From patchwork Thu Mar 19 13:03:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 11447185 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 156981667 for ; Thu, 19 Mar 2020 13:25:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E929420CC7 for ; Thu, 19 Mar 2020 13:25:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624358; bh=kJdYtdkXoUJqBCbsGNBYogiLr8GIFp4ngkilDarlmMY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=pUnblxrTsQEsM0sDPLw+SLpsqxYDFy89lTalnSHbzUfVfYNBRwvnB+7fZZTz82vei tCgJOBpF18CXDFGSL8ndzZwTIoal1+CK7jc94JyCAlhX6xZMycXsA2crwZEpjko/pb WHieTSqxxA/bwjUBx3zS88r6tHrXdl7wwUnGsNAQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730229AbgCSNZw (ORCPT ); Thu, 19 Mar 2020 09:25:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:53602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730694AbgCSNZv (ORCPT ); Thu, 19 Mar 2020 09:25:51 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8045D208C3; Thu, 19 Mar 2020 13:25:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624351; bh=kJdYtdkXoUJqBCbsGNBYogiLr8GIFp4ngkilDarlmMY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WDmgnlBAdY82QQ6cayWDQgfBx8T2WYBPyIabciDR/EpXXhdW5eRGUyf/dBCU70sHQ Yq+nFlDEu7H42l/sG75fjmLUsvXQj2Tk5Fs99e+xSSz0u2/ocJy/IaxPZDjGJTWmAE ro2MdfcbAec7sI6WfswFNrbhft+CdaV2MiiubkAk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Bruce Ashfield , Victor Kamensky , Paul Burton , linux-mips@vger.kernel.org, Ralf Baechle , James Hogan , Vincenzo Frascino , richard.purdie@linuxfoundation.org, Sasha Levin Subject: [PATCH 5.5 13/65] mips: vdso: fix jalr t9 crash in vdso code Date: Thu, 19 Mar 2020 14:03:55 +0100 Message-Id: <20200319123930.497716995@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200319123926.466988514@linuxfoundation.org> References: <20200319123926.466988514@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Victor Kamensky [ Upstream commit d3f703c4359ff06619b2322b91f69710453e6b6d ] Observed that when kernel is built with Yocto mips64-poky-linux-gcc, and mips64-poky-linux-gnun32-gcc toolchain, resulting vdso contains 'jalr t9' instructions in its code and since in vdso case nobody sets GOT table code crashes when instruction reached. On other hand observed that when kernel is built mips-poky-linux-gcc toolchain, the same 'jalr t9' instruction are replaced with PC relative function calls using 'bal' instructions. The difference boils down to -mrelax-pic-calls and -mexplicit-relocs gcc options that gets different default values depending on gcc target triplets and corresponding binutils. -mrelax-pic-calls got enabled by default only in mips-poky-linux-gcc case. MIPS binutils ld relies on R_MIPS_JALR relocation to convert 'jalr t9' into 'bal' and such relocation is generated only if -mrelax-pic-calls option is on. Please note 'jalr t9' conversion to 'bal' can happen only to static functions. These static PIC calls use mips local GOT entries that are supposed to be filled with start of DSO value by run-time linker (missing in VDSO case) and they do not have dynamic relocations. Global mips GOT entries must have dynamic relocations and they should be prevented by cmd_vdso_check Makefile rule. Solution call out -mrelax-pic-calls and -mexplicit-relocs options explicitly while compiling MIPS vdso code. That would get correct and consistent between different toolchains behaviour. Reported-by: Bruce Ashfield Signed-off-by: Victor Kamensky Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: Ralf Baechle Cc: James Hogan Cc: Vincenzo Frascino Cc: richard.purdie@linuxfoundation.org Signed-off-by: Sasha Levin --- arch/mips/vdso/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile index e05938997e696..96afd73c94e8a 100644 --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -29,6 +29,7 @@ endif cflags-vdso := $(ccflags-vdso) \ $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \ -O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ + -mrelax-pic-calls -mexplicit-relocs \ -fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \ $(call cc-option, -fno-asynchronous-unwind-tables) \ $(call cc-option, -fno-stack-protector) From patchwork Thu Mar 19 13:03:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 11447201 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 385821667 for ; Thu, 19 Mar 2020 13:28:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1871F208D6 for ; Thu, 19 Mar 2020 13:28:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624532; bh=5iPR7XCLsazQnaDrcx+zT2BH4J3il51Isf+Aw05JtG4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Zi+vZ6XdVHnB3QbgTmJ7JlVHncCNQ97cX22FE5uU1/QH+mR7k+8ZVAI6vnZMyB8jE baH6L0MSt5TYXWlg/RorHYpJ8ZuSEJQvixLZS9/BAkMyh94YKiATMX4VCDRIR4sOvc pIC9t5ROWPadD98UCCSLgr/v1lRl3qG5Eoc3M2Ds= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730709AbgCSNZ6 (ORCPT ); Thu, 19 Mar 2020 09:25:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:53740 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730515AbgCSNZ5 (ORCPT ); Thu, 19 Mar 2020 09:25:57 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 578FD2080C; Thu, 19 Mar 2020 13:25:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624355; bh=5iPR7XCLsazQnaDrcx+zT2BH4J3il51Isf+Aw05JtG4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V00+g1ReQ5ZN/S2LQRGaxu6CjECtb2pY2qLqmqQStO9M/zo7vl+bjuSiQdu8A32yP ZGoB69yUYBSPk0Dcc97B8VUPv/G949VaOvPGrXMgx4DVltRdhHD6ZAoEJoeMFYZjXw cHNJ+xcNquBqNGl77AlhtjEDZ7XaSmsMXL6aZJeg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Victor Kamensky , Paul Burton , linux-mips@vger.kernel.org, Ralf Baechle , James Hogan , Vincenzo Frascino , bruce.ashfield@gmail.com, richard.purdie@linuxfoundation.org, Sasha Levin Subject: [PATCH 5.5 15/65] mips: vdso: add build time check that no jalr t9 calls left Date: Thu, 19 Mar 2020 14:03:57 +0100 Message-Id: <20200319123931.264495151@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200319123926.466988514@linuxfoundation.org> References: <20200319123926.466988514@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Victor Kamensky [ Upstream commit 976c23af3ee5bd3447a7bfb6c356ceb4acf264a6 ] vdso shared object cannot have GOT based PIC 'jalr t9' calls because nobody set GOT table in vdso. Contributing into vdso .o files are compiled in PIC mode and as result for internal static functions calls compiler will generate 'jalr t9' instructions. Those are supposed to be converted into PC relative 'bal' calls by linker when relocation are processed. Mips global GOT entries do have dynamic relocations and they will be caught by cmd_vdso_check Makefile rule. Static PIC calls go through mips local GOT entries that do not have dynamic relocations. For those 'jalr t9' calls could be present but without dynamic relocations and they need to be converted to 'bal' calls by linker. Add additional build time check to make sure that no 'jalr t9' slip through because of some toolchain misconfiguration that prevents 'jalr t9' to 'bal' conversion. Signed-off-by: Victor Kamensky Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: Ralf Baechle Cc: James Hogan Cc: Vincenzo Frascino Cc: bruce.ashfield@gmail.com Cc: richard.purdie@linuxfoundation.org Signed-off-by: Sasha Levin --- arch/mips/vdso/Makefile | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile index e8585a22b925c..bfb65b2d57c7f 100644 --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -93,12 +93,18 @@ GCOV_PROFILE := n UBSAN_SANITIZE := n KCOV_INSTRUMENT := n +# Check that we don't have PIC 'jalr t9' calls left +quiet_cmd_vdso_mips_check = VDSOCHK $@ + cmd_vdso_mips_check = if $(OBJDUMP) --disassemble $@ | egrep -h "jalr.