From patchwork Tue Apr 15 23:31:08 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 14052933 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 167E11DED7B; Tue, 15 Apr 2025 23:31:50 +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=1744759911; cv=none; b=UUtaS3ZFEbKcZSU14hU1Qrh7DP49pbKbxLs1vIRTCCwkhCmXBIc+N0Dzze1431Io2RtfX5GkmRoaFqVOiXX/gcs2P0eRn3Tvxe5BYKtyKhTDFKI4hR+HzVxlSd0Vv17qkAMQQ6LSexf3t63cyrC6PZzxszOSK6m1STb54sxjOGk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744759911; c=relaxed/simple; bh=WNu0OLOihMi+UEPYq0gT9FeK408SxvwJ3tMV5PWv/8o=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=bbf4VH6qXZg9MGmXa0v3a6q8GYXnFzWthJVQNxHxmx9fHUFCosdcwuvo7IJhX6A4UlrZZEiP4wdrwH+was3vq4IgpOjpJ+fq/cRpUoWyoJKWma449v93XUBAJeNDbqV/Pq/F9y3BgElokY0G+sc7bvGUpiIV72OM73In3K1rB2A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KVPpAf8N; 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="KVPpAf8N" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FC2EC4CEEB; Tue, 15 Apr 2025 23:31:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744759910; bh=WNu0OLOihMi+UEPYq0gT9FeK408SxvwJ3tMV5PWv/8o=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=KVPpAf8NUGyoRLsSRbxV9EMJp4JMpkc+ZFosXiKNYwSAEGH4Wkm5HVzCEHntNz7BO ZoVERVa36tpTWUPG2W/2Bmc++xqJU2RCb3pD5jIC283jU4onmSorZXv11piXl1xP5V BbYkvbtKx9sa5ShrD1d6TZH1LeFK1vDp8BfCv5gamRA3W+cJofW8H0Ed5hJnjpXRUg fwkBZ212Ct+VfyNEZfVNqnf1Z0LyxyFaX6eGEINPbsSWKviHOx15E1McCoCYEx4Eit Qyub9Dwe6l7msM274BlHN/j6IgkyZ9by07e0ERJupNo21ikHINO9hajFp2nJshexFH Gsds0p/vlyxww== From: Mark Brown Date: Wed, 16 Apr 2025 00:31:08 +0100 Subject: [PATCH RFT v16 1/8] arm64/gcs: Return a success value from gcs_alloc_thread_stack() Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20250416-clone3-shadow-stack-v16-1-2ffc9ca3917b@kernel.org> References: <20250416-clone3-shadow-stack-v16-0-2ffc9ca3917b@kernel.org> In-Reply-To: <20250416-clone3-shadow-stack-v16-0-2ffc9ca3917b@kernel.org> To: "Rick P. Edgecombe" , Deepak Gupta , Szabolcs Nagy , "H.J. Lu" , Florian Weimer , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Christian Brauner , Shuah Khan Cc: linux-kernel@vger.kernel.org, Catalin Marinas , Will Deacon , jannh@google.com, bsegall@google.com, Yury Khrustalev , Wilco Dijkstra , linux-kselftest@vger.kernel.org, linux-api@vger.kernel.org, Mark Brown , Kees Cook X-Mailer: b4 0.15-dev-c25d1 X-Developer-Signature: v=1; a=openpgp-sha256; l=3763; i=broonie@kernel.org; h=from:subject:message-id; bh=WNu0OLOihMi+UEPYq0gT9FeK408SxvwJ3tMV5PWv/8o=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBn/uxUE3jX6+kLmTuZsV7yKktQtATaFXtl5TriIZQR HmtaqLmJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZ/7sVAAKCRAk1otyXVSH0I0XB/ 9/pj7fJ1pcGm3v+StTkLm7y4AAd/vyYRzrFOQz6Aoch+Kg9prvit4X5ZE94YDQ1+ZEDvrUCQJtaiYj gH7/0r1iK8OWOBipE0uLsDU4hkFWIRCZ+q6KcNVdn58DUdZrI24RiIJqHDDzBtixnCssQ5Mf/vxLK7 9O4MzZ2ivTP1QifWSWqiU5XZqo1Rz8Hhp8e8fK3MCPqw6CwSsd+8KzA1SWSQ3EBiUhdDe4Pcv5TUuj BYJYku775adX+oCeBo6sbiIsDKVQntfc/lhpa52BV3KMMvVUIp2A4O4evRurVZDupzLWtYFoy2IAgI qK/OEd2lnhscEZrGlCkHx+ti8Bv12S X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB Currently as a result of templating from x86 code gcs_alloc_thread_stack() returns a pointer as an unsigned int however on arm64 we don't actually