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 AA676140E3C; Thu, 11 Apr 2024 10:42:07 +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=1712832127; cv=none; b=jcHxODtTIWMfPAOIZ9zaSgdKm4HTJPcZvTS9dcZrM3P094tR23ALpG6bDc63MovwuVOyEKmTst58eewjEMul4FNRiHQJUbakVAEB6Ojh0krtzwmlcLQvyFOoXeWbW3V8sUms+DRV5vMLs6z99sg0kvFE7F9qcoJ1fHHHWQ9Ndj8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712832127; c=relaxed/simple; bh=bpAzt+3Z1Wbz7ND/OlGZnHtpd46B3VX7hgi8auhzVQA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CZgTiO/+Vjy568pP09FzZa3NyXQsmBotsJpj/xQfl0ZqVMGzhA9wt9em2tZetiBL2uAFZ+M48VIOGHUij/kqBjZBELgkec3lZSeMQDmuFfGo812lSI7XSgVhph7c7vgmKiLG7LSCDi1tRV3QVGz3l93W8eIQ55oErVHpPLOeCtU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Sk8GIxzl; 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="Sk8GIxzl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3428EC433C7; Thu, 11 Apr 2024 10:42:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712832127; bh=bpAzt+3Z1Wbz7ND/OlGZnHtpd46B3VX7hgi8auhzVQA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Sk8GIxzlGn6zTyk+uyRQ3NP2a7LdbxbA0SJv92RXYd88FiXdwb2XMyu5vyoj248H7 WxZHyIPAdFCqb3dbeJN1Z5vP1e2f7aGOEOToUYIcSlG8gFjhzJDTGh0HgymhLoDLhc YwY/HXfKhU4jsvzQaXp85uhYsnpdGpptOo9WDwmg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, kernel test robot , "Borislav Petkov (AMD)" , Linus Torvalds Subject: [PATCH 5.10 239/294] x86/retpoline: Do the necessary fixup to the Zen3/4 srso return thunk for !SRSO Date: Thu, 11 Apr 2024 11:56:42 +0200 Message-ID: <20240411095442.770858885@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095435.633465671@linuxfoundation.org> References: <20240411095435.633465671@linuxfoundation.org> User-Agent: quilt/0.67 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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Borislav Petkov (AMD)" Commit 0e110732473e14d6520e49d75d2c88ef7d46fe67 upstream. The srso_alias_untrain_ret() dummy thunk in the !CONFIG_MITIGATION_SRSO case is there only for the altenative in CALL_UNTRAIN_RET to have a symbol to resolve. However, testing with kernels which don't have CONFIG_MITIGATION_SRSO enabled, leads to the warning in patch_return() to fire: missing return thunk: srso_alias_untrain_ret+0x0/0x10-0x0: eb 0e 66 66 2e WARNING: CPU: 0 PID: 0 at arch/x86/kernel/alternative.c:826 apply_returns (arch/x86/kernel/alternative.c:826 Put in a plain "ret" there so that gcc doesn't put a return thunk in in its place which special and gets checked. In addition: ERROR: modpost: "srso_alias_untrain_ret" [arch/x86/kvm/kvm-amd.ko] undefined! make[2]: *** [scripts/Makefile.modpost:145: Module.symvers] Chyba 1 make[1]: *** [/usr/src/linux-6.8.3/Makefile:1873: modpost] Chyba 2 make: *** [Makefile:240: __sub-make] Chyba 2 since !SRSO builds would use the dummy return thunk as reported by petr.pisar@atlas.cz, https://bugzilla.kernel.org/show_bug.cgi?id=218679. Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202404020901.da75a60f-oliver.sang@intel.com Signed-off-by: Borislav Petkov (AMD) Link: https://lore.kernel.org/all/202404020901.da75a60f-oliver.sang@intel.com/ Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/x86/lib/retpoline.S | 1 + 1 file changed, 1 insertion(+) --- a/arch/x86/lib/retpoline.S +++ b/arch/x86/lib/retpoline.S @@ -108,6 +108,7 @@ SYM_START(srso_alias_untrain_ret, SYM_L_ ret int3 SYM_FUNC_END(srso_alias_untrain_ret) +__EXPORT_THUNK(srso_alias_untrain_ret) #endif SYM_START(srso_alias_safe_ret, SYM_L_GLOBAL, SYM_A_NONE)