From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 5591E2877E8; Wed, 12 Aug 2026 00:44:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786495452; cv=none; b=om+nW1yjzC5mSKJd22DcaI2PvavszgxY5bMRtNzy58uNHRK/atqKwWZ2JsgHIuJKk9Z1+TYV042ZsS/em8ZwLX9p5dzQr9tZxcQSWOLh2wNxRUMBxy8GS74tapGHyEtKYwBKnt6KA43CIZfU+1h3/kerPwlYIkyK9ImUp90Dz/A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786495452; c=relaxed/simple; bh=oj155J8WdN24CH7OTppEnli8Za/z6mHS1JU++3ERia4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=NOSPAy7HUBU9+pi9gZ+y6nk8RTDZMyEF9cXNccWAUUUZRU/hAuDnDYomjkmG3uZXmMxZgul2w+Tf8cxkfcR2JlSEIGAQhqxs5qZjU8t9S/5Hanpe77kJfMQILK5ZFZ8p+YLK/1cDA6JZlTyNyBTPK1SxY+3zsImMK2BI95Sw+h4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nebqLtJ+; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nebqLtJ+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43FD01F000E9; Wed, 12 Aug 2026 00:44:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786495451; bh=bCWjy227zq95PX7LUF27D+H8lsveDD20rzvQ0kh5R1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nebqLtJ+DftQC/tN738fe9tNVd0j18/lSiL2k5GJ/9cKiyaEoRIdE03fDFSJDO8un E1jhjOFEK61koPdEeEuRt/OTYOuUh9c9idCxE8jjTjSr9Y8HZxiicYTZPgUf6FWwrm Lsel3A4mDvTVT6ZM9yU33d8vKObtw685jzMLX1PneAZaZ4RiofxaRJsB8VI2K0oAYe OGWvDb9LCi1AsVsGnomLMqMFdAPgHgiR9vBJTOuBkVYBGbPeoCc1wVtF6DSyvzBI5b 0rjxjMwRvAggi6wEi+qpIT+S8jIFwY5LFCURyJt3FfZVGi3PmyiJthSUH9bjG8KElg 0/wPZjHyEL2hg== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Masami Hiramatsu , Shuah Khan Cc: Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH v3 4/4] selftests/ftrace: Add persistent ring buffer testcases Date: Wed, 12 Aug 2026 09:44:06 +0900 Message-ID: <178649544683.438282.14573895196260214231.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <178649540853.438282.4271870161169100680.stgit@devnote2> References: <178649540853.438282.4271870161169100680.stgit@devnote2> User-Agent: StGit/0.19 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit From: Masami Hiramatsu (Google) Add test cases for persistent ring buffer (reserve_mem= combined with trace_instance=) and backup instance (trace_instance=backup=boot_map). These test cases verify: - persistent-01-reserve-mem: Memory reservation via reserve_mem= and trace_instance=boot_map@trace. Verifies trace data retention in the boot_map instance across guest crash/reboot via sysrq-trigger. - persistent-02-backup-instance: Backup instance creation via trace_instance=backup=boot_map. Verifies that previous boot trace log is preserved in the backup instance on the subsequent boot. These test cases specify '# REBOOT: 1' to enable multi-boot guest crash/reboot testing with doubled QEMU timeout. Assisted-by: Antigravity:gemini-3.6-flash Signed-off-by: Masami Hiramatsu (Google) --- Changes in v2: - Increase reserve_mem alignment to 32M (reserve_mem=12M:32M:trace) to ensure stable physical memory placement across KASLR reboots. --- .../cmdlines/persistent-01-reserve-mem.cmdline | 1 + .../cmdlines/persistent-02-backup-instance.cmdline | 1 + .../boottime/tests/persistent-01-reserve-mem.sh | 28 ++++++++++++++ .../tests/persistent-02-backup-instance.sh | 40 ++++++++++++++++++++ 4 files changed, 70 insertions(+) create mode 100644 tools/testing/selftests/ftrace/boottime/cmdlines/persistent-01-reserve-mem.cmdline create mode 100644 tools/testing/selftests/ftrace/boottime/cmdlines/persistent-02-backup-instance.cmdline create mode 100644 tools/testing/selftests/ftrace/boottime/tests/persistent-01-reserve-mem.sh create mode 100644 tools/testing/selftests/ftrace/boottime/tests/persistent-02-backup-instance.sh diff --git a/tools/testing/selftests/ftrace/boottime/cmdlines/persistent-01-reserve-mem.cmdline