From nobody Fri May 26 15:43:57 2023 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 4QSTjp21K7z4Wsr2; Fri, 26 May 2023 15:43:58 +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 "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4QSTjp1RBJz3x2X; Fri, 26 May 2023 15:43:58 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1685115838; 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=gbq0qLbWQ3hmgQqINldHYfLgPtHYFA52CERd8+92g1k=; b=crimvrucUJZ+h6AxbZErCd+o7d6YlPp/k/dxLyExeBd+K5vpvphvbcUf8Tor5UUSVisAGb /GxYRP7Y0myD86YHP4M1IcRibzk9TOMsFy8bK4vPgYM89uI9tLBQKp0Cbebs26uuAMC8rO tu3KQ/QRpnsvvS0DLg5Xg0q7DyHcPT4yAiX2wao9MjgqXuXf+Fx2L80kFCInWDvtzMUe6m aWQH79B0ZWVgavEhVlOHuNOaVv8qP6lbCuhXG56FirGQMN1dsx3CRZghZd2tv6B8AoAGx1 zZElwf4pBcYTlNe+3zE3GsWC54n70tvciO0ubwNg9ona4dgtFN7YXA8Nq99V6Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1685115838; 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=gbq0qLbWQ3hmgQqINldHYfLgPtHYFA52CERd8+92g1k=; b=Ky5HZjgwM0xY3r7+dEiHIp84V68cY3nquZYyM8tdYyoiy8E/Nv1gEeT93eYFiUUI3YsGKC GRhBHvqKBdBpvIsLtvZiHt12F2l7/cLUXQe79hccYPujJVXQ1XNHoTclXtUntQu5G/3vfZ IKizK7YH2JIBlnFG574D/DuPefXC+Ovd260SeONDjXwSuKq6ISeYKM/SLRC/111MawGZNW qJfY2dENqBcFXQe3FS9dTeJZ+rIhxmysOzsttRZHYi+w56U7kLn/TU90lLhqVx+IH3psRs Hise5myCXiI4Brc7deOtMhNn2bM5mWdgMPgQnmu7K2wsWvuH7aEgx5R7avGXTQ== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1685115838; a=rsa-sha256; cv=none; b=KVwjnObPk99tBH2R7zf58oaOnJ1CIX8PhYhdajucVePCYMkp12cZiF0AwPtT2yxOsSjoGe zSAZHUMJoEJpQy1DPOVEBpJ4gN8WzXvcVeKmRm3oi6+TEZdpDak12wXpx+Ca/uJMIc9/oL 6nVwUTGZr+lohE3UnlydpZVFr9wWpNY1Oo65dUyIU0R4jo6Cr17b4mXnLNixgWzAeHUj6G 8j0W0MmzbXHlN4CBymB1yuFvDXISTHMtQnkEFAzsspSwxbuI/k043Uw8eFhGDzebB9QFzt Ry9ODS5rIN1lf48o8uKgolXs6i37DsZjUkQjIvpmyuHi/BDy7DeU2PMZHpxRJg== 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 4QSTjp0VHQz1BqS; Fri, 26 May 2023 15:43:58 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 34QFhv70069266; Fri, 26 May 2023 15:43:57 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 34QFhvsM069265; Fri, 26 May 2023 15:43:57 GMT (envelope-from git) Date: Fri, 26 May 2023 15:43:57 GMT Message-Id: <202305261543.34QFhvsM069265@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Christos Margiolis Subject: git: 5c134fba225f - main - kinst: fix memcpy() tracing crash 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: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: christos X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 5c134fba225fabb2e0f9c763aaca0eeee81d8f9f Auto-Submitted: auto-generated X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by christos: URL: https://cgit.FreeBSD.org/src/commit/?id=5c134fba225fabb2e0f9c763aaca0eeee81d8f9f commit 5c134fba225fabb2e0f9c763aaca0eeee81d8f9f Author: Christos Margiolis AuthorDate: 2023-05-26 15:43:37 +0000 Commit: Christos Margiolis CommitDate: 2023-05-26 15:43:37 +0000 kinst: fix memcpy() tracing crash Tracing memcpy() would crash the kernel, because we'd also trace the memcpy() calls from kinst_invop(). To fix this, introduce kinst_memcpy() whose arguments are 'volatile', so that we avoid having the compiler replace it with a regular memcpy(). Reviewed by: markj Approved by: markj (mentor) Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D40284 --- .../cmd/dtrace/test/tst/amd64/kinst/tst.basic.ksh | 1 + sys/cddl/dev/kinst/amd64/kinst_isa.c | 6 +++--- sys/cddl/dev/kinst/kinst.c | 21 +++++++++++++++++++++ sys/cddl/dev/kinst/kinst.h | 1 + 4 files changed, 26 insertions(+), 3 deletions(-) diff --git a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/amd64/kinst/tst.basic.ksh b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/amd64/kinst/tst.basic.ksh index e3585ca70793..3005da74c895 100644 --- a/cddl/contrib/opensolaris/cmd/dtrace/test/tst/amd64/kinst/tst.basic.ksh +++ b/cddl/contrib/opensolaris/cmd/dtrace/test/tst/amd64/kinst/tst.basic.ksh @@ -21,6 +21,7 @@ kinst::vm_fault: {} kinst::amd64_syscall: {} kinst::exit1: {} kinst::spinlock_enter: {} +kinst::memcpy: {} tick-10s {exit(0);} __EOF__ diff --git a/sys/cddl/dev/kinst/amd64/kinst_isa.c b/sys/cddl/dev/kinst/amd64/kinst_isa.c index 7aba79c1d481..d29f1cd4181f 100644 --- a/sys/cddl/dev/kinst/amd64/kinst_isa.c +++ b/sys/cddl/dev/kinst/amd64/kinst_isa.c @@ -107,10 +107,10 @@ kinst_trampoline_populate(struct kinst_probe *kp, uint8_t *tramp) ilen = kp->kp_md.tinstlen; - memcpy(tramp, kp->kp_md.template, ilen); + kinst_memcpy(tramp, kp->kp_md.template, ilen); if ((kp->kp_md.flags & KINST_F_RIPREL) != 0) { disp = kinst_riprel_disp(kp, tramp); - memcpy(&tramp[kp->kp_md.dispoff], &disp, sizeof(uint32_t)); + kinst_memcpy(&tramp[kp->kp_md.dispoff], &disp, sizeof(uint32_t)); } /* @@ -126,7 +126,7 @@ kinst_trampoline_populate(struct kinst_probe *kp, uint8_t *tramp) tramp[ilen + 4] = 0x00; tramp[ilen + 5] = 0x00; instr = kp->kp_patchpoint + kp->kp_md.instlen; - memcpy(&tramp[ilen + 6], &instr, sizeof(uintptr_t)); + kinst_memcpy(&tramp[ilen + 6], &instr, sizeof(uintptr_t)); } int diff --git a/sys/cddl/dev/kinst/kinst.c b/sys/cddl/dev/kinst/kinst.c index 46b9bf2f41e8..e30b813e0400 100644 --- a/sys/cddl/dev/kinst/kinst.c +++ b/sys/cddl/dev/kinst/kinst.c @@ -65,6 +65,27 @@ static dtrace_provider_id_t kinst_id; struct kinst_probe_list *kinst_probetab; static struct cdev *kinst_cdev; +/* + * Tracing memcpy() will crash the kernel when kinst tries to trace an instance + * of the memcpy() calls in kinst_invop(). To fix this, we can use + * kinst_memcpy() in those cases, with its arguments marked as 'volatile' to + * "outsmart" the compiler and avoid having it replaced by a regular memcpy(). + */ +volatile void * +kinst_memcpy(volatile void *dst, volatile const void *src, size_t len) +{ + volatile const unsigned char *src0; + volatile unsigned char *dst0; + + src0 = src; + dst0 = dst; + + while (len--) + *dst0++ = *src0++; + + return (dst); +} + int kinst_excluded(const char *name) { diff --git a/sys/cddl/dev/kinst/kinst.h b/sys/cddl/dev/kinst/kinst.h index ee756dc87d09..1107a274333f 100644 --- a/sys/cddl/dev/kinst/kinst.h +++ b/sys/cddl/dev/kinst/kinst.h @@ -46,6 +46,7 @@ extern struct kinst_probe_list *kinst_probetab; struct linker_file; struct linker_symval; +volatile void *kinst_memcpy(volatile void *, volatile const void *, size_t); int kinst_excluded(const char *); int kinst_md_excluded(const char *); int kinst_invop(uintptr_t, struct trapframe *, uintptr_t);