On Mon, Jan 24, 2022 at 07:02:08PM +0100, andrey.konovalov@xxxxxxxxx wrote: > From: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > > Hi, > > This patchset adds vmalloc tagging support for SW_TAGS and HW_TAGS > KASAN modes. > > The tree with patches is available here: > > https://github.com/xairy/linux/tree/up-kasan-vmalloc-tags-v6 > > About half of patches are cleanups I went for along the way. None of > them seem to be important enough to go through stable, so I decided > not to split them out into separate patches/series. > > The patchset is partially based on an early version of the HW_TAGS > patchset by Vincenzo that had vmalloc support. Thus, I added a > Co-developed-by tag into a few patches. > > SW_TAGS vmalloc tagging support is straightforward. It reuses all of > the generic KASAN machinery, but uses shadow memory to store tags > instead of magic values. Naturally, vmalloc tagging requires adding > a few kasan_reset_tag() annotations to the vmalloc code. > > HW_TAGS vmalloc tagging support stands out. HW_TAGS KASAN is based on > Arm MTE, which can only assigns tags to physical memory. As a result, > HW_TAGS KASAN only tags vmalloc() allocations, which are backed by > page_alloc memory. It ignores vmap() and others. I could use some help here. Ever since this series, our system starts to trigger bad page state bugs from time to time. Any thoughts? BUG: Bad page state in process systemd-udevd pfn:83ffffcd page:fffffc20fdfff340 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x83ffffcd flags: 0xbfffc0000001000(reserved|node=0|zone=2|lastcpupid=0xffff) raw: 0bfffc0000001000 fffffc20fdfff348 fffffc20fdfff348 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set page_owner info is not present (never set?) CPU: 76 PID: 1873 Comm: systemd-udevd Not tainted 5.18.0-rc4-next-20220428-dirty #67 Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack bad_page free_pcp_prepare free_unref_page __free_pages free_pages.part.0 free_pages kasan_depopulate_vmalloc_pte (inlined by) kasan_depopulate_vmalloc_pte at mm/kasan/shadow.c:361 apply_to_pte_range apply_to_pmd_range apply_to_pud_range __apply_to_page_range apply_to_existing_page_range kasan_release_vmalloc (inlined by) kasan_release_vmalloc at mm/kasan/shadow.c:469 __purge_vmap_area_lazy purge_vmap_area_lazy alloc_vmap_area __get_vm_area_node.constprop.0 __vmalloc_node_range module_alloc move_module layout_and_allocate load_module __do_sys_finit_module __arm64_sys_finit_module invoke_syscall el0_svc_common.constprop.0 do_el0_svc el0_svc el0t_64_sync_handler el0t_64_sync Disabling lock debugging due to kernel taint BUG: Bad page state in process systemd-udevd pfn:83ffffcc page:fffffc20fdfff300 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x83ffffcc flags: 0xbfffc0000001000(reserved|node=0|zone=2|lastcpupid=0xffff) raw: 0bfffc0000001000 fffffc20fdfff308 fffffc20fdfff308 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set page_owner info is not present (never set?) CPU: 76 PID: 1873 Comm: systemd-udevd Tainted: G B 5.18.0-rc4-next-20220428-dirty #67 Call trace: dump_backtrace show_stack dump_stack_lvl dump_stack bad_page free_pcp_prepare free_unref_page __free_pages free_pages.part.0 free_pages kasan_depopulate_vmalloc_pte apply_to_pte_range apply_to_pmd_range apply_to_pud_range __apply_to_page_range apply_to_existing_page_range kasan_release_vmalloc __purge_vmap_area_lazy purge_vmap_area_lazy alloc_vmap_area __get_vm_area_node.constprop.0 __vmalloc_node_range module_alloc move_module layout_and_allocate load_module __do_sys_finit_module __arm64_sys_finit_module invoke_syscall el0_svc_common.constprop.0 do_el0_svc el0_svc el0t_64_sync_handler el0t_64_sync
