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

From: Ingo Molnar
Date: Fri Oct 23 2015 - 06:27:39 EST



* 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;

?

Thanks,

Ingo

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