Thanks Paul for highlighting the issue. + Rick, who highlighted some potential issues with this. (also attached the stack trace). > On Mar 27, 2022, at 3:36 AM, Paul Menzel wrote: > > Dear Song, > > > Am 26.03.22 um 19:46 schrieb Paul Menzel: >> #regzbot introduced: fac54e2bfb5be2b0bbf115fe80d45f59fd773048 >> #regzbot title: BUG: Bad page state in process systemd-udevd > >> Am 04.02.22 um 19:57 schrieb Song Liu: >>> From: Song Liu >>> >>> This enables module_alloc() to allocate huge page for 2MB+ requests. >>> To check the difference of this change, we need enable config >>> CONFIG_PTDUMP_DEBUGFS, and call module_alloc(2MB). Before the change, >>> /sys/kernel/debug/page_tables/kernel shows pte for this map. With the >>> change, /sys/kernel/debug/page_tables/ show pmd for thie map. >>> >>> Signed-off-by: Song Liu >>> --- >>> arch/x86/Kconfig | 1 + >>> 1 file changed, 1 insertion(+) >>> >>> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >>> index 6fddb63271d9..e0e0d00cf103 100644 >>> --- a/arch/x86/Kconfig >>> +++ b/arch/x86/Kconfig >>> @@ -159,6 +159,7 @@ config X86 >>> select HAVE_ALIGNED_STRUCT_PAGE if SLUB >>> select HAVE_ARCH_AUDITSYSCALL >>> select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE >>> + select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP >>> select HAVE_ARCH_JUMP_LABEL >>> select HAVE_ARCH_JUMP_LABEL_RELATIVE >>> select HAVE_ARCH_KASAN if X86_64 >> Testing Linus’ current master branch, Linux logs critical messages like below: >> BUG: Bad page state in process systemd-udevd pfn:102e03 >> I bisected to your commit fac54e2bfb5 (x86/Kconfig: select HAVE_ARCH_HUGE_VMALLOC with HAVE_ARCH_HUGE_VMAP). > > Sorry, I forget to mention, that this is a 32-bit (i686) userspace, but a 64-bit Linux kernel, so it might be the same issue as mentioned in commit eed1fcee556f (x86: Disable HAVE_ARCH_HUGE_VMALLOC on 32-bit x86), but didn’t fix the issue for 64-bit Linux kernel and 32-bit userspace. I will look more into this tomorrow. To clarify, what is the 32-bit user space that triggers this? Is it systemd-udevd? Is the systemd also i686? Thanks, Song