From patchwork Thu Oct 7 17:50:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marcelo Tosatti X-Patchwork-Id: 12542581 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3FA14C433F5 for ; Thu, 7 Oct 2021 18:04:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 155AE61175 for ; Thu, 7 Oct 2021 18:04:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243268AbhJGSGq (ORCPT ); Thu, 7 Oct 2021 14:06:46 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:24960 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242934AbhJGSGq (ORCPT ); Thu, 7 Oct 2021 14:06:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633629892; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=SvmEJiZPEiga2z/GCLjuSjyWe3sHIHwKTSDAhwqIbKg=; b=a3pqCuryVuKlfUsXIWOXceCf6/xuxkA6XXin3xtLKJ4ZpXSwQHqHaxSsa2AvT1PYHdlZHL VZEDJHsIOdxw12XXh8JU8XGhist+PdrpaiQLN7sOejKzWH+sscr6NRsB88ITcpBOPkwcL3 pCSsHspPmjscQZf+rRVvdp2ekvdO5zY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-579-qpx3fiAjPFSjweyUC2UWCQ-1; Thu, 07 Oct 2021 14:04:51 -0400 X-MC-Unique: qpx3fiAjPFSjweyUC2UWCQ-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1CDF11172CA9; Thu, 7 Oct 2021 17:50:49 +0000 (UTC) Received: from fuller.cnet (ovpn-112-2.gru2.redhat.com [10.97.112.2]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 132A75D9DE; Thu, 7 Oct 2021 17:50:41 +0000 (UTC) Received: by fuller.cnet (Postfix, from userid 1000) id 823AD4179DC3; Thu, 7 Oct 2021 14:50:37 -0300 (-03) Date: Thu, 7 Oct 2021 14:50:37 -0300 From: Marcelo Tosatti To: bpf@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Nitesh Narayan Lal , Nicolas Saenz Julienne , Thomas Gleixner , Peter Zijlstra , Peter Xu , Andrii Nakryiko , Song Liu Subject: [PATCH v2 bpf-next] bpf: introduce helper bpf_raw_read_cpu_clock Message-ID: <20211007175037.GA439973@fuller.cnet> References: <20211006175106.GA295227@fuller.cnet> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20211006175106.GA295227@fuller.cnet> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add bpf_raw_read_cpu_clock helper, to read architecture specific CPU clock. In x86's case, this is the TSC. This is necessary to synchronize bpf traces from host and guest bpf-programs (after subtracting guest tsc-offset from guest timestamps). Signed-off-by: Marcelo Tosatti --- v2: - drop redundant addition to bpf_tracing_func_proto (Song Liu) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index ab83c22d274e..832bb1f65f28 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -95,6 +95,7 @@ config X86 select ARCH_HAS_UBSAN_SANITIZE_ALL select ARCH_HAS_DEBUG_WX select ARCH_HAS_ZONE_DMA_SET if EXPERT + select ARCH_HAS_BPF_RAW_CPU_CLOCK select ARCH_HAVE_NMI_SAFE_CMPXCHG select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI select ARCH_MIGHT_HAVE_PC_PARPORT diff --git a/arch/x86/include/asm/bpf_raw_cpu_clock.h b/arch/x86/include/asm/bpf_raw_cpu_clock.h new file mode 100644 index 000000000000..6951c399819e --- /dev/null +++ b/arch/x86/include/asm/bpf_raw_cpu_clock.h @@ -0,0 +1,10 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_BPF_RAW_CPU_CLOCK_H_ +#define _ASM_X86_BPF_RAW_CPU_CLOCK_H_ + +static inline unsigned long long read_raw_cpu_clock(void) +{ + return rdtsc_ordered(); +} + +#endif /* _ASM_X86_BPF_RAW_CPU_CLOCK_H_ */ diff --git a/drivers/media/rc/bpf-lirc.c b/drivers/media/rc/bpf-lirc.c index 3eff08d7b8e5..844a44ff508d 100644 --- a/drivers/media/rc/bpf-lirc.c +++ b/drivers/media/rc/bpf-lirc.c @@ -105,6 +105,8 @@ lirc_mode2_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_ktime_get_ns_proto; case BPF_FUNC_ktime_get_boot_ns: return &bpf_ktime_get_boot_ns_proto; + case BPF_FUNC_read_raw_cpu_clock: + return &bpf_read_raw_cpu_clock_proto; case BPF_FUNC_tail_call: return &bpf_tail_call_proto; case BPF_FUNC_get_prandom_u32: diff --git a/include/linux/bpf.h b/include/linux/bpf.h index d604c8251d88..b6cb426085fb 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2058,6 +2058,7 @@ extern const struct bpf_func_proto bpf_get_numa_node_id_proto; extern const struct bpf_func_proto bpf_tail_call_proto; extern const struct bpf_func_proto