Re: net-next/master boot bisection: v5.3-13203-gc01ebd6c4698 on bcm2836-rpi-2-b

[Guillaume Tucker <guillaume.tucker@collabora.com>]

On 02/10/2019 11:05, kernelci.org bot wrote:
> * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
> * This automated bisection report was sent to you on the basis  *
> * that you may be involved with the breaking commit it has      *
> * found.  No manual investigation has been done to verify it,   *
> * and the root cause of the problem may be somewhere else.      *
> *                                                               *
> * If you do send a fix, please include this trailer:            *
> *   Reported-by: "kernelci.org bot" <bot@kernelci.org>          *
> *                                                               *
> * Hope this helps!                                              *
> * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
> 
> net-next/master boot bisection: v5.3-13203-gc01ebd6c4698 on bcm2836-rpi-2-b
> 
> Summary:
>   Start:      c01ebd6c4698 r8152: Use guard clause and fix comment typos
>   Details:    https://kernelci.org/boot/id/5d942a9059b514a119d857e9
>   Plain log:  https://storage.kernelci.org//net-next/master/v5.3-13203-gc01ebd6c4698/arm/bcm2835_defconfig/gcc-8/lab-collabora/boot-bcm2836-rpi-2-b.txt
>   HTML log:   https://storage.kernelci.org//net-next/master/v5.3-13203-gc01ebd6c4698/arm/bcm2835_defconfig/gcc-8/lab-collabora/boot-bcm2836-rpi-2-b.html
>   Result:     ac7c3e4ff401 compiler: enable CONFIG_OPTIMIZE_INLINING forcibly
> 
> Checks:
>   revert:     PASS
>   verify:     PASS
> 
> Parameters:
>   Tree:       net-next
>   URL:        git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
>   Branch:     master
>   Target:     bcm2836-rpi-2-b
>   CPU arch:   arm
>   Lab:        lab-collabora
>   Compiler:   gcc-8
>   Config:     bcm2835_defconfig
>   Test suite: boot
> 
> Breaking commit found:
> 
> -------------------------------------------------------------------------------
> commit ac7c3e4ff401b304489a031938dbeaab585bfe0a
> Author: Masahiro Yamada <yamada.masahiro@socionext.com>
> Date:   Wed Sep 25 16:47:42 2019 -0700
> 
>     compiler: enable CONFIG_OPTIMIZE_INLINING forcibly
>     
>     Commit 9012d011660e ("compiler: allow all arches to enable
>     CONFIG_OPTIMIZE_INLINING") allowed all architectures to enable this
>     option.  A couple of build errors were reported by randconfig, but all of
>     them have been ironed out.
>     
>     Towards the goal of removing CONFIG_OPTIMIZE_INLINING entirely (and it
>     will simplify the 'inline' macro in compiler_types.h), this commit changes
>     it to always-on option.  Going forward, the compiler will always be
>     allowed to not inline functions marked 'inline'.
>     
>     This is not a problem for x86 since it has been long used by
>     arch/x86/configs/{x86_64,i386}_defconfig.
>     
>     I am keeping the config option just in case any problem crops up for other
>     architectures.

It seems like this isn't the case on the Raspberry Pi 2b with
bcm2835_defconfig.  Here's an example of the kernel errors:

    https://lava.collabora.co.uk/scheduler/job/1859342#L327

There doesn't appear to be any problem with multi_v7_defconfig on
the same platform as shown with this test:

    https://lava.collabora.co.uk/scheduler/job/1858986

So it's not entirely broken, but some investigation needs to be
done to find out what differences between bcm2835_defconfig and
multi_v7_defconfig are making the problem apparent.

I guess people can turn the option off in their local configs in
the meantime.  It doesn't seem like turning it off in
bcm2835_defconfig would be a solution though as it would only
hide the issue for a bit longer until the option is removed.

