From nobody Wed May 28 21:05:32 2025 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 4b728X6m72z5xG3K; Wed, 28 May 2025 21:05:32 +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 "R11" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4b728X3r7Gz3PJQ; Wed, 28 May 2025 21:05:32 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1748466332; h=from:from: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=/T4Wp3t2yYnZ3iuAkPDh4QgvX8VLgONDf97jvQO8xRY=; b=ewxG5h9CGKC/NzqDfJ6eiKm2Axi0RmmEzVq0SA7LJZbTIms/UPf+jPc/5EIaQmuYsIHq7i UFre7vhNyTOYzsHWDzAA16CemDAXS9BAghzJm/l8Wv6vrPCOuGWdw83x7PpNToSmUUK/O6 0v5rzrCB3GVxMsFDUoXtA4ytD8/tAualC8uQ9TX9tBzIoe7M6PUi2yd4/d3a0HsonPEewL sOYwD/T27axPq9b4ZOFviOozQD6L+YgxH01XMKijA6TSDWCU69HzQQpBIMlGuRkjBCsrwr MoMEyY1WM2OwPRAINQp0NOOOePxo9l3d2rilct2TK/kOYbgZwMvhEHMPrm6k0Q== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1748466332; a=rsa-sha256; cv=none; b=OuyMT5jlpBqGBv72x4is/+lFghDgFpmonsOVROFTbJxlxP86G+iHgQ3W03Mm0eZOiFOtK/ QuQfSzCZuMF/+2QwGiK5ahDP0jT0SmNIN5UacbRmZzfXJ2/EmERoTVLEUfDSiIkga49nwb fYlzagcjaKYS2pXyVoYteN53AWBzCpyVTypkIYsrDhLz075PmlKUo4c9lVM1Bz0B7bWLf2 PpdHjDl09AhTKPttpky9ONgnKvT16I1RmvkJp6l6yzfh8KmtWJnDZL/Leo0JWRTKn71gna 0V01X5qZp2z4+ag+Ep0v6X/gUVHs9gpqYAgBLsJBOoLGBSQB3UVqK3GD/7Zkng== 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=1748466332; h=from:from: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=/T4Wp3t2yYnZ3iuAkPDh4QgvX8VLgONDf97jvQO8xRY=; b=BkFhKt+nxB6KnA7IHjLUWlWnnrjNXxuS/61i85QvU3F0koEOglwzCu1qk0ci7JE623xA2/ zenttw/J4oFhsVDvCKCx1ZSSXy6H3Hj89wcgQT92Tw4Axd8x+sw5E7yReygkijH5TIIefI T2tB0MRFhujJEfViUYkumReUT9usTyDmnUKR/QCIa0aKzFK8ruqdVWyibRfRLTtc5Ft20R pee3QPyX3m5SXJ48uLboA0H2uS9akV1kue8se7Xt/3Ewwgykxj80sZti0eqX0aODA/NwMs AIrqPRTAEcQXN10fNpJiwiYlXqDOnCp4959K4FP5N8x4iJotCfP/UJ2EQe6+fQ== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (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 did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4b728X2SgKztL7; Wed, 28 May 2025 21:05:32 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.18.1/8.18.1) with ESMTP id 54SL5WDd062082; Wed, 28 May 2025 21:05:32 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.18.1/8.18.1/Submit) id 54SL5WZo062079; Wed, 28 May 2025 21:05:32 GMT (envelope-from git) Date: Wed, 28 May 2025 21:05:32 GMT Message-Id: <202505282105.54SL5WZo062079@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Mark Johnston Subject: git: 0440b3d2cbf8 - main - dtrace: Add compiler barriers around updates to per-CPU flags 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 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: 0440b3d2cbf83afb55209a9938b31a48912f222c Auto-Submitted: auto-generated The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=0440b3d2cbf83afb55209a9938b31a48912f222c commit 0440b3d2cbf83afb55209a9938b31a48912f222c Author: Mark Johnston AuthorDate: 2025-05-28 20:45:27 +0000 Commit: Mark Johnston CommitDate: 2025-05-28 21:05:16 +0000 dtrace: Add compiler barriers around updates to per-CPU flags Otherwise there's nothing preventing reordering of memory accesses with respect to these flags being set or cleared. Since their most common use is to create a section in dtrace probe context where memory faults are intercepted by dtrace_trap(), such reordering can turn dtrace errors into fatal exceptions. MFC after: 2 weeks Sponsored by: Innovate UK --- sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c | 2 ++ sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h | 16 +++++++++++----- 2 files changed, 13 insertions(+), 5 deletions(-) diff --git a/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c b/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c index cfd403ac1a01..7192df200ae2 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c +++ b/sys/cddl/contrib/opensolaris/uts/common/dtrace/dtrace.c @@ -549,10 +549,12 @@ dtrace_load##bits(uintptr_t addr) \ return (0); \ } \ \ + __compiler_membar(); \ *flags |= CPU_DTRACE_NOFAULT; \ /*CSTYLED*/ \ rval = *((volatile uint##bits##_t *)addr); \ *flags &= ~CPU_DTRACE_NOFAULT; \ + __compiler_membar(); \ \ return (!(*flags & CPU_DTRACE_FAULT) ? rval : 0); \ } diff --git a/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h b/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h index 263b254b9021..c274a9f3357a 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h +++ b/sys/cddl/contrib/opensolaris/uts/common/sys/dtrace.h @@ -2421,11 +2421,17 @@ extern void dtrace_helpers_destroy(proc_t *); #define DTRACE_CPUFLAG_ISSET(flag) \ (cpu_core[curcpu].cpuc_dtrace_flags & (flag)) -#define DTRACE_CPUFLAG_SET(flag) \ - (cpu_core[curcpu].cpuc_dtrace_flags |= (flag)) - -#define DTRACE_CPUFLAG_CLEAR(flag) \ - (cpu_core[curcpu].cpuc_dtrace_flags &= ~(flag)) +#define DTRACE_CPUFLAG_SET(flag) do { \ + __compiler_membar(); \ + cpu_core[curcpu].cpuc_dtrace_flags |= (flag); \ + __compiler_membar(); \ +} while (0) + +#define DTRACE_CPUFLAG_CLEAR(flag) do { \ + __compiler_membar(); \ + cpu_core[curcpu].cpuc_dtrace_flags &= ~(flag); \ + __compiler_membar(); \ +} while (0) #endif /* _KERNEL */