From nobody Tue Jul 28 11:54:35 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 4h8YmJ40Tfz6mfZ6 for ; Tue, 28 Jul 2026 11:54:40 +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 "YR1" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 4h8YmJ3SS6z3w7d for ; Tue, 28 Jul 2026 11:54:40 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1785239680; 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=ZbIRnexBtVSSfrI56iIaVThe9TP62SDdQQCwQI1k1bk=; b=DuZkGzHnns2oA0MI6L9H5mJM2kZ/FPU+aKFMrgmYTWZYD4m8MDfFTPyvLbrPklcCQV3fpc 2vr1Ahl2JSzAzA+P6+cWNXCz5pfLK9fZs1G2NJpN0z0yndm0GSzjSWd48QZPqHaD56dhDl lvlHJlQiMgstK4BAZSvbz09CFu1Pw+BKFuV9RodiutmPq0Rm6xjTq1sTUunglR9jQVRTX1 0Wx8zpAEaxulw7umiMfShX8CAI672XqNtXzSu7F0StWz6rp//eOfZIT8HE6DEY1Qo0VMGg ZpTT90kzAdool9lSVu+0KdVnB7e82lZ1dkMl7f94vMfUq1JmSXiBV0J3wiWURw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1785239680; a=rsa-sha256; cv=none; b=mbB7JnljVfMdJVKgQLwqgxX5nClt4O6Eqrn9MghMEIUl9KMU4UVwkfi2N6r4p8oZS+LO+r x6kwEZHgXJ9a67KeiTK3tRUbO0XGtL0dxvm2yC0NXLMwKtrhTBWI8tqQsuEcb0sJXX00bH 6AM35eAWZWUidXrzTfbUI1TWlJNjsIcmzAYF+cuVzY3+zY+/dKWTt+Lb61lQ3Q8/vc9sf6 Qr2Yilp8foWTs7r+OLNwDxLkf6CnNj82kheQRj4KfLtOW/PR+x/KmodH4yzh7zDNxI++Jt gj2zvtCY3TqZCgonC8D15bVhe7g4igDswZnQBLCK960hrTXtWc9Ak6JOn22pyw== 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=1785239680; 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=ZbIRnexBtVSSfrI56iIaVThe9TP62SDdQQCwQI1k1bk=; b=mxHs5pHA4e3hP3ebGZCU22mVSewkEGRPpBK/X3TxxdniBRiI2JXK1QA5FG4ILXqonO20zT DmlbPGPmAb0mm7XUa7YOu6q34pfXYdDtD+Ffrp4O+4Z8YZfsopseo98qed4PlZa5aORv9D 2je+wvCe2YqrxxzSFU3zyAGR8ZNHGpI1WYzx2EHUELbWU1icmpoU/qeAU5MggseaUZIP7l WKMJSil8FB674UsQtnM2eMGAPsF2my4bMp2W6lpj6LyvBNfZ2j+L2XylSZ8eOEy8idLqI3 txlOR1j+aPeMGMwqFXpoxR7JZn5xPh+uwe8Q/q8zqm7GVay0r/ZUNzO17xqvlQ== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4h8YmJ2MvyzfXw for ; Tue, 28 Jul 2026 11:54:40 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 32f8e by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Tue, 28 Jul 2026 11:54:35 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Jessica Clarke Subject: git: 70509d1d9cba - main - Merge commit 6b0a46958c56 from llvm-project (by Piotr Kubaj): 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: jrtc27 X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 70509d1d9cba254dfd5b3dd83d8a011b5e125788 Auto-Submitted: auto-generated Date: Tue, 28 Jul 2026 11:54:35 +0000 Message-Id: <6a68987b.32f8e.3d475221@gitrepo.freebsd.org> The branch main has been updated by jrtc27: URL: https://cgit.FreeBSD.org/src/commit/?id=70509d1d9cba254dfd5b3dd83d8a011b5e125788 commit 70509d1d9cba254dfd5b3dd83d8a011b5e125788 Author: Jessica Clarke AuthorDate: 2026-07-28 11:54:04 +0000 Commit: Jessica Clarke CommitDate: 2026-07-28 11:54:04 +0000 Merge commit 6b0a46958c56 from llvm-project (by Piotr Kubaj): [libunwind][PPC64] Fix unw_getcontext corrupting callee-saved VSX registers on LE (#198371) This is the first of two independent fixes for libunwind on ppc64le (ELFv2 ABI, little-endian), where two separate bugs together cause SIGSEGV during backtracing. This commit addresses the VSX register corruption; the TOC-restore fault is handled in a follow-up. Both were discovered while debugging lang/rust build failures with RUST_BACKTRACE=1 on FreeBSD/powerpc64le (IBM POWER9). On ppc64le, `unw_getcontext` saves each VS register with an in-place `xxswapd n, n` followed by `stxvd2x`. The swap is needed because `stxvd2x` stores doublewords in the wrong order on LE. However, the macro never applies a second `xxswapd` to restore the register after the store, so all 64 VS registers are permanently corrupted on return from `unw_getcontext`. This affects every callee-saved VSX register: f14-f31 (VSR14-VSR31) and VR20-VR31 (VSR52-VSR63). After `_Unwind_Backtrace` returns, any code that uses these registers sees wrong values. In practice this manifests as SIGSEGV inside hashbrown's `reserve_rehash`: VR20-VR31 are corrupted before a SIMD comparison loop runs, producing an out-of-bounds access. Fix: add a second `xxswapd n, n` after the `stxvd2x` store. Since `xxswapd` is its own inverse, the pair is a no-op on the architectural register while still writing the correctly byte-swapped value to memory. MFC after: 1 week --- contrib/llvm-project/libunwind/src/UnwindRegistersSave.S | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/contrib/llvm-project/libunwind/src/UnwindRegistersSave.S b/contrib/llvm-project/libunwind/src/UnwindRegistersSave.S index 5139a551ad24..bd41dfcb9db4 100644 --- a/contrib/llvm-project/libunwind/src/UnwindRegistersSave.S +++ b/contrib/llvm-project/libunwind/src/UnwindRegistersSave.S @@ -418,9 +418,13 @@ LnoR2Fix: // register in the incorrect doubleword order. // FIXME: when supporting targets older than Power9 on LE is no longer required // this can be changed to simply `stxv n, 16 * n(4)`. +// Restore the register after storing: xxswapd is its own inverse, so a second +// xxswapd undoes the in-place corruption of callee-saved VSRs (f14-f31, +// VR20-VR31) that would otherwise persist after unw_getcontext returns. #define PPC64_STVS(n) \ xxswapd n, n ;\ stxvd2x n, 0, 4 ;\ + xxswapd n, n ;\ addi 4, 4, 16 #else #define PPC64_STVS(n) \