USE_ARRAY_FOR_64BIT_TYPES logic broken ?

[Christos Zoulas]

On Jan 11, 10:22pm, vapier at gentoo.org (Mike Frysinger) wrote:
-- Subject: USE_ARRAY_FOR_64BIT_TYPES logic broken ?

| i was cross-compiling file-4.16 for an amd64/uClibc host and when i tried to 
| use it natively, it kept giving me crap like:
| /bin/bash: ERROR: error seeking (Invalid argument)
| 
| i traced it back to configure setting the size of all the uint types 
| (8/16/32/64 bits) to 0 because it was a cross-compile, thus forcing the logic 
| of USE_ARRAY_FOR_64BIT_TYPES to be enabled
| 
| for example, this code:
|             if (dophn_core(ms, class, swap, fd,
| #ifdef USE_ARRAY_FOR_64BIT_TYPES
|                 (off_t)getu32(swap, elfhdr.e_phoff[1]),
| #else
|                 (off_t)getu64(swap, elfhdr.e_phoff),
| #endif
|                 getu16(swap, elfhdr.e_phnum),
|                 (size_t)getu16(swap, elfhdr.e_phentsize)) == -1)
| 
| that getu32() only swaps & uses the 2nd set of 32bits and disregards the first 
| set of 32bits (thus leading to my funky problem of bogus lseek() calls)
| -mike

Yes, this logic is bogus and it will only work on big endian machines for
small offsets. The small offsets problem is probably ok, but the big endian
is not. We need to deal with endianness properly, at which point we should
read both words :-)

christos