Commit 81112927 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'slab-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab 

Pull slab fixes from Vlastimil Babka:

 - Stable fixes for CONFIG_SMP=n where _nolock() allocations in NMI both
   at kmalloc and page allocator levels are not properly protected by
   the spin_trylock() semantics on !SMP (Harry Yoo)

* tag 'slab-for-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/slab: return NULL early from kmalloc_nolock() in NMI on UP
  mm/page_alloc: return NULL early from alloc_frozen_pages_nolock() in NMI on UP
parents cffcf520 5b31044e

mm/page_alloc.c

+5 −0
Original line number Diff line number Diff line
@@ -7737,6 +7737,11 @@ struct page *alloc_frozen_pages_nolock_noprof(gfp_t gfp_flags, int nid, unsigned 
	 */

	if (IS_ENABLED(CONFIG_PREEMPT_RT) && (in_nmi() || in_hardirq()))

		return NULL;



	/* On UP, spin_trylock() always succeeds even when it is locked */

	if (!IS_ENABLED(CONFIG_SMP) && in_nmi())

		return NULL;



	if (!pcp_allowed_order(order))

		return NULL;

mm/slub.c

+4 −0
Original line number Diff line number Diff line
@@ -5339,6 +5339,10 @@ void *kmalloc_nolock_noprof(size_t size, gfp_t gfp_flags, int node) 
	if (IS_ENABLED(CONFIG_PREEMPT_RT) && (in_nmi() || in_hardirq()))

		return NULL;



	/* On UP, spin_trylock() always succeeds even when it is locked */

	if (!IS_ENABLED(CONFIG_SMP) && in_nmi())

		return NULL;



retry:

	if (unlikely(size > KMALLOC_MAX_CACHE_SIZE))

		return NULL;