From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793373896; b=xI3x23FYIRZbRYMucNc/lFGW6lF7MjA21hzfkxVMZ/nrI0HE+4EdaxZa6e5V5a/8UJLn wxwfwLtidgFvH2iIEJBlPTgUfgyYhlArdtdpVWGAvRFpEypWrxIw6O2NYQ++zFJGJUt78 LipJQHK8GQV7DMORu7Lr5a56lMcnIgFtQRThEpyt3e269108lYtaafnGRk8gVQpGjub64 9skARLev5MZOR+xk6AKA5wR3qBPuBoeRzGB99sM7NgV0vmMd4xFd1MMewZ7wdGaBoOgu+ ipad6/0oNjQDzPETik+IgQ7S0+yOF/CcSgoMrsZz2iQ2p282XAFXs8cAA8HrY1kHfow== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793373896; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=mrroWNn8F+zR8VFNwwAy0uWTVNXtUEJ+MXPcimsejzQ=; b=0ylT4dzbm6iZRd3cCwd3HXYVB6eExRynne8gC6QfeJ5hdsUmDhnb/r+mtLWvJKasqbjU VKr3BhA8YV58dBxcrjA+8c6akSCnc0ho605bl+Lzlze8dQy627+ovSnEkpiRR2/uckA9c aaZ7+rtmyHTFZ8B3X/sRzomtOmuxB69I7X0xHLYJDID3kqLTXfk3WtG6FLaJPCZHHJ1mg Qmnoh/bjofDmnMewvAzN+9ZZqpmZGWbrwLJpIt+vgrdpIuGjYtlXVsZsm52b49yvKjKUS ZqNvk+EpLeLsjpP7OXtniPzwNLe7bG0JO6sNaPbBno4SkL7GZKaqmTd0YZNGUEu9yUQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Q4zgnlKf; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E8EBD606A31E for ; Fri, 30 Oct 2026 15:24:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Q4zgnlKf Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BE421F00A1A; Fri, 30 Oct 2026 15:24:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793373895; bh=mrroWNn8F+zR8VFNwwAy0uWTVNXtUEJ+MXPcimsejzQ=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Q4zgnlKfTjj4OhKcm8Qme+RoCMfxeWPM440svUWcz7WC2XcShgrY6/EA7FH/JE+Sa vfT3ZkN4Ql9grqsDDC8S7tlXqP3eNyh35yjtBSO2bGl+XcRJ/m1jocRmgPxKIY6uEI tgV6aQa6V+3MN/NybVnVVJLLDwBa5/1Zto+xW3GlTwrS3DvI3LPRh+8QqwIygrH3Rg tqIr/ZUbOQFrCq0DJPnoaEE5QrN3HnKhXU788sh3PEECUEej1E/M6LruFBI4pY27aq AJZyT7naBQDkA4f5hYRndEheBc67McGAUdh/O0JNiutXtfbqHQ4g6F8O5oRhD40Ez0 8x2cyxLGb0n4w== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 14/14] perf tests: Check CoreSight emulated instruction entry and exit Reply-To: sashiko-reviews@lists.linux.dev To: "Leo Yan" Cc: linux-perf-users@vger.kernel.org In-Reply-To: <20261030-perf_cs_etm_fix_non_taken-v3-14-7629b52ab047@arm.com> References: <20261030-perf_cs_etm_fix_non_taken-v3-0-7629b52ab047@arm.com> <20261030-perf_cs_etm_fix_non_taken-v3-14-7629b52ab047@arm.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 30 Oct 2026 15:24:55 +0000 X-Mailing-List: linux-perf-users@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > Use traploop's EL0 read of ID_AA64ISAR0_EL1 to check an emulated > instruction. The kernel emulates MRS and advances the return PC by four > bytes. >=20 > Select MRS entries by instruction encoding and reuse the common FIFO > recorder and pair checker. An instruction page fault at MRS also matches > the opcode filter and returns to the same PC. Retry recordings when the > pair check fails or finds no complete pair, and fail after three > unsuccessful attempts. Recording and decoding errors fail immediately. >=20 > For example, an expected int/iret pair is: >=20 > int 5cc808 =3D> ffff800080010c00 insn: 00 06 38 d5 > ... > iret ffff800080012284 =3D> 5cc80c insn: e0 03 9f d6 >=20 > The entry instruction is MRS X0, ID_AA64ISAR0_EL1. After emulating the > read at 0x5cc808, the kernel returns via ERET to the next instruction at > 0x5cc80c. >=20 > Reviewed-by: James Clark > Signed-off-by: Leo Yan Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261030-perf_cs_et= m_fix_non_taken-v3-0-7629b52ab047@arm.com?part=3D14