From mboxrd@z Thu Jan 1 00:00:00 1970 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 45C41256C84; Wed, 25 Feb 2026 01:44:24 +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=1771983865; cv=none; b=g1RVPN4SQge8Yp2tp6/yGU7PJtCAp0ajCaOYdnZvSqpGr69tIMp7/BsI5KhR1E2HF2ET9MneFck7BHnwzeFMWnvosIBtYhG/uU+Fg+JOVs48uZTHoOZPPK9fak6rjU+YxHfcq5/S7k3HtZwqM7Uih83kFNzuILqws5Z+7RSp/Fs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771983865; c=relaxed/simple; bh=jl1grz7Xs4/GJ12i07Ou5YHOTsLL5VtKfM0T6Ut4drI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pdVQ39kzXXDTFtilZSJ2YCxENEs58JUORfWILVHOXSD76BDfiDymFB/IcYqHBbcG9yyqpJJeWLejRMPPHA/CePzrV/7zgGWDxWzYzlut0/sf8WWZbXSLRceyOA8ywjlkaH17z8kv2vhxirjfqrq2fcS7vtYAzy2mzoVuDKJnM1s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fRse0po3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="fRse0po3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AC18CC116D0; Wed, 25 Feb 2026 01:44:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771983864; bh=jl1grz7Xs4/GJ12i07Ou5YHOTsLL5VtKfM0T6Ut4drI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fRse0po3hJnokdN9Ykk/ibo6ihhSJh/LN5VkC7UvlzRVjetiKtRFFSV/P4jpoHaOJ aJZPGins8W0uQVdX9mo8yclnc2Jt0IWi9DyC5ThMo8dO0zJ0ReLW7uuDEyGT/ioqJ3 6uNh6BUWHwQ1YqKqOvZItYavyuXDjG2hVnFrzAEM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Christophe Leroy , Madhavan Srinivasan , Sasha Levin Subject: [PATCH 6.18 142/641] powerpc/uaccess: Move barrier_nospec() out of allow_read_{from/write}_user() Date: Tue, 24 Feb 2026 17:17:48 -0800 Message-ID: <20260225012352.560063812@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260225012348.915798704@linuxfoundation.org> References: <20260225012348.915798704@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christophe Leroy [ Upstream commit 5fbc09eb0b4f4b1a4b33abebacbeee0d29f195e9 ] Commit 74e19ef0ff80 ("uaccess: Add speculation barrier to copy_from_user()") added a redundant barrier_nospec() in copy_from_user(), because powerpc is already calling barrier_nospec() in allow_read_from_user() and allow_read_write_user(). But on other architectures that call to barrier_nospec() was missing. So change powerpc instead of reverting the above commit and having to fix other architectures one by one. This is now possible because barrier_nospec() has also been added in copy_from_user_iter(). Move barrier_nospec() out of allow_read_from_user() and allow_read_write_user(). This will also allow reuse of those functions when implementing masked user access which doesn't require barrier_nospec(). Don't add it back in raw_copy_from_user() as it is already called by copy_from_user() and copy_from_user_iter(). Fixes: 74e19ef0ff80 ("uaccess: Add speculation barrier to copy_from_user()") Signed-off-by: Christophe Leroy Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/f29612105c5fcbc8ceb7303808ddc1a781f0f6b5.1766574657.git.chleroy@kernel.org Signed-off-by: Sasha Levin --- arch/powerpc/include/asm/kup.h | 2 -- arch/powerpc/include/asm/uaccess.h | 4 ++++ 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h index dab63b82a8d4f..f2009d7c8cfa7 100644 --- a/arch/powerpc/include/asm/kup.h +++ b/arch/powerpc/include/asm/kup.h @@ -134,7 +134,6 @@ static __always_inline void kuap_assert_locked(void) static __always_inline void allow_read_from_user(const void __user *from, unsigned long size) { - barrier_nospec(); allow_user_access(NULL, from, size, KUAP_READ); } @@ -146,7 +145,6 @@ static __always_inline void allow_write_to_user(void __user *to, unsigned long s static __always_inline void allow_read_write_user(void __user *to, const void __user *from, unsigned long size) { - barrier_nospec(); allow_user_access(to, from, size, KUAP_READ_WRITE); } diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h index 4f5a46a77fa2b..3987a5c33558b 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -301,6 +301,7 @@ do { \ __typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr)); \ \ might_fault(); \ + barrier_nospec(); \ allow_read_from_user(__gu_addr, __gu_size); \ __get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err); \ prevent_read_from_user(__gu_addr, __gu_size); \ @@ -329,6 +330,7 @@ raw_copy_in_user(void __user *to, const void __user *from, unsigned long n) { unsigned long ret; + barrier_nospec(); allow_read_write_user(to, from, n); ret = __copy_tofrom_user(to, from, n); prevent_read_write_user(to, from, n); @@ -415,6 +417,7 @@ static __must_check __always_inline bool user_access_begin(const void __user *pt might_fault(); + barrier_nospec(); allow_read_write_user((void __user *)ptr, ptr, len); return true; } @@ -431,6 +434,7 @@ user_read_access_begin(const void __user *ptr, size_t len) might_fault(); + barrier_nospec(); allow_read_from_user(ptr, len); return true; } -- 2.51.0