From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f171.google.com (mail-yw1-f171.google.com [209.85.128.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CC9AE35B12B for ; Sun, 11 Oct 2026 20:16:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.171 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791749808; cv=none; b=WPM4Icrv5lGS6hcuY5EoERGH5+AmuIZ9SZ/yTIu0dMfubxX9nr5eGJQyNmFO2It0Nc3y0TdOdtUkqeHZ9vJP3GpE1fQ4QcdrqqN5NsJ9DKJwQWQRdxsBNBDt7sSV9e2/qnPT6O8nHTb9D+nrXzC5qMQxzvIW468hPq20OZFTaAA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791749808; c=relaxed/simple; bh=mUa5JfPytUIBNId27ct+pI+y+lXe6dkBu7TtmZ2Okr0=; h=From:Subject:Date:Message-Id:MIME-Version:Content-Type:To:Cc; b=EdSyO17M+MjCZBJWTYCJu8lQz4S8KPkX+OujRgk5Z27ZlLBZzRIqrTI36gZC37gNZsKVu3oZDuNIbp/3OCb5dzpM5J3avk7AbzS9Na3tJ3lKRobj5zF9lfKDJs+ZxNaKzldAXbjQv22heA/WqP5Jouh7Aupe5L4zUA3JZO5Hwyc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=fxG8KF6k; arc=none smtp.client-ip=209.85.128.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fxG8KF6k" Received: by mail-yw1-f171.google.com with SMTP id 00721157ae682-8b06c0794cfso8866217b3.0 for ; Sun, 11 Oct 2026 13:16:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1791749806; x=1792354606; darn=vger.kernel.org; h=cc:to:content-transfer-encoding:content-type:mime-version :message-id:date:subject:from:from:to:cc:subject:date:message-id :reply-to:content-type; bh=LMIFt4Dv9YYDb9vJ6+cJXhs5xmH9sVe/KBqI/bov4Ps=; b=fxG8KF6k5+mW6gdTNTG4F67fBO+eA4n5qdO34dC9x5APqsqi4uaQ8CyYedrMMEiBWt UAo/sFIm2V1ZmlPWeWJr1CdOyWs+WZjnBCyihF3bRTIy3klYKMd9ceBGWF+/i4DxDMBe SBWvTI0CVPSSS73Obasmzh+SkbTwl9TaWx+xPLFU+suSQNmYCglKIU6LBN3kD+Chq2ic PvmWkQHj1UTFyMb0TPAv0Ru4zFIzAsWg/6dEQhTWsNR91niQvCmFY/csPLNlqTE2zc6e uAhyBNm410MaLyAxeqEQ3gCkY3o8COIIu6va8k/deJghbt9MtvlmHYmmxh8Q8+lyM2fD s1tA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1791749806; x=1792354606; h=cc:to:content-transfer-encoding:content-type:mime-version :message-id:date:subject:from:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to:content-type; bh=LMIFt4Dv9YYDb9vJ6+cJXhs5xmH9sVe/KBqI/bov4Ps=; b=s2vN5/KVx7zfbiQeg0xJsOhfJhoAgMj01L4l1fKRtb2I9I9tRDe33aXXz8cqae/Zh6 D9vEBoDkqo7qo8NAx8zt39UWBnl942Z4vBIiDU6cpvmW8Z18cTZgUV9hmiuiLGdiEVzg U+aWm6sO4oUMVYBuEdDqrqRHyuhpZsAdeK6UGI25QaTIBrp6TVk3+OLPP6IVcDoLJfv4 StTwKObX3xOQXg02Gq62fT91FfhEzFaTDAk8dgan0iU8rxOTv8eEfV0h3w1l2eZAm3QH fht5doZQ/fPSQCBlOumPSXRxyHp5jx4H+jGeCg9yQci7ihzVBDB7xRVdFrU7Z/g/rQf+ YK5A== X-Forwarded-Encrypted: i=1; AKwUvBzPoKswNpZ2pWIQQZ0BdU2c/7BVt9bct2tjwfeMtkqFPRn8HD2A/xtHI51ds//sO71RPv+ZabcVGkwL9IY=@vger.kernel.org X-Gm-Message-State: AFq9FYLLSYWaKiZ79wKjw/tyJVL7DBXG7/wHZQguJxo4srOGVuOIXGZ3 RL6itC798agg+VCnpO4RPUA2uSW2cY/Dp1zicvNul/zDhqUA7bxm5a5f X-Gm-Gg: AYBFou0GyEj2FqHY0a0ZxLTjpKOp3eLQ22Xnswo8oC3HHjpSZLvMZAwplQ2ExTHFzai 5Xw/EPDKOciVXiyOhIwcT+0BvD2GJDCphmu96277zy7yKuGSAPf3xpBpIjFIxF7nZpHF65UkTze qTmcnVPb/E1OCCHhdk1wN3BEa8oexrG1TsApVzJMiRIcYYyu33rQgT/uQiAlppYwG7iVeNkzvWp 9qUsNOWtlYfHufbGZiVmbE+beh3pkhz0pV+28VOLCW8WP3LgkGdw3qGklOi0CSujnvgk+uA0cP+ HsvvYCea8TBtEUswBalrrDHZDpVt2SXVPAJtOzak+m9lyYpCidi8rTtw+RiaHvMfxICl/KLAMOQ o10EzYh0KeMlc6UJTOOwvt0col4JgjEF3v5E14r89WdgI5nOyBib5SQm6swQWddlwj4L6ZQEEiF QAebiH5hmDT44uk1SQTRyujqkISAvm3qdxF+j7ZRb1Cbgxcum8yq6H9aR02OHWKyh93AWq1eYFG +VwgRFgvizTwjXEKDpxcx7PtlaL9mhzFRB3mk3v83eYAQpYdEJ494zb X-Received: by 2002:a05:690c:6e85:b0:8b0:a352:f96d with SMTP id 00721157ae682-8b0a352fd2bmr4001297b3.11.1791749805566; Sun, 11 Oct 2026 13:16:45 -0700 (PDT) Received: from localhost ([2600:1702:7a90:6f9f:8bc4:8aec:108d:7a04]) by smtp.gmail.com with ESMTPSA id 00721157ae682-8b07f1ea845sm28267397b3.24.2026.10.11.13.16.