__errno_location binary standard

__errno_location() = 0x7f631c659698

__errno_location -- address of errno variable

snapshot from the binary file /bin/ls
^@strstr^@__errno_location^@mempcpy^@_setjmp^

http://refspecs.freestandards.org/LSB_3.1.0/LSB-Core-generic/LSB-Core-generic/baselib-errno-location-1.html