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 ADD96C8FB; Tue, 11 Jun 2024 14:52:35 +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=1718117555; cv=none; b=bcbWtq8HQUHLW3PL9DO0abhISoEkxhbIuzjtvHWgTYyiSqdOqz4WLRNHRFw3NTSd5zddfklDmf0i/HEk5PykDSuu22tOYzGdOLJ7qdT4mJvhaN3YaSjnMhg5MzhJMjZOgSTCyhRNhYVaqgrj9eu5FvpHTwD2JbRgVknAiqILIYg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718117555; c=relaxed/simple; bh=eNbDNNAuqp/CblfbjmFVWsYldsOh15uvWduPZlV6ox8=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=T1mu/eaWsxM203A6Wq83YlP1ZcTDtMr86Dn6JDYDXfLjWtOiUuJveaqs16qEZqhedWfVFq9Hp6eu35nHv+IvwYPUIxcNrYdqf6R8gDNn9iaY332lDpEK4FwxwFsGcimGOsAZgHAge/9q9wdzgwb+WPLkseiDWFn8V6m39ccdzvs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=l2qn/9SC; 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="l2qn/9SC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B910AC2BD10; Tue, 11 Jun 2024 14:52:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1718117555; bh=eNbDNNAuqp/CblfbjmFVWsYldsOh15uvWduPZlV6ox8=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=l2qn/9SCNKz5QiFJF3cuiRWVAiq7wohguBn/+HKH9qTEJM9mcCyryzZbX1TWn4ueL JQrONN4x9Y4FJsXo+jBueCQ24Ue+hUAnsvMQ/s0EAreatREGoa+8ULUUC1gwHNlrpR APlERx/0NXqxllIYB9JHmrqNeyvn20Bm2Tw6ttKEq5wObrqrVPj3i2Cl+ooPDw1nJl bVnDYobae5KjehxTsG+HHK2eMDl9nnmYze3I9XyBGFZ6VoMt7lMoi1yAWvx68UCmMh iU/vdfvuT5HPxLeVJfP2qa6XtzapOiNg0Xwar4kZvQMkgXxV3CNowj7YCZy1pbIAnV h+iyFGMwJx7Mw== Date: Tue, 11 Jun 2024 23:52:28 +0900 From: Masami Hiramatsu (Google) To: Jiri Olsa Cc: Steven Rostedt , Oleg Nesterov , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , 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: Re: [PATCHv8 bpf-next 0/9] uprobe: uretprobe speed up Message-Id: <20240611235228.f70de698f8e43a3c177a15b8@kernel.org> In-Reply-To: <20240611112158.40795-1-jolsa@kernel.org> References: <20240611112158.40795-1-jolsa@kernel.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Tue, 11 Jun 2024 13:21:49 +0200 Jiri Olsa wrote: > 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 Applied patch [1/9] - [8/9] on probes/for-next in git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git Thank you! > > 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 -- Masami Hiramatsu (Google)