I ought to have added that it's +8 because info is the second parameter, where the parameter space is

divided into slots of 8 bytes on amd64 and 4 bytes on the 32-bit architectures. on amd64, the first parameter is passed in a register (BP);

as on some of the RISC machines. on amd64, the second parameter is +8(FP), third is +16(FP), and so on.

 on x86/32 the first parameter is passed on the stack, so it's +0(FP), +4(FP), ...