1 files changed, 47 insertions, 16 deletions

diff --git a/arch/sh/mm/fault_32.c b/arch/sh/mm/fault_32.c
index 0c776fdfbdda..898d477e47c1 100644
--- a/arch/sh/mm/fault_32.c
+++ b/arch/sh/mm/fault_32.c
@@ -2,7 +2,7 @@
  * Page fault handler for SH with an MMU.
  *
  *  Copyright (C) 1999  Niibe Yutaka
- *  Copyright (C) 2003 - 2007  Paul Mundt
+ *  Copyright (C) 2003 - 2008  Paul Mundt
  *
  *  Based on linux/arch/i386/mm/fault.c:
  *   Copyright (C) 1995  Linus Torvalds
@@ -15,6 +15,7 @@
 #include <linux/mm.h>
 #include <linux/hardirq.h>
 #include <linux/kprobes.h>
+#include <linux/marker.h>
 #include <asm/io_trapped.h>
 #include <asm/system.h>
 #include <asm/mmu_context.h>
@@ -37,10 +38,10 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
 	int fault;
 	siginfo_t info;
 
-#ifdef CONFIG_SH_KGDB
-	if (kgdb_nofault && kgdb_bus_err_hook)
-		kgdb_bus_err_hook();
-#endif
+	/*
+	 * We don't bother with any notifier callbacks here, as they are
+	 * all handled through the __do_page_fault() fast-path.
+	 */
 
 	tsk = current;
 	si_code = SEGV_MAPERR;
@@ -61,7 +62,6 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
 		pgd = get_TTB() + offset;
 		pgd_k = swapper_pg_dir + offset;
 
-		/* This will never happen with the folded page table. */
 		if (!pgd_present(*pgd)) {
 			if (!pgd_present(*pgd_k))
 				goto bad_area_nosemaphore;
@@ -71,9 +71,13 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
 
 		pud = pud_offset(pgd, address);
 		pud_k = pud_offset(pgd_k, address);
-		if (pud_present(*pud) || !pud_present(*pud_k))
-			goto bad_area_nosemaphore;
-		set_pud(pud, *pud_k);
+
+		if (!pud_present(*pud)) {
+			if (!pud_present(*pud_k))
+				goto bad_area_nosemaphore;
+			set_pud(pud, *pud_k);
+			return;
+		}
 
 		pmd = pmd_offset(pud, address);
 		pmd_k = pmd_offset(pud_k, address);
@@ -242,6 +246,25 @@ do_sigbus:
 		goto no_context;
 }
 
+static inline int notify_page_fault(struct pt_regs *regs, int trap)
+{
+	int ret = 0;
+
+	trace_mark(kernel_arch_trap_entry, "trap_id %d ip #p%ld",
+		   trap >> 5, instruction_pointer(regs));
+
+#ifdef CONFIG_KPROBES
+	if (!user_mode(regs)) {
+		preempt_disable();
+		if (kprobe_running() && kprobe_fault_handler(regs, trap))
+			ret = 1;
+		preempt_enable();
+	}
+#endif
+
+	return ret;
+}
+
 #ifdef CONFIG_SH_STORE_QUEUES
 /*
  * This is a special case for the SH-4 store queues, as pages for this
@@ -265,12 +288,18 @@ asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs,
 	pmd_t *pmd;
 	pte_t *pte;
 	pte_t entry;
+	int ret = 0;
+
+	if (notify_page_fault(regs, lookup_exception_vector()))
+		goto out;
 
 #ifdef CONFIG_SH_KGDB
 	if (kgdb_nofault && kgdb_bus_err_hook)
 		kgdb_bus_err_hook();
 #endif
 
+	ret = 1;
+
 	/*
 	 * We don't take page faults for P1, P2, and parts of P4, these
 	 * are always mapped, whether it be due to legacy behaviour in
@@ -280,24 +309,23 @@ asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs,
 		pgd = pgd_offset_k(address);
 	} else {
 		if (unlikely(address >= TASK_SIZE || !current->mm))
-			return 1;
+			goto out;
 
 		pgd = pgd_offset(current->mm, address);
 	}
 
 	pud = pud_offset(pgd, address);
 	if (pud_none_or_clear_bad(pud))
-		return 1;
+		goto out;
 	pmd = pmd_offset(pud, address);
 	if (pmd_none_or_clear_bad(pmd))
-		return 1;
-
+		goto out;
 	pte = pte_offset_kernel(pmd, address);
 	entry = *pte;
 	if (unlikely(pte_none(entry) || pte_not_present(entry)))
-		return 1;
+		goto out;
 	if (unlikely(writeaccess && !pte_write(entry)))
-		return 1;
+		goto out;
 
 	if (writeaccess)
 		entry = pte_mkdirty(entry);
@@ -314,5 +342,8 @@ asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs,
 	set_pte(pte, entry);
 	update_mmu_cache(NULL, address, entry);
 
-	return 0;
+	ret = 0;
+out:
+	trace_mark(kernel_arch_trap_exit, MARK_NOARGS);
+	return ret;
 }