lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CA+icZUW5jNJY3L5EcxrtOttwpbdAWQ7=U_bZaLHcTogOdNuTcQ@mail.gmail.com>
Date:   Fri, 19 Jul 2019 13:37:41 +0200
From:   Sedat Dilek <sedat.dilek@...il.com>
To:     Thomas Gleixner <tglx@...utronix.de>,
        Josh Poimboeuf <jpoimboe@...hat.com>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        Nathan Chancellor <natechancellor@...il.com>,
        clang-built-linux <clang-built-linux@...glegroups.com>,
        x86@...nel.org
Subject: Re: x86 - clang / objtool status

On Thu, Jul 18, 2019 at 10:40 PM Thomas Gleixner <tglx@...utronix.de> wrote:
>
> Folks,
>
> after picking up Josh's objtool updates I gave clang a test ride again.
>
> clan is built with https://github.com/ClangBuiltLinux/tc-build.git
>
> That's using the llvm master branch. top commit is:
>
>   0c99d19470b ("[OPENMP]Fix sharing of threadprivate variables with TLS support.")
>
> I merged
>
>   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/urgent
>
> into the tip of Linus tree to pick up the latest objtool changes.
>
> Here are the results for different configs:
>
> 1) defconfig
>
>  objtool warnings:
>
>   drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: .altinstr_replacement+0x88: redundant UACCESS disable
>
>
> 2) debian distro config
>
>  objtool warnings:
>
>   drivers/gpu/drm/amd/amdgpu/atom.o: warning: objtool: atom_op_move() falls through to next function atom_op_and()
>   drivers/infiniband/hw/hfi1/platform.o: warning: objtool: tune_serdes() falls through to next function apply_tx_lanes()
>   drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: .altinstr_replacement+0x86: redundant UACCESS disable
>   drivers/gpu/drm/radeon/evergreen_cs.o: warning: objtool: evergreen_cs_parse() falls through to next function evergreen_dma_cs_parse()
>
>  Build fails with:
>
>   clang-10: error: unknown argument: '-mpreferred-stack-boundary=4'
>   make[5]: *** [linux/scripts/Makefile.build:279: drivers/gpu/drm/amd/amdgpu/../display/dc/dcn20/dcn20_resource.o] Error 1
>
>
> 3) allmodconfig:
>
>  objtool warnings:
>
>   arch/x86/kernel/signal.o: warning: objtool: x32_setup_rt_frame()+0x255: call to memset() with UACCESS enabled
>   arch/x86/kernel/signal.o: warning: objtool: __setup_rt_frame()+0x254: call to memset() with UACCESS enabled
>   arch/x86/ia32/ia32_signal.o: warning: objtool: ia32_setup_rt_frame()+0x247: call to memset() with UACCESS enabled
>
>   mm/kasan/common.o: warning: objtool: kasan_report()+0x52: call to __stack_chk_fail() with UACCESS enabled
>   drivers/ata/sata_dwc_460ex.o: warning: objtool: sata_dwc_bmdma_start_by_tag()+0x3a0: can't find switch jump table
>
>   lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch()+0x88: call to memset() with UACCESS enabled
>   lib/ubsan.o: warning: objtool: ubsan_type_mismatch_common()+0x610: call to __stack_chk_fail() with UACCESS enabled
>   lib/ubsan.o: warning: objtool: __ubsan_handle_type_mismatch_v1()+0x88: call to memset() with UACCESS enabled
>   drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: .altinstr_replacement+0x56: redundant UACCESS disable
>
>  Build fails with:
>
>   ERROR: "__compiletime_assert_2801" [drivers/net/wireless/intel/iwlwifi/iwlwifi.ko] undefined!
>   ERROR: "__compiletime_assert_2446" [drivers/net/wireless/intel/iwlwifi/iwlwifi.ko] undefined!
>   ERROR: "__compiletime_assert_2452" [drivers/net/wireless/intel/iwlwifi/iwlwifi.ko] undefined!
>   ERROR: "__compiletime_assert_2790" [drivers/net/wireless/intel/iwlwifi/iwlwifi.ko] undefined!
>
>  This also emits a boatload of warnings like this:
>
>   linux/fs/nfs/dir.c:451:34: warning: variable 'wq' is uninitialized when used within its own initialization
>       [-Wuninitialized]
>         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
>                                         ^~
>   linux/include/linux/wait.h:74:63: note: expanded from macro 'DECLARE_WAIT_QUEUE_HEAD_ONSTACK'
>         struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name)
>                                ~~~~                                  ^~~~
>   linux/include/linux/wait.h:72:33: note: expanded from macro '__WAIT_QUEUE_HEAD_INIT_ONSTACK'
>         ({ init_waitqueue_head(&name); name; })
>
> Thanks,
>
>         tglx
>

Hi Thomas,

Thanks for the feedback.

The last days I tried several iterations of Josh's "v0", v1 and v2.

First of all I find out that it is possible to download and apply the
series (here: v2) from patchwork (see [1]).
I highly appreciate to have this in Josh's Git [2].

BTW, what is/was the base for the patchset?
I tried next-20190712 as this was the base in Josh's Git.
Later next-20190717 and next-20190718.
Please clarify.

With v2 applied on top of next-20190718 and an adapted/customized
kernel-config based on an official Debian/experimental 5.0.2  kernel I
fell over exactly the same 4 objtool warnings.

drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool:
.altinstr_replacement+0x86: redundant UACCESS disable

drivers/gpu/drm/radeon/atom.o: warning: objtool: atom_op_move() falls
through to next function atom_op_and()
drivers/gpu/drm/radeon/evergreen_cs.o: warning: objtool:
evergreen_cs_parse() falls through to next function
evergreen_dma_cs_parse()
drivers/infiniband/hw/hfi1/platform.o: warning: objtool: tune_serdes()
falls through to next function apply_tx_lanes()

Kconfigs?
I highly appreciate to turn off AMDGPU if you do not need it.

Yes, I know all the patches mentioned in this thread as reading the
ClangBuiltLinux (CBL) mailing-list and following the CBL issue-tracker
(being a part of the project).
To get/attract more followers all these patches should be placed
somewhere (preferable Git) and/or be easily pickable.
Or at least a list or be tagged in patchwork.
I have no idea for an ideal patch-management in this topic.

I can boot into QEMU.
But on bare metal it looks like BPF and systemd-udevd/systemd-journald
do end in a maintenance mode.
I saved the dmesg-log.

Kernel-config, dmesg-log and systemd-log attached.

I have not tried with Debian/buster GCC v8 and/or dropping Josh's
objtool patchset.
I am building with a pre-release of Clang v9-pre and linking with LLD v9-pre.

As a recommendation:
apt.llvm.org offers binaries for Debian/buster.
I can send you my APT stuff if you like.

Regards,
- Sedat -

[0] https://lore.kernel.org/patchwork/project/lkml/list/?series=402470
[1] https://lore.kernel.org/patchwork/series/402470/mbox/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/jpoimboe/linux.git/log/?h=objtool-many-fixes

View attachment "dmesg_5.2.0-4-amd64-cbl-asmgoto.txt" of type "text/plain" (134984 bytes)

Download attachment "config-5.2.0-4-amd64-cbl-asmgoto" of type "application/octet-stream" (219492 bytes)

View attachment "systemctl-failed.txt" of type "text/plain" (1246 bytes)

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