Re: [PATCH 7/7] linux-user: limit check to HOST_LONG_BITS < TARGET_ABI_BITS

[Laurent Vivier]

Le 25/05/2020 à 15:18, Thomas Huth a écrit :
> From: Alex Bennée <address@hidden>
> 
> Newer clangs rightly spot that you can never exceed the full address
> space of 64 bit hosts with:
> 
>   linux-user/elfload.c:2076:41: error: result of comparison 'unsigned
>   long' > 18446744073709551615 is always false
>   [-Werror,-Wtautological-type-limit-compare]
>   4685         if ((guest_hiaddr - guest_base) > ~(uintptr_t)0) {
>   4686             ~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~
>   4687 1 error generated.
> 
> So lets limit the check to 32 bit hosts only.
> 
> Fixes: ee94743034bf
> Reported-by: Thomas Huth <address@hidden>
> Signed-off-by: Alex Bennée <address@hidden>
> [thuth: Use HOST_LONG_BITS < TARGET_ABI_BITS instead of HOST_LONG_BITS == 32]
> Signed-off-by: Thomas Huth <address@hidden>
> ---
>  linux-user/elfload.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index 01a9323a63..ebc663ea0b 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -2073,12 +2073,14 @@ static void pgb_have_guest_base(const char 
> *image_name, abi_ulong guest_loaddr,
>              exit(EXIT_FAILURE);
>          }
>      } else {
> +#if HOST_LONG_BITS < TARGET_ABI_BITS
>          if ((guest_hiaddr - guest_base) > ~(uintptr_t)0) {
>              error_report("%s: requires more virtual address space "
>                           "than the host can provide (0x%" PRIx64 ")",
>                           image_name, (uint64_t)guest_hiaddr - guest_base);
>              exit(EXIT_FAILURE);
>          }
> +#endif
>      }
>  
>      /*
> 

Philippe sent the same patch:

https://www.mail-archive.com/address@hidden/msg699796.html

Thanks,
Laurent