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 ABBFD299A84 for ; Wed, 13 Aug 2025 15:59:51 +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=1755100791; cv=none; b=tpuwF9UgmNU/9fKVcNa0QUnKflqfRtHKRmv5fYPHa/T+eT90e1UkxmoqKIMsUw9694rz1CoYwF2uGv7fFkAET1PSckErTHSqInGzhmAU4oTDX77L2C11GACxbtkhMjq/5xiyvSeySe8LHTvOU0oqlMfco/ZglGIF6DTR5WxhLfY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755100791; c=relaxed/simple; bh=jDDwobTYRwBoVuPmcs8mFfjkQmVxR+OkbSYAgSZjsNY=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=V8QLPgjgI+M4PY2xUHRXMzjUwJ4cHllZJAN3RFEoI7ptcvWcK9DdaxMGMlQFBi8OxEh3hxY6ejytWpU9KobYsdNvTDirZ0d97YI/JbQDWujmcuyQEzMsEJzD7pCu60d+0AuR1UcrEeBX5sam2hF967yc3gPJ37uZEBx0H+OCsg8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rOZlKu6M; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rOZlKu6M" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63FA2C4CEEF; Wed, 13 Aug 2025 15:59:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755100791; bh=jDDwobTYRwBoVuPmcs8mFfjkQmVxR+OkbSYAgSZjsNY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rOZlKu6MofilR6z3OmFgXmMbJUiTgdqCE0E52EYEoxRzxIlt9PDgQ6F851E7M3anZ N+uZg5v/HvEqoZmGj0DctoFs+Kux6i9IkLiuVkfuH+QHLC8hv9NujqD7W6fdnHYgMx cRaG0hM7K2dnxqMdz6gxDaMkuwbniEoD8bKTC6eff6eYc/Nex2UN3LY8VdgjrCpf5a EAq+xYEwuWH9CQpmg654ODnx0WW9QBSNwGQP2qAq3bhnyN4Iy6/em6KkweH+veXPDp quDA/mc3O45RhdKItJE7ybmj21cysQY/97iWM0nIWWyXAaKFfiDoFuLav9gdbEJBHJ j0xrNam4AD34g== From: Sasha Levin To: stable@vger.kernel.org Cc: Dave Hansen , Chao Gao , Alison Schofield , Peter Zijlstra , Sasha Levin Subject: [PATCH 5.15.y] x86/fpu: Delay instruction pointer fixup until after warning Date: Wed, 13 Aug 2025 11:59:47 -0400 Message-Id: <20250813155947.2053690-1-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <2025081250-ominous-saddling-5ac5@gregkh> References: <2025081250-ominous-saddling-5ac5@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Dave Hansen [ Upstream commit 1cec9ac2d071cfd2da562241aab0ef701355762a ] Right now, if XRSTOR fails a console message like this is be printed: Bad FPU state detected at restore_fpregs_from_fpstate+0x9a/0x170, reinitializing FPU registers. However, the text location (...+0x9a in this case) is the instruction *AFTER* the XRSTOR. The highlighted instruction in the "Code:" dump also points one instruction late. The reason is that the "fixup" moves RIP up to pass the bad XRSTOR and keep on running after returning from the #GP handler. But it does this fixup before warning. The resulting warning output is nonsensical because it looks like the non-FPU-related instruction is #GP'ing. Do not fix up RIP until after printing the warning. Do this by using the more generic and standard ex_handler_default(). Fixes: d5c8028b4788 ("x86/fpu: Reinitialize FPU registers if restoring FPU state fails") Signed-off-by: Dave Hansen Reviewed-by: Chao Gao Acked-by: Alison Schofield Acked-by: Peter Zijlstra (Intel) Cc:stable@vger.kernel.org Link: https://lore.kernel.org/all/20250624210148.97126F9E%40davehans-spike.ostc.intel.com [ Replace fpu_reset_from_exception_fixup() with __restore_fpregs_from_fpstate() ] Signed-off-by: Sasha Levin --- arch/x86/mm/extable.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/extable.c b/arch/x86/mm/extable.c index a9c7efd4b794..cba212d7146a 100644 --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -60,13 +60,12 @@ static bool ex_handler_fault(const struct exception_table_entry *fixup, static bool ex_handler_fprestore(const struct exception_table_entry *fixup, struct pt_regs *regs) { - regs->ip = ex_fixup_addr(fixup); - WARN_ONCE(1, "Bad FPU state detected at %pB, reinitializing FPU registers.", (void *)instruction_pointer(regs)); __restore_fpregs_from_fpstate(&init_fpstate, xfeatures_mask_fpstate()); - return true; + + return ex_handler_default(fixup, regs); } static bool ex_handler_uaccess(const struct exception_table_entry *fixup, -- 2.39.5