From nobody Fri Dec 19 04:23:32 2025 Received: from mail-io1-f44.google.com (mail-io1-f44.google.com [209.85.166.44]) (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 B26A42556E for ; Thu, 11 Apr 2024 15:31:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.44 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712849504; cv=none; b=f1mMsiBTNPdcFUBor+uEY4ifQkD/mnep5GIME1ss08jClEexuPa/aX0frvsXN+tz+GB6sIktd0/Zq8f3qEm9/0OvGJOCG56Sjk/qeuItnQB1xB1xtzS1JMqKdVLDKuwwWnyxQv5vS6Mmkm+TajVC3yUqLYYdfln5YCP6AQPSY4Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712849504; c=relaxed/simple; bh=TZBv3QxQEHQifRazqOUvpuU1rG3ph2R3aVTk3X9Gap0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FC3ja+bOI/8MrL0JWdXuo7U104SDrTlJFt+M4sISxIvkz81Xss2Qs06js7k8BrFecdDBY3B8Rvwy2d7hqV1j3O1xXvOOZZT4ES9E7r4v86s2z0ZPvAVM0EU7MaXw1Q4/4g/uKjZ+CtLJj2B/95eiddZXwDk3AOMEHAbNUozGp+c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=g/tCYKRS; arc=none smtp.client-ip=209.85.166.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="g/tCYKRS" Received: by mail-io1-f44.google.com with SMTP id ca18e2360f4ac-7d0772bb5ffso180583239f.0 for ; Thu, 11 Apr 2024 08:31:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1712849500; x=1713454300; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=vnTaAM7cR5Yq5Ow6bam+JWxgxFhkDbGidFejqzVzbL8=; b=g/tCYKRS4Gmfowos5Xy4WF98hwrGj8aGi010fS5yC/rsdTDOylQ27kAm8iIJbLmSgT 97NFfrnsiLt8MEnEv06QwYmaYxMn63YmHeXmTcSOjyD1AOCxwaBgjwt/1bgCoGF2fkoB m8l+PC6DyjdMEYFtWiU7f/GqZpn7pE5hu3rdgpzV8hDbSDrKL+Yy/Q7L8tfskMKu1MK9 h7G8URRWolNkqw/UdZw+eV0Dbpb1BEDfrK98uHBpaem5fEEgMHrPNiyGUjlp53amjzE+ +5DeFIdg+2IKw0N/yH0EUoi1kXe8CNUAj5BE2W4tRKOChduX9+qfoaO5MHaOrA3+9AcD kFDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712849500; x=1713454300; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=vnTaAM7cR5Yq5Ow6bam+JWxgxFhkDbGidFejqzVzbL8=; b=drHNVq6J5byvSpiUdO6saZuZ/1VYRBY5RZl8dcZJfuFaAwtnjE8VkJnhDNnVj7pAs/ W64ECY3YGrvTojHFHaRRylX98fayzZCEu8MHItAUlgFzFwi9JvstUH+v5XvFJG8zOA3J I91ucJitz7J34z5mINo4K65cqbshfui/6uzasH3+fdMtwZFPaRPFAjaCyim4MYxfJaDw xQHrVhjjpVbi9YuUKoEcMbTJwATxRzyjht9SzV403T+8e7wTpZhetLiVusSqtYRpkyHM s/VI3CNoRyeGdHzc7/51uDxCs4tkU6fCNAs7f5yA/VDDxouoKK8o3vHMoeZSIpPeB4NG 7hlg== X-Gm-Message-State: AOJu0YwaGN9GiE08NM20IX6bhNVXfAsXSWwT//SoXsDs4huco//EcdBr OGJyn8zUlj3nuz4Lr/xEioNOy9q4tZHheLfV32cR3sWvWQtPy5Uzz8YVNA4ktrh41eDpJe/+ayI G X-Google-Smtp-Source: AGHT+IHCYhbVjeiN6ZbVGZ5FXT6s+PbBwUNcZSjkCcgCxerd5TEJ92G6njbB511lBWV6yPsPhU9+ZQ== X-Received: by 2002:a92:c56f:0:b0:369:e37d:541f with SMTP id b15-20020a92c56f000000b00369e37d541fmr6975632ilj.1.1712849500395; Thu, 11 Apr 2024 08:31:40 -0700 (PDT) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id jc25-20020a056638891900b0047f14b7f6c0sm457056jab.5.2024.04.11.08.31.