From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C9F3811C83 for ; Mon, 28 Aug 2023 10:28:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49721C433C7; Mon, 28 Aug 2023 10:28:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1693218529; bh=FRfCfCc8urFFR44PVq4E3n3EdMbzR1W4uJKuwnZh0oE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YiQtyTiXcw1BokoEXCsNhHg40ug1wfhay68NUsACxlWUZnY4h0RjK3B3t0SAumibD HXRjT14bb1McASRVM8JqrjYiVEqyM+T/LQUGJ0Q9lB+8GWhRJNUVMZcrwavh/RO9j6 afO5jv4Ql+l+C18dATWy9iovhalvaz4If3ej3XUM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Thomas Zimmermann , Javier Martinez Canillas , Daniel Vetter , Geert Uytterhoeven , Sam Ravnborg , Sasha Levin Subject: [PATCH 4.19 091/129] fbdev: Fix sys_imageblit() for arbitrary image widths Date: Mon, 28 Aug 2023 12:13:05 +0200 Message-ID: <20230828101156.694037000@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230828101153.030066927@linuxfoundation.org> References: <20230828101153.030066927@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Zimmermann [ Upstream commit 61bfcb6a3b981e8f19e044ac8c3de6edbe6caf70 ] Commit 6f29e04938bf ("fbdev: Improve performance of sys_imageblit()") broke sys_imageblit() for image width that are not aligned to 8-bit boundaries. Fix this by handling the trailing pixels on each line separately. The performance improvements in the original commit do not regress by this change. Signed-off-by: Thomas Zimmermann Fixes: 6f29e04938bf ("fbdev: Improve performance of sys_imageblit()") Reviewed-by: Javier Martinez Canillas Acked-by: Daniel Vetter Tested-by: Geert Uytterhoeven Cc: Thomas Zimmermann Cc: Javier Martinez Canillas Cc: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20220313192952.12058-2-tzimmermann@suse.de Stable-dep-of: c2d22806aecb ("fbdev: fix potential OOB read in fast_imageblit()") Signed-off-by: Sasha Levin --- drivers/video/fbdev/core/sysimgblt.c | 29 ++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/drivers/video/fbdev/core/sysimgblt.c b/drivers/video/fbdev/core/sysimgblt.c index 722c327a381bd..335e92b813fc4 100644 --- a/drivers/video/fbdev/core/sysimgblt.c +++ b/drivers/video/fbdev/core/sysimgblt.c @@ -188,7 +188,7 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p, { u32 fgx = fgcolor, bgx = bgcolor, bpp = p->var.bits_per_pixel; u32 ppw = 32/bpp, spitch = (image->width + 7)/8; - u32 bit_mask, eorx; + u32 bit_mask, eorx, shift; const char *s = image->data, *src; u32 *dst; const u32 *tab; @@ -229,17 +229,23 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p, for (i = image->height; i--; ) { dst = dst1; + shift = 8; src = s; + /* + * Manually unroll the per-line copying loop for better + * performance. This works until we processed the last + * completely filled source byte (inclusive). + */ switch (ppw) { case 4: /* 8 bpp */ - for (j = k; j; j -= 2, ++src) { + for (j = k; j >= 2; j -= 2, ++src) { *dst++ = colortab[(*src >> 4) & bit_mask]; *dst++ = colortab[(*src >> 0) & bit_mask]; } break; case 2: /* 16 bpp */ - for (j = k; j; j -= 4, ++src) { + for (j = k; j >= 4; j -= 4, ++src) { *dst++ = colortab[(*src >> 6) & bit_mask]; *dst++ = colortab[(*src >> 4) & bit_mask]; *dst++ = colortab[(*src >> 2) & bit_mask]; @@ -247,7 +253,7 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p, } break; case 1: /* 32 bpp */ - for (j = k; j; j -= 8, ++src) { + for (j = k; j >= 8; j -= 8, ++src) { *dst++ = colortab[(*src >> 7) & bit_mask]; *dst++ = colortab[(*src >> 6) & bit_mask]; *dst++ = colortab[(*src >> 5) & bit_mask]; @@ -259,6 +265,21 @@ static void fast_imageblit(const struct fb_image *image, struct fb_info *p, } break; } + + /* + * For image widths that are not a multiple of 8, there + * are trailing pixels left on the current line. Print + * them as well. + */ + for (; j--; ) { + shift -= ppw; + *dst++ = colortab[(*src >> shift) & bit_mask]; + if (!shift) { + shift = 8; + ++src; + } + } + dst1 += p->fix.line_length; s += spitch; } -- 2.40.1