From nobody Mon Sep 28 15:14:33 2026 X-Original-To: dev-commits-src-branches@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 4htlGK74MRz6Wnvw for ; Mon, 28 Sep 2026 15:14:33 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (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 "mxrelay.nyi.freebsd.org", Issuer "YR2" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4htlGK6cbmz4JCT for ; Mon, 28 Sep 2026 15:14:33 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1790608473; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=gsrHBFwGSUOOlFM1BRB2eJJErb55Z2YucJni7j04yXE=; b=Z8/jPF2HK5EhvgbP7svvzmNxAiBje9dPHcMdRGyMUoMQzqYeVMNpsEphCLg0m9YqmZcD54 YfVE8SNXNLkqDMWh9QAZGepCXLwtHY0z8fG4qCOI2k+U+9tUGIVZS7uXsI4snBK7tBwV5R Tifi/Uj+qMddBoDKaT1nzQWiIfl2CToHuK5jkTGpI+cDC4mwQuJCcq10czTDAIaSOJXHvS sBbm7yQXu/QRlOI4FhcZ88qXNfqRgURes0bcvmfRKPmy/n/d3mPCa81bFkEwFzw55mYGf7 P2NA9omBbVK33L0JQBZnqkN7lDI2LeuhE9MwNXcEXCu5HM2OYdy5ZMdU36P8FQ== ARC-Seal: i=1; a=rsa-sha256; d=freebsd.org; s=dkim; cv=none; t=1790608473; b=OM2qAoN2kWs+Y1qkgTf/0ixoveAoy1pi5bTwsPPAzvLj0EFnU95eqRNlG4CRvb40zErgzI 4jT+hwpyb8LenYjrjEOsr9M9K/bTjoZdjgvUf11ik1EOZ0b14whEDnvPvCAlpIXzrlPx6T xtT30Qv6CRjgcIuDvw35jTRwPkda3m7CSQj2WOYOR4KGlKIIPoMsVzRPoX4NIeU/fQP7eL JNnmaPptJRqK7J0GCc2S6nNgWAGg5fsldJSckk7VSi1mkoXdyXDQPBGVr72JXnX/SoH5IL E6gJ4H46T0xvXLhuaL59YQwIPK0JeEomG2kxfrjEz9NZRCZsz9VAq1JNaiQxmg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1790608473; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=gsrHBFwGSUOOlFM1BRB2eJJErb55Z2YucJni7j04yXE=; b=ecujPwd5tTXBSZ774d7FM+Kqg91MO3QJR23Zk+vbQLreSJaTsmLp8VvSS8X781M1wyXg8e Q7OWsV0kpZQhd8iYdpkvVZMRpPmvZxgHJnHGMyWjcbHbe5tjSmfYgqRzx+GTx92HaBEu6x Be0G79Z9c4PdkEJJGWqQbzJ91BEVwttPapa4Q/naToUs1FDpt/Oo7ybcMFxcXribhBfmnt 4bjTLJeMeJuYhTO1O0RFxmWkor65Ep32nD2BqZ9uSNGvSXx2TmutSvc1irI+EhABPeCsbL X6Sl2imJN/wPGPervQa723gR9Gzk6tIqSCs0JTt1plAxeo7HFITf/QnjKWDGJg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4htlGK55sczYQh for ; Mon, 28 Sep 2026 15:14:33 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 2193c by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Mon, 28 Sep 2026 15:14:33 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Cc: Benjamin Jacobs From: Mark Johnston Subject: git: 52850d1831de - stable/15 - dtrace/arm64: de-pessimize dtrace_copy List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-branches@freebsd.org Sender: owner-dev-commits-src-branches@FreeBSD.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: markj X-Git-Repository: src X-Git-Refname: refs/heads/stable/15 X-Git-Reftype: branch X-Git-Commit: 52850d1831de7a3e1ab4aeba3919b26f68f4b7dc Auto-Submitted: auto-generated Date: Mon, 28 Sep 2026 15:14:33 +0000 Message-Id: <6aba8459.2193c.53e01d40@gitrepo.freebsd.org> The branch stable/15 has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=52850d1831de7a3e1ab4aeba3919b26f68f4b7dc commit 52850d1831de7a3e1ab4aeba3919b26f68f4b7dc Author: Benjamin Jacobs AuthorDate: 2026-09-09 09:57:12 +0000 Commit: Mark Johnston CommitDate: 2026-09-28 13:38:01 +0000 dtrace/arm64: de-pessimize dtrace_copy When DTrace catches a data abort exception it resumes execution on the next instruction. If a probe executes copyinto from unmapped memory, then dtrace_copy keeps faulting on successive bytes until the loop counter is exhausted. Detect the situation by witnessing the absence of zero-extension from an aborted unprivileged load. Reviewed by: markj MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D59341 (cherry picked from commit 464b29857ff18801aca49d1001643c5cdd1324e8) --- sys/cddl/dev/dtrace/aarch64/dtrace_asm.S | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/sys/cddl/dev/dtrace/aarch64/dtrace_asm.S b/sys/cddl/dev/dtrace/aarch64/dtrace_asm.S index a934733251a3..decca6f79e0c 100644 --- a/sys/cddl/dev/dtrace/aarch64/dtrace_asm.S +++ b/sys/cddl/dev/dtrace/aarch64/dtrace_asm.S @@ -109,8 +109,11 @@ dtrace_copy(uintptr_t uaddr, uintptr_t kaddr, size_t size) ENTRY(dtrace_copy) cbz x2, 2f /* If len == 0 then skip loop */ 1: - ldtrb w4, [x0] /* Load from uaddr */ + mvn x4, xzr /* Set all bits */ + ldtrb w4, [x0] /* Load from uaddr or raise data abort */ add x0, x0, #1 + lsr x3, x4, #32 /* Extract zero-extended high bits */ + cbnz x3, 2f /* If high bits != 0 then break */ strb w4, [x1], #1 /* Store in kaddr */ sub x2, x2, #1 /* len-- */ cbnz x2, 1b @@ -120,15 +123,16 @@ END(dtrace_copy) /* void -dtrace_copystr(uintptr_t uaddr, uintptr_t kaddr, size_t size, - volatile uint16_t *flags) -XXX: Check for flags? +dtrace_copystr(uintptr_t uaddr, uintptr_t kaddr, size_t size) */ ENTRY(dtrace_copystr) cbz x2, 2f /* If len == 0 then skip loop */ 1: - ldtrb w4, [x0] /* Load from uaddr */ + mvn x4, xzr /* Set all bits */ + ldtrb w4, [x0] /* Load from uaddr or raise data abort */ add x0, x0, #1 + lsr x3, x4, #32 /* Extract zero-extended high bits */ + cbnz x3, 2f /* If high bits != 0 then break */ strb w4, [x1], #1 /* Store in kaddr */ cbz w4, 2f /* If == 0 then break */ sub x2, x2, #1 /* len-- */