYcNdVPGSLk3aSbt aQJlXXFVYQ9UeNAH+/5Rl8y5fXcdbbH/V5AQMYB/4tVKG0C/fL0MdJXI/urYW6mIa45TA XYKjhVkOkjcI60tKCSHwBUA/UpyAYetVTQaVw8lobkzmxZ3eAMX0LVKDHc5WTbyo7/mtU 9R9CZ9V5VPhhyVPlI5SDqYav5qioDZQJN3pDuE/UB9dX63ajrbhOlm4WGjDe2IfiPqkiG 9b8BIfSuePXSf+YN0Le6W4V8M0XrekaZ43URHMSljqTYYCo+Kb+iM4QxMNCZGBvn0aw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793210589; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=e4GR0jUQg+uQThyoWS6+BKF5w6X09JKF2vyncmRAvd4=; b=YrW1P/ct38nIXX7u7+T0mjVJqXSDJg1Pbw7OMpYjtEVJh78YKuMuqo8XtDMdXWQnRJ3y t69YVzVTMFzu1z0b3OApSbYzCgHFFeDHrBCjQk0GXyGzhWGOTISDW6EbgOKw+DDTZUVFn D9SbDAoUMaHekJceRPqK0yan+YlfYNYBtNS151isgyeg62ywIqRuM+jB2ghyPiTsRZsvj qJ6771mj/zPiueykbnRyXPDMxbIUPPO49WLDsgiviUvnO0/zNSWuGJ1X+7YPskmtRW6Cm McqEkQVrkPz1IRndRrIlnIFoVu3/NDhqELXooSx7rGFMh4/SOaqrFYyQzYc558WZuGw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=1RgyMZzF; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 98D0D606A31A; Wed, 28 Oct 2026 18:03:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=1RgyMZzF Received: by smtp.kernel.org (Postfix) with ESMTPSA id E5C251F01825; Wed, 28 Oct 2026 18:03:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793210589; bh=e4GR0jUQg+uQThyoWS6+BKF5w6X09JKF2vyncmRAvd4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1RgyMZzFeeNAFFaAxBWkfNz6+GZaSjeiJeAljdRTtcaFuCe94zcMk3AJ/D53V/Eat JXNunF8xA+KH/vHU8MSU3FVhYTRjWVcxva0E0QXdGBsnMBM7LHCLJahz/dELWdfWYF yxeBGGXXAhckGwT+Q6231nlsG1RIeCqiTJM5CGaE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dan Carpenter , Muhammad Bilal , Sasha Levin Subject: [PATCH 5.15 077/571] staging: sm750fb: fix mono image source stride mismatch in lynxfb_ops_imageblit() Date: Wed, 28 Oct 2026 17:53:44 +0100 Message-ID: <20261028170009.853265997@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170008.009143722@linuxfoundation.org> References: <20261028170008.009143722@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Muhammad Bilal [ Upstream commit cc7cd2a9228175c975f62ad56ed7c767701cb4fa ] sm750_hw_imageblit() advances its monochrome source pointer by src_delta per scanline, and computes the correct rounded-up stride internally as: bytes_per_scan = (width + start_bit + 7) / 8; Its only caller, lynxfb_ops_imageblit(), instead passed src_delta as image->width >> 3. For widths not a multiple of 8 this under-counted the stride, so the source pointer fell further behind the real per-scanline layout on every line, corrupting the rendered image. Rather than just fixing the caller's calculation, remove src_delta as a parameter entirely and have sm750_hw_imageblit() advance by the bytes_per_scan it already computes for itself. There has only ever been one caller, and that caller was passing an out-of-sync derivative of the same width/start_bit values sm750_hw_imageblit() already has, so keeping stride as a separate parameter served no purpose beyond letting the two calculations drift apart, which is exactly what happened here. Rounding up, rather than down, is the direction consistent with the rest of the fbdev core: struct fb_image mono bitmap data (the same image->data this driver receives) is walked elsewhere with byte strides derived from a ceiling division of width by 8. The generic mono bit iterator in drivers/video/fbdev/core/fb_imageblit.h advances scanlines with "iter->data += BITS_TO_BYTES(iter->width)", and BITS_TO_BYTES() (include/linux/bitops.h) is a ceiling division. sm750_hw_imageblit()'s own "(width + start_bit + 7) / 8" is that same ceiling division with an added start_bit offset, so the caller's ">> 3" (floor) was the one calculation out of step with how this data layout is handled everywhere else. Found by code review of sm750_hw_imageblit()'s internal stride calculation against what its only caller was passing in, and confirmed with a clean -Werror