On Wed, Oct 25, 2023 at 08:56:10AM +0200, Peter Zijlstra wrote: > > config3: 32-bit mode, pre-boot objdump > > > > entry_SYSENTER_32: > > ... > > c8e: 58 pop %eax > > c8f: 90 nop > > c90: 90 nop > > c91: 90 nop > > c92: 90 nop > > c93: 90 nop > > c94: 90 nop > > c95: 90 nop > > c96: fb sti > > c97: 0f 35 sysexit > > > > If you look at arch/x86/include/asm/nops.h, you'll find (for 32bit): > > * 7: leal 0x0(%esi,%eiz,1),%esi > > Which reads as: > > load-effective-address of %esi[0] into %esi Wow, never imagined that this would be one of the magician's trick. I will go read on why is it better than NOPL.
