parisc: mm: Fix a memory leak related to pmd not attached to the pgd

Commit 0e0da48dee8d ("parisc: mm: don't count preallocated pmds")
introduced a memory leak.

After this commit, the 'return' statement in pmd_free is executed in all
cases. Even for pmd that are not attached to the pgd.  So 'free_pages'
can never be called anymore, leading to a memory leak.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org  # v4.0+
Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/arch/parisc/include/asm/pgalloc.h b/arch/parisc/include/asm/pgalloc.h
index 3a08eae3318fe8da341a563613ae16e82e64912b..3edbb9fc91b4e055307d3c7519592a00201d988a 100644 (file)
--- a/arch/parisc/include/asm/pgalloc.h
+++ b/arch/parisc/include/asm/pgalloc.h
@@ -72,7 +72,7 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
 
 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
 {
-       if(pmd_flag(*pmd) & PxD_FLAG_ATTACHED)
+       if (pmd_flag(*pmd) & PxD_FLAG_ATTACHED) {
                /*
                 * This is the permanent pmd attached to the pgd;
                 * cannot free it.
@@ -81,6 +81,7 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
                 */
                mm_inc_nr_pmds(mm);
                return;
+       }
        free_pages((unsigned long)pmd, PMD_ORDER);
 }