x86_64 machine executes x86 binary

[joannechiou]

dear all,

i am executing 32-bit x86 binary on x86_64 machine,
does it need to do some action like switch mode between x86 and x86_64 ??
if so, how does it perform??

[AndreyKarpov]

64-bit lessons:
Lesson 2. Support of 32-bit applications in the 64-bit Windows environment.

[TimP]

Both Windows and linux support running 32-bit applications under 64-bit OS, with the CPU mode bit reset. This appears to introduce additional opportunities for exploits.