From 384a746bb55960aa5ffb3a67de08f11fc2f51042 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Wed, 5 Jun 2024 11:17:10 +0200 Subject: Revert "mm: init_mlocked_on_free_v3" There was insufficient review and no agreement that this is the right approach. There are serious flaws with the implementation that make processes using mlock() not even work with simple fork() [1] and we get reliable crashes when rebooting. Further, simply because we might be unmapping a single PTE of a large mlocked folio, we shouldn't zero out the whole folio. ... especially because the code can also *corrupt* urelated memory because kernel_init_pages(page, folio_nr_pages(folio)); Could end up writing outside of the actual folio if we work with a tail page. Let's revert it. Once there is agreement that this is the right approach, the issues were fixed and there was reasonable review and proper testing, we can consider it again. [1] https://lkml.kernel.org/r/4da9da2f-73e4-45fd-b62f-a8a513314057@redhat.com Link: https://lkml.kernel.org/r/20240605091710.38961-1-david@redhat.com Fixes: ba42b524a040 ("mm: init_mlocked_on_free_v3") Signed-off-by: David Hildenbrand Reported-by: David Wang <00107082@163.com> Closes: https://lore.kernel.org/lkml/20240528151340.4282-1-00107082@163.com/ Reported-by: Lance Yang Closes: https://lkml.kernel.org/r/20240601140917.43562-1-ioworker0@gmail.com Acked-by: Lance Yang Cc: York Jasper Niebuhr Cc: Matthew Wilcox (Oracle) Cc: Kees Cook Signed-off-by: Andrew Morton --- include/linux/mm.h | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) (limited to 'include/linux/mm.h') diff --git a/include/linux/mm.h b/include/linux/mm.h index 9849dfda44d4..9a5652c5fadd 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3776,14 +3776,7 @@ DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free); static inline bool want_init_on_free(void) { return static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON, - &init_on_free); -} - -DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON, init_mlocked_on_free); -static inline bool want_init_mlocked_on_free(void) -{ - return static_branch_maybe(CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON, - &init_mlocked_on_free); + &init_on_free); } extern bool _debug_pagealloc_enabled_early; -- cgit v1.2.3 From 399ab86ea55039f9d0a5f621a68cb4631f796f37 Mon Sep 17 00:00:00 2001 From: Jeff Xu Date: Fri, 14 Jun 2024 23:20:14 +0000 Subject: /proc/pid/smaps: add mseal info for vma MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add sl in /proc/pid/smaps to indicate vma is sealed Link: https://lkml.kernel.org/r/20240614232014.806352-2-jeffxu@google.com Fixes: 8be7258aad44 ("mseal: add mseal syscall") Signed-off-by: Jeff Xu Acked-by: David Hildenbrand Cc: Adhemerval Zanella Cc: Jann Horn Cc: Jorge Lucangeli Obes Cc: Kees Cook Cc: Randy Dunlap Cc: Stephen Röttger Signed-off-by: Andrew Morton --- include/linux/mm.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/linux/mm.h') diff --git a/include/linux/mm.h b/include/linux/mm.h index 9a5652c5fadd..eb7c96d24ac0 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -406,6 +406,11 @@ extern unsigned int kobjsize(const void *objp); #define VM_ALLOW_ANY_UNCACHED VM_NONE #endif +#ifdef CONFIG_64BIT +/* VM is sealed, in vm_flags */ +#define VM_SEALED _BITUL(63) +#endif + /* Bits set in the VMA until the stack is in its final location */ #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ | VM_STACK_EARLY) -- cgit v1.2.3