From nobody Thu Apr 2 13:15:13 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 76359C6FA82 for ; Fri, 23 Sep 2022 08:51:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230387AbiIWIvQ (ORCPT ); Fri, 23 Sep 2022 04:51:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230487AbiIWIu5 (ORCPT ); Fri, 23 Sep 2022 04:50:57 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47CF8126B7E; Fri, 23 Sep 2022 01:50:55 -0700 (PDT) Received: from kwepemi500012.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MYm4j0QwHzpT3m; Fri, 23 Sep 2022 16:47:49 +0800 (CST) Received: from huawei.com (10.67.174.53) by kwepemi500012.china.huawei.com (7.221.188.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 23 Sep 2022 16:50:39 +0800 From: Liao Chang To: , , , , , , , , , , , CC: , , , Subject: [PATCH 1/3] riscv/kprobe: Optimize the performance of patching single-step slot Date: Fri, 23 Sep 2022 16:46:56 +0800 Message-ID: <20220923084658.99304-2-liaochang1@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220923084658.99304-1-liaochang1@huawei.com> References: <20220923084658.99304-1-liaochang1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.53] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi500012.china.huawei.com (7.221.188.12) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Single-step slot would not be used until kprobe is enabled, that means no race condition occurs on it under SMP, hence it is safe to pacth ss slot without stopping machine. Acked-by: Masami Hiramatsu (Google) Signed-off-by: Liao Chang --- arch/riscv/kernel/probes/kprobes.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/probes/kprobes.c b/arch/riscv/kernel/probes/= kprobes.c index e6e950b7cf32..bc1f39b96e41 100644 --- a/arch/riscv/kernel/probes/kprobes.c +++ b/arch/riscv/kernel/probes/kprobes.c @@ -24,12 +24,14 @@ post_kprobe_handler(struct kprobe *, struct kprobe_ctlb= lk *, struct pt_regs *); static void __kprobes arch_prepare_ss_slot(struct kprobe *p) { unsigned long offset =3D GET_INSN_LENGTH(p->opcode); + kprobe_opcode_t slot[MAX_INSN_SIZE]; =20 p->ainsn.api.restore =3D (unsigned long)p->addr + offset; =20 - patch_text(p->ainsn.api.insn, p->opcode); - patch_text((void *)((unsigned long)(p->ainsn.api.insn) + offset), - __BUG_INSN_32); + memcpy(slot, &p->opcode, offset); + *(kprobe_opcode_t *)((unsigned long)slot + offset) =3D __BUG_INSN_32; + patch_text_nosync(p->ainsn.api.insn, slot, + offset + GET_INSN_LENGTH(__BUG_INSN_32)); } =20 static void __kprobes arch_prepare_simulate(struct kprobe *p) --=20 2.17.1 From nobody Thu Apr 2 13:15:13 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4E93C6FA82 for ; Fri, 23 Sep 2022 08:51:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231199AbiIWIvD (ORCPT ); Fri, 23 Sep 2022 04:51:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38264 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230463AbiIWIu4 (ORCPT ); Fri, 23 Sep 2022 04:50:56 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EBDEC126B49; Fri, 23 Sep 2022 01:50:54 -0700 (PDT) Received: from kwepemi500012.china.huawei.com (unknown [172.30.72.56]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MYm3Q04rLzWgpB; Fri, 23 Sep 2022 16:46:41 +0800 (CST) Received: from huawei.com (10.67.174.53) by kwepemi500012.china.huawei.com (7.221.188.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 23 Sep 2022 16:50:39 +0800 From: Liao Chang To: , , , , , , , , , , , CC: , , , Subject: [PATCH 2/3] csky/kprobe: Optimize the performance of patching single-step slot Date: Fri, 23 Sep 2022 16:46:57 +0800 Message-ID: <20220923084658.99304-3-liaochang1@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220923084658.99304-1-liaochang1@huawei.com> References: <20220923084658.99304-1-liaochang1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.53] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi500012.china.huawei.com (7.221.188.12) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Single-step slot would not be used until kprobe is enabled, that means no race condition occurs on it under SMP, hence it is safe to pacth ss slot without stopping machine. Acked-by: Masami Hiramatsu (Google) Signed-off-by: Liao Chang --- arch/csky/kernel/probes/kprobes.