build. I do not have this hardware, so this has not been exercised at runtime on real sm750 silicon. Fixes: 81dee67e215b2 ("staging: sm750fb: add sm750 to staging") Cc: stable@vger.kernel.org Reviewed-by: Dan Carpenter Signed-off-by: Muhammad Bilal Link: https://patch.msgid.link/20260901113031.161610-1-meatuni001@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/staging/sm750fb/sm750.c | 2 +- drivers/staging/sm750fb/sm750.h | 2 +- drivers/staging/sm750fb/sm750_accel.c | 6 ++---- drivers/staging/sm750fb/sm750_accel.h | 4 +--- 4 files changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/staging/sm750fb/sm750.c b/drivers/staging/sm750fb/sm750.c index 90f0983767f33..c92db34b2ad6d 100644 --- a/drivers/staging/sm750fb/sm750.c +++ b/drivers/staging/sm750fb/sm750.c @@ -275,7 +275,7 @@ static void lynxfb_ops_imageblit(struct fb_info *info, spin_lock(&sm750_dev->slock); sm750_dev->accel.de_imageblit(&sm750_dev->accel, - image->data, image->width >> 3, 0, + image->data, 0, base, pitch, Bpp, image->dx, image->dy, image->width, image->height, diff --git a/drivers/staging/sm750fb/sm750.h b/drivers/staging/sm750fb/sm750.h index aff69661c8e62..a693d9f1d0d5e 100644 --- a/drivers/staging/sm750fb/sm750.h +++ b/drivers/staging/sm750fb/sm750.h @@ -73,7 +73,7 @@ struct lynx_accel { u32 rop2); int (*de_imageblit)(struct lynx_accel *accel, const char *p_srcbuf, - u32 src_delta, u32 start_bit, u32 d_base, u32 d_pitch, + u32 start_bit, u32 d_base, u32 d_pitch, u32 byte_per_pixel, u32 dx, u32 dy, u32 width, u32 height, u32 f_color, u32 b_color, u32 rop2); diff --git a/drivers/staging/sm750fb/sm750_accel.c b/drivers/staging/sm750fb/sm750_accel.c index 24b9077a634a6..eb47c18a585d0 100644 --- a/drivers/staging/sm750fb/sm750_accel.c +++ b/drivers/staging/sm750fb/sm750_accel.c @@ -301,8 +301,6 @@ static unsigned int deGetTransparency(struct lynx_accel *accel) * sm750_hw_imageblit * @accel: Acceleration device data * @pSrcbuf: pointer to start of source buffer in system memory - * @srcDelta: Pitch value (in bytes) of the source buffer, +ive means top down - * and -ive mean button up * @startBit: Mono data can start at any bit in a byte, this value should be * 0 to 7 * @dBase: Address of destination: offset in frame buffer @@ -317,7 +315,7 @@ static unsigned int deGetTransparency(struct lynx_accel *accel) * @rop2: ROP value */ int sm750_hw_imageblit(struct lynx_accel *accel, const char *pSrcbuf, - u32 srcDelta, u32 startBit, u32 dBase, u32 dPitch, + u32 startBit, u32 dBase, u32 dPitch, u32 bytePerPixel, u32 dx, u32 dy, u32 width, u32 height, u32 fColor, u32 bColor, u32 rop2) { @@ -406,7 +404,7 @@ int sm750_hw_imageblit(struct lynx_accel *accel, const char *pSrcbuf, write_dpPort(accel, *(unsigned int *)ajRemain); } - pSrcbuf += srcDelta; + pSrcbuf += ulBytesPerScan; } return 0; diff --git a/drivers/staging/sm750fb/sm750_accel.h b/drivers/staging/sm750fb/sm750_accel.h index 2c79cb730a0a6..df48ed57a054e 100644 --- a/drivers/staging/sm750fb/sm750_accel.h +++ b/drivers/staging/sm750fb/sm750_accel.h @@ -220,8 +220,6 @@ int sm750_hw_copyarea(struct lynx_accel *accel, /** * sm750_hw_imageblit * @pSrcbuf: pointer to start of source buffer in system memory - * @srcDelta: Pitch value (in bytes) of the source buffer, +ive means top down - *>----- and -ive mean button up * @startBit: Mono data can start at any bit in a byte, this value should be *>----- 0 to 7 * @dBase: Address of destination: offset in frame buffer @@ -236,7 +234,7 @@ int sm750_hw_copyarea(struct lynx_accel *accel, * @rop2: ROP value */ int sm750_hw_imageblit(struct lynx_accel *accel, const char *pSrcbuf, - u32 srcDelta, u32 startBit, u32 dBase, u32 dPitch, + u32 startBit, u32 dBase, u32 dPitch, u32 bytePerPixel, u32 dx, u32 dy, u32 width, u32 height, u32 fColor, u32 bColor, u32 rop2); -- 2.53.0