From nobody Thu Aug 6 18:03:28 2026 X-Original-To: dev-commits-src-branches@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 4hGFWh6BFKz6nRTs for ; Thu, 06 Aug 2026 18:03:28 +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 4hGFWh2jHQz3gW0 for ; Thu, 06 Aug 2026 18:03:28 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1786039408; 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=q12eT5PaS+fW+zOaxGsKxRBe7/r/pmwpIW8WMvktm64=; b=kfQbV+1BJcui6erCeS5o+q0BJG0+97riHgS+Hn2pS2ZKiYhBmPyfsGzmYUGLGKrU4WhjzH xAdGIP7UKU8OQbuiiMkQ9CPNaRqQuYEt8Q0/iy3udT6eQtqd7G/9KlNr43Xx5xIZXdrEMU ayNx9WCOA1v2loU+IK9YgVPxWJrf4FpMI2e7blsJ7Na0gbfHlYD2mzz+meCeVPxUBitXJb DjRLz6TacWzbFSI+ys9SCR8wssh7dWV8MmEbFHWxXdenubzXQPx18EEvhosr09ensrKY9C VdwJPU2J5eJW4EKQVbwVV+PpPpi0Uv1Q08mvlRo2YhuwkaFVJUj21QDRjFQhiw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1786039408; a=rsa-sha256; cv=none; b=TgrToKigkkxtvvRoNUo75+GQe9wunsVw60wpQvvvpmucIRKNybb6irH+I5tFkEDD8UqOi0 y9papsVb9Ww78F5V70R8JsSQh9fYAFtzAoC0ILL7ejeA0Rw8Td8gMe9EL1SAELmNH06r8c G8gvywn5eDRg/4iTbWnYQw4ZOIpQ3PVBH4JeOHi9MSLpFmVh1ZKQjK7MHGUlG503Lh1frb xs2q1FGQ27vyYtn+QgQFvuDKwpOjlKOcZBHuJVqpkkPXXDydMddf+tPey6uW7c5UoPKn9w A6wr8ee3GBkqSXouwqXfhlmH/OeY7MaDmVTvGwoavOjRWpGMiepOASbvIv14nA== 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=1786039408; 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=q12eT5PaS+fW+zOaxGsKxRBe7/r/pmwpIW8WMvktm64=; b=Jn4SY2b4NQL8lB344vsJDY4+MmxN4IMqbtfxyF/Xi7YL6dXHIjVyS1eTs7YHmubTJLXlXc +IgAGF4QQ1AHX3V2RiDebuILHyz3PoFgxTal4hMjAjHFdfl74WTr7aLKEpZ0tc0avAiMTY nJJkj8Yz3I+kC+pS2XU6v9tvBKHt7oQJFSGlv8l9BydVxdBWILXEQp2l9TywapzSnNqGgf OWGFVMMBnXt44OXB9nFD6jT5bIdKw53FnWcJvSY+KzT/SML7uQx9FJvwAT1WU6TlTIP2hD UyQQfi0fIKARNH7bE593kNygeh5aZwEg6qKnl9hGWKYTlIz25EJJ2+HOroYdjw== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4hGFWh1bn1zX78 for ; Thu, 06 Aug 2026 18:03:28 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from git (uid 1279) (envelope-from git@FreeBSD.org) id 31cd8 by gitrepo.freebsd.org (DragonFly Mail Agent v0.13+ on gitrepo.freebsd.org); Thu, 06 Aug 2026 18:03:28 +0000 To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org From: Jessica Clarke Subject: git: ac26e70f96c0 - stable/15 - Merge commit 6b0a46958c56 from llvm-project (by Piotr Kubaj): List-Id: Commits to the stable branches of the FreeBSD src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-branches List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-branches@freebsd.org Sender: owner-dev-commits-src-branches@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/stable/15 X-Git-Reftype: branch X-Git-Commit: ac26e70f96c0d4acd9b1ece52c8768784f2586f8 Auto-Submitted: auto-generated Date: Thu, 06 Aug 2026 18:03:28 +0000 Message-Id: <6a74cc70.31cd8.6716e0fc@gitrepo.freebsd.org> The branch stable/15 has been updated by jrtc27: URL: https://cgit.FreeBSD.org/src/commit/?id=ac26e70f96c0d4acd9b1ece52c8768784f2586f8 commit ac26e70f96c0d4acd9b1ece52c8768784f2586f8 Author: Jessica Clarke AuthorDate: 2026-07-28 11:54:04 +0000 Commit: Jessica Clarke CommitDate: 2026-08-06 18:02:34 +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 (cherry picked from commit 70509d1d9cba254dfd5b3dd83d8a011b5e125788) --- 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) \