Re: hppa64-linux-ld: mm/hugetlb.o(.text+0x50dc): cannot reach printk

[Helge Deller]

On 1/25/21 9:47 PM, Helge Deller wrote:
>>>> On Sat, Jan 16, 2021 at 6:37 AM kernel test robot <lkp@xxxxxxxxx> wrote:
>>>>> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
>>>>> head:   1d94330a437a573cfdf848f6743b1ed169242c8a
>>>>> commit: eff8728fe69880d3f7983bec3fb6cea4c306261f vmlinux.lds.h: Add PGO and AutoFDO input sections
>>>>> date:   5 months ago
>>>>> config: parisc-randconfig-r032-20210116 (attached as .config)
>>>>> compiler: hppa64-linux-gcc (GCC) 9.3.0
>>>>> reproduce (this is a W=1 build):
>>>>>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>>>>>         chmod +x ~/bin/make.cross
>>>>>         # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=eff8728fe69880d3f7983bec3fb6cea4c306261f
>>>>>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>>>>>         git fetch --no-tags linus master
>>>>>         git checkout eff8728fe69880d3f7983bec3fb6cea4c306261f
>>>>>         # save the attached .config to linux build tree
>>>>>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=parisc
>>>>>
>>>>> If you fix the issue, kindly add following tag as appropriate
>>>>> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>>>>>
>>>>> All errors (new ones prefixed by >>):
>>>>>
>>>>>    hppa64-linux-ld: mm/page_alloc.o(.ref.text+0x110): cannot reach unknown
>>>>>    hppa64-linux-ld: mm/memblock.o(.text+0x27c): cannot reach __warn_printk
>>>>>    hppa64-linux-ld: mm/memblock.o(.meminit.text+0xc4): cannot reach printk
> ....
>
> The problem with this .config is, that both CONFIG_MODULES and
> CONFIG_MLONGCALLS are set to "n".
> The Kconfig autodetection needs fixing to enable CONFIG_MLONGCALLS in
> this case.
>
>
> This patch fixes it for me:
>
> [PATCH] Require -mlong-calls gcc option for !CONFIG_MODULES
>
> When building a kernel without module support, the CONFIG_MLONGCALL
> option needs to be enabled. This patch fixes the autodetection in the
> Kconfig script and uses a far call to preempt_schedule_irq() in
> intr_do_preempt().
>
> Signed-off-by: Helge Deller <deller@xxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>

There's a small bug in the code below:
	BL	preempt_schedule_irq
needs to be
	BL	preempt_schedule_irq, %r0

I'll do some more testing and will push the final version
through the parisc tree.

Helge


> ---
>
> diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
> index 78b17621ee4a..278462186ac4 100644
> --- a/arch/parisc/Kconfig
> +++ b/arch/parisc/Kconfig
> @@ -202,9 +202,8 @@ config PREFETCH
>  	depends on PA8X00 || PA7200
>
>  config MLONGCALLS
> -	bool "Enable the -mlong-calls compiler option for big kernels"
> -	default y if !MODULES || UBSAN || FTRACE
> -	default n
> +	def_bool y if !MODULES || UBSAN || FTRACE
> +	bool "Enable the -mlong-calls compiler option for big kernels" if MODULES && !UBSAN && !FTRACE
>  	depends on PA8X00
>  	help
>  	  If you configure the kernel to include many drivers built-in instead
> diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
> index beba9816cc6c..6320f6a8397c 100644
> --- a/arch/parisc/kernel/entry.S
> +++ b/arch/parisc/kernel/entry.S
> @@ -997,10 +997,19 @@ intr_do_preempt:
>  	bb,<,n	%r20, 31 - PSW_SM_I, intr_restore
>  	nop
>
> -	BL	preempt_schedule_irq, %r2
> -	nop
> +	/* ssm PSW_SM_I done later in intr_restore */
> +#ifdef CONFIG_MLONGCALLS
> +	ldil    L%intr_restore, %r2
> +	load32	preempt_schedule_irq, %r1
> +	bv	%r0(%r1)
> +	ldo     R%intr_restore(%r2), %r2
> +#else
> +	ldil    L%intr_restore, %r2
> +	BL	preempt_schedule_irq
> +	ldo     R%intr_restore(%r2), %r2
> +#endif
> +
>
> -	b,n	intr_restore		/* ssm PSW_SM_I done by intr_restore */
>  #endif /* CONFIG_PREEMPTION */
>
>  	/*
>
>