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Diffstat (limited to 'arch/sh/mm/fault_32.c')
-rw-r--r--arch/sh/mm/fault_32.c63
1 files changed, 47 insertions, 16 deletions
diff --git a/arch/sh/mm/fault_32.c b/arch/sh/mm/fault_32.c
index 0c776fdfbdd..898d477e47c 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;
}