2021-02-05 00:10:34

by Will Deacon

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

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 <[email protected]>
> ---
> 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.

Will

2021-02-05 00:34:08

by Lecopzer Chen

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

> 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 <[email protected]>
> > ---
> > 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?

Thanks,
Lecopzer