From nobody Sat Oct 11 12:07:00 2025 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 08E5D27FD56; Tue, 10 Jun 2025 09:32:05 +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=1749547926; cv=none; b=e/UNGl0JbiKuizNPzeqtDvjpWLOm26lFnBZK8WgRLRSy6ALjXpr5Ptf6yg159CnRzZbgPMM5hcSQHcZTEYnbRlI9qlICKdcMsaAZIYVbEkB0b+fhyI349Hq/ay02IYahodN9wNyG8mfTF800KmiEHqyjWiW2cJFt6lsLsVAiu74= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749547926; c=relaxed/simple; bh=UIVDYVCfkXYdQKg+JzIWbx5aKZWOpeiPIbE1ZtnzTh0=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=haqe/7ANCY/4hH7y+O9+2SqL4VCMdnJDwwyPqqrvarCo/XlP2TeChfchoi+/ksUz3v6cavheO3Ze1IqWYbNlCC4xVMzKT1pwMOZn4t7H1uCIhNF0krR6k6b0/FyoavlIRCAtHOWMR4GDJM20dPsydF8fBX7Rmgtj2pQDdXl+rag= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ODPsLHWn; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ODPsLHWn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 36A2DC4CEEF; Tue, 10 Jun 2025 09:32:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749547925; bh=UIVDYVCfkXYdQKg+JzIWbx5aKZWOpeiPIbE1ZtnzTh0=; h=From:To:Cc:Subject:Date:From; b=ODPsLHWnEGPj51M8X+WShetoHBGztO9IuHayMjIiqnA2/05Y8GZJrHm0J5htsVVgC rZ6kBVNz7NqYeHiZog9F5RZ2G56mKvM1Ey49nDO8+/x1Zq1PjeiXR6MSL6YzoYCRRF gqTs6W14flVOWO2prg69erRMmNajgMvxAL4W1vmNk0fm+0uN+BsNS+RowBG+4KGA7P aVYIsgIIgkZUCJr5dvK+afWgAnO8cBsiZkSDKHEMksAYCKaxuRQRxoDkQ4okrqewnk yhBEqy8WTy7C4nhpUHGNunRYxaqITPhl6kwYFsOACInMuRGYGdK/gr+SAeTl7bOZcI 0PSrHLmoRTluw== From: Arnd Bergmann To: Hugues Fruchet , Mauro Carvalho Chehab , Peter Griffin Cc: Arnd Bergmann , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] st-delta: avoid excessive stack usage Date: Tue, 10 Jun 2025 11:31:56 +0200 Message-Id: <20250610093201.2645325-1-arnd@kernel.org> X-Mailer: git-send-email 2.39.5 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Arnd Bergmann Building with a reduced stack warning limit shows that delta_mjpeg_decode() copies a giant structure to the stack each time but only uses three of its members: drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c: In function 'delta_m= jpeg_decode': drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c:427:1: error: the fra= me size of 1296 bytes is larger than 1280 bytes [-Werror=3Dframe-larger-tha= n=3D] Open-code the passing of the structure members that are actually used here. Fixes: 433ff5b4a29b ("[media] st-delta: add mjpeg support") Signed-off-by: Arnd Bergmann --- .../platform/st/sti/delta/delta-mjpeg-dec.c | 20 ++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c b/driver= s/media/platform/st/sti/delta/delta-mjpeg-dec.c index 0533d4a083d2..a078f1107300 100644 --- a/drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c +++ b/drivers/media/platform/st/sti/delta/delta-mjpeg-dec.c @@ -239,7 +239,7 @@ static int delta_mjpeg_ipc_open(struct delta_ctx *pctx) return 0; } =20 -static int delta_mjpeg_ipc_decode(struct delta_ctx *pctx, struct delta_au = *au) +static int delta_mjpeg_ipc_decode(struct delta_ctx *pctx, dma_addr_t pstar= t, dma_addr_t pend) { struct delta_dev *delta =3D pctx->dev; struct delta_mjpeg_ctx *ctx =3D to_ctx(pctx); @@ -256,8 +256,8 @@ static int delta_mjpeg_ipc_decode(struct delta_ctx *pct= x, struct delta_au *au) =20 memset(params, 0, sizeof(*params)); =20 - params->picture_start_addr_p =3D (u32)(au->paddr); - params->picture_end_addr_p =3D (u32)(au->paddr + au->size - 1); + params->picture_start_addr_p =3D pstart; + params->picture_end_addr_p =3D pend; =20 /* * !WARNING! @@ -374,12 +374,14 @@ static int delta_mjpeg_decode(struct delta_ctx *pctx,= struct delta_au *pau) struct delta_dev *delta =3D pctx->dev; struct delta_mjpeg_ctx *ctx =3D to_ctx(pctx); int ret; - struct delta_au au =3D *pau; + void *au_vaddr =3D pau->vaddr; + dma_addr_t au_dma =3D pau->paddr; + size_t au_size =3D pau->size; unsigned int data_offset =3D 0; struct mjpeg_header *header =3D &ctx->header_struct; =20 if (!ctx->header) { - ret =3D delta_mjpeg_read_header(pctx, au.vaddr, au.size, + ret =3D delta_mjpeg_read_header(pctx, au_vaddr, au_size, header, &data_offset); if (ret) { pctx->stream_errors++; @@ -405,17 +407,17 @@ static int delta_mjpeg_decode(struct delta_ctx *pctx,= struct delta_au *pau) goto err; } =20 - ret =3D delta_mjpeg_read_header(pctx, au.vaddr, au.size, + ret =3D delta_mjpeg_read_header(pctx, au_vaddr, au_size, ctx->header, &data_offset); if (ret) { pctx->stream_errors++; goto err; } =20 - au.paddr +=3D data_offset; - au.vaddr +=3D data_offset; + au_dma +=3D data_offset; + au_vaddr +=3D data_offset; =20 - ret =3D delta_mjpeg_ipc_decode(pctx, &au); + ret =3D delta_mjpeg_ipc_decode(pctx, au_dma, au_dma + au_size - 1); if (ret) goto err; =20 --=20 2.39.5