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Apr 2024 08:31:38 -0700 (PDT) From: Jens Axboe To: linux-kernel@vger.kernel.org Cc: Jens Axboe Subject: [PATCH 007/437] mm/util: add iterdup_nul() and iterdup() helpers Date: Thu, 11 Apr 2024 09:12:27 -0600 Message-ID: <20240411153126.16201-8-axboe@kernel.dk> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240411153126.16201-1-axboe@kernel.dk> References: <20240411153126.16201-1-axboe@kernel.dk> 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" This is identical to the memdup variants, except it operates on a struct iov_iter rather than a direct user pointer. Signed-off-by: Jens Axboe --- include/linux/string.h | 4 +++ mm/util.c | 57 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 61 insertions(+) diff --git a/include/linux/string.h b/include/linux/string.h index 9ba8b4597009..1983d2bf8840 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -18,6 +18,10 @@ extern void *memdup_user(const void __user *, size_t); extern void *vmemdup_user(const void __user *, size_t); extern void *memdup_user_nul(const void __user *, size_t); =20 +struct iov_iter; +void *iterdup_nul(struct iov_iter *, size_t); +void *iterdup(struct iov_iter *, size_t); + /** * memdup_array_user - duplicate array from user space * @src: source address in user space diff --git a/mm/util.c b/mm/util.c index 669397235787..5d701cf693b0 100644 --- a/mm/util.c +++ b/mm/util.c @@ -224,6 +224,32 @@ void *memdup_user(const void __user *src, size_t len) } EXPORT_SYMBOL(memdup_user); =20 +/** + * iterdup - duplicate memory region + * + * @src: source iov_iter + * @len: number of bytes to copy + * + * Return: an ERR_PTR() on failure. Result is physically + * contiguous, to be freed by kfree(). + */ +void *iterdup(struct iov_iter *src, size_t len) +{ + void *p; + + p =3D kmalloc_track_caller(len, GFP_USER | __GFP_NOWARN); + if (!p) + return ERR_PTR(-ENOMEM); + + if (!copy_from_iter_full(p, len, src)) { + kfree(p); + return ERR_PTR(-EFAULT); + } + + return p; +} +EXPORT_SYMBOL(iterdup); + /** * vmemdup_user - duplicate memory region from user space * @@ -312,6 +338,37 @@ void *memdup_user_nul(const void __user *src, size_t l= en) } EXPORT_SYMBOL(memdup_user_nul); =20 +/** + * iterdup_nul - duplicate memory region from iov_iter and NUL-terminate + * + * @src: source address to copy from + * @len: number of bytes to copy + * + * Return: an ERR_PTR() on failure. + */ +void *iterdup_nul(struct iov_iter *src, size_t len) +{ + char *p; + + /* + * Always use GFP_KERNEL, since copy_from_iter_full() can sleep and + * cause pagefault, which makes it pointless to use GFP_NOFS + * or GFP_ATOMIC. + */ + p =3D kmalloc_track_caller(len + 1, GFP_KERNEL); + if (!p) + return ERR_PTR(-ENOMEM); + + if (!copy_from_iter_full(p, len, src)) { + kfree(p); + return ERR_PTR(-EFAULT); + } + p[len] =3D '\0'; + + return p; +} +EXPORT_SYMBOL(iterdup_nul); + /* Check if the vma is being used as a stack by this task */ int vma_is_stack_for_current(struct vm_area_struct *vma) { --=20 2.43.0