Merge master.kernel.org:/pub/scm/linux/kernel/git/gregkh/i2c-2.6

[linux-2.6-omap-h63xx.git] / arch / ia64 / kernel / kprobes.c

diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c
index 50ae8c7d453d5075641a191dcfdf5bf0d4087ece..789881ca83d43606e389b65b481a8fc99083fb54 100644 (file)
--- a/arch/ia64/kernel/kprobes.c
+++ b/arch/ia64/kernel/kprobes.c
@@ -34,6 +34,7 @@
 #include <asm/pgtable.h>
 #include <asm/kdebug.h>
 #include <asm/sections.h>
+#include <asm/uaccess.h>
 
 extern void jprobe_inst_return(void);
 
@@ -722,13 +723,50 @@ static int __kprobes kprobes_fault_handler(struct pt_regs *regs, int trapnr)
        struct kprobe *cur = kprobe_running();
        struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
 
-       if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
-               return 1;
 
-       if (kcb->kprobe_status & KPROBE_HIT_SS) {
-               resume_execution(cur, regs);
-               reset_current_kprobe();
+       switch(kcb->kprobe_status) {
+       case KPROBE_HIT_SS:
+       case KPROBE_REENTER:
+               /*
+                * We are here because the instruction being single
+                * stepped caused a page fault. We reset the current
+                * kprobe and the instruction pointer points back to
+                * the probe address and allow the page fault handler
+                * to continue as a normal page fault.
+                */
+               regs->cr_iip = ((unsigned long)cur->addr) & ~0xFULL;
+               ia64_psr(regