Re: [PATCH 2/2] efi: Fix warning of int-to-pointer-cast on x86 32-bit builds

[Ingo Molnar]

* Ingo Molnar <mingo@xxxxxxxxxx> wrote:

> 
> * Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> 
> > 
> > * Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> wrote:
> > 
> > > From: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx>
> > > 
> > > Commit 0f96a99dab36 ("efi: Add "efi_fake_mem" boot option")
> > > introduces the following warning message:
> > > 
> > >   drivers/firmware/efi/fake_mem.c:186:20: warning: cast to pointer
> > >   from integer of different size [-Wint-to-pointer-cast]
> > > 
> > > new_memmap_phy was defined as a u64 value and cast to void*, causing
> > > a int-to-pointer-cast warning on x86 32-bit builds.
> > > However, since the void* type is inappropriate for a physical
> > > address, the definition of struct efi_memory_map::phys_map has been
> > > changed to phys_addr_t in the previous patch, and so the cast can be
> > > dropped entirely.
> > > 
> > > This patch also changes the type of the "new_memmap_phy" variable
> > > from "u64" to "phys_addr_t" to align with the types of
> > > memblock_alloc() and struct efi_memory_map::phys_map.
> > > 
> > > Reported-by: Ingo Molnar <mingo@xxxxxxxxxx>
> > > Signed-off-by: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx>
> > > [ard.biesheuvel: removed void* cast, updated commit log]
> > > Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> > > ---
> > >  drivers/firmware/efi/fake_mem.c | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/drivers/firmware/efi/fake_mem.c b/drivers/firmware/efi/fake_mem.c
> > > index 32bcb14df2c8..ed3a854950cc 100644
> > > --- a/drivers/firmware/efi/fake_mem.c
> > > +++ b/drivers/firmware/efi/fake_mem.c
> > > @@ -59,7 +59,7 @@ void __init efi_fake_memmap(void)
> > >  	u64 start, end, m_start, m_end, m_attr;
> > >  	int new_nr_map = memmap.nr_map;
> > >  	efi_memory_desc_t *md;
> > > -	u64 new_memmap_phy;
> > > +	phys_addr_t new_memmap_phy;
> > >  	void *new_memmap;
> > >  	void *old, *new;
> > >  	int i;
> > > @@ -183,7 +183,7 @@ void __init efi_fake_memmap(void)
> > >  	/* swap into new EFI memmap */
> > >  	efi_unmap_memmap();
> > >  	memmap.map = new_memmap;
> > > -	memmap.phys_map = (void *)new_memmap_phy;
> > > +	memmap.phys_map = new_memmap_phy;
> > >  	memmap.nr_map = new_nr_map;
> > >  	memmap.map_end = memmap.map + memmap.nr_map * memmap.desc_size;
> > 
> > Please guys, think for a change!
> > 
> > How is this supposed to work with:
> > 
> >    include/linux/efi.h:    void *phys_map;
> > 
> > ?
> 
> Ah, I take that back, now I see your patch 1/2 that changes it to phys_addr_t.
> 
> That's the right solution, and it also cleans up the code:
> 
>   Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>

Matt, do you want to take these fixes, or should I apply them directly?

Thanks,

	Ingo
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