How programs get run: ELF binaries

To be maximally pedantic, AT_SYSINFO_EHDR doesn't exactly indicate the location of the vDSO page: that was the job of the (older, deprecated) AT_SYSINFO entry. AT_SYSINFO_EHDR points directly to the ELF headers within the vDSO page rather than to the start of the page, making life easier for ld.so since it doesn't need to work out where they're located.