From patchwork Tue Jun 11 11:21:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13693469 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 59A8A13E8AE; Tue, 11 Jun 2024 11:22:05 +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=1718104926; cv=none; b=WxxvhQRTwD078S/dDxfdODQmVsxmjujyvhA8lWplQ9+XdqHZBDYaTjdrrx5CKNzmCJpxBTJbkAWb9qQQN/2HnF1bFfvq02v3y+R5cfxijIFfR8/Iu43QAUd4tBE5s/oMhZdIVAjxcdjQGp2j26fEZp68OEg/2B0Y6lyeW9Cr7Hk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718104926; c=relaxed/simple; bh=YhLvdXo+bgU9zbCGfGQR0N/YY1+urUBInzEGRzY7tnE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=M8b1G/AyZ1RAkWqtQRMKDTmgFkfsCbN8+cr95sWjBkFaULmKrtLrhMC3M6d0MKOO7kpWoNyYhSlTvM1SEmmDvr2I23FvEKwYG6qmLrVt2Avgh3wojd1I6az6H0vzXwyZDbSDe2lnZ/ogGJOONDTOPTMK4o96b0qE7IuP7nyEuMk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=G6/uNApW; 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="G6/uNApW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A10D6C2BD10; Tue, 11 Jun 2024 11:22:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718104925; bh=YhLvdXo+bgU9zbCGfGQR0N/YY1+urUBInzEGRzY7tnE=; h=From:To:Cc:Subject:Date:From; b=G6/uNApWfJG5oj1Poo3GOdINKoAZzGzL5J4O7Mrvc/2AEMccK5swiqCJyH7+3WBCU zvAADBWRBZ2pW8wfXGn4VlzzdaWEo94PpUISbg6sn/GIb0sSI6rXWs9ZY30Izz2A59 /RHvdXBz0ofMl5T0GfrPA64BL6CJX2pYksfOo0krWZc7zU1cE4HmRv997sReIwcpgK XSvM5ddDBFc4EEGX1V5hAM/ZApOAnHAFCe3V5uoyZ228+vh7K7rYSneZQTHAQpWnE2 aQmuWCI6O9Oi7WPNRPcjk1bG4QzptfQuOLxQTzNjqMXBgfLgrFXM8aXQpld58Pa2pG FL4O3Bws+3Mxw== From: Jiri Olsa To: Steven Rostedt , Masami Hiramatsu , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-api@vger.kernel.org, linux-man@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, Song Liu , Yonghong Song , John Fastabend , Peter Zijlstra , Thomas Gleixner , "Borislav Petkov (AMD)" , Ingo Molnar , Andy Lutomirski , "Edgecombe, Rick P" , Deepak Gupta Subject: [PATCHv8 bpf-next 0/9] uprobe: uretprobe speed up Date: Tue, 11 Jun 2024 13:21:49 +0200 Message-ID: <20240611112158.40795-1-jolsa@kernel.org> X-Mailer: git-send-email 2.45.1 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 hi, as part of the effort on speeding up the uprobes [0] coming with return uprobe optimization by using syscall instead of the trap on the uretprobe trampoline. The speed up depends on instruction type that uprobe is installed and depends on specific HW type, please check patch 1 for details. Patches 1-8 are based on bpf-next/master, but patch 2 and 3 are apply-able on linux-trace.git tree probes/for-next branch. Patch 9 is based on man-pages master. v8 changes: - rebased (another new syscall got merged) - added acks Also available at: https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git uretprobe_syscall thanks, jirka Notes to check list items in Documentation/process/adding-syscalls.rst: - System Call Alternatives New syscall seems like the best way in here, because we need just to quickly enter kernel with no extra arguments processing, which we'd need to do if we decided to use another syscall. - Designing the API: Planning for Extension The uretprobe syscall is very specific and most likely won't be extended in the future. At the moment it does not take any arguments and even if it does in future, it's allowed to be called only from trampoline prepared by kernel, so there'll be no broken user. - Designing the API: Other Considerations N/A because uretprobe syscall does not return reference to kernel object. - Proposing the API Wiring up of the uretprobe system call is in separate change, selftests and man page changes are part of the patchset. - Generic System Call Implementation There's no CONFIG option for the new functionality because it keeps the same behaviour from the user POV. - x86 System Call Implementation It's 64-bit syscall only. - Compatibility System Calls (Generic) N/A uretprobe syscall has no arguments and is not supported for compat processes. - Compatibility System Calls (x86) N/A uretprobe syscall is not supported for compat processes. - System Calls Returning Elsewhere N/A. - Other Details N/A. - Testing Adding new bpf selftests and ran ltp on top of this change. - Man Page Attached. - Do not call System Calls in the Kernel N/A. [0] https://lore.kernel.org/bpf/ZeCXHKJ--iYYbmLj@krava/ --- Jiri Olsa (8): x86/shstk: Make return uprobe work with shadow stack uprobe: Wire up uretprobe system call uprobe: Add uretprobe syscall to speed up return probe selftests/x86: Add return uprobe shadow stack test selftests/bpf: Add uretprobe syscall test for regs integrity selftests/bpf: Add uretprobe syscall test for regs changes selftests/bpf: Add uretprobe syscall call from user space test selftests/bpf: Add uretprobe shadow stack test arch/x86/entry/syscalls/syscall_64.tbl | 1 + arch/x86/include/asm/shstk.h | 4 + arch/x86/kernel/shstk.c | 16 ++++ arch/x86/kernel/uprobes.c | 124 ++++++++++++++++++++++++++++- include/linux/syscalls.h | 2 + include/linux/uprobes.h | 3 + include/uapi/asm-generic/unistd.h | 5 +- kernel/events/uprobes.c | 24 ++++-- kernel/sys_ni.c | 2 + tools/include/linux/compiler.h | 4 + tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c | 123 ++++++++++++++++++++++++++++- tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c | 385 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ tools/testing/selftests/bpf/progs/uprobe_syscall.c | 15 ++++ tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c | 17 ++++ tools/testing/selftests/x86/test_shadow_stack.c | 145 ++++++++++++++++++++++++++++++++++ 15 files changed, 860 insertions(+), 10 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/uprobe_syscall.c create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall.c create mode 100644 tools/testing/selftests/bpf/progs/uprobe_syscall_executed.c Jiri Olsa (1): man2: Add uretprobe syscall page man/man2/uretprobe.2 | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 man/man2/uretprobe.2