From nobody Thu Apr 9 07:16:34 2026 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 920001C8603 for ; Tue, 10 Mar 2026 10:01:37 +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=1773136897; cv=none; b=HIStW+jXcrQcZtJq7rfvD+OAr35cyZkcUiqBQ5x1RPyENPzky3QFSK53pkovdl1Os1qLCT1j3fOqG7BT/GsW9aGA1lC+FkAJjWJayvE/f3mDjvBzV289oIQvtGdoi52zbZk8QgggVl3Js4bXKnmoWndcBdyO/rYfud9I34bJcbI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773136897; c=relaxed/simple; bh=YV9k7v/oOmBH0LfirOp+fEdnB8gQFUnL7tP1uq5fYJA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=cd61B5YyozIJZgc3GzaBwn3MwC8zV+wAvI1wBiBFhXCqaBOQPTr5FmDQ5q6g/scshXn6MRn70gQd0EO+E612nsFW05yFszY/PA7lDN9Putw2AhmLCPw0JjCGIlE4AbQiZVvN+tQPzPve8qew5z/Z00sKZ1SGdsc5nN68+fUY/A4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=EzB3UDwy; 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="EzB3UDwy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 84DA0C19423; Tue, 10 Mar 2026 10:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773136897; bh=YV9k7v/oOmBH0LfirOp+fEdnB8gQFUnL7tP1uq5fYJA=; h=From:To:Cc:Subject:Date:From; b=EzB3UDwyT+fh+jNBwMSleFQSNLfZPccXs9QD/uFG7EuQ2n/d8gQgZwR6fIJKz98Gn Y6ZRHgFGcamYi+iqgsOwSWfnAg9iPt/+hFCnzYUijAsBjtF/UmizKjKzmrQjBTf3K8 uy78R0jGF61MtsAkjzLWDdy1blA2IniKrQm75B561CMxkdfOzNRgNlhPvxha37HVth yumg/fMcZtRHNsQaqdlzdZw6HAzNcvZOlwti3wnwQ6I6hWsKQl2tjjcjPK3KQPFFaY XkRVXsrRIePogSupdc/kqR0nGx4eP+7C1kzb7TeBp+J4Ls3STGqSTAU1sGLGPols8t dM+kCZ6nrknow== From: "Christophe Leroy (CS GROUP)" To: Michael Ellerman , Nicholas Piggin , Madhavan Srinivasan Cc: "Christophe Leroy (CS GROUP)" , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH] powerpc/align: Convert emulate_spe() to scoped user access Date: Tue, 10 Mar 2026 11:01:31 +0100 Message-ID: <4ff83cb240da4e2d0c34e2bce4b8b6ef19a33777.1773136880.git.chleroy@kernel.org> X-Mailer: git-send-email 2.49.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3573; i=chleroy@kernel.org; h=from:subject:message-id; bh=YV9k7v/oOmBH0LfirOp+fEdnB8gQFUnL7tP1uq5fYJA=; b=owGbwMvMwCV2d0KB2p7V54MZT6slMWSuf/07Myr3uEvVmW8N0yK/pq3wisr9xua6Q2iJ8PuUK 14SHofUOkpZGMS4GGTFFFmO/+feNaPrS2r+1F36MHNYmUCGMHBxCsBEIrwYGVbXP7Y66fxC6Ets WPeiTqtyh+NltTbVoV+Vax5wMd7bU8jwv0C0vuzL9J7+uuqJJ49d0rVMLZz6fOvE23bh39dfzNU 8yg4A X-Developer-Key: i=chleroy@kernel.org; a=openpgp; fpr=10FFE6F8B390DE17ACC2632368A92FEB01B8DD78 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Commit 861574d51bbd ("powerpc/uaccess: Implement masked user access") provides optimised user access by avoiding the cost of access_ok(). Convert emulate_spe() to scoped user access to benefit from masked user access. Scoped user access also make the code simpler. Signed-off-by: Christophe Leroy (CS GROUP) --- arch/powerpc/kernel/align.c | 75 ++++++++++++++++--------------------- 1 file changed, 33 insertions(+), 42 deletions(-) diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c index 3e37ece06739..61409431138f 100644 --- a/arch/powerpc/kernel/align.c +++ b/arch/powerpc/kernel/align.c @@ -165,25 +165,23 @@ static int emulate_spe(struct pt_regs *regs, unsigned= int reg, temp.ll =3D data.ll =3D 0; p =3D addr; =20 - if (!user_read_access_begin(addr, nb)) - return -EFAULT; - - switch (nb) { - case 8: - unsafe_get_user(temp.v[0], p++, Efault_read); - unsafe_get_user(temp.v[1], p++, Efault_read); - unsafe_get_user(temp.v[2], p++, Efault_read); - unsafe_get_user(temp.v[3], p++, Efault_read); - fallthrough; - case 4: - unsafe_get_user(temp.v[4], p++, Efault_read); - unsafe_get_user(temp.v[5], p++, Efault_read); - fallthrough; - case 2: - unsafe_get_user(temp.v[6], p++, Efault_read); - unsafe_get_user(temp.v[7], p++, Efault_read); + scoped_user_read_access_size(addr, nb, efault) { + switch (nb) { + case 8: + unsafe_get_user(temp.v[0], p++, efault); + unsafe_get_user(temp.v[1], p++, efault); + unsafe_get_user(temp.v[2], p++, efault); + unsafe_get_user(temp.v[3], p++, efault); + fallthrough; + case 4: + unsafe_get_user(temp.v[4], p++, efault); + unsafe_get_user(temp.v[5], p++, efault); + fallthrough; + case 2: + unsafe_get_user(temp.v[6], p++, efault); + unsafe_get_user(temp.v[7], p++, efault); + } } - user_read_access_end(); =20 switch (instr) { case EVLDD: @@ -252,25 +250,23 @@ static int emulate_spe(struct pt_regs *regs, unsigned= int reg, if (flags & ST) { p =3D addr; =20 - if (!user_write_access_begin(addr, nb)) - return -EFAULT; - - switch (nb) { - case 8: - unsafe_put_user(data.v[0], p++, Efault_write); - unsafe_put_user(data.v[1], p++, Efault_write); - unsafe_put_user(data.v[2], p++, Efault_write); - unsafe_put_user(data.v[3], p++, Efault_write); - fallthrough; - case 4: - unsafe_put_user(data.v[4], p++, Efault_write); - unsafe_put_user(data.v[5], p++, Efault_write); - fallthrough; - case 2: - unsafe_put_user(data.v[6], p++, Efault_write); - unsafe_put_user(data.v[7], p++, Efault_write); + scoped_user_write_access_size(addr, nb, efault) { + switch (nb) { + case 8: + unsafe_put_user(data.v[0], p++, efault); + unsafe_put_user(data.v[1], p++, efault); + unsafe_put_user(data.v[2], p++, efault); + unsafe_put_user(data.v[3], p++, efault); + fallthrough; + case 4: + unsafe_put_user(data.v[4], p++, efault); + unsafe_put_user(data.v[5], p++, efault); + fallthrough; + case 2: + unsafe_put_user(data.v[6], p++, efault); + unsafe_put_user(data.v[7], p++, efault); + } } - user_write_access_end(); } else { *evr =3D data.w[0]; regs->gpr[reg] =3D data.w[1]; @@ -278,12 +274,7 @@ static int emulate_spe(struct pt_regs *regs, unsigned = int reg, =20 return 1; =20 -Efault_read: - user_read_access_end(); - return -EFAULT; - -Efault_write: - user_write_access_end(); +efault: return -EFAULT; } #endif /* CONFIG_SPE */ --=20 2.49.0