From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 23E161A314B; Mon, 11 Aug 2025 14:10:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754921426; cv=none; b=ry2TIJxA+ITD8w6Z8pApPweu96OIeyAjTtaM6ZBZbSsfBJwBeNPvM5+pq2JneSrt1wZvYW2ooH/5N5jiLS+6R207pnOJFT3VZoDC5NPHrGtOcOdKi1MCIpBNPJhpN0P3VKRXQZ14Mo1+HAiVnsOUOquICBEO3mK90FcqEtTJ4og= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754921426; c=relaxed/simple; bh=PqOif4n6dhkjVJrz7stPxn20AD/68S05JuHGOWUPVtk=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=J43rRZMl5AjWY1RiU5EImeSqz1Q1018GCwN3FBilGgyCFv2fdTlzHD/zpV5DLOy60OxUFeuZQAEMevSmPhncJ6h4ywWYBh8yE08TuSIPrc67x6L+6TrfdUsiBXSg1gRWE5QCwvcrQtvIEGcJxSNmC2d/MED7RGLqiNeBtWCgY4o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D98271A32; Mon, 11 Aug 2025 07:10:14 -0700 (PDT) Received: from u200865.usa.arm.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 669FF3F738; Mon, 11 Aug 2025 07:10:22 -0700 (PDT) From: Jeremy Linton To: linux-trace-kernel@vger.kernel.org Cc: linux-perf-users@vger.kernel.org, mhiramat@kernel.org, oleg@redhat.com, peterz@infradead.org, mingo@redhat.com, acme@kernel.org, namhyung@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, kan.liang@linux.intel.com, thiago.bauermann@linaro.org, broonie@kernel.org, yury.khrustalev@arm.com, kristina.martsenko@arm.com, liaochang1@huawei.com, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Jeremy Linton Subject: [PATCH v5 0/7] arm64: Enable UPROBES with GCS Date: Mon, 11 Aug 2025 09:10:03 -0500 Message-ID: <20250811141010.741989-1-jeremy.linton@arm.com> X-Mailer: git-send-email 2.50.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Currently uprobes and the Arm Guarded Control Stack (GCS) feature are exclusive of each other. This restriction needs to be lifted in order to utilize GCS for generic Linux distro images where the expectation is that core debugging features like uprobes work. This series adds some user accessors to read/push/pop the userspace shadow stack. It then utilizes those functions in the uprobe paths as needed to synchronize GCS with the changes in control flow at probe locations. The KCONFIG restriction is then dropped. v4->v5: Fix ret xn handing Renames, comment tweaks, formatting, per review comments rebase 6.17, drop first patch Add reviewed-by's v3->v4: Much delayed v4 rebased to 6.16 Move existing gcs accessors to gcs.h and then add the new ones. This fixes some of the forward reference issues, the build break and keeps them all together. v2->v3: Cleanup RET logic to alwaays use LR, and not update IP on aborts Correct generic uprobe_warn bug even though we aren't using it v1->v2: Drop uprobe_warn() patch Fix copy_thread_gcs() bug created by fixing task_gcs_el0_enabled() Comments, now describe issues with reading userspace GCS pages Rebased to 6.15 Jeremy Linton (7): arm64: probes: Break ret out from bl/blr arm64: uaccess: Move existing GCS accessors definitions to gcs.h arm64: uaccess: Add additional userspace GCS accessors arm64: probes: Add GCS support to bl/blr/ret arm64: uprobes: Add GCS support to uretprobes arm64: Kconfig: Remove GCS restrictions on UPROBES uprobes: uprobe_warn should use passed task arch/arm64/Kconfig | 1 - arch/arm64/include/asm/gcs.h | 89 ++++++++++++++++++++++++ arch/arm64/include/asm/uaccess.h | 40 ----------- arch/arm64/kernel/probes/decode-insn.c | 7 +- arch/arm64/kernel/probes/simulate-insn.c | 50 ++++++++++--- arch/arm64/kernel/probes/simulate-insn.h | 3 +- arch/arm64/kernel/probes/uprobes.c | 33 +++++++++ kernel/events/uprobes.c | 2 +- 8 files changed, 171 insertions(+), 54 deletions(-) -- 2.50.1