On Wed, May 08, 2024 at 12:20:41PM GMT, Catalin Marinas wrote: > On Tue, Apr 30, 2024 at 11:05:01AM -0500, Maxwell Bland wrote: > > -ptdump is a debugfs interface that provides a detailed dump of the Hi Catalin! Apologies for the delayed response to this review, life got in the way. A version 4 that addresses your comments is available here: https://lore.kernel.org/all/aw675dhrbplkitj3szjut2vyidsxokogkjj3vi76wl2x4wybtg@5rhk5ca5zpmv/ > > +Assessing these attributes can assist in understanding the memory layout, > > +access patterns and security characteristics of the kernel pages. > > I presume there's some new text here. Yes. Though after having a bit of time to think on it, I just reworked the presentation altogether for version 4. > > > }, { > > .mask = PTE_UXN, > > .val = PTE_UXN, > > Since you are adding a separate pmd_bits[] array, I think we could get > rid of the PTE_TABLE_BIT entry. It doesn't make sense for ptes anyway. Done! Sweet. > > +static const struct prot_bits pud_bits[] = { > [...] > > +}; > > Do we need pud_bits[] as well? Can we not just use pmd_bits[]? Call it > pxd_bits if you want, the format is the same for all p*d entries. Thanks, done! > > Please separate the alignment changes into a different patch Done! > > + delta = (addr - st->start_address); > > What's this supposed to show? In your example, it's strange that the PGD > is shown as 128 bytes: This was a bug due to my misunderstanding of what we were going for here. Thank you for pointing it out, as it made it easy to notice and patch. > > if (pgd_leaf(val)) { > > st->note_page(st, addr, 0, pgd_val(val)); > > walk->action = ACTION_CONTINUE; > > Is the difference between leaf and non-leaf calls only the walk->action? > We could have a single call to st->note_page() and keep the walk->action > setting separately. Do we also need to set ACTION_SUBTREE in case the > entry is a table entry? Or is it done in the caller somewhere? I could > not figure out. ACTION_SUBTREE is the default walk action, so it is implicitly set for table descriptors. > > An alternative would be to have an ARCH_WANT_NON_LEAF_PTDUMP Kconfig > option instead of a bool note_non_leaf in struct ptdump_state. This > option seems to be entirely static, not sure it's worth a struct member > for it. You'd use IS_ENABLED() above instead of st->note_non_leaf. This was an excellent idea, thank you. Incorporated. BRs and thanks again for your help on this, Maxwell Bland
