From nobody Thu Sep 10 09:16:01 2026 X-Original-To: dev-commits-src-all@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 4hgX924G7mz6rjWJ for ; Thu, 10 Sep 2026 09:16:06 +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 4hgX923Zglz4TCX for ; Thu, 10 Sep 2026 09:16:06 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1789031766; 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=3zTcx1+IxWOcam+vKalRlJgQgAdJHJvfUsVd1viugjU=; b=RW/FUw2EYii0wvtbU1QKBJxNm1o2F+pCOdFFABk9pIL2e7gu7XWIbtvYRQ+MHGRRSwalC+ h/7tJzgFLMfpj1wWIuaJTZZqPLuBsfmc6usKwHKm96zSpaZcCeVasS67gHCbPRGxsrLx26 i09Nt3CXWHeZwCI7QeYZ0RJ8GCXzuku0JVXtDjkLXlGMJS2wAlWF20f+s6STSvyoKO1n+X FRr/KhWuPt6GOMoPJlchlB9wPYbZzzwbFdhPpJHqp9H55QKnT6xdSbkksW/CK5rZD8o9i7 kGRau9YCgMxxZy+jTUaEeBs1y1McJ91qkYDEbfl1mfc6JZBhKr1ChzkxfYyIIg== ARC-Seal: i=1; a=rsa-sha256; d=freebsd.org; s=dkim; cv=none; t=1789031766; b=aSOf/K54JneBRmGDk8HVHQGughYq/XDs4Jk8PRdHN4ElC3YQh3iQw7pCTk/OdOQdVg9pFE Feubr4KM3Z3RC0bCnllXtjeVKwGgqhWe7ZH+VwD2cDPquKPG1jU3M8PWqmb2zZZcgganm4 pTvcRrbd8Cu84pXHHD0xlqXwMEhk2c+LFevWU+xqL/+xU2hJcqMLK7+tnptEfXYGlU34AU wbgC2HuNLa/VW3N4lgdCAZhrFSkRRCwCozCY2u/p+S47m/i4bZHyyhiNAjf88lPxcLJFwN yMKU0OxmUUNP/+sj+UmAHNaI21jgxCKVT8rEBotrA6jXwd+MfCv8ec1Emv5gFg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1789031766; 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=3zTcx1+IxWOcam+vKalRlJgQgAdJHJvfUsVd1viugjU=; b=St7j5Et6cQGshPu3alXKqLXN6neKwDQwsVITnOcO6VSv57BNs4KvxsgcTrhRoa9nLanV0U Sn86DElq+9KmSt7JOqqVjY0mrqDNvAgNxUQ9gSyv0tjq7vCNWtrwqLTAtRv6Veoi2c+pSv R5nUHvyTOjn+LiLMGidaXX8unhYSrylzQY54j25tRU1OHfhzExd3mh/3FmdHt1EsJ1fXi9 6sWzSmaFa6DohpDHOor0Esb8FHwPXnGyBUnHXEvPHbgieC0F/WknRTX/h3hIPeiX7MLgq7 nJRTP0p40ENFrKswETS20mjCvwWyNgS2PWQxCmrCleCeAibC4pM5w7Dd8Obxrw== 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 4hgX922d0xzLRT for ; Thu, 10 Sep 2026 09:16:06 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 22db0 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Thu, 10 Sep 2026 09:16:01 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Cc: Benjamin Jacobs From: Mark Johnston Subject: git: 464b29857ff1 - main - dtrace/arm64: de-pessimize dtrace_copy List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@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/main X-Git-Reftype: branch X-Git-Commit: 464b29857ff18801aca49d1001643c5cdd1324e8 Auto-Submitted: auto-generated Date: Thu, 10 Sep 2026 09:16:01 +0000 Message-Id: <6aa27551.22db0.e124329@gitrepo.freebsd.org> The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=464b29857ff18801aca49d1001643c5cdd1324e8 commit 464b29857ff18801aca49d1001643c5cdd1324e8 Author: Benjamin Jacobs AuthorDate: 2026-09-09 09:57:12 +0000 Commit: Mark Johnston CommitDate: 2026-09-10 09:14:29 +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 --- 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-- */