From nobody Tue Jul 28 11:54:35 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 4h8YmC5qCcz6mfkK for ; Tue, 28 Jul 2026 11:54:35 +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 4h8YmC3gwmz3w0S for ; Tue, 28 Jul 2026 11:54:35 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1785239675; 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=KMDn12ZAvCIjD6QDHoRgJ2rorMWFnHgF6qMDty6SjdlLFoyIsk0fgW14R7X8A1rrJUwTXB UkX1FwGChH6ZznT8Tvu32TUDGlmo9xon3IPntGbOHFT7kXCZR7To3GurwNHA4uB/aV/8nQ HZV7uqFjcjDzWIKeoVvaKfU2gpR9B6TOlwqrR+JkNx51kvrIhLBE3bNkGKd1oTWIike3/e k9PoTP8yjRmycJDCOp7QIP7LxdUPBQQXQkTLDtLmAaRj7B9BBC4m4Y0+sQikb+5ZbtiUE6 so3m5eUugneQFI/yqdySgY89wz+n+B6PKbNcgMqBnbBlPBXHedG3uNJU0/GCDg== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1785239675; a=rsa-sha256; cv=none; b=b8FNXajyVXH6HQTfEJYbmuauu3tcj/qBIhzAIt8kBX3wNkSUMujP76MHT8+32tO26XjCDu FGQqQE7J8yLjbUMhiDYP2rUA/79FGRWsuh4/WIQjFiFpC4hsNZj2EG4I3CY2yud/yjTg0m jG9MCqa04JvtmwYz1DHgPjlM/be6VnI3ERYCtAKXAOUAO+OOYNkwYigJJgDpNedewEm6ls leIYAWIjZIOuWTd60Rkn/bnnnkGtHsoPUDw1N8RZf7bq0OCQRHClKZIjdsdSLsbhVrhdTQ HBDeUkOlCCIbZN/nqlz+U9lavKClVqn0mI3tUUctaSg5jpa1Ex4is44EwtRupg== 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=1785239675; 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=DkDNSFk8qJbz0bM1EL2bALv7MT5u+JdAbY653rH2+3GFdoWzR3T/YghiG/JZxoj1vjmJBo Rv2Kxp4HPxwYyOLVdVib8lzrERK05ykf7OIPO5QBTVEnJlZpGHapXgaaS3K+uxj30W+7HC NRL4PxieD/k1U8i4CFay/afVdQBB0gAoald84MN3Y7xI6knN0XMPWwhymltXVXyRjkCyOC YQ1Gjb3UOHhc2XEvP/f9+KhrTonyI5Jy8/c5vCt/SoTPeLieE+cyoSxpI74NDxnldzqoiA whMvW5HM2Q2PZ5q283ASPYmk8Xadgu7Mv1smkAA98tPbiCTYEVpANBwrjDtRLA== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) by mxrelay.nyi.freebsd.org (Postfix) with ESMTP id 4h8YmC2Ckzzfkr for ; Tue, 28 Jul 2026 11:54:35 +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 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: 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) \