use this pointer value as anything other than a pass/fail flag. Simplify the interface to just return an int with 0 on success and a negative error code on failure. Acked-by: Deepak Gupta Reviewed-by: Catalin Marinas Signed-off-by: Mark Brown --- arch/arm64/include/asm/gcs.h | 8 ++++---- arch/arm64/kernel/process.c | 8 ++++---- arch/arm64/mm/gcs.c | 8 ++++---- 3 files changed, 12 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/gcs.h b/arch/arm64/include/asm/gcs.h index f50660603ecf..d8923b5f03b7 100644 --- a/arch/arm64/include/asm/gcs.h +++ b/arch/arm64/include/asm/gcs.h @@ -64,8 +64,8 @@ static inline bool task_gcs_el0_enabled(struct task_struct *task) void gcs_set_el0_mode(struct task_struct *task); void gcs_free(struct task_struct *task); void gcs_preserve_current_state(void); -unsigned long gcs_alloc_thread_stack(struct task_struct *tsk, - const struct kernel_clone_args *args); +int gcs_alloc_thread_stack(struct task_struct *tsk, + const struct kernel_clone_args *args); static inline int gcs_check_locked(struct task_struct *task, unsigned long new_val) @@ -91,8 +91,8 @@ static inline bool task_gcs_el0_enabled(struct task_struct *task) static inline void gcs_set_el0_mode(struct task_struct *task) { } static inline void gcs_free(struct task_struct *task) { } static inline void gcs_preserve_current_state(void) { } -static inline unsigned long gcs_alloc_thread_stack(struct task_struct *tsk, - const struct kernel_clone_args *args) +static inline int gcs_alloc_thread_stack(struct task_struct *tsk, + const struct kernel_clone_args *args) { return -ENOTSUPP; } diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 42faebb7b712..45130ea7ea6e 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -297,7 +297,7 @@ static void flush_gcs(void) static int copy_thread_gcs(struct task_struct *p, const struct kernel_clone_args *args) { - unsigned long gcs; + int ret; if (!system_supports_gcs()) return 0; @@ -305,9 +305,9 @@ static int copy_thread_gcs(struct task_struct *p, p->thread.gcs_base = 0; p->thread.gcs_size = 0; - gcs = gcs_alloc_thread_stack(p, args); - if (IS_ERR_VALUE(gcs)) - return PTR_ERR((void *)gcs); + ret = gcs_alloc_thread_stack(p, args); + if (ret != 0) + return ret; p->thread.gcs_el0_mode = current->thread.gcs_el0_mode; p->thread.gcs_el0_locked = current->thread.gcs_el0_locked; diff --git a/arch/arm64/mm/gcs.c b/arch/arm64/mm/gcs.c index 5c46ec527b1c..1f633a482558 100644 --- a/arch/arm64/mm/gcs.c +++ b/arch/arm64/mm/gcs.c @@ -38,8 +38,8 @@ static unsigned long gcs_size(unsigned long size) return max(PAGE_SIZE, size); } -unsigned long gcs_alloc_thread_stack(struct task_struct *tsk, - const struct kernel_clone_args *args) +int gcs_alloc_thread_stack(struct task_struct *tsk, + const struct kernel_clone_args *args) { unsigned long addr, size; @@ -59,13 +59,13 @@ unsigned long gcs_alloc_thread_stack(struct task_struct *tsk, size = gcs_size(size); addr = alloc_gcs(0, size); if (IS_ERR_VALUE(addr)) - return addr; + return PTR_ERR((void *)addr); tsk->thread.gcs_base = addr; tsk->thread.gcs_size = size; tsk->thread.gcspr_el0 = addr + size - sizeof(u64); - return addr; + return 0; } SYSCALL_DEFINE3(map_shadow_stack, unsigned long, addr, unsigned long, size, unsigned int, flags)