From patchwork Mon Feb 24 14:01:43 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 13988196 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 2EBB5158858; Mon, 24 Feb 2025 14:04:00 +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=1740405840; cv=none; b=TdQlprNRkKKro1c9sW365akZeliG+BHhSfky7C/AfVO6pb6koYQE0jm6ttwS5ImaZuesRAPCLG1jcpdwQy9vuzLobTlFntZ0B/x0fsxDa5319KKm8MTUlrd/p6q24NvZreL2zG/luuWy8CE/LCqA0Gy0U875nyS9kPsAmbLJxy4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740405840; c=relaxed/simple; bh=7sclEyut+IWCsV/dgLzSESLGACLKNCIjwTjTpfPd//E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WvqJ8a6u8OcBJH1WvyJUuEUz4E/4qIEHp8EjAfGFxBiN1GjOw+G/QaRJgZNA2ncIZ6PZn5IEouXWi30/gAZPSRhwqCv/UVjYPh+mKM+X+Gd7zR27OuJRtAFk3afgjnQLFXl7Zp/B9tCf9mzx32lfP82SgiXwJwR85lpOjxKMiHk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=X4wNfpv+; 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="X4wNfpv+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 068FBC4CED6; Mon, 24 Feb 2025 14:03:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740405840; bh=7sclEyut+IWCsV/dgLzSESLGACLKNCIjwTjTpfPd//E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X4wNfpv+acHMvw67GB1CbgA+xYBwAr6sv9KPjylORPa6O6qb2bOWgklq8NNzG/agM VPdYE/QAnXQjC1z4qIEuU69qjouAsVfLlO4+WZ/ZEup1ac60qq8o6i/eU0Q/3hzEQN xVSzVPyP9OeiQuWbdVXkACvuY/bH2NrV/BVARBxC4OjNismyKWgFqfWshO9GOqIVG5 97aVJNoFPU4x+frrarfYEZNUiksPCg9wOAp7Cxpo3WIMM+DhoRg3DhJsjcjurSiybk sQh9c8qF6gOnF1K0wV4qOS/sWb5umIrf0+i4GMlDcQlI1T9PfbN89VeWD0jA/HBiha 9YE9uV7Q5HlVQ== From: Jiri Olsa To: Oleg Nesterov , Peter Zijlstra , Andrii Nakryiko Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org, Song Liu , Yonghong Song , John Fastabend , Hao Luo , Steven Rostedt , Masami Hiramatsu , Alan Maguire , David Laight , =?utf-8?q?Thomas_Wei=C3=9Fschuh?= Subject: [PATCH RFCv2 11/18] uprobes/x86: Add support to emulate nop5 instruction Date: Mon, 24 Feb 2025 15:01:43 +0100 Message-ID: <20250224140151.667679-12-jolsa@kernel.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250224140151.667679-1-jolsa@kernel.org> References: <20250224140151.667679-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-State: RFC Adding support to emulate nop5 as the original uprobe instruction. Signed-off-by: Jiri Olsa --- arch/x86/kernel/uprobes.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 8d4eb8133221..e8aebbda83bc 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -308,6 +308,11 @@ static int uprobe_init_insn(struct arch_uprobe *auprobe, struct insn *insn, bool return -ENOTSUPP; } +static int is_nop5_insn(uprobe_opcode_t *insn) +{ + return !memcmp(insn, x86_nops[5], 5); +} + #ifdef CONFIG_X86_64 asm ( @@ -927,6 +932,11 @@ void arch_uprobe_clear_state(struct mm_struct *mm) node = next; } } + +static bool emulate_nop5_insn(struct arch_uprobe *auprobe) +{ + return is_nop5_insn((uprobe_opcode_t *) &auprobe->insn); +} #else /* 32-bit: */ /* * No RIP-relative addressing on 32-bit @@ -940,6 +950,10 @@ static void riprel_pre_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) static void riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs) { } +static bool emulate_nop5_insn(struct arch_uprobe *auprobe) +{ + return false; +} #endif /* CONFIG_X86_64 */ struct uprobe_xol_ops { @@ -1171,6 +1185,8 @@ static int branch_setup_xol_ops(struct arch_uprobe *auprobe, struct insn *insn) break; case 0x0f: + if (emulate_nop5_insn(auprobe)) + goto setup; if (insn->opcode.nbytes != 2) return -ENOSYS; /*