On 27/05/2020 18.36, Alex Bennée wrote: > > Thomas Huth <th...@redhat.com> writes: > >> On 27/05/2020 16.44, Laurent Vivier wrote: >>> Le 25/05/2020 à 15:18, Thomas Huth a écrit : >>>> From: Alex Bennée <alex.ben...@linaro.org> >>>> >>>> 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 <th...@redhat.com> >>>> Signed-off-by: Alex Bennée <alex.ben...@linaro.org> >>>> [thuth: Use HOST_LONG_BITS < TARGET_ABI_BITS instead of HOST_LONG_BITS == >>>> 32] >>>> Signed-off-by: Thomas Huth <th...@redhat.com> >>>> --- >>>> 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/qemu-devel@nongnu.org/msg699796.html >> >> Indeed, but looking more closely, he's using slightly different >> locations for the #if and #endif ... not sure what's better though...? > > Richard was more inclined to suppress the warning: > > Subject: Re: [PATCH v2] linux-user: limit check to HOST_LONG_BITS == 32 > From: Richard Henderson <richard.hender...@linaro.org> > Message-ID: <3069bc1b-115d-f361-8271-c775bf695...@linaro.org> > Date: Thu, 21 May 2020 20:15:51 -0700 > > One reason I dropped the f32 patch from my last PR was because this > wasn't the only warning the latest clang picks up.
... but this is currently the only spot that is required to get the gitlab CI going again, so I think we should include this patch until we have a final decision whether to disable the warning or not (and we can still revert this patch after we disabled the warning). Ok? Thomas