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 37BF3D6AAEC for ; Thu, 2 Apr 2026 17:00:04 +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=hnQnlRNLWRBYJ2adhkVyrZB6k8P/ZToXFqlxV/C+eno=; b=pFNcKBztVozH9nqafxNC7uQfZr QOrWo8oU2iA6OJm+3TSVNmSd7sIvoguIgAlhdX0Tl+APtKGO6DMsWomH0PD/1l+L+Dto20GSDaCjZ 2hFTnKctwxCwzjjPMw8XFEP/meraUUtPizhUU0YNNMjBjXEAWDVzTMehWPJngN57HHT1Ol6stgNTP 6IqxFO6hboWXaUxKwjsZodQroTM2QEHCXVAqod1kra9spPj+futCvrnXHjcUyDQRjYZdxsbGn4J9l 1bywQzbufwPkSmxaF2N8dJP/QIPvGL1oQXxM+MBoTiPvVmRiIxHPssYwe77sWP+Z9yc3LqrsnB1+O O42Y+1aA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w8LOh-00000000Z3Y-0KoT; Thu, 02 Apr 2026 16:59:59 +0000 Received: from out-170.mta0.migadu.com ([2001:41d0:1004:224b::aa]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w8LOe-00000000Z2u-16s8 for linux-arm-kernel@lists.infradead.org; Thu, 02 Apr 2026 16:59:57 +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=1775149192; 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=hnQnlRNLWRBYJ2adhkVyrZB6k8P/ZToXFqlxV/C+eno=; b=jhPLdVJ3ZrNZYk3Pyt/IoBeHl4k5e3RUV8qzh5weS9XrgSLmTwfWasLfnWiTqts2mCqd6a Gxp9X/3iw9Eatu+/e6EIdNfcFtDnwmd+7A3qlK2BGUO+eNArIk+bTRPDZPHRWiyB/I0vh/ bjFbNLEEfTuwy6CIpbyTr+WZKFHR5hY= 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: Thu, 2 Apr 2026 18:59:35 +0200 Message-ID: <20260402165933.895706-4-thorsten.blum@linux.dev> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=978; i=thorsten.blum@linux.dev; h=from:subject; bh=KGm3LCDb6uenDpT0wQR4w1aCAHUzrT837r/6S14WP6A=; b=owGbwMvMwCUWt7pQ4caZUj3G02pJDJnnFpRe3nauPGqvvLiv1KTjYt2X3dqjf7suXOHAW3Ti9 F/ujTFKHaUsDGJcDLJiiiwPZv2Y4VtaU7nJJGInzBxWJpAhDFycAjCR+fMY/me4qykubbzvExdV dOPQ7Vn3tev2HFSUv/a5/ovLOcH+jJ2MDNtCHIKaYlc7NGzq8726P3t3f/Raw5WzV/dNnHyp5Lp MFxMA X-Developer-Key: i=thorsten.blum@linux.dev; a=openpgp; fpr=1D60735E8AEF3BE473B69D84733678FD8DFEEAD4 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-20260402_095956_446929_48D06905 X-CRM114-Status: UNSURE ( 7.68 ) 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 37584e786bb5..49791024bb86 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);