Subject: Re: linux-next: build failure after merge of the final tree (tip/s390 trees related)

From: Ralf Baechle <[email-masked]>
Date: Thu, 18 Oct 2012 16:51:01 +0200

On Thu, Oct 18, 2012 at 05:22:01PM +1100, Stephen Rothwell wrote:

> After merging the final tree, today's linux-next build (s390 allyesconfig)
> failed like this:
> 
> mm/huge_memory.c:1424:2: error: implicit declaration of function 'pmd_pgprot' [-Werror=implicit-function-declaration]
> mm/huge_memory.c:1424:7: error: incompatible types when assigning to type 'pgprot_t' from type 'int'
> 
> (see http://kisskb.ellerman.id.au/kisskb/buildresult/7383823/)
> 
> Caused by commit 35d3d3427314 ("s390/thp: select
> HAVE_ARCH_TRANSPARENT_HUGEPAGE") from the s390 tree interacting with
> commit 93c9d633bd9e ("mm/thp: Preserve pgprot across huge page split")
> from the tip tree.
> 
> N.B. Mips also selects HAVE_ARCH_TRANSPARENT_HUGEPAGE as of commit
> e21a828a1bba ("MIPS: Transparent Huge Pages support") from the mips tree
> and so will be broken in some configs now as well.
> 
> Anyone have suggested merge fix patches I can apply?

See below.  There's further MIPS breakage in -next; more on than in a
separate email.

  Ralf

Signed-off-by: Ralf Baechle <[email-masked]>

 arch/mips/include/asm/pgtable.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
index 252202d..5f7c615 100644
--- a/arch/mips/include/asm/pgtable.h
+++ b/arch/mips/include/asm/pgtable.h
@@ -534,6 +534,8 @@ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 	return pmd;
 }
 
+#define pmd_pgprot(x) __pgprot(pmd_val(x) & ~_PAGE_CHG_MASK)
+
 static inline pmd_t pmd_mknotpresent(pmd_t pmd)
 {
 	pmd_val(pmd) &= ~(_PAGE_PRESENT | _PAGE_VALID | _PAGE_DIRTY);