[RFC PATCH v2 3/3] mm: make generic pXd_addr_end() macros inline functions

Gerald Schaefer
2020-09-07T18:04:40Z

From: Alexander Gordeev <agordeev@linux.ibm.com>

Since pXd_addr_end() macros take pXd page-table entry as a
parameter it makes sense to check the entry type on compile.
Even though most archs do not make use of page-table entries
in pXd_addr_end() calls, checking the type in traversal code
paths could help to avoid subtle bugs.

Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
---
include/linux/pgtable.h | 36 ++++++++++++++++++++----------------
1 file changed, 20 insertions(+), 16 deletions(-)

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 67ebc22cf83d..d9e7d16c2263 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -656,31 +656,35 @@ static inline int arch_unmap_one(struct mm_struct *mm,
*/

#ifndef pgd_addr_end
-#define pgd_addr_end(pgd, addr, end) \
-({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \
- (__boundary - 1 < (end) - 1)? __boundary: (end); \
-})
+#define pgd_addr_end pgd_addr_end
+static inline unsigned long pgd_addr_end(pgd_t pgd, unsigned long addr, unsigned long end)
+{ unsigned long __boundary = (addr + PGDIR_SIZE) & PGDIR_MASK;
+ return (__boundary - 1 < end - 1) ? __boundary : end;
+}
#endif

#ifndef p4d_addr_end
-#define p4d_addr_end(p4d, addr, end) \
-({ unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK; \
- (__boundary - 1 < (end) - 1)? __boundary: (end); \
-})
+#define p4d_addr_end p4d_addr_end
+static inline unsigned long p4d_addr_end(p4d_t p4d, unsigned long addr, unsigned long end)
+{ unsigned long __boundary = (addr + P4D_SIZE) & P4D_MASK;
+ return (__boundary - 1 < end - 1) ? __boundary : end;
+}
#endif

#ifndef pud_addr_end
-#define pud_addr_end(pud, addr, end) \
-({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \
- (__boundary - 1 < (end) - 1)? __boundary: (end); \
-})
+#define pud_addr_end pud_addr_end
+static inline unsigned long pud_addr_end(pud_t pud, unsigned long addr, unsigned long end)
+{ unsigned long __boundary = (addr + PUD_SIZE) & PUD_MASK;
+ return (__boundary - 1 < end - 1) ? __boundary : end;
+}
#endif

#ifndef pmd_addr_end
-#define pmd_addr_end(pmd, addr, end) \
-({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \
- (__boundary - 1 < (end) - 1)? __boundary: (end); \
-})
+#define pmd_addr_end pmd_addr_end
+static inline unsigned long pmd_addr_end(pmd_t pmd, unsigned long addr, unsigned long end)
+{ unsigned long __boundary = (addr + PMD_SIZE) & PMD_MASK;
+ return (__boundary - 1 < end - 1) ? __boundary : end;
+}
#endif

/*
--
2.17.1