Linux Kernel Stack Size

From testing,

Linux kernel 2.6.24 set process kernel stack size as 4KB
while kernel 2.6.32 set size as 8KB.

Usage: calculating current from ESP, mask 12 or 13 bits....

http://lxr.linux.no/linux+v2.6.32/arch/x86/include/asm/page_32_types.h#L23