Building on 32 bits with pmd_leaf() not returning always false leads
to the following error:
CC arch/powerpc/mm/pgtable.o
arch/powerpc/mm/pgtable.c: In function '__find_linux_pte':
arch/powerpc/mm/pgtable.c:506:1: error: function may return address of local
variable [-Werror=return-local-addr]
506 | }
| ^
arch/powerpc/mm/pgtable.c:394:15: note: declared here
394 | pud_t pud, *pudp;
| ^~~
arch/powerpc/mm/pgtable.c:394:15: note: declared here
This is due to pmd_offset() being a no-op in that case.
So rework it for powerpc/32 so that pXd_offset() are used on real
pointers and not on on-stack copies.
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
Reviewed-by: Oscar Salvador <osalva...@suse.de>
---
v3: Removed p4dp and pudp locals for PPC32 and add a comment.
v4: Properly set pdshift on PPC32 case
---
arch/powerpc/mm/pgtable.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 9e7ba9c3851f..bce8a8619589 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -382,8 +382,10 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
bool *is_thp, unsigned *hpage_shift)
{
pgd_t *pgdp;
+#ifdef CONFIG_PPC64
p4d_t p4d, *p4dp;
pud_t pud, *pudp;
+#endif
pmd_t pmd, *pmdp;
pte_t *ret_pte;
hugepd_t *hpdp = NULL;
@@ -401,8 +403,12 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
* page fault or a page unmap. The return pte_t * is still not
* stable. So should be checked there for above conditions.
* Top level is an exception because it is folded into p4d.
+ *
+ * On PPC32, P4D/PUD/PMD are folded into PGD so go straight to
+ * PMD level.
*/
pgdp = pgdir + pgd_index(ea);
+#ifdef CONFIG_PPC64
p4dp = p4d_offset(pgdp, ea);
p4d = READ_ONCE(*p4dp);
pdshift = P4D_SHIFT;
@@ -442,8 +448,11 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
goto out_huge;
}
- pdshift = PMD_SHIFT;
pmdp = pmd_offset(&pud, ea);
+#else
+ pmdp = pmd_offset(pud_offset(p4d_offset(pgdp, ea), ea), ea);
+#endif
+ pdshift = PMD_SHIFT;
pmd = READ_ONCE(*pmdp);
/*
--
2.44.0
