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authorMichal Hocko <mhocko@suse.com>2018-02-22 01:46:01 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-22 02:35:43 +0300
commit698d0831ba87b92ae10b15e8203cfd59f5a59a35 (patch)
tree278028f8b10798d696543a5249432f85eec1b855 /mm/vmalloc.c
parentbdefe01a6b14bde268741435ac854fda4ef7e847 (diff)
downloadlinux-698d0831ba87b92ae10b15e8203cfd59f5a59a35.tar.xz
vmalloc: fix __GFP_HIGHMEM usage for vmalloc_32 on 32b systems
Kai Heng Feng has noticed that BUG_ON(PageHighMem(pg)) triggers in drivers/media/common/saa7146/saa7146_core.c since 19809c2da28a ("mm, vmalloc: use __GFP_HIGHMEM implicitly"). saa7146_vmalloc_build_pgtable uses vmalloc_32 and it is reasonable to expect that the resulting page is not in highmem. The above commit aimed to add __GFP_HIGHMEM only for those requests which do not specify any zone modifier gfp flag. vmalloc_32 relies on GFP_VMALLOC32 which should do the right thing. Except it has been missed that GFP_VMALLOC32 is an alias for GFP_KERNEL on 32b architectures. Thanks to Matthew to notice this. Fix the problem by unconditionally setting GFP_DMA32 in GFP_VMALLOC32 for !64b arches (as a bailout). This should do the right thing and use ZONE_NORMAL which should be always below 4G on 32b systems. Debugged by Matthew Wilcox. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20180212095019.GX21609@dhcp22.suse.cz Fixes: 19809c2da28a ("mm, vmalloc: use __GFP_HIGHMEM implicitlyā€¯) Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Kai Heng Feng <kai.heng.feng@canonical.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Laura Abbott <labbott@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/vmalloc.c')
-rw-r--r--mm/vmalloc.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 673942094328..ebff729cc956 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1943,11 +1943,15 @@ void *vmalloc_exec(unsigned long size)
}
#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
-#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
+#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
-#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
+#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
#else
-#define GFP_VMALLOC32 GFP_KERNEL
+/*
+ * 64b systems should always have either DMA or DMA32 zones. For others
+ * GFP_DMA32 should do the right thing and use the normal zone.
+ */
+#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
#endif
/**