On 09/12/2024 11:03, Peter Zijlstra wrote: > On Fri, Dec 06, 2024 at 10:11:02AM +0000, Kevin Brodsky wrote: >> kernel_pgtables_set_pkey() allows setting the pkey of all page table >> pages in swapper_pg_dir, recursively. This will be needed by >> kpkeys_hardened_pgtables, as it relies on all PTPs being mapped with >> a non-default pkey. Those initial kernel page tables cannot >> practically be assigned a non-default pkey right when they are >> allocated, so mutating them during (early) boot is required. >> >> Signed-off-by: Kevin Brodsky <kevin.brod...@arm.com> >> --- >> >> It feels that some sort of locking is called for in >> kernel_pgtables_set_pkey(), but I couldn't figure out what would be >> appropriate. > init_mm.page_table_lock is typically the one used to serialize kernel > page tables IIRC.
That does seem to be the case, thanks! Hopefully holding that spinlock for the entire duration of the loop in kernel_pgtables_set_pkey() won't be an issue. - Kevin
