On Tue, Feb 25, 2025 at 7:18 AM Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx> wrote: > > Jeff - looking further in this series, I asked for a couple things for this > series which you've not provided: > > 1. Some assurance based on code that the kernel-side code doesn't rely on > VDSO/VVAR etc. mapping. I gave up waiting for this and went and checked > myself, it looks fine for arm64, x86-64. But it might have been nice had > you done it :) Apologies if you had and I just missed it. > Thanks for checking this. Do ppc in kernel code unmap/remap vdso ? I am aware that userspace can remap/unmap special mappings, but I don't know if the kernel will remap/unmap a special mapping. Could you please point out the code ? > 2. Tests - could you please add some tests to assert that mremap() fails > for VDSO for instance? You've edited an existing test for VDSO in x86 to > skip the test should this be enabled, but this is not the same as a self > test. And obviously doesn't cover arm64. > > This should be relatively strightforward right? You already have code > for finding out whether VDSO is msealed, so just use that to see if you > skip, then attempt mremap(), mmap() over etc. + assert it fails. > > Ideally these tests would cover all the cases you've changed. > It is not as easy. The config is disabled by default. And I don't know a way to detect KCONFIG from selftest itself. Without this, I can't reasonably determine the test result.
