ARM: 9278/1: kfence: only handle translation faults

This is a similar fixup like arm64 does, only handle translation faults
in case of unexpected kfence report when alignment faults on ARM, see
more from commit 0bb1fbffc631 ("arm64: mm: kfence: only handle translation
faults").

Fixes: 75969686ec0d ("ARM: 9166/1: Support KFENCE for ARM")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 46cccd6..de988cb 100644 (file)
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -105,6 +105,19 @@ static inline bool is_write_fault(unsigned int fsr)
        return (fsr & FSR_WRITE) && !(fsr & FSR_CM);
 }
 
+static inline bool is_translation_fault(unsigned int fsr)
+{
+       int fs = fsr_fs(fsr);
+#ifdef CONFIG_ARM_LPAE
+       if ((fs & FS_MMU_NOLL_MASK) == FS_TRANS_NOLL)
+               return true;
+#else
+       if (fs == FS_L1_TRANS || fs == FS_L2_TRANS)
+               return true;
+#endif
+       return false;
+}
+
 static void die_kernel_fault(const char *msg, struct mm_struct *mm,
                             unsigned long addr, unsigned int fsr,
                             struct pt_regs *regs)
@@ -140,7 +153,8 @@ __do_kernel_fault(struct mm_struct *mm, unsigned long addr, unsigned int fsr,
        if (addr < PAGE_SIZE) {
                msg = "NULL pointer dereference";
        } else {
-               if (kfence_handle_page_fault(addr, is_write_fault(fsr), regs))
+               if (is_translation_fault(fsr) &&
+                   kfence_handle_page_fault(addr, is_write_fault(fsr), regs))
                        return;
 
                msg = "paging request";
@@ -208,7 +222,7 @@ static inline bool is_permission_fault(unsigned int fsr)
 {
        int fs = fsr_fs(fsr);
 #ifdef CONFIG_ARM_LPAE
-       if ((fs & FS_PERM_NOLL_MASK) == FS_PERM_NOLL)
+       if ((fs & FS_MMU_NOLL_MASK) == FS_PERM_NOLL)
                return true;
 #else
        if (fs == FS_L1_PERM || fs == FS_L2_PERM)

diff --git a/arch/arm/mm/fault.h b/arch/arm/mm/fault.h
index 83b5ab3..54927ba 100644 (file)
--- a/arch/arm/mm/fault.h
+++ b/arch/arm/mm/fault.h
@@ -14,8 +14,9 @@
 
 #ifdef CONFIG_ARM_LPAE
 #define FSR_FS_AEA             17
+#define FS_TRANS_NOLL          0x4
 #define FS_PERM_NOLL           0xC
-#define FS_PERM_NOLL_MASK      0x3C
+#define FS_MMU_NOLL_MASK       0x3C
 
 static inline int fsr_fs(unsigned int fsr)
 {
@@ -23,8 +24,10 @@ static inline int fsr_fs(unsigned int fsr)
 }
 #else
 #define FSR_FS_AEA             22
-#define FS_L1_PERM             0xD
-#define FS_L2_PERM             0xF
+#define FS_L1_TRANS            0x5
+#define FS_L2_TRANS            0x7
+#define FS_L1_PERM             0xD
+#define FS_L2_PERM             0xF
 
 static inline int fsr_fs(unsigned int fsr)
 {