From nobody Thu Sep 03 15:05:34 2026 X-Original-To: dev-commits-src-main@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 4hbNFV3Gy2z6rPKM for ; Thu, 03 Sep 2026 15:05:34 +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 4hbNFV2MqXz43PN for ; Thu, 03 Sep 2026 15:05:34 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1788447934; 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=K3tQBSTm9j2MJFgUvk9GeZFrmWiLzHl7taJuvBLo7OQ=; b=tMUpHxf5X3UwrPl4zv9VsHrVDSh7aHqZFeGENAh13UJvlZgu/d/AoDp6VLawpOHhtHQt7Z kfsznyBQzRfmOB9/ia3epMZGeibLPoU3cP9gSnv32oc8zxdwYr1pcVRTUhP8Yhb3lc7X4v oJsn0nh8UFeVKPRZocNrgV59DK1z0Y5ZvmahNS14mDTsjWvyaRgiXp0eQrOf6FpVFesHm/ rFclnVJyYBbdjiZIAZfaMPpwXoK5i2JHDBEzbAAu0sdSPMqfKyHfI5PY8y6QHieZ/YM/i6 vVWOGA86xGSkod1NCdcxbgorxt395eFfbR+ZdE/MAQHfSuajBLMGUfiG+G26FQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1788447934; a=rsa-sha256; cv=none; b=UcQ8vNNdnKXMOEqaq13aESEcmf+pPJ2QlGHk+6ww6vugXTErFYaDnRWZF/T5X2S8WwXVAA s5IlSfYZMT8Wb4JnN5y8xwvASG0vjHS4Xe4qU5g8X4oU448GJ3ixzJocE6xyVcNd2jaEpy 3uD7ifr1eEJmSV3sadTRiu6i4YK34QySexIdPjUKjxrPCvPy5S2D8qTqVYkJ0AZ/PLDF/Y h0KNB0f1JL8fdkAlAz8WcRn3fDns93JbVikSYZgnSRkfrCxh6bDZ9Uel5VwB6Ig/BPJTYS 4jFFEk8MBQd16Mw+lo7QdSO2OneKfCGds/shhBfw1DRTdg4LsoOi0MfqGk5r5Q== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1788447934; 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=K3tQBSTm9j2MJFgUvk9GeZFrmWiLzHl7taJuvBLo7OQ=; b=RBR3W+zJB4gGkFxmhKtMQKDxfOINliInC5N/TrMOT1lRM0ryn8tE2Cdb27p0Tmp5QEaz8g +eDOJtbbWLIClFKzHsSC6CoTP3jsssjtLmhzZACwIwF3ZSKIpJQhhnk/5+Aukvyw5Nn9ui 9lbEovplUVF9o4qZ1HFw9Wpon5tfBY1t73Y6pirmOyjytEPyfVrGPqQTVtgrSfn+bLnmqJ ZHbkoIozgH4fZMDutQDOQ8S4S8iF70KSHhF8gIvqvRIqIwE1tr1LC6vzo+Iiq6M1pPSRci H+eaFas8IeIzgGGWFIesKjjnDdIo4sYmoK9eiWfOWnfmRXtQGQiBMKwHcONvcw== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4hbNFV13jzz3d7 for ; Thu, 03 Sep 2026 15:05:34 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 26a56 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Thu, 03 Sep 2026 15:05:34 +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: c874d312e78f - main - dtrace/arm: Fix and de-pessimize dtrace_copy List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@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: c874d312e78fc60e6731a043fc45b47165618370 Auto-Submitted: auto-generated Date: Thu, 03 Sep 2026 15:05:34 +0000 Message-Id: <6a998cbe.26a56.25038a33@gitrepo.freebsd.org> The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=c874d312e78fc60e6731a043fc45b47165618370 commit c874d312e78fc60e6731a043fc45b47165618370 Author: Benjamin Jacobs AuthorDate: 2026-09-03 13:52:21 +0000 Commit: Mark Johnston CommitDate: 2026-09-03 15:05:03 +0000 dtrace/arm: Fix and de-pessimize dtrace_copy Use an unprivileged load to access user memory from dtrace_copy, which is running in SVC mode. Abort the loop if the load is trapped, as it is useless, hence wasteful, to keep faulting on successive addresses. I believe that this de-pessimization should also be done on aarch64 and riscv. PR: 298064 MFC after: 1 month Reviewed by: markj Differential Revision: https://reviews.freebsd.org/D59280 --- sys/cddl/dev/dtrace/arm/dtrace_asm.S | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/sys/cddl/dev/dtrace/arm/dtrace_asm.S b/sys/cddl/dev/dtrace/arm/dtrace_asm.S index b0eba6f1ed9f..d4730384b581 100644 --- a/sys/cddl/dev/dtrace/arm/dtrace_asm.S +++ b/sys/cddl/dev/dtrace/arm/dtrace_asm.S @@ -130,13 +130,14 @@ dtrace_copy(uintptr_t uaddr, uintptr_t kaddr, size_t size) ENTRY(dtrace_copy) stmfd sp!, {r4-r5} /* stack is 8 byte aligned */ teq r2, #0x00000000 - mov r5, #0x00000000 beq 2f -1: ldrb r4, [r0], #0x0001 - add r5, r5, #0x00000001 - strb r4, [r1], #0x0001 - teqne r5, r2 +1: mov r4, r0 + ldrbt r3, [r0], #1 + teq r0, r4 /* Check if the load was trapped */ + beq 2f /* Yes, quit now */ + strb r3, [r1], #1 + subs r2, r2, #1 bne 1b 2: ldmfd sp!, {r4-r5} /* stack is 8 byte aligned */