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/csky/kernel/probes/kprobes.c b/arch/csky/kernel/probes/kp= robes.c index 3c6e5c725d81..4feb5ce16264 100644 --- a/arch/csky/kernel/probes/kprobes.c +++ b/arch/csky/kernel/probes/kprobes.c @@ -57,7 +57,11 @@ static void __kprobes arch_prepare_ss_slot(struct kprobe= *p) =20 p->ainsn.api.restore =3D (unsigned long)p->addr + offset; =20 - patch_text(p->ainsn.api.insn, p->opcode); + memcpy(p->ainsn.api.insn, &p->opcode, offset); + dcache_wb_range((unsigned long)p->ainsn.api.insn, + (unsigned long)p->ainsn.api.insn + offset); + icache_inv_range((unsigned long)p->ainsn.api.insn, + (unsigned long)p->ainsn.api.insn + offset); } =20 static void __kprobes arch_prepare_simulate(struct kprobe *p) --=20 2.17.1 From nobody Thu Apr 2 13:15:13 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 180AFC6FA86 for ; Fri, 23 Sep 2022 08:51:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231205AbiIWIvM (ORCPT ); Fri, 23 Sep 2022 04:51:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230469AbiIWIu5 (ORCPT ); Fri, 23 Sep 2022 04:50:57 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EC36D126B4B; Fri, 23 Sep 2022 01:50:54 -0700 (PDT) Received: from kwepemi500012.china.huawei.com (unknown [172.30.72.53]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4MYm3Q4S2lzWgy5; Fri, 23 Sep 2022 16:46:42 +0800 (CST) Received: from huawei.com (10.67.174.53) by kwepemi500012.china.huawei.com (7.221.188.12) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Fri, 23 Sep 2022 16:50:40 +0800 From: Liao Chang To: , , , , , , , , , , , CC: , , , Subject: [PATCH 3/3] arm64/kprobe: Optimize the performance of patching single-step slot Date: Fri, 23 Sep 2022 16:46:58 +0800 Message-ID: <20220923084658.99304-4-liaochang1@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20220923084658.99304-1-liaochang1@huawei.com> References: <20220923084658.99304-1-liaochang1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.53] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi500012.china.huawei.com (7.221.188.12) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Single-step slot would not be used until kprobe is enabled, that means no race condition occurs on it under SMP, hence it is safe to pacth ss slot without stopping machine. Since I and D caches are coherent within single-step slot from aarch64_insn_patch_text_nosync(), hence no need to do it again via flush_icache_range(). Acked-by: Masami Hiramatsu (Google) Signed-off-by: Liao Chang Acked-by: Will Deacon --- arch/arm64/kernel/probes/kprobes.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/= kprobes.c index d1d182320245..29b98bc12833 100644 --- a/arch/arm64/kernel/probes/kprobes.c +++ b/arch/arm64/kernel/probes/kprobes.c @@ -44,13 +44,10 @@ post_kprobe_handler(struct kprobe *, struct kprobe_ctlb= lk *, struct pt_regs *); static void __kprobes arch_prepare_ss_slot(struct kprobe *p) { kprobe_opcode_t *addr =3D p->ainsn.api.insn; - void *addrs[] =3D {addr, addr + 1}; - u32 insns[] =3D {p->opcode, BRK64_OPCODE_KPROBES_SS}; =20 /* prepare insn slot */ - aarch64_insn_patch_text(addrs, insns, 2); - - flush_icache_range((uintptr_t)addr, (uintptr_t)(addr + MAX_INSN_SIZE)); + aarch64_insn_patch_text_nosync(addr, p->opcode); + aarch64_insn_patch_text_nosync(addr + 1, BRK64_OPCODE_KPROBES_SS); =20 /* * Needs restoring of return address after stepping xol. --=20 2.17.1