From nobody Thu Oct 9 02:57:41 2025 Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 020481C84D0; Sun, 22 Jun 2025 10:20:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=93.17.236.30 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750587646; cv=none; b=FTv2ZquAL6sqkfMdJCltG/fePTEW2bUY6kG2E8SS4jUWaNYJOFOcEkRYdkoRndW8pxhCrTkbtN344S8jIJcSZP0W3oMB4YJiMnj2mzQ/WpzRFFeEiVvT59N+zKOylwNZBXmPcWzERLNlNyxMSS8sv7IJeOvCKjFNZPpd91+dJ0k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750587646; c=relaxed/simple; bh=aBr5ug3pbfIIRk62LUQKZ+EqAMQWAhKPmPnsru18T2w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BMfN6ilOLAz9gJQyv9+Xe2UNbQ2X6HGLjALl/iIDc6uSCAoXyqwjHXP2QSTx5vw9UJJSMKK00VGS1tUjYOFy44c+J4qdUZXjp9LTOa9jaUPMzPzxr9Y7AGKhe+IclRo98eBLORK0x7d0VOEL6lhe0kXhhsOz7ud8E1JLssFqOHU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=csgroup.eu; spf=pass smtp.mailfrom=csgroup.eu; arc=none smtp.client-ip=93.17.236.30 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=csgroup.eu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=csgroup.eu Received: from localhost (mailhub3.si.c-s.fr [192.168.12.233]) by localhost (Postfix) with ESMTP id 4bQ62p3Ttmz9sZD; Sun, 22 Jun 2025 11:52:50 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6FkHDcQTmUzv; Sun, 22 Jun 2025 11:52:50 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4bQ62p2bPnz9sXD; Sun, 22 Jun 2025 11:52:50 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 50BE08B765; Sun, 22 Jun 2025 11:52:50 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id B7f7mpVTx9fe; Sun, 22 Jun 2025 11:52:50 +0200 (CEST) Received: from PO20335.idsi0.si.c-s.fr (unknown [192.168.235.99]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 598B58B764; Sun, 22 Jun 2025 11:52:49 +0200 (CEST) From: Christophe Leroy To: Michael Ellerman , Nicholas Piggin , Naveen N Rao , Madhavan Srinivasan , Alexander Viro , Christian Brauner , Jan Kara , Thomas Gleixner , Ingo Molnar , Peter Zijlstra , Darren Hart , Davidlohr Bueso , "Andre Almeida" , Andrew Morton , David Laight , Dave Hansen , Linus Torvalds Cc: Christophe Leroy , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 1/5] uaccess: Add masked_user_{read/write}_access_begin Date: Sun, 22 Jun 2025 11:52:39 +0200 Message-ID: <6fddae0cf0da15a6521bb847b63324b7a2a067b1.1750585239.git.christophe.leroy@csgroup.eu> X-Mailer: git-send-email 2.49.0 In-Reply-To: References: 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=ed25519-sha256; t=1750585958; l=3699; i=christophe.leroy@csgroup.eu; s=20211009; h=from:subject:message-id; bh=aBr5ug3pbfIIRk62LUQKZ+EqAMQWAhKPmPnsru18T2w=; b=aJLPxkFnAJjAAnY0M+etgKWknkSFXagT8tFBPQmYzWl+GOTm3envK6GdDSt+ZAJhzvqm23pRc 8C2dbv0jA/oBse2u5aACyUyBHpCpJRg5EdA/oAqEDbh/PIRmkp3wF2J X-Developer-Key: i=christophe.leroy@csgroup.eu; a=ed25519; pk=HIzTzUj91asvincQGOFx6+ZF5AoUuP9GdOtQChs7Mm0= Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Allthough masked_user_access_begin() seems to only be used when reading data from user at the moment, introduce masked_user_read_access_begin() and masked_user_write_access_begin() in order to match user_read_access_begin() and user_write_access_begin(). Have them default to masked_user_access_begin() when they are not defined. Signed-off-by: Christophe Leroy --- fs/select.c | 2 +- include/linux/uaccess.h | 8 ++++++++ kernel/futex/futex.h | 4 ++-- lib/strncpy_from_user.c | 2 +- lib/strnlen_user.c | 2 +- 5 files changed, 13 insertions(+), 5 deletions(-) diff --git a/fs/select.c b/fs/select.c index 9fb650d03d52..d8547bedf5eb 100644 --- a/fs/select.c +++ b/fs/select.c @@ -777,7 +777,7 @@ static inline int get_sigset_argpack(struct sigset_argp= ack *to, // the path is hot enough for overhead of copy_from_user() to matter if (from) { if (can_do_masked_user_access()) - from =3D masked_user_access_begin(from); + from =3D masked_user_read_access_begin(from); else if (!user_read_access_begin(from, sizeof(*from))) return -EFAULT; unsafe_get_user(to->p, &from->p, Efault); diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 7c06f4795670..682a0cd2fe51 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -41,6 +41,14 @@ #define mask_user_address(src) (src) #endif =20 +#ifndef masked_user_write_access_begin +#define masked_user_write_access_begin masked_user_access_begin +#endif +#ifndef masked_user_read_access_begin +#define masked_user_read_access_begin masked_user_access_begin +#endif + + /* * Architectures should provide two primitives (raw_copy_{to,from}_user()) * and get rid of their private instances of copy_{to,from}_user() and diff --git a/kernel/futex/futex.h b/kernel/futex/futex.h index fcd1617212ee..6cfcafa00736 100644 --- a/kernel/futex/futex.h +++ b/kernel/futex/futex.h @@ -305,7 +305,7 @@ static __always_inline int futex_get_value(u32 *dest, u= 32 __user *from) u32 val; =20 if (can_do_masked_user_access()) - from =3D masked_user_access_begin(from); + from =3D masked_user_read_access_begin(from); else if (!user_read_access_begin(from, sizeof(*from))) return -EFAULT; unsafe_get_user(val, from, Efault); @@ -320,7 +320,7 @@ static __always_inline int futex_get_value(u32 *dest, u= 32 __user *from) static __always_inline int futex_put_value(u32 val, u32 __user *to) { if (can_do_masked_user_access()) - to =3D masked_user_access_begin(to); + to =3D masked_user_read_access_begin(to); else if (!user_read_access_begin(to, sizeof(*to))) return -EFAULT; unsafe_put_user(val, to, Efault); diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c index 6dc234913dd5..5bb752ff7c61 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -126,7 +126,7 @@ long strncpy_from_user(char *dst, const char __user *sr= c, long count) if (can_do_masked_user_access()) { long retval; =20 - src =3D masked_user_access_begin(src); + src =3D masked_user_read_access_begin(src); retval =3D do_strncpy_from_user(dst, src, count, count); user_read_access_end(); return retval; diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c index 6e489f9e90f1..4a6574b67f82 100644 --- a/lib/strnlen_user.c +++ b/lib/strnlen_user.c @@ -99,7 +99,7 @@ long strnlen_user(const char __user *str, long count) if (can_do_masked_user_access()) { long retval; =20 - str =3D masked_user_access_begin(str); + str =3D masked_user_read_access_begin(str); retval =3D do_strnlen_user(str, count, count); user_read_access_end(); return retval; --=20 2.49.0