From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7CEF2CCD19A for ; Fri, 17 Oct 2025 10:28:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=W1IDrz3RmQ+DjnJHgkvZJfeGuFV4FYY3VXTJn4UzdsY=; b=2vy/dWr6uG+m06I9iN3KpIfLlU 5KHf7lTDycqEqkrX/EmHjD1TUiQ2r2n1XwBqmhQGmiDDpKWaej9/agRHgnZHQADaEtCmfPZ4UiM36 hR4bauqFVVIknB3R2fLG7+Py1xv524EyXoJTSeEChrMgz+2uYJKaNu5i27V2A70nvxli8x9iz9JXv Hm+7Zpz3mJS2LXmEId2171la2W0/i5pg95YYjWmmisWeCIbyua7MMDPtpeUrktbt/n/pSyu8NKYz0 Vyl2dojgF7sXOpJwuMFTTLDAl+yuE0avz9wTh0DzAehcMXAdphmIp6I+yoPDHVDE4c5g8B3kb+04A DqTQ4LCg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v9hhK-00000007XF9-1kef; Fri, 17 Oct 2025 10:28:34 +0000 Received: from out-187.mta1.migadu.com ([2001:41d0:203:375::bb]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v9hhI-00000007XE0-0S44 for linux-arm-kernel@lists.infradead.org; Fri, 17 Oct 2025 10:28:33 +0000 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1760696907; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=W1IDrz3RmQ+DjnJHgkvZJfeGuFV4FYY3VXTJn4UzdsY=; b=LQG4n4Vai/wW3aF62q1eiUNmJjL5j3yRF7CeP3SbZ8TiUo9B8fklD1tcXvOIKbIQDhkTN+ BuQVstW4GNimda8ZTHaPXOaCfuAXBZ1TGQCSEYCQRj/yTtLznR5VJlXq8+B2m/kuwNgGWI TN1vWPrCLBg0AHc+mvYBIoymOLwKMik= From: Thorsten Blum To: Alexander Shishkin , Maxime Coquelin , Alexandre Torgue Cc: Thorsten Blum , linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH RESEND 1/2] stm class: Replace kmalloc + copy_from_user with memdup_user Date: Fri, 17 Oct 2025 12:27:42 +0200 Message-ID: <20251017102743.75394-2-thorsten.blum@linux.dev> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251017_032832_285370_76B55A1A X-CRM114-Status: UNSURE ( 7.49 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Replace kmalloc() followed by copy_from_user() with memdup_user() to simplify and improve stm_char_write(). Allocate and copy only 'count' bytes instead of 'count + 1' since the extra byte is unused. Signed-off-by: Thorsten Blum --- drivers/hwtracing/stm/core.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-) diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index cdba4e875b28..5834f796e86b 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -645,15 +645,9 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf, return err; } - kbuf = kmalloc(count + 1, GFP_KERNEL); - if (!kbuf) - return -ENOMEM; - - err = copy_from_user(kbuf, buf, count); - if (err) { - kfree(kbuf); - return -EFAULT; - } + kbuf = memdup_user(buf, count); + if (IS_ERR(kbuf)) + return PTR_ERR(kbuf); pm_runtime_get_sync(&stm->dev); -- 2.51.0