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 BAC26352FF0; Tue, 26 Aug 2025 13:58:49 +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=1756216729; cv=none; b=SmAXs12Ab+miemsDaTxYj7nC3urRkP4VKkeKEfVmEqqio8/g/w+IfpDy8wE/BUTlLqSr5uELLemssfKMWfDinP5pVcNxfUXowTW6L48zSLcsQIytCKstH01tGm7AalDeAGRX0qGnkOt8Z6OXusHfox7MJ81mYws5pQvo5C5K42U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756216729; c=relaxed/simple; bh=AvxVh6FosuCGoLiv2giagHt9Ck29X3uEyBCygyDkbLU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bCVNZuVZTVQyFNK0B/RUVvDXlQ7AZHkN/qz+XTd5EI0qMI9KK0tQiWo0TtKFOBYdhU3MJJGmZp25r8YhDUzdjl3v5+YW8VGUgmU5MGQwEOgCfA40G6FwrCXuhPGdvGe83b4C/6hDKH9RNMn9etBwZMYcU+2l2m1AfxTFkfa8I+I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZMeBRmkH; 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="ZMeBRmkH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E02CCC4CEF1; Tue, 26 Aug 2025 13:58:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1756216729; bh=AvxVh6FosuCGoLiv2giagHt9Ck29X3uEyBCygyDkbLU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZMeBRmkHUXHeJOnOzA3ORwhnR7PjQo2QNEdJ10lvLSTgPl1onBjD0r9XoNPYiZkBX Vzu293nc33qaMr41qFVqN9Zwtwrl8yn7KS9OsKexxgcuTYKW7ANB7/jJmYz71ZybX9 yJzIrV4vye6d7WUohqj2rsRpktuiCR6qpgABBvNQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dave Hansen , Chao Gao , Alison Schofield , "Peter Zijlstra (Intel)" , Sasha Levin Subject: [PATCH 5.15 521/644] x86/fpu: Delay instruction pointer fixup until after warning Date: Tue, 26 Aug 2025 13:10:12 +0200 Message-ID: <20250826110959.418421094@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250826110946.507083938@linuxfoundation.org> References: <20250826110946.507083938@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/extable.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -60,13 +60,12 @@ static bool ex_handler_fault(const struc 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,