On Mon, Oct 30, 2023 at 11:33:24AM +0000, RVP wrote: > The NetBSD copyinstr() _disables_ SMAP before copying data from > userspace. The dtrace version _does not_. I think this is what > fails on some CPUs. My Intel CPU's more than 10 years old so it > doesn't support SMAP (only SMEP), dtrace works for me. If you and > bch tell me that your CPUs support SMAP, then that would be the > smoking gun.
# cpuctl identify 0 | grep SMAP cpu0: features5 0xf1bf97a9<AVX512F,AVX512DQ,RDSEED,ADX,SMAP,AVX512_IFMA> Looks that way! Thomas