*t9" > /dev/null; \ + then (echo >&2 "$@: PIC 'jalr t9' calls are not supported"; \ + rm -f $@; /bin/false); fi + # # Shared build commands. # quiet_cmd_vdsold_and_vdso_check = LD $@ - cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check) + cmd_vdsold_and_vdso_check = $(cmd_vdsold); $(cmd_vdso_check); $(cmd_vdso_mips_check) quiet_cmd_vdsold = VDSO $@ cmd_vdsold = $(CC) $(c_flags) $(VDSO_LDFLAGS) \ From patchwork Thu Mar 19 13:04:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 11447181 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0DA531667 for ; Thu, 19 Mar 2020 13:25:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E138E21D7F for ; Thu, 19 Mar 2020 13:25:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624326; bh=Tkr/6mrr1glEaInkhIb3wjUGtu3WF0DzZoe3urzNmhE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=R2K5GMS+HeBXKMLoI+Ad9hJ0gAe8nia0UNqO1oePjJq5Wxm5pgdC6M7AJxQqGHBsm rPlvRrHkdRdPhtvG71TP8h3GYX9BY8Iu7oE6Y9up2Wh43JoPtGBo/ISHjxLSYEYu1M eaIn2jms4do+evvvV1srH94Ys7VRKsyBWzpg/lxo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730608AbgCSNZR (ORCPT ); Thu, 19 Mar 2020 09:25:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:52754 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730605AbgCSNZQ (ORCPT ); Thu, 19 Mar 2020 09:25:16 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 64AB12098B; Thu, 19 Mar 2020 13:25:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584624315; bh=Tkr/6mrr1glEaInkhIb3wjUGtu3WF0DzZoe3urzNmhE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ubelOgWI6SWwRNjFJKr8nhVUyc4t+U6IYPyk8yfFEsm+mUczZO6GHkKuONfuArz8+ 1Etx39qGUSVCj7cjzmUXqv6f1QV3Jos77cZIHiWQABSarXIAZZfH1yHT/djw9D3uki AG83i1kRk/57C6OH71U/yNmbGKRHhlA1k8tHpmIM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Nathan Chancellor , Nick Desaulniers , Paul Burton , Ralf Baechle , linux-mips@vger.kernel.org, clang-built-linux@googlegroups.com, Sasha Levin Subject: [PATCH 5.5 20/65] MIPS: vdso: Wrap -mexplicit-relocs in cc-option Date: Thu, 19 Mar 2020 14:04:02 +0100 Message-Id: <20200319123932.742469978@linuxfoundation.org> X-Mailer: git-send-email 2.25.2 In-Reply-To: <20200319123926.466988514@linuxfoundation.org> References: <20200319123926.466988514@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Nathan Chancellor [ Upstream commit 72cf3b3df423c1bbd8fa1056fed009d3a260f8a9 ] Clang does not support this option and errors out: clang-11: error: unknown argument: '-mexplicit-relocs' Clang does not appear to need this flag like GCC does because the jalr check that was added in commit 976c23af3ee5 ("mips: vdso: add build time check that no 'jalr t9' calls left") passes just fine with $ make ARCH=mips CC=clang CROSS_COMPILE=mipsel-linux-gnu- malta_defconfig arch/mips/vdso/ even before commit d3f703c4359f ("mips: vdso: fix 'jalr t9' crash in vdso code"). -mrelax-pic-calls has been supported since clang 9, which is the earliest version that could build a working MIPS kernel, and it is the default for clang so just leave it be. Fixes: d3f703c4359f ("mips: vdso: fix 'jalr t9' crash in vdso code") Link: https://github.com/ClangBuiltLinux/linux/issues/890 Signed-off-by: Nathan Chancellor Reviewed-by: Nick Desaulniers Tested-by: Nick Desaulniers Signed-off-by: Paul Burton Cc: Ralf Baechle Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: clang-built-linux@googlegroups.com Signed-off-by: Sasha Levin --- arch/mips/vdso/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile index bfb65b2d57c7f..2cf4b6131d88d 100644 --- a/arch/mips/vdso/Makefile +++ b/arch/mips/vdso/Makefile @@ -29,7 +29,7 @@ endif cflags-vdso := $(ccflags-vdso) \ $(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \ -O3 -g -fPIC -fno-strict-aliasing -fno-common -fno-builtin -G 0 \ - -mrelax-pic-calls -mexplicit-relocs \ + -mrelax-pic-calls $(call cc-option, -mexplicit-relocs) \ -fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \ $(call cc-option, -fno-asynchronous-unwind-tables) \ $(call cc-option, -fno-stack-protector)