From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f177.google.com (mail-pf1-f177.google.com [209.85.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 086343446CC for ; Mon, 9 Feb 2026 10:19:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770632353; cv=none; b=ZIscLoEBL/lyEMFXm1Kb4Ld4wmwk4XHuXL/3gr7WTpR2HrOka0KA5I1zph+u6DiIdhT0II4Si6I9Q++uGGPZEqUc+Xtq0X0TX7PtCPx+j65OHBTvfpqYxw3BvOOs8gGqpegLVyIzP3kGPzG5unAmNoO9j+02TmKEHYKUP+yMY5U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770632353; c=relaxed/simple; bh=0w0jXSbiYvV9PkfHd7Y/gTBwbMDBXcyLKCKvbcT9SVw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=t6/kkJOHrBMBuWnOdC7suG7Ds56deVJlTPP9QnJbVSI6ktIzaGjbzPNWD1o8/HaVHKCVpHoW3MH/tCRMx4CsW843ibmMS+p/P3meZLLsDEav7RBMIS3bYM0s09V8nk0OtjuYmFTrX5rhjkDtVnSS4mUi0uOP3dfxXJr1KW6XUFM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=hSpCOWGW; arc=none smtp.client-ip=209.85.210.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="hSpCOWGW" Received: by mail-pf1-f177.google.com with SMTP id d2e1a72fcca58-823c56765fdso2350346b3a.1 for ; Mon, 09 Feb 2026 02:19:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1770632352; x=1771237152; darn=lists.linux.dev; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=P0yJ30IO6L9zumScY2O/11JIUZV+AhdfVdk5gSKn/lk=; b=hSpCOWGWQdGIDa7290oqhckAWorI7wGqwkxFPjc3rRM1YInE0MNvDO8pyxYMDu70OY ydg44demuYmDwm7ruZNTYu8YnmELE31zkRTShxvzdaM4DEaIDsvHXsX1O6VtRKKPzQ9w nRArM01bn1hut1v2VYItKMMerjo7zfAycaDVP97+1p7aAz75cvIn9VbEaPjSXbncPC5m oNITAb+gB333amH5hjSxmPj/fJAa2SJBmvdKCAs+rIJ0taXDohpZV55IshaSyRNyB7W/ escRJZVD1Mwi3jMZWVxrgOxs739wzXYNa042aL2C0lm/Ehzu9+f/qy4DlNxqi3Vc/Q4C j22A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770632352; x=1771237152; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=P0yJ30IO6L9zumScY2O/11JIUZV+AhdfVdk5gSKn/lk=; b=gcslH93pwWjlzdF3qjNL9w0S1ZKBvS6QK7SghtO0v/l+8IW9JM1rDldqyjQ9bur/zb vKPPbCMSGkFwP9y9y4l+6h4GsmKHVfU5HNThcGIHPofdFB2fxqirpLfQAkYDmGOeXXqX 4Il5K0wK/z0QPBhPvo4S/lRLSv5fnUC44/X+8nQT2ulzLSg8SeorBbR6EIvP6gKalaNv eYnk36V3eIDKYSICEBKc7yghYGqODwEGbnScPuKWsn7Y3tB/U41p//2g1jCNShWax75e ZSwGvUvBGl1frtSwe6xUmebdbzrG/NqH6cIdA7iDzyEMIEz7mEuy49779m3z8fEYPwP0 eq3g== X-Gm-Message-State: AOJu0YyhwJHpZp0qzwXOXxAkTIS8UeDaL9cgm+pqfoQV0RHNTfIJk88r RACV2S49xyBbB3+11d3Gb1iiniWFEVsUOdGXFRGwHceA+qzwvimbr+qH X-Gm-Gg: AZuq6aJh2PDc4b4feLZz9IKfqO/4PWfD8w11RLfCXuO49AMLvdFUehGjAWS83DL7nEW ivB+aa0KajpZ5/tyro/6dgbgjZgn3PbX+f0UXPmCUUMSVa227rlYWKQb02WlGYbgC1jd1nxLAGu ZxLNU6Ukmc5/3v1NBTbnPk+BT2I6Tuj3ocMB2Xqi6JDTg4RVn9ArRC32g1flj1z29JIaYnCO/12 vXBSJgRn5jwMh50dciuMOZUpFXi4BNqZedBC7vj3vwtoC/FdJkWXNwOjmhlqwnE8EbBn8oAJHfB Bk4D9rhQRkclUUIrsLBJuzFYwHj8S41F03jVZxLVHyJ4tLtu3/TkXzyL70CJA7PqTUOMGBeZ+a7 pV6yxIHYY4+AVAwaV1L+s12by5Ty+68GdwCbWtGR/FgRVnJv9RonhIEpVahHGwHOcPsHixX17Uw s/bRLXDn3xLCZtUSFkvgHo1R+2TREZc9TKE2pjKn4YHmi+65KoDp5TA2BctS20vBgGeFq9ZtcqU cffkMp94GAiiD9w/2v0vHSc0LPf407RbEx4wMP1/5ohI0eD7aRzqUPTprU= X-Received: by 2002:a05:6a00:4507:b0:822:d43a:103f with SMTP id d2e1a72fcca58-824417a44f5mr9635358b3a.60.1770632352256; Mon, 09 Feb 2026 02:19:12 -0800 (PST) Received: from ThinkPad-E14-Gen-6.. ([2401:4900:b92b:c483:8daf:fce0:4f79:1dc6]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-824418856d5sm9159740b3a.38.2026.02.09.02.19.