From patchwork Thu Mar 20 11:41:45 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 14023815 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 503CE21D3D2; Thu, 20 Mar 2025 11:43:58 +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=1742471040; cv=none; b=sda8zGN2DVMoIy2XDXN5T5C9co0X0O0WdEyAoyEH2icom0WVoqJM4d2kv5X+AYBILAZPnsJgCABu2OnVb55eY7HFZS5oSWg9XCkYlk9I9yFeEJniSajI2vA4R/F8wMZ3O2mEnri6D1O40uF/o9IAFyjO7dd0XXbM/a50YZWBLgw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742471040; c=relaxed/simple; bh=4aj2bBFJzCjQzuazdxB0n//R64oA/bqZDTXmWuoBJpM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iudVDPJuGedizivhSs+A7qfNgTKrs5gJScxXjspqk0u+nJ2wHPgqfOw64O555wCU3madr0yfdrrGu+FKKpmUaL5Lhiyxuoh6V6RDLlMi9qvOnhEqAADMYVSuPKOb7Y40TQzhgXFfooCopaYP7CRnl7ZCEUStA4tlZ6c4DZNUFGA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ERe2JQHH; 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="ERe2JQHH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4268C4CEDD; Thu, 20 Mar 2025 11:43:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742471038; bh=4aj2bBFJzCjQzuazdxB0n//R64oA/bqZDTXmWuoBJpM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ERe2JQHH8XmDc5g0oJzuGntYGPDAMBx0gs/bGEsr5Dtu51qudPqG6TWBqS/MyfWU9 6vgKjQVpg/DT+4NDgyIxXgWBnNP/1zpiPKK/uaR46GDaGHXNgOjEMhEG82nMj995dI NqEfbADeL4E7d0E4JWQ0kej0DO9664/91RX9QeTCPXkwrZURn124/DWzYC2IvM4h78 goOpYLh9XmT3vMck5/LpLVA/1ILFq9ixXVs/g6oX2su275HX/r2hgtKE51IWhdQ1Ue +DsKDvMbTfjFq7s0WeNPmagsYb7ClwypI/1XBt8X4sM3NKNlJIS68s4xVIUeVdQnm/ jSwBq/DyCN0hQ== 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 RFCv3 10/23] uprobes/x86: Add support to emulate nop5 instruction Date: Thu, 20 Mar 2025 12:41:45 +0100 Message-ID: <20250320114200.14377-11-jolsa@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250320114200.14377-1-jolsa@kernel.org> References: <20250320114200.14377-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 5ee2cce4c63e..1661e0ab2a3d 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 ( @@ -865,6 +870,11 @@ void arch_uprobe_clear_state(struct mm_struct *mm) hlist_for_each_entry_safe(tramp, n, &state->head_tramps, node) destroy_uprobe_trampoline(tramp); } + +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 @@ -878,6 +888,10 @@ 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 { @@ -1109,6 +1123,8 @@ 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; /*