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 512BE321F48; Mon, 27 Oct 2025 19:31:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761593468; cv=none; b=nHA8g2OmG1noy1CcFzWgWFYNrKLHkpnMfux2Taa9vkd0Mv2EBgz8F4RQTKmaV0rLy4WOoLTrurhnn+wc3BwDNP2+csPyetcd2PTaFP/KC0rfvIN5/FcwP0KFdqBHqngSNzr1xO6b6vlenQZGNy/5Oc6Fyzh3+624dpgmjLVShjI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761593468; c=relaxed/simple; bh=WHZD+THu76bUh2NkrWDx2xcoWpWpsanBcB9FTbxUt3U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LJil/38+E1nyAg8UTIP3vbouOsafLpKNDfXsMB0KEzu48vAuehd4Ml5hga97T6/jd6u42AnJH03livLdwoXoht6d2NYUmsq3fzL34y21Maou3E7dZgbquZp2exkonAJULV4JEuX3WxcnjANHFloCXOjB12rOhlF5JltSC6n2tjo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qDgv/Vy9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="qDgv/Vy9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4E16CC4CEF1; Mon, 27 Oct 2025 19:31:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1761593467; bh=WHZD+THu76bUh2NkrWDx2xcoWpWpsanBcB9FTbxUt3U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qDgv/Vy9HR8m/y7UaAokn3FvKtWE9THzfZyh+PZDUEYLSFhEFVWaoRyOkM5jyLXFB vnJP1hBM1i843kSe6riWsJ1eQOQaGTvm8MTnlFk18SeomjrQoy8GwA42cmjhQVzCPb mpH9saTEGTL2t/JAsnBpNaNgrJQqeZk6gaKTU6i4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Javier Martinez Canillas , Jocelyn Falempe , Sasha Levin Subject: [PATCH 6.17 142/184] drm/panic: Fix 24bit pixel crossing page boundaries Date: Mon, 27 Oct 2025 19:37:04 +0100 Message-ID: <20251027183518.765987060@linuxfoundation.org> X-Mailer: git-send-email 2.51.1 In-Reply-To: <20251027183514.934710872@linuxfoundation.org> References: <20251027183514.934710872@linuxfoundation.org> User-Agent: quilt/0.69 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 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jocelyn Falempe [ Upstream commit 23437509a69476d4f896891032d62ac868731668 ] When using page list framebuffer, and using RGB888 format, some pixels can cross the page boundaries, and this case was not handled, leading to writing 1 or 2 bytes on the next virtual address. Add a check and a specific function to handle this case. Fixes: c9ff2808790f0 ("drm/panic: Add support to scanout buffer as array of pages") Reviewed-by: Javier Martinez Canillas Link: https://lore.kernel.org/r/20251009122955.562888-7-jfalempe@redhat.com Signed-off-by: Jocelyn Falempe Signed-off-by: Sasha Levin --- drivers/gpu/drm/drm_panic.c | 46 +++++++++++++++++++++++++++++++++++-- 1 file changed, 44 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c index 1bc15c44207b4..f52752880e1c9 100644 --- a/drivers/gpu/drm/drm_panic.c +++ b/drivers/gpu/drm/drm_panic.c @@ -174,6 +174,33 @@ static void drm_panic_write_pixel24(void *vaddr, unsigned int offset, u32 color) *p = color & 0xff; } +/* + * Special case if the pixel crosses page boundaries + */ +static void drm_panic_write_pixel24_xpage(void *vaddr, struct page *next_page, + unsigned int offset, u32 color) +{ + u8 *vaddr2; + u8 *p = vaddr + offset; + + vaddr2 = kmap_local_page_try_from_panic(next_page); + + *p++ = color & 0xff; + color >>= 8; + + if (offset == PAGE_SIZE - 1) + p = vaddr2; + + *p++ = color & 0xff; + color >>= 8; + + if (offset == PAGE_SIZE - 2) + p = vaddr2; + + *p = color & 0xff; + kunmap_local(vaddr2); +} + static void drm_panic_write_pixel32(void *vaddr, unsigned int offset, u32 color) { u32 *p = vaddr + offset; @@ -231,7 +258,14 @@ static void drm_panic_blit_page(struct page **pages, unsigned int dpitch, page = new_page; vaddr = kmap_local_page_try_from_panic(pages[page]); } - if (vaddr) + if (!vaddr) + continue; + + // Special case for 24bit, as a pixel might cross page boundaries + if (cpp == 3 && offset + 3 > PAGE_SIZE) + drm_panic_write_pixel24_xpage(vaddr, pages[page + 1], + offset, fg32); + else drm_panic_write_pixel(vaddr, offset, fg32, cpp); } } @@ -321,7 +355,15 @@ static void drm_panic_fill_page(struct page **pages, unsigned int dpitch, page = new_page; vaddr = kmap_local_page_try_from_panic(pages[page]); } - drm_panic_write_pixel(vaddr, offset, color, cpp); + if (!vaddr) + continue; + + // Special case for 24bit, as a pixel might cross page boundaries + if (cpp == 3 && offset + 3 > PAGE_SIZE) + drm_panic_write_pixel24_xpage(vaddr, pages[page + 1], + offset, color); + else + drm_panic_write_pixel(vaddr, offset, color, cpp); } } if (vaddr) -- 2.51.0