From nobody Fri Nov 21 07:12:55 2025 X-Original-To: freebsd-current@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4dCRJB31dCz6Gjrs for ; Fri, 21 Nov 2025 07:12:58 +0000 (UTC) (envelope-from mmel@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R13" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4dCRJB1CqHz3sCx; Fri, 21 Nov 2025 07:12:58 +0000 (UTC) (envelope-from mmel@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1763709178; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=aheaZkn47dANNpNUtWcbwOSgMdOYaCQXCjq2ggZhL7I=; b=Srl9BKgClkHB4M1Jcq2JYSRwvpyoxg2M4yopVGLrUYa/wjyZpAa2Z21poVl1HaUlh4nfV/ AqWY+gPiYz8LZyp2U6j2kBn02k0SHfBrujLo0Zy9yMtP1cmW4oEHgtUFzyPJb3BMUHYMnh atyp3a3I28YCm6qqa2CiB56/jzcGvW//30YHF3zKeFlPmXxKPzDtlSRrx1jX//GEfH7LVW TJEQ8MXk5/MP5/rwzkgKTlmorO+BuHEiUXAtFCLZXgUqGFU9RiCeM4VsbUYZQYX0eGrlYY ymkS4Jy4S5IKMZWtrtq9M936dnIwCZrUS2VrOjKqBAG9G6+6qr2YmSY584WAoQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1763709178; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=aheaZkn47dANNpNUtWcbwOSgMdOYaCQXCjq2ggZhL7I=; b=iLrBcg6N3PqAqt2F/icYA25VwhICiTnleBFm7Mk2vcEuw9nhLZd0zhVvxhZ/Av7Hv9M5QZ xZX64KCibYIOR4H5ya64dD7apY1de7CoHCGKuVHvjztkTTGerPIETcPfPUTldGjgWXIToF qG423XR702/U1n+s8JOutzcJLu1i9hSvZ/PQouCRg3SO4MJvknOIT4wb2IAQrxrshXA5So DSW3524SIQJeDagkQsjfJGvW8AQSCjVLteC3yS1QBznczbcYUt5TAN4o6zk9uw793UJT7X O2WwMf/qiaC4+ZQFGlegho1qLg3F9x49dgVhUF7QVvOVavaHvjJZWhTWLg6v8g== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1763709178; a=rsa-sha256; cv=none; b=pYPDufup9svmQGBGTy9quvoGh5yXfwiNJdAUwydbJY7LMn251izpp4/Zf/l0TzgRQvFN+1 t5BVf+XHM8kraLwlseELARFd6bqDS+lcX/28tZgLWBKiQRlZQAPeTMr2WNvRUmFQ3y4PKY 0pfkUXu+zKJ2bUcjQ4QhVDoY1Zc3g5SaqZrhN7L1PBBVaYy751x0mGqbtUTpmJsVek5j1p +EQJ3/1S4dJizsJS4jcN72hBIgHu7krBBwdwPct8WO6yiBqbggxHbMTS+HSo1Lu8mNcjE0 JvJQfVP7Zxy+z/ME9AxrNB/vGvEwD9MOt8zsrJbW68qMRywaQjDQKIT5D5ztnw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from [192.168.168.195] (internet-251.radiolinkplus.cz [109.205.241.251]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: mmel/mail) by smtp.freebsd.org (Postfix) with ESMTPSA id 4dCRJ95PjKz1LRS; Fri, 21 Nov 2025 07:12:57 +0000 (UTC) (envelope-from mmel@FreeBSD.org) Message-ID: <8657a2f4-cb32-49a5-bbf6-cd5a4394c7be@FreeBSD.org> Date: Fri, 21 Nov 2025 08:12:55 +0100 List-Id: Discussions about the use of FreeBSD-current List-Archive: https://lists.freebsd.org/archives/freebsd-current List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-current@FreeBSD.org MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Reply-To: mmel@FreeBSD.org Content-Language: cs, en-US To: FreeBSD Current , Konstantin Belousov From: Michal Meloun Subject: mmap( MAP_ANON) is broken on current. (was Still seeing Failed assertion: "p[i] == 0" on armv7 buildworld) Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit I have confirmed that jmalloc assertions are caused by mmap() failure. It can return non-zeroed page(s) for mmap(MAP_ANON), which is clearly a bug. I have confirmed this on native ARMv7, and according to Mark, it is also reproducible on ARM32 and i386 jails. I think I saw it also on a memory-constrained (4 GB) aarch64, but I cannot reproduce it yet. Have somebody idea how to identify vm faults associated with anon mmap to trigger detection of this failure in kernel? Or any other hint? Thanks, Michal