Re: [PATCH v2 2/4] arm64: kasan: abstract _text and _end to KERNEL_START/END

From: Will Deacon <will@kernel.org>
To: Lecopzer Chen <lecopzer@gmail.com>
Cc: akpm@linux-foundation.org, andreyknvl@google.com,
	ardb@kernel.org, aryabinin@virtuozzo.com, broonie@kernel.org,
	catalin.marinas@arm.com, dan.j.williams@intel.com,
	dvyukov@google.com, glider@google.com, gustavoars@kernel.org,
	kasan-dev@googlegroups.com, lecopzer.chen@mediatek.com,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org,
	linux-mm@kvack.org, linux@roeck-us.net, robin.murphy@arm.com,
	rppt@kernel.org, tyhicks@linux.microsoft.com,
	vincenzo.frascino@arm.com, yj.chiang@mediatek.com
Subject: Re: [PATCH v2 2/4] arm64: kasan: abstract _text and _end to KERNEL_START/END
Date: Thu, 4 Feb 2021 14:55:48 +0000	[thread overview]
Message-ID: <20210204145547.GD20815@willie-the-truck> (raw)
In-Reply-To: <20210204145127.75856-1-lecopzer@gmail.com>

On Thu, Feb 04, 2021 at 10:51:27PM +0800, Lecopzer Chen wrote:
> > On Sat, Jan 09, 2021 at 06:32:50PM +0800, Lecopzer Chen wrote:
> > > Arm64 provide defined macro for KERNEL_START and KERNEL_END,
> > > thus replace them by the abstration instead of using _text and _end.
> > > 
> > > Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
> > > ---
> > >  arch/arm64/mm/kasan_init.c | 6 +++---
> > >  1 file changed, 3 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
> > > index 39b218a64279..fa8d7ece895d 100644
> > > --- a/arch/arm64/mm/kasan_init.c
> > > +++ b/arch/arm64/mm/kasan_init.c
> > > @@ -218,8 +218,8 @@ static void __init kasan_init_shadow(void)
> > >  	phys_addr_t pa_start, pa_end;
> > >  	u64 i;
> > >  
> > > -	kimg_shadow_start = (u64)kasan_mem_to_shadow(_text) & PAGE_MASK;
> > > -	kimg_shadow_end = PAGE_ALIGN((u64)kasan_mem_to_shadow(_end));
> > > +	kimg_shadow_start = (u64)kasan_mem_to_shadow(KERNEL_START) & PAGE_MASK;
> > > +	kimg_shadow_end = PAGE_ALIGN((u64)kasan_mem_to_shadow(KERNEL_END));
> > >  
> > >  	mod_shadow_start = (u64)kasan_mem_to_shadow((void *)MODULES_VADDR);
> > >  	mod_shadow_end = (u64)kasan_mem_to_shadow((void *)MODULES_END);
> > > @@ -241,7 +241,7 @@ static void __init kasan_init_shadow(void)
> > >  	clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
> > >  
> > >  	kasan_map_populate(kimg_shadow_start, kimg_shadow_end,
> > > -			   early_pfn_to_nid(virt_to_pfn(lm_alias(_text))));
> > > +			   early_pfn_to_nid(virt_to_pfn(lm_alias(KERNEL_START))));
> > 
> > To be honest, I think this whole line is pointless. We should be able to
> > pass NUMA_NO_NODE now that we're not abusing the vmemmap() allocator to
> > populate the shadow.
> 
> Do we need to fix this in this series? it seems another topic.
> If not, should this patch be removed in this series?

Since you're reposting anyway, you may as well include a patch doing that.
If you don't, then I will.

Will