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 643721CAA99; Thu, 17 Apr 2025 18:38:11 +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=1744915091; cv=none; b=r1hKZyh2BRzR/J4RnHIJfzuVrID5nMW9o4g2ofbaPDh44BAdibvVB04kTz7ID7Wk+uizhBQ7ZCvRq2l5wLcNppDNWKSgHnYUtULXHNvwSV3KtCJIpQKafuBXD3DR76yhEG1RpPl3yEa+LKURzTVXx38NdzAHZzad1x2SP5vOY+E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744915091; c=relaxed/simple; bh=ysvXi3Km1Q8gByeinX46wBdlU0Vu7+SYuE9qnfyF8ds=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CtDJucuAelTfuramDUJElP3oSc/bDyIgA+RogtHKGXGOPiZf8YaYaeg6ubIWM2rqw6/Rz1IqXqwyv5xfqG4oUBq5C02Iyhq/jP3DAK7+NPPDCyk0l4Xh/5zrsJW4PAc00XapYoBpHpzLLGL8c1l27oxhgNISZjiEl4A2F79sKec= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LnYe95wW; 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="LnYe95wW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA329C4CEE4; Thu, 17 Apr 2025 18:38:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1744915091; bh=ysvXi3Km1Q8gByeinX46wBdlU0Vu7+SYuE9qnfyF8ds=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LnYe95wWVYQFPjzc5t8jK4GIN2teqdW3BkhFa3sxLfq3oxQ7DBeO9t6M55kuOBu74 BMZwuLujPL3KeO16gFLlqF6VP+HtQ9XPyOZro47lEg2LnSwyQEvScpCYSi2NEg+vu7 atYSp/DxPZEnU2+ZTjtjHUP/nokHsqXwRm1zv4yM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Andrew Cooper , Josh Poimboeuf , Ingo Molnar , Linus Torvalds , Sasha Levin Subject: [PATCH 6.12 016/393] objtool: Fix INSN_CONTEXT_SWITCH handling in validate_unret() Date: Thu, 17 Apr 2025 19:47:05 +0200 Message-ID: <20250417175108.248968342@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250417175107.546547190@linuxfoundation.org> References: <20250417175107.546547190@linuxfoundation.org> User-Agent: quilt/0.68 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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josh Poimboeuf [ Upstream commit a8df7d0ef92eca28c610206c6748daf537ac0586 ] The !CONFIG_IA32_EMULATION version of xen_entry_SYSCALL_compat() ends with a SYSCALL instruction which is classified by objtool as INSN_CONTEXT_SWITCH. Unlike validate_branch(), validate_unret() doesn't consider INSN_CONTEXT_SWITCH in a non-function to be a dead end, so it keeps going past the end of xen_entry_SYSCALL_compat(), resulting in the following warning: vmlinux.o: warning: objtool: xen_reschedule_interrupt+0x2a: RET before UNTRAIN Fix that by adding INSN_CONTEXT_SWITCH handling to validate_unret() to match what validate_branch() is already doing. Fixes: a09a6e2399ba ("objtool: Add entry UNRET validation") Reported-by: Andrew Cooper Signed-off-by: Josh Poimboeuf Signed-off-by: Ingo Molnar Cc: Linus Torvalds Link: https://lore.kernel.org/r/f5eda46fd09f15b1f5cde3d9ae3b92b958342add.1744095216.git.jpoimboe@kernel.org Signed-off-by: Sasha Levin --- tools/objtool/check.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 286a2c0af02aa..127862fa05c61 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -3990,6 +3990,11 @@ static int validate_unret(struct objtool_file *file, struct instruction *insn) WARN_INSN(insn, "RET before UNTRAIN"); return 1; + case INSN_CONTEXT_SWITCH: + if (insn_func(insn)) + break; + return 0; + case INSN_NOP: if (insn->retpoline_safe) return 0; -- 2.39.5