bpf_ktime_get_ns_proto; extern const struct bpf_func_proto bpf_ktime_get_boot_ns_proto; +extern const struct bpf_func_proto bpf_read_raw_cpu_clock_proto; extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto; extern const struct bpf_func_proto bpf_get_current_uid_gid_proto; extern const struct bpf_func_proto bpf_get_current_comm_proto; diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 6fc59d61937a..52191791b089 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4037,6 +4037,13 @@ union bpf_attr { * Return * Current *ktime*. * + * u64 bpf_read_raw_cpu_clock(void) + * Description + * Return the architecture specific CPU clock value. + * For x86, this is the TSC clock. + * Return + * *CPU clock value* + * * long bpf_seq_printf(struct seq_file *m, const char *fmt, u32 fmt_size, const void *data, u32 data_len) * Description * **bpf_seq_printf**\ () uses seq_file **seq_printf**\ () to print @@ -5089,6 +5096,7 @@ union bpf_attr { FN(task_pt_regs), \ FN(get_branch_snapshot), \ FN(trace_vprintk), \ + FN(read_raw_cpu_clock), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/bpf/Kconfig b/kernel/bpf/Kconfig index a82d6de86522..5815db157220 100644 --- a/kernel/bpf/Kconfig +++ b/kernel/bpf/Kconfig @@ -21,6 +21,10 @@ config HAVE_EBPF_JIT config ARCH_WANT_DEFAULT_BPF_JIT bool +# Used by archs to tell they support reading raw CPU clock +config ARCH_HAS_BPF_RAW_CPU_CLOCK + bool + menu "BPF subsystem" config BPF_SYSCALL diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index b6c72af64d5d..8e2359dfd582 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2345,6 +2345,8 @@ const struct bpf_func_proto bpf_get_numa_node_id_proto __weak; const struct bpf_func_proto bpf_ktime_get_ns_proto __weak; const struct bpf_func_proto bpf_ktime_get_boot_ns_proto __weak; const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto __weak; +const struct bpf_func_proto bpf_read_raw_cpu_clock_proto __weak; + const struct bpf_func_proto bpf_get_current_pid_tgid_proto __weak; const struct bpf_func_proto bpf_get_current_uid_gid_proto __weak; diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 1ffd469c217f..90b9e5efaf65 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -18,6 +18,10 @@ #include "../../lib/kstrtox.h" +#ifdef CONFIG_ARCH_HAS_BPF_RAW_CPU_CLOCK +#include +#endif + /* If kernel subsystem is allowing eBPF programs to call this function, * inside its own verifier_ops->get_func_proto() callback it should return * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments @@ -168,6 +172,21 @@ const struct bpf_func_proto bpf_ktime_get_boot_ns_proto = { .ret_type = RET_INTEGER, }; +BPF_CALL_0(bpf_read_raw_cpu_clock) +{ +#ifdef CONFIG_ARCH_HAS_BPF_RAW_CPU_CLOCK + return read_raw_cpu_clock(); +#else + return sched_clock(); +#endif +} + +const struct bpf_func_proto bpf_read_raw_cpu_clock_proto = { + .func = bpf_read_raw_cpu_clock, + .gpl_only = false, + .ret_type = RET_INTEGER, +}; + BPF_CALL_0(bpf_ktime_get_coarse_ns) { return ktime_get_coarse_ns(); @@ -1366,6 +1385,8 @@ bpf_base_func_proto(enum bpf_func_id func_id) return &bpf_ktime_get_boot_ns_proto; case BPF_FUNC_ktime_get_coarse_ns: return &bpf_ktime_get_coarse_ns_proto; + case BPF_FUNC_read_raw_cpu_clock: + return &bpf_read_raw_cpu_clock_proto; case BPF_FUNC_ringbuf_output: return &bpf_ringbuf_output_proto; case BPF_FUNC_ringbuf_reserve: diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 6fc59d61937a..52191791b089 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4037,6 +4037,13 @@ union bpf_attr { * Return * Current *ktime*. * + * u64 bpf_read_raw_cpu_clock(void) + * Description + * Return the architecture specific CPU clock value. + * For x86, this is the TSC clock. + * Return + * *CPU clock value* + * * long bpf_seq_printf(struct seq_file *m, const char *fmt, u32 fmt_size, const void *data, u32 data_len) * Description * **bpf_seq_printf**\ () uses seq_file **seq_printf**\ () to print @@ -5089,6 +5096,7 @@ union bpf_attr { FN(task_pt_regs), \ FN(get_branch_snapshot), \ FN(trace_vprintk), \ + FN(read_raw_cpu_clock), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper