From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D8AF237997D; Mon, 9 Feb 2026 14:26:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770647208; cv=none; b=lPpHHWmeToYJBQ0wrJP2FUbSOze2Nw8gZPUNmb6wRzQz5Rq7qiJ2JhuE6061Jxyo8uhHcyiZZTeSXGatr09NcE5hF8xjlo9nlKebrq9Tmhgvvxt2WIMQDZZ0fdTTWpFjhhVfgiZRSH+ajUXbiK1fYy2taixOeloG2z8K3TlHy/U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770647208; c=relaxed/simple; bh=tQMAY3LqY7ovZ5Ikb3TXG1xQozyQe0bRquQ3JxFSpq0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WWjt6rVJiOjdstMnuH/CQorq7mu78dJ7yajTJKWMCN81jTP6dGy/uYEkSvagm3XzjHsH9YJC8GVLHTZWNsuStjADw7TqswWU8Rn72nG6yHB3DnKPhSHlyuJPjyvFN8ulOrq0tMd+F+ZxYe6cwfvKAJQRrYnq1Qn6eA7m3He53oA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=aNp8tA9T; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="aNp8tA9T" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3391C116C6; Mon, 9 Feb 2026 14:26:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770647208; bh=tQMAY3LqY7ovZ5Ikb3TXG1xQozyQe0bRquQ3JxFSpq0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aNp8tA9T863/eCzp7FSmokxdIWxdLVuzmjAKfYwKRz9o7ZnfdDMN5L/k5JBD6bOIP RQgZts6FcNiCViUwiCW73yNygre4DkFL94/JbwTnQ2LIxVgq4YM5bW4HVuSBUWG+t2 RdP15yoI7ht+wLvmoFu5ASyxOV3FP4xlyzxdm/DE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhiquan Li , Sean Christopherson Subject: [PATCH 6.18 032/175] KVM: selftests: Add -U_FORTIFY_SOURCE to avoid some unpredictable test failures Date: Mon, 9 Feb 2026 15:21:45 +0100 Message-ID: <20260209142321.630936614@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260209142320.474120190@linuxfoundation.org> References: <20260209142320.474120190@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhiquan Li commit e396a74222654486d6ab45dca5d0c54c408b8b91 upstream. Some distributions (such as Ubuntu) configure GCC so that _FORTIFY_SOURCE is automatically enabled at -O1 or above. This results in some fortified version of definitions of standard library functions are included. While linker resolves the symbols, the fortified versions might override the definitions in lib/string_override.c and reference to those PLT entries in GLIBC. This is not a problem for the code in host, but it is a disaster for the guest code. E.g., if build and run x86/nested_emulation_test on Ubuntu 24.04 will encounter a L1 #PF due to memset() reference to __memset_chk@plt. The option -fno-builtin-memset is not helpful here, because those fortified versions are not built-in but some definitions which are included by header, they are for different intentions. In order to eliminate the unpredictable behaviors may vary depending on the linker and platform, add the "-U_FORTIFY_SOURCE" into CFLAGS to prevent from introducing the fortified definitions. Signed-off-by: Zhiquan Li Link: https://patch.msgid.link/20260122053551.548229-1-zhiquan_li@163.com Fixes: 6b6f71484bf4 ("KVM: selftests: Implement memcmp(), memcpy(), and memset() for guest use") Cc: stable@vger.kernel.org [sean: tag for stable] Signed-off-by: Sean Christopherson Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/kvm/Makefile.kvm | 1 + 1 file changed, 1 insertion(+) --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -245,6 +245,7 @@ LINUX_TOOL_INCLUDE = $(top_srcdir)/tools LINUX_TOOL_ARCH_INCLUDE = $(top_srcdir)/tools/arch/$(ARCH)/include CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \ -Wno-gnu-variable-sized-type-not-at-end -MD -MP -DCONFIG_64BIT \ + -U_FORTIFY_SOURCE \ -fno-builtin-memcmp -fno-builtin-memcpy \ -fno-builtin-memset -fno-builtin-strnlen \ -fno-stack-protector -fno-PIE -fno-strict-aliasing \