[PATCH] unpaged: fix sound Bad page states

Earlier I unifdefed PageCompound, so that snd_pcm_mmap_control_nopage and
others can give out a 0-order component of a higher-order page, which won't
be mistakenly freed when zap_pte_range unmaps it.  But many Bad page states
reported a PG_reserved was freed after all: I had missed that we need to
say __GFP_COMP to get compound page behaviour.

Some of these higher-order pages are allocated by snd_malloc_pages, some by
snd_malloc_dev_pages; or if SBUS, by sbus_alloc_consistent - but that has
no gfp arg, so add __GFP_COMP into its sparc32/64 implementations.

I'm still rather puzzled that DRM seems not to need a similar change.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/sparc/kernel/ioport.c

@@ -252,7 +252,7 @@ void *sbus_alloc_consistent(struct sbus_dev *sdev, long len, u32 *dma_addrp)
 	}
 
 	order = get_order(len_total);
-	if ((va = __get_free_pages(GFP_KERNEL, order)) == 0)
+	if ((va = __get_free_pages(GFP_KERNEL|__GFP_COMP, order)) == 0)
 		goto err_nopages;
 
 	if ((res = kmalloc(sizeof(struct resource), GFP_KERNEL)) == NULL)