b/tools/testing/selftests/ftrace/boottime/cmdlines/persistent-01-reserve-mem.cmdline new file mode 100644 index 000000000000..c69eeb27deb6 --- /dev/null +++ b/tools/testing/selftests/ftrace/boottime/cmdlines/persistent-01-reserve-mem.cmdline @@ -0,0 +1 @@ +reserve_mem=12M:32M:trace trace_instance=boot_map@trace diff --git a/tools/testing/selftests/ftrace/boottime/cmdlines/persistent-02-backup-instance.cmdline b/tools/testing/selftests/ftrace/boottime/cmdlines/persistent-02-backup-instance.cmdline new file mode 100644 index 000000000000..43217c986ca1 --- /dev/null +++ b/tools/testing/selftests/ftrace/boottime/cmdlines/persistent-02-backup-instance.cmdline @@ -0,0 +1 @@ +reserve_mem=12M:32M:trace trace_instance=boot_map@trace trace_instance=backup=boot_map diff --git a/tools/testing/selftests/ftrace/boottime/tests/persistent-01-reserve-mem.sh b/tools/testing/selftests/ftrace/boottime/tests/persistent-01-reserve-mem.sh new file mode 100644 index 000000000000..49abaf518481 --- /dev/null +++ b/tools/testing/selftests/ftrace/boottime/tests/persistent-01-reserve-mem.sh @@ -0,0 +1,28 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2026, Google LLC. +# Check persistent ring buffer across guest crash/reboot +# REBOOT: 1 +TRACEDIR="/sys/kernel/tracing" + +if [ ! -f "$TRACEDIR/instances/boot_map/trace" ]; then + echo "FAIL: persistent trace instance boot_map/trace file missing" + exit 1 +fi + +# Check if Boot 1 marker was already written +if grep -q "BOOT1_MARKER" "$TRACEDIR/instances/boot_map/trace" 2>/dev/null; then + # Second boot: verify persistent ring buffer content from first boot + echo "PASS: persistent-01-reserve-mem" + exit 0 +fi + +# First boot: write marker to persistent buffer and trigger kernel crash/reboot +echo "BOOT1_MARKER" > "$TRACEDIR/instances/boot_map/trace_marker" +sync + +# Trigger reboot to restart into second boot +echo b > /proc/sysrq-trigger 2>/dev/null || echo c > /proc/sysrq-trigger 2>/dev/null || true +sleep 5 +echo "FAIL: reboot trigger failed on first boot" +exit 1 diff --git a/tools/testing/selftests/ftrace/boottime/tests/persistent-02-backup-instance.sh b/tools/testing/selftests/ftrace/boottime/tests/persistent-02-backup-instance.sh new file mode 100644 index 000000000000..0b2a2f03ce4f --- /dev/null +++ b/tools/testing/selftests/ftrace/boottime/tests/persistent-02-backup-instance.sh @@ -0,0 +1,40 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2026, Google LLC. +# Check persistent backup instance across guest crash/reboot +# REBOOT: 1 +TRACEDIR="/sys/kernel/tracing" + +# Ensure both boot_map/trace and backup/trace files exist +if [ ! -f "$TRACEDIR/instances/boot_map/trace" ]; then + echo "FAIL: boot_map/trace file missing" + exit 1 +fi + +if [ ! -f "$TRACEDIR/instances/backup/trace" ]; then + echo "FAIL: backup/trace file missing" + exit 1 +fi + +# Check if BOOT1_MARKER is in boot_map/trace (indicates second boot) +if grep -q "BOOT1_MARKER" "$TRACEDIR/instances/boot_map/trace" 2>/dev/null; then + # Second boot: verify BOOT1_MARKER was copied into backup/trace from Boot 1 + if grep -q "BOOT1_MARKER" "$TRACEDIR/instances/backup/trace" 2>/dev/null; then + echo "PASS: persistent-02-backup-instance" + exit 0 + else + echo "FAIL: BOOT1_MARKER found in boot_map/trace" \ + "but missing from backup/trace on second boot" + exit 1 + fi +fi + +# First boot: write BOOT1_MARKER to boot_map and reboot via sysrq-trigger +echo "BOOT1_MARKER" > "$TRACEDIR/instances/boot_map/trace_marker" +sync + +# Trigger reboot to restart into second boot +echo b > /proc/sysrq-trigger 2>/dev/null || echo c > /proc/sysrq-trigger 2>/dev/null || true +sleep 5 +echo "FAIL: reboot trigger failed on first boot" +exit 1