syscalls don't clobber argument regs
Since 2001 the kernel was saving/restoring most registers and glibc made use of this, i.e. it expects only rcx and r11 to be clobbered. Let's clarify the wording to that effect.
Since 2001 the kernel was saving/restoring most registers and glibc made use of this, i.e. it expects only rcx and r11 to be clobbered. Let's clarify the wording to that effect.