On 3/30/21 12:00 AM, Andrey Konovalov wrote: > On Mon, Mar 29, 2021 at 2:10 PM Vlastimil Babka <vbabka@xxxxxxx> wrote: >> >> > commit 855a9c4018f3219db8be7e4b9a65ab22aebfde82 >> > Author: Andrey Konovalov <andreyknvl@xxxxxxxxx> >> > Date: Thu Mar 18 17:01:40 2021 +1100 >> > >> > kasan, mm: integrate page_alloc init with HW_TAGS >> >> But the mmotm patch/-next commit also changes post_alloc_hook() >> >> Before the patch it was: >> kernel_unpoison_pages(page, 1 << order); >> ... >> kernel_init_free_pages(page, 1 << order); >> >> Now it is (for !kasan_has_integrated_init()): >> >> kernel_init_free_pages(page, 1 << order); >> >> kernel_unpoison_pages(page, 1 << order); >> >> That has to be wrong, because we init the page with zeroes and then call >> kernel_unpoison_pages() which checks for the 0xaa pattern. Andrey? > > It's similar to free_pages_prepare(): kernel_unpoison_pages() and > want_init_on_alloc() are exclusive, so the order shouldn't matter. Am > I missing something? Yeah, when the allocation has __GFP_ZERO, want_init_on_alloc() will return true even with the static branches disabled.