Guillaume

>     The code clean-up will be done after confirming this is solid.
>     
>     Link: http://lkml.kernel.org/r/20190830034304.24259-1-yamada.masahiro@socionext.com
>     Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>     Acked-by: Nick Desaulniers <ndesaulniers@google.com>
>     Cc: Ingo Molnar <mingo@redhat.com>
>     Cc: Borislav Petkov <bp@alien8.de>
>     Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
>     Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
> 
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index 6b1b1703a646..93d97f9b0157 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -311,7 +311,7 @@ config HEADERS_CHECK
>  	  relevant for userspace, say 'Y'.
>  
>  config OPTIMIZE_INLINING
> -	bool "Allow compiler to uninline functions marked 'inline'"
> +	def_bool y
>  	help
>  	  This option determines if the kernel forces gcc to inline the functions
>  	  developers have marked 'inline'. Doing so takes away freedom from gcc to
> @@ -322,8 +322,6 @@ config OPTIMIZE_INLINING
>  	  decision will become the default in the future. Until then this option
>  	  is there to test gcc for this.
>  
> -	  If unsure, say N.
> -
>  config DEBUG_SECTION_MISMATCH
>  	bool "Enable full Section mismatch analysis"
>  	help
> -------------------------------------------------------------------------------
> 
> 
> Git bisection log:
> 
> -------------------------------------------------------------------------------
> git bisect start
> # good: [b41dae061bbd722b9d7fa828f35d22035b218e18] Merge tag 'xfs-5.4-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
> git bisect good b41dae061bbd722b9d7fa828f35d22035b218e18
> # bad: [c01ebd6c46980654220f6d2b660308a074ee29df] r8152: Use guard clause and fix comment typos
> git bisect bad c01ebd6c46980654220f6d2b660308a074ee29df
> # good: [45824fc0da6e46cc5d563105e1eaaf3098a686f9] Merge tag 'powerpc-5.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
> git bisect good 45824fc0da6e46cc5d563105e1eaaf3098a686f9
> # good: [bfe7b00de6d1e25fee08484c4fbf1c1ed175be78] mm, thp: introduce FOLL_SPLIT_PMD
> git bisect good bfe7b00de6d1e25fee08484c4fbf1c1ed175be78
> # bad: [972a2bf7dfe39ebf49dd47f68d27c416392e53b1] Merge tag 'nfs-for-5.4-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
> git bisect bad 972a2bf7dfe39ebf49dd47f68d27c416392e53b1
> # good: [2e959dd87a9f58f1ad824d830e06388c9e328239] Merge tag 'for-5.4/post-2019-09-24' of git://git.kernel.dk/linux-block
> git bisect good 2e959dd87a9f58f1ad824d830e06388c9e328239
> # bad: [a22fea94992a2bc5328005e62f368413ede49c14] arch/sparc/include/asm/pgtable_64.h: fix build
> git bisect bad a22fea94992a2bc5328005e62f368413ede49c14
> # good: [351c8a09b00b5c51c8f58b016fffe51f87e2d820] Merge branch 'i2c/for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
> git bisect good 351c8a09b00b5c51c8f58b016fffe51f87e2d820
> # bad: [ac7c3e4ff401b304489a031938dbeaab585bfe0a] compiler: enable CONFIG_OPTIMIZE_INLINING forcibly
> git bisect bad ac7c3e4ff401b304489a031938dbeaab585bfe0a
> # good: [94fb98450456da82a16a378816390d99b85edb55] checkpatch: allow consecutive close braces
> git bisect good 94fb98450456da82a16a378816390d99b85edb55
> # good: [4fadcd1c14d810ec6a695039cfc71e03ae742deb] fs/reiserfs/fix_node.c: remove set but not used variables
> git bisect good 4fadcd1c14d810ec6a695039cfc71e03ae742deb
> # good: [8495f7e6732ed248b648d36439795b42ec650b9e] fork: improve error message for corrupted page tables
> git bisect good 8495f7e6732ed248b648d36439795b42ec650b9e
> # good: [7c3a6aedcd6aae0a32a527e68669f7dd667492d1] kexec: bail out upon SIGKILL when allocating memory.
> git bisect good 7c3a6aedcd6aae0a32a527e68669f7dd667492d1
> # good: [9dd819a15162f8f82a6001b090caa38c18297b39] uaccess: add missing __must_check attributes
> git bisect good 9dd819a15162f8f82a6001b090caa38c18297b39
> # first bad commit: [ac7c3e4ff401b304489a031938dbeaab585bfe0a] compiler: enable CONFIG_OPTIMIZE_INLINING forcibly
> -------------------------------------------------------------------------------
>