Re: [PATCH] arch: x86: boot: compressed: eboot: fix cast warnings on32b platforms

From: Borislav Petkov
Date: Wed Dec 26 2012 - 03:00:12 EST


On Sat, Dec 22, 2012 at 11:23:25AM +0100, Stefan Hasko wrote:
> Fixed different size cast warnings in function setup_efi_pci
>
> Signed-off-by: Stefan Hasko <hasko.stevo@xxxxxxxxx>

You might want to add the actual compiler warnings to the commit
message:

arch/x86/boot/compressed/eboot.c: In function âsetup_efi_pciâ:
arch/x86/boot/compressed/eboot.c:259:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
arch/x86/boot/compressed/eboot.c:262:10: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
arch/x86/boot/compressed/eboot.c:348:17: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
arch/x86/boot/compressed/eboot.c:350:29: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]

And yes, I see them in all{mod,yes}config builds here too. The issue,
AFAICT, is that setup_data is __u64 to obviously accomodate 8-byte
pointers on x86-64 but on 32-bit they're half the size. And we obviously
cannot change struct setup_data since this is an ABI so I'd guess the
casts to native pointer sizes are ok. So

Acked-by: Borislav Petkov <bp@xxxxxxxxx>

> ---
> arch/x86/boot/compressed/eboot.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
> index b1942e2..dd99fca 100644
> --- a/arch/x86/boot/compressed/eboot.c
> +++ b/arch/x86/boot/compressed/eboot.c
> @@ -256,10 +256,10 @@ static efi_status_t setup_efi_pci(struct boot_params *params)
> int i;
> struct setup_data *data;
>
> - data = (struct setup_data *)params->hdr.setup_data;
> + data = (struct setup_data *)(uintptr_t)params->hdr.setup_data;
>
> while (data && data->next)
> - data = (struct setup_data *)data->next;
> + data = (struct setup_data *)(uintptr_t)data->next;
>
> status = efi_call_phys5(sys_table->boottime->locate_handle,
> EFI_LOCATE_BY_PROTOCOL, &pci_proto,
> @@ -345,9 +345,9 @@ static efi_status_t setup_efi_pci(struct boot_params *params)
> memcpy(rom->romdata, pci->romimage, pci->romsize);
>
> if (data)
> - data->next = (uint64_t)rom;
> + data->next = (uintptr_t)rom;
> else
> - params->hdr.setup_data = (uint64_t)rom;
> + params->hdr.setup_data = (uintptr_t)rom;
>
> data = (struct setup_data *)rom;
>
> --
> 1.7.10.4

Thanks.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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