summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMichal Hocko <mhocko@suse.com>2018-02-21 14:46:01 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-02-25 11:15:44 +0100
commit0e6f5f6c23678eed229ea1798441677660f3ebc7 (patch)
tree15ac6f7a0d6d251ace3d4382b27bfc5565e2ee42
parentfc3a0d7d6b81a7889648f77cbbc1eba0558c13c6 (diff)
downloadlinux-stable-0e6f5f6c23678eed229ea1798441677660f3ebc7.tar.gz
linux-stable-0e6f5f6c23678eed229ea1798441677660f3ebc7.tar.bz2
linux-stable-0e6f5f6c23678eed229ea1798441677660f3ebc7.zip
vmalloc: fix __GFP_HIGHMEM usage for vmalloc_32 on 32b systems
commit 698d0831ba87b92ae10b15e8203cfd59f5a59a35 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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
/**