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 11 Oct 2026 13:16:43 -0700 (PDT) From: Matt Turner Subject: [PATCH 0/4] alpha: perf register sampling and user stack dumps Date: Sun, 11 Oct 2026 16:16:40 -0400 Message-Id: <20261011-alpha-perf-regs-v3-v1-0-eaa625a39712@gmail.com> 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: 7bit X-B4-Tracking: v=1; b=H4sIAAAAAAAC/x3MSQqAMAxA0auUrA10wAGvIi5KjRoQLSkUofTuF pdv8X+BRMKUYFYFhDInfu4G0ykIp78PQt6awWo7GK0N+iueHiPJjkJHwuxwJOt6PQUTvIUWRqG d33+6rLV+S01NGGQAAAA= X-Change-ID: 20261001-alpha-perf-regs-v3-7e23508c1ca2 To: Richard Henderson , Magnus Lindholm Cc: linux-alpha@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-perf-users@vger.kernel.org, Matt Turner X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=1840; i=mattst88@gmail.com; h=from:subject:message-id; bh=mUa5JfPytUIBNId27ct+pI+y+lXe6dkBu7TtmZ2Okr0=; b=owGbwMvMwCW25rVmCc8sv+mMp9WSGLJOv1uptCh8YuRrwxtOx3f+klebfddBfEKC3JNCEUmFt ctMreJNOz6yMIhxMcwUU2SJW6/IMqttx1Kf09K/YOawMoEMkRZpYAACFga+3MS8UiMdIz1TbUM9 QyBDxygeIqfHoJFZXFyaWqSbVlDkkJdfkliSmZ9XrJdfkJpXkF6gl5aZVpKRkV9UnAo0Qi8vtcT U1dHNyNDAxNLRwszJwtHUxNnZydDJzdHR2dXJyNLcxMDZ0tHE1dKcgYtTAOaaa4sZGXo7mf1+B+ z12/Eu/shBuwOFs9f1RPd5T66Yfn13a9Os2HJGhkel4i1b+KpcHhzx1so9zvd5YZnmqdYzFw/NM lGfOpWvgBsA X-Developer-Key: i=mattst88@gmail.com; a=openpgp; fpr=3BB639E56F861FA2E86505690FDD682D974CA72A This lets perf sample registers and dump the user stack on alpha, which perf record --call-graph dwarf needs to unwind user space. r9-r15 are not in pt_regs, so they cannot be sampled. An unwinder therefore cannot get past a first frame that uses $15 as its frame pointer (-O0 code or alloca). The perf tool side is a separate patch for perf-tools-next. libdw also needs alpha unwinding support, which I am sending to elfutils-devel. --- Matt Turner (4): alpha: fix stale user_stack_pointer() alpha: stop storing the user stack pointer in pt_regs alpha: use user_stack_pointer() in KSTK_ESP() and dump_elf_thread() alpha: add HAVE_PERF_REGS and HAVE_PERF_USER_STACK_DUMP support .../features/perf/perf-regs/arch-support.txt | 2 +- .../features/perf/perf-stackdump/arch-support.txt | 2 +- arch/alpha/Kconfig | 2 + arch/alpha/include/asm/processor.h | 3 +- arch/alpha/include/asm/ptrace.h | 7 +-- arch/alpha/include/uapi/asm/perf_regs.h | 45 +++++++++++++++++ arch/alpha/include/uapi/asm/ptrace.h | 2 +- arch/alpha/kernel/Makefile | 1 + arch/alpha/kernel/asm-offsets.c | 1 - arch/alpha/kernel/entry.S | 5 -- arch/alpha/kernel/perf_regs.c | 56 ++++++++++++++++++++++ arch/alpha/kernel/process.c | 2 +- arch/alpha/kernel/ptrace.c | 12 +++++ arch/alpha/kernel/traps.c | 8 ---- 14 files changed, 122 insertions(+), 26 deletions(-) --- base-commit: 8f5dbfb93440d1aba216a1a34369a65654b94be9 change-id: 20261001-alpha-perf-regs-v3-7e23508c1ca2 Best regards, -- Matt Turner