ARM kprobes: add the kprobes hook to the page fault handler

Signed-off-by: Nicolas Pitre <nico@marvell.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index a8a7dab757eb..1e7b1ed304d8 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -12,6 +12,7 @@
 #include <linux/signal.h>
 #include <linux/mm.h>
 #include <linux/init.h>
+#include <linux/kprobes.h>
 
 #include <asm/system.h>
 #include <asm/pgtable.h>
@@ -20,6 +21,29 @@
 
 #include "fault.h"
 
+
+#ifdef CONFIG_KPROBES
+static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr)
+{
+        int ret = 0;
+
+        if (!user_mode(regs)) {
+                /* kprobe_running() needs smp_processor_id() */
+                preempt_disable();
+                if (kprobe_running() && kprobe_fault_handler(regs, fsr))
+                        ret = 1;
+                preempt_enable();
+        }
+
+        return ret;
+}
+#else
+static inline int notify_page_fault(struct pt_regs *regs, unsigned int fsr)
+{
+        return 0;
+}
+#endif
+
 /*
  * This is useful to dump out the page tables associated with
  * 'addr' in mm 'mm'.
@@ -222,6 +246,9 @@ do_page_fault(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
         struct mm_struct *mm;
         int fault, sig, code;
 
+        if (notify_page_fault(regs, fsr))
+                return 0;
+
         tsk = current;
         mm  = tsk->mm;