From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9C3DC433EF for ; Fri, 18 Mar 2022 16:22:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238937AbiCRQX0 (ORCPT ); Fri, 18 Mar 2022 12:23:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40644 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239072AbiCRQW0 (ORCPT ); Fri, 18 Mar 2022 12:22:26 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CD40E388C; Fri, 18 Mar 2022 09:19:16 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B06EBB824A7; Fri, 18 Mar 2022 16:18:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A6346C340E8; Fri, 18 Mar 2022 16:18:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647620322; bh=RgoWd82TMVKvPEj2mnBFasnr1ktgCyI38ZWKS1kuPxg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=APZoUKBgMpBIwFM0bEG+PS2SzirGBi23hexZigjRmwDwwGzCkbwv9ZuJD4lNeIdNv xK3hW+2gO3tl28yY9flvMRxQbJVaRJ2q/2wrlQZzZook95jfPtVMedaofVZDgZx4d3 HLaBuYixoz1U85AzJ5iYmWPHmyKfETwYnEAGJ3Co= Date: Fri, 18 Mar 2022 17:18:39 +0100 From: Greg Kroah-Hartman To: James Morse Cc: Florian Fainelli , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Catalin Marinas , Sasha Levin Subject: Re: [PATCH 5.4 18/43] arm64: entry: Add macro for reading symbol addresses from the trampoline Message-ID: References: <20220317124527.672236844@linuxfoundation.org> <20220317124528.180267687@linuxfoundation.org> <113e7675-4263-2a20-81d0-9634f03511d2@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 18, 2022 at 12:11:32PM +0000, James Morse wrote: > Hi Florian, > > On 3/17/22 8:48 PM, Florian Fainelli wrote: > > On 3/17/22 5:45 AM, Greg Kroah-Hartman wrote: > > > From: James Morse > > > > > > commit b28a8eebe81c186fdb1a0078263b30576c8e1f42 upstream. > > > > > > The trampoline code needs to use the address of symbols in the wider > > > kernel, e.g. vectors. PC-relative addressing wouldn't work as the > > > trampoline code doesn't run at the address the linker expected. > > > > > > tramp_ventry uses a literal pool, unless CONFIG_RANDOMIZE_BASE is > > > set, in which case it uses the data page as a literal pool because > > > the data page can be unmapped when running in user-space, which is > > > required for CPUs vulnerable to meltdown. > > > > > > Pull this logic out as a macro, instead of adding a third copy > > > of it. > > > > > > Reviewed-by: Catalin Marinas > > > Signed-off-by: James Morse > > > Signed-off-by: Sasha Levin > > > > This commit causes a linking failure with CONFIG_ARM_SDE_INTERFACE=y > > enabled in the kernel: > > > > LD .tmp_vmlinux.kallsyms1 > > /local/users/fainelli/buildroot/output/arm64/host/bin/aarch64-linux-ld: > > arch/arm64/kernel/entry.o: in function `__sdei_asm_exit_trampoline': > > /local/users/fainelli/buildroot/output/arm64/build/linux-custom/arch/arm64/kernel/entry.S:1352: > > undefined reference to `__sdei_asm_trampoline_next_handler' > > make[2]: *** [Makefile:1100: vmlinux] Error 1 > > make[1]: *** [package/pkg-generic.mk:295: > > /local/users/fainelli/buildroot/output/arm64/build/linux-custom/.stamp_built] > > Error 2 > > make: *** [Makefile:27: _all] Error 2 > > ... and with CONFIG_RANDOMIZE_BASE turned off, which is why allyesconfig didn't catch it. > This is because I kept the next_handler bit of the label when it conflicted, which isn't needed > because the __entry_tramp bit added by the macro serves the same purpose. > > The below diff fixes it: > ----------%<---------- > diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S > index e4b5a15c2e2e..cfc0bb6c49f7 100644 > --- a/arch/arm64/kernel/entry.S > +++ b/arch/arm64/kernel/entry.S > @@ -1190,7 +1190,7 @@ __entry_tramp_data_start: > __entry_tramp_data_vectors: > .quad vectors > #ifdef CONFIG_ARM_SDE_INTERFACE > -__entry_tramp_data___sdei_asm_trampoline_next_handler: > +__entry_tramp_data___sdei_asm_handler: > .quad __sdei_asm_handler > #endif /* CONFIG_ARM_SDE_INTERFACE */ > .popsection // .rodata > @@ -1319,7 +1319,7 @@ ENTRY(__sdei_asm_entry_trampoline) > */ > 1: str x4, [x1, #(SDEI_EVENT_INTREGS + S_ORIG_ADDR_LIMIT)] > - tramp_data_read_var x4, __sdei_asm_trampoline_next_handler > + tramp_data_read_var x4, __sdei_asm_handler > br x4 > ENDPROC(__sdei_asm_entry_trampoline) > NOKPROBE(__sdei_asm_entry_trampoline) > ----------%<---------- > > Good news - this didn't happen with v5.10. > > I don't see this in v5.4.185 yet. > > Greg/Sasha, what is least work for you?: > A new version of this patch, > A fixup on top of the series, > Reposting the series with this fixed. Let me merge this into this commit. thanks! greg k-h