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 CB1253054D8; Wed, 15 Oct 2025 12:58:27 +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=1760533108; cv=none; b=jLNI+9ovE2DOp0cSBy4CaVWcYrhe00FlaYPOzxrCGWJycXNtyJmjmbP4Im3y9ywfqRhEzs1cCmsuj5F770QMd612ouTqfWs71uyrqQuDFO13RmD3Juc91Wg/nS8z501QiJ/5rLj4/1qmwrEtPw4mIltzytIqNqw57pqs36ukdsU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760533108; c=relaxed/simple; bh=/chiFouok07D6GPiWTz73e9FYQNi+Yxs5DQX1oU2ntc=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=j98weNNanth9JBG0ID07AOnqeoFmQp4VA2FW7Rzw9hIYfwghBNi+fNiAtbAMIyxx7A4EDC60ThcrEYr9Z6gtUqMslkrz5299WMMQkOcFgaxSLRHR+vsvpNl4L+oYJGSh3ii0RoMebpsggAqKYR521i86dc38ifKrglr6IlbIH9A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=p+6FzE+K; 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="p+6FzE+K" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 350C1C4CEFE; Wed, 15 Oct 2025 12:58:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760533107; bh=/chiFouok07D6GPiWTz73e9FYQNi+Yxs5DQX1oU2ntc=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=p+6FzE+KXRRKRzsecRxd6ZrGPanaId9aszOeAINgHfzdda2HvAhfxZMG8UMk09cwu gR7n62Rmr5s8kZqjD8VynRcuZ4J1z4wYadu/9hBAupzXE3t/aF74UOI6NWrSYO5Tzo iIvNzXpth7+3iXsKUSQzyGqRddn+sH0YzYoKnLarh8R8aST4QygIviFJGzsPOM4vU8 Nh8kQoXnnv4IlmLb/oLq+/hEFs1rKBsyuAtzAvNnEtBtogz18NAhvqEEw9vGDqpPbJ dury4aOM0MNjVyaGQcuBX5b9UpSYRG8T96h5nps6VdxslpOfkF6WN/qN94OLtXOtvu 84NJeKN5Pj6VQ== From: Mark Brown Date: Wed, 15 Oct 2025 13:49:05 +0100 Subject: [PATCH v22 1/8] arm64/gcs: Return a success value from gcs_alloc_thread_stack() Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20251015-clone3-shadow-stack-v22-1-a8c8da011427@kernel.org> References: <20251015-clone3-shadow-stack-v22-0-a8c8da011427@kernel.org> In-Reply-To: <20251015-clone3-shadow-stack-v22-0-a8c8da011427@kernel.org> To: "Rick P. Edgecombe" , Deepak Gupta , "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, Andrew Morton , Yury Khrustalev , "H.J. Lu" , Adhemerval Zanella Netto , Wilco Dijkstra , CarlosO'Donell , Florian Weimer , Rich Felker , linux-kselftest@vger.kernel.org, linux-api@vger.kernel.org, Mark Brown , Kees Cook X-Mailer: b4 0.15-dev-96507 X-Developer-Signature: v=1; a=openpgp-sha256; l=3646; i=broonie@kernel.org; h=from:subject:message-id; bh=/chiFouok07D6GPiWTz73e9FYQNi+Yxs5DQX1oU2ntc=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBo75pf3NHeqAdVzx/1eahcc4lfV4AUULQjqCEXm LnU4HIYTe+JATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCaO+aXwAKCRAk1otyXVSH 0EjBB/44FeWxrtl/BCRscMGE/9vYMws3Kmufn0VrASAp6p5I2cDsV7lC82nvgGTuycFW3btV0+E W0QHunctABhBDzHtZkPtG1AEqhmYpJ6e7RAkjfunhscez383Rotan6VcbQqOniMTYigB7FOMHGg xNY0ZspWXxHug79yQuboEhafh/aocd5EwjrU0skeOHvpvn6/4cNDVYV1sp0llSJGAfA7Xsoh3gg ZbqLeRXNU4O0LkpyQekyi1GlCBkQu6+I1pglXEvPsJg+SRU7UI5E3Bx/mUcjjAhRSbXoUqjL3BC 7/isTEMdEaGk2vZa3S72Nhmly6eZ8AA7yq3I0WUtEBOldGzZ 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 8fa0707069e8..534ea5ae9281 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) @@ -171,8 +171,8 @@ static inline void put_user_gcs(unsigned long val, unsigned long __user *addr, int *err) { } static inline void push_user_gcs(unsigned long val, int *err) { } -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 fba7ca102a8c..4dadc70df16b 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -299,7 +299,7 @@ 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; @@ -310,9 +310,9 @@ static int copy_thread_gcs(struct task_struct *p, p->thread.gcs_el0_mode = current->thread.gcs_el0_mode; p->thread.gcs_el0_locked = current->thread.gcs_el0_locked; - 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; return 0; } diff --git a/arch/arm64/mm/gcs.c b/arch/arm64/mm/gcs.c index 6e93f78de79b..3abcbf9adb5c 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) -- 2.47.2