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 5B3561E3772; Tue, 3 Dec 2024 11:35:11 +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=1733225711; cv=none; b=B2S2yAL2s/h+aUZUKIOY7mDlL4ea0JKc5qtASePqELwrkNy8BzJzJZcreMNY9jg0pCwlccleAahvjUtmAZevfDkWkNE4UKoGd75H/OY+IAg1Ky2f/nqz5HTyqkYB4gQ+PTfxPgOxvJjj/xl6XKgn0VKfJUjSTpYBDbJWazVabwo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733225711; c=relaxed/simple; bh=3MWjk85NmWlbYMWabiD2fBNYO8K3kUK/Onp9ETA+5Y4=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=IcHBbB0rq4Q3MNAW869ly13Bap1GzXoQ69zBOrQdv5vqGLKGIfveqVqMVTW00us4u0thtyg6xyDgZBoDNFXHQ2wa4AOFruDbLOUe8nrS7cQfbN3dEsLXEEDMZxgH9+4vfbk3S7nqPS0cmfHiwQlcriNGMVLWs0NTEIhLIsHK3/o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hHI3kOxC; 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="hHI3kOxC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5EC7EC4CECF; Tue, 3 Dec 2024 11:35:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733225710; bh=3MWjk85NmWlbYMWabiD2fBNYO8K3kUK/Onp9ETA+5Y4=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=hHI3kOxCigtxutre/XbKF8THCbBA15kF2UzeEXnrSamiyaEFqVM4H3c+96TIZ2v3I HpVLl0bl7MdznOYha2Hc7OVvTbjLuiVZMzAqTxx+ERgiEdIkVs/pCTEQkvtMRCQyLe H0mf7yKzj8unWbqRt7i0h7nFlGz4JXTX754TN7l4wpS8dqXRMW9jffGxoM5SjQRdh6 Zv01tQD3eXXzbR8kSvH8wD+zrSXGo5LIQHFCi4NwGDjs8BFDAK66oRovKf3ry8z2bo zpV+LoHnrso1bIivSeWZJBBQIdTGVKZrArvCYv36KO5jZfoKUYZRjAIY42MCc40VXh wUqFRvWrHkh1w== From: =?utf-8?B?QmrDtnJuIFTDtnBlbA==?= To: Celeste Liu , Oleg Nesterov , Paul Walmsley , Palmer Dabbelt , Albert Ou , Eric Biederman , Kees Cook , Shuah Khan Cc: Alexandre Ghiti , "Dmitry V. Levin" , Andrea Bolognani , Thomas Gleixner , Ron Economos , Charlie Jenkins , Quan Zhou , Felix Yan , Ruizhe Pan , Shiqi Zhang , Guo Ren , Yao Zi , Han Gao , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, stable@vger.kernel.org, linux-kselftest@vger.kernel.org, Celeste Liu Subject: Re: [PATCH v2 1/2] riscv/ptrace: add new regset to access original a0 register In-Reply-To: <20241203-riscv-new-regset-v2-1-d37da8c0cba6@coelacanthus.name> References: <20241203-riscv-new-regset-v2-0-d37da8c0cba6@coelacanthus.name> <20241203-riscv-new-regset-v2-1-d37da8c0cba6@coelacanthus.name> Date: Tue, 03 Dec 2024 12:35:07 +0100 Message-ID: <87ed2pdmok.fsf@all.your.base.are.belong.to.us> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Celeste Liu writes: > The orig_a0 is missing in struct user_regs_struct of riscv, and there is > no way to add it without breaking UAPI. (See Link tag below) > > Like NT_ARM_SYSTEM_CALL do, we add a new regset name NT_RISCV_ORIG_A0 to > access original a0 register from userspace via ptrace API. > > Link: https://lore.kernel.org/all/59505464-c84a-403d-972f-d4b2055eeaac@gm= ail.com/ > Cc: stable@vger.kernel.org > Signed-off-by: Celeste Liu > --- > arch/riscv/kernel/ptrace.c | 32 ++++++++++++++++++++++++++++++++ > include/uapi/linux/elf.h | 1 + > 2 files changed, 33 insertions(+) > > diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c > index ea67e9fb7a583683b922fe2c017ea61f3bc848db..18ce07ffb27bb1180667769ee= d800f6fdf96c083 100644 > --- a/arch/riscv/kernel/ptrace.c > +++ b/arch/riscv/kernel/ptrace.c > @@ -31,6 +31,7 @@ enum riscv_regset { > #ifdef CONFIG_RISCV_ISA_SUPM > REGSET_TAGGED_ADDR_CTRL, > #endif > + REGSET_ORIG_A0, > }; >=20=20 > static int riscv_gpr_get(struct task_struct *target, > @@ -184,6 +185,29 @@ static int tagged_addr_ctrl_set(struct task_struct *= target, > } > #endif >=20=20 > +static int riscv_orig_a0_get(struct task_struct *target, > + const struct user_regset *regset, > + struct membuf to) > +{ > + return membuf_store(&to, task_pt_regs(target)->orig_a0); > +} > + > +static int riscv_orig_a0_set(struct task_struct *target, > + const struct user_regset *regset, > + unsigned int pos, unsigned int count, > + const void *kbuf, const void __user *ubuf) > +{ > + unsigned long orig_a0 =3D task_pt_regs(target)->orig_a0; > + int ret; > + > + ret =3D user_regset_copyin(&pos, &count, &kbuf, &ubuf, &orig_a0, 0, -1); > + if (ret) > + return ret; > + > + task_pt_regs(target)->orig_a0 =3D orig_a0; > + return ret; Nit: Could be return 0, for readability. Regardless, Reviewed-by: Bj=C3=B6rn T=C3=B6pel