From patchwork Mon Apr 7 16:19:45 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeremy Linton X-Patchwork-Id: 14041242 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1B0A020DD67; Mon, 7 Apr 2025 16:20:07 +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=1744042809; cv=none; b=mZm7a+Rv6GbpKom2ZUfKNvAF77XM6lovqEnTAjwEFlL3/GjAMxle2IFeRQWAd03aTB6Hf5kP43v6+WCvFQyInxJ0kq4e+kocxGXgAY6cXoyWeoAJM+JDcSrTz7bQE4LI/tT05kbgrWgdiXTF1N1XGRbzGXE135MOlCZw42TK+b4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744042809; c=relaxed/simple; bh=JDPA6wKqzvHim0qA4SSjZ7cp9/9aIauy8o/GHqLnmcs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=nzT+ZVqpvr0ZrJ7kRnU9hHJ3AGpzOmkJSzfDwqqLFFsMgdxKO+KFEnPiLbinYK8r7HYa9rHPvjk6Mqlu8+rsdFHXRuE3rNaBCPE7MxIyIyjcmtndbn52OIsPP5pN5Gp44lV42gapCvJilFl2c8VJ+CJrdkO9UIjCg4xafZY75NE= 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 4C208106F; Mon, 7 Apr 2025 09:20:08 -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 AF1D53F694; Mon, 7 Apr 2025 09:20:06 -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, 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 v2 0/6] arm64: Enable UPROBES with GCS Date: Mon, 7 Apr 2025 11:19:45 -0500 Message-ID: <20250407161951.560865-1-jeremy.linton@arm.com> X-Mailer: git-send-email 2.49.0 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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. Along the way we fix a bug in the core gcs task handling and export some uprobe quality of life functionality for use in arch specific code. The KCONFIG restriction is then dropped. 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 (6): arm64/gcs: task_gcs_el0_enable() should use passed task arm64: probes: Break ret out from bl/blr 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 arch/arm64/Kconfig | 1 - arch/arm64/include/asm/gcs.h | 2 +- arch/arm64/include/asm/uaccess.h | 42 ++++++++++++++++++++++++ arch/arm64/kernel/probes/decode-insn.c | 7 ++-- arch/arm64/kernel/probes/simulate-insn.c | 38 ++++++++++++++++++--- arch/arm64/kernel/probes/simulate-insn.h | 3 +- arch/arm64/kernel/probes/uprobes.c | 30 +++++++++++++++++ arch/arm64/kernel/process.c | 6 ++-- 8 files changed, 115 insertions(+), 14 deletions(-)