[PATCH] slab debug and ARCH_SLAB_MINALIGN don't get along (a44b56d3) · Commits · 戴 / test

When CONFIG_SLAB_DEBUG is used in combination with ARCH_SLAB_MINALIGN, some debug flags should be disabled which depend on BYTES_PER_WORD alignment. The disabling of these debug flags is not properly handled when BYTES_PER_WORD < ARCH_SLAB_MEMALIGN < cache_line_size() This patch fixes that and also adds an alignment check to cache_alloc_debugcheck_after() when ARCH_SLAB_MINALIGN is used. Signed-off-by:

Kevin Hilman <khilman@mvista.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

mm/slab.c

+11 −6

Original line number	Diff line number	Diff line
		@@ -2197,18 +2197,17 @@ kmem_cache_create (const char *name, size_t size, size_t align,
		if (flags & SLAB_RED_ZONE \|\| flags & SLAB_STORE_USER)
		ralign = BYTES_PER_WORD;

		/* 2) arch mandated alignment: disables debug if necessary */
		/* 2) arch mandated alignment */
		if (ralign < ARCH_SLAB_MINALIGN) {
		ralign = ARCH_SLAB_MINALIGN;
		if (ralign > BYTES_PER_WORD)
		flags &= ~(SLAB_RED_ZONE \| SLAB_STORE_USER);
		}
		/* 3) caller mandated alignment: disables debug if necessary */
		/* 3) caller mandated alignment */
		if (ralign < align) {
		ralign = align;
		}
		/* disable debug if necessary */
		if (ralign > BYTES_PER_WORD)
		flags &= ~(SLAB_RED_ZONE \| SLAB_STORE_USER);
		}
		/*
		* 4) Store it.
		*/
		@@ -3063,6 +3062,12 @@ static void cache_alloc_debugcheck_after(struct kmem_cache cachep,

		cachep->ctor(objp, cachep, ctor_flags);
		}
		#if ARCH_SLAB_MINALIGN
		if ((u32)objp & (ARCH_SLAB_MINALIGN-1)) {
		printk(KERN_ERR "0x%p: not aligned to ARCH_SLAB_MINALIGN=%d\n",
		objp, ARCH_SLAB_MINALIGN);
		}
		#endif
		return objp;
		}
		#else

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