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 A36CB36C9EC for ; Sat, 28 Feb 2026 18:12:18 +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=1772302338; cv=none; b=qX+KxHKK9qo+kmAIoKith+bBlnGXHCmB2H5dp98NdikctK2LBoSnjWb7SrqlaiNZGD5Lh5e1+JH1WJZKH9Gc7lSxsdoZGUCfFllMkp3SSQBU/85iwiXjawkBC/0SAzVfZqy0+AaWUdEslGiYavRg424cW9izPOvRVeAcuxRRyxM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302338; c=relaxed/simple; bh=6ZxmtBtTxQjqQyCAXN+7opXGUs8LRTAUIr/hP8f0kL8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=slKmzRUpjODxDrUizHm1xk/yTKC/q68XY1o54BzFH84HusDsjRjQz3OPaNtyIZoTX42PoPQK6JQNQg5uI9d+f2gg5Dcybi9gEYreOavlHrFtZBM8mBQ8FNGkvQ2x2AZkRdxqNRUzfYplNuULJ4qilwBC+WcY+2OjaYk5qooM9sY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=h5yqR8Y+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="h5yqR8Y+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 122A3C19425; Sat, 28 Feb 2026 18:12:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772302338; bh=6ZxmtBtTxQjqQyCAXN+7opXGUs8LRTAUIr/hP8f0kL8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=h5yqR8Y+FAVvbnBaTwXTC277WGSGQ+RjLeIPQ8pPKVY1yS6PbGLSII0IEKWf/NigS liGt6bu3D2h3GhqvTe1+f4U+Nk/wdu/0DM9iWh6OYEDLf2eUGgS+GgpVx0/61GqyhC 92dcYxrlFpuHa3OB07DMCPs11JXym4xFqO36SkG6Jg4Fzju5XvWHxxaME7fEnBRJWj 2mcUs1asl6sqmQ3FtcxkMazeJYySx+HhiJMcasE1GeHgO3mbwXHRvnRhUdmTB4xAkO bADWrzaPkDCSGatjnALwfX8XqgwV+3ULmdKxxtWPnMc/FaHRGndHgtUZghxEhe5y8J qlbMSEpGGBxfw== From: Sasha Levin To: patches@lists.linux.dev Cc: Christophe Leroy , Madhavan Srinivasan , Sasha Levin Subject: [PATCH 6.1 060/232] powerpc/uaccess: Move barrier_nospec() out of allow_read_{from/write}_user() Date: Sat, 28 Feb 2026 13:08:33 -0500 Message-ID: <20260228181127.1592657-60-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228181127.1592657-1-sashal@kernel.org> References: <20260228181127.1592657-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit 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 d751ddd081108..6ee6601f5d4e9 100644 --- a/arch/powerpc/include/asm/kup.h +++ b/arch/powerpc/include/asm/kup.h @@ -163,7 +163,6 @@ static __always_inline void restore_user_access(unsigned long flags) 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); } @@ -175,7 +174,6 @@ 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 63e7c3107cc88..0d874e343b9f6 100644 --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -285,6 +285,7 @@ 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); \ @@ -313,6 +314,7 @@ 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); @@ -401,6 +403,7 @@ static __must_check inline bool user_access_begin(const void __user *ptr, size_t might_fault(); + barrier_nospec(); allow_read_write_user((void __user *)ptr, ptr, len); return true; } @@ -417,6 +420,7 @@ 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