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Feb 2026 02:19:11 -0800 (PST) From: Yuvraj Singh Chauhan To: parthiban.veerasooran@microchip.com, christian.gromm@microchip.com, gregkh@linuxfoundation.org Cc: linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, Yuvraj Singh Chauhan Subject: [PATCH] staging: most: dim2: replace BUG_ON with WARN_ON_ONCE and error handling Date: Mon, 9 Feb 2026 15:48:29 +0530 Message-ID: <20260209101829.2121131-1-ysinghcin@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Replace BUG_ON() with WARN_ON_ONCE() and proper error handling in the DIM2 driver. BUG_ON() crashes the entire kernel, which is excessive for conditions that can be handled by returning error codes or exiting the function early. Changes made: - try_start_dim_transfer(): Check hdm_ch validity and initialization status, returning -EINVAL on failure. Check mbo->bus_address validity, releasing the spinlock and returning -EFAULT if zero. - service_done_flag(): Check hdm_ch validity and initialization status, returning early if checks fail. - configure_channel(), enqueue(), poison_channel(): Validate ch_idx bounds and return -EINVAL if out of range. WARN_ON_ONCE() is used instead of WARN_ON() to prevent log flooding if the condition triggers repeatedly. Signed-off-by: Yuvraj Singh Chauhan --- drivers/staging/most/dim2/dim2.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/drivers/staging/most/dim2/dim2.c b/drivers/staging/most/dim2/dim2.c index dad2abe6c0c9..58b09fa581e0 100644 --- a/drivers/staging/most/dim2/dim2.c +++ b/drivers/staging/most/dim2/dim2.c @@ -166,8 +166,10 @@ static int try_start_dim_transfer(struct hdm_channel *hdm_ch) unsigned long flags; struct dim_ch_state st; - BUG_ON(!hdm_ch); - BUG_ON(!hdm_ch->is_initialized); + if (WARN_ON_ONCE(!hdm_ch)) + return -EINVAL; + if (WARN_ON_ONCE(!hdm_ch->is_initialized)) + return -EINVAL; spin_lock_irqsave(&dim_lock, flags); if (list_empty(head)) { @@ -188,7 +190,10 @@ static int try_start_dim_transfer(struct hdm_channel *hdm_ch) return -EAGAIN; } - BUG_ON(mbo->bus_address == 0); + if (WARN_ON_ONCE(mbo->bus_address == 0)) { + spin_unlock_irqrestore(&dim_lock, flags); + return -EFAULT; + } if (!dim_enqueue_buffer(&hdm_ch->ch, mbo->bus_address, buf_size)) { list_del(head->next); spin_unlock_irqrestore(&dim_lock, flags); @@ -269,8 +274,10 @@ static void service_done_flag(struct dim2_hdm *dev, int ch_idx) unsigned long flags; u8 *data; - BUG_ON(!hdm_ch); - BUG_ON(!hdm_ch->is_initialized); + if (WARN_ON_ONCE(!hdm_ch)) + return; + if (WARN_ON_ONCE(!hdm_ch->is_initialized)) + return; spin_lock_irqsave(&dim_lock, flags); @@ -455,7 +462,8 @@ static int configure_channel(struct most_interface *most_iface, int ch_idx, int const ch_addr = ch_idx * 2 + 2; struct hdm_channel *const hdm_ch = dev->hch + ch_idx; - BUG_ON(ch_idx < 0 || ch_idx >= DMA_CHANNELS); + if (WARN_ON_ONCE(ch_idx < 0 || ch_idx >= DMA_CHANNELS)) + return -EINVAL; if (hdm_ch->is_initialized) return -EPERM; @@ -567,7 +575,8 @@ static int enqueue(struct most_interface *most_iface, int ch_idx, struct hdm_channel *hdm_ch = dev->hch + ch_idx; unsigned long flags; - BUG_ON(ch_idx < 0 || ch_idx >= DMA_CHANNELS); + if (WARN_ON_ONCE(ch_idx < 0 || ch_idx >= DMA_CHANNELS)) + return -EINVAL; if (!hdm_ch->is_initialized) return -EPERM; @@ -643,7 +652,8 @@ static int poison_channel(struct most_interface *most_iface, int ch_idx) u8 hal_ret; int ret = 0; - BUG_ON(ch_idx < 0 || ch_idx >= DMA_CHANNELS); + if (WARN_ON_ONCE(ch_idx < 0 || ch_idx >= DMA_CHANNELS)) + return -EINVAL; if (!hdm_ch->is_initialized) return -EPERM; base-commit: 05f7e89ab9731565d8a62e3b5d1ec206485eeb0b -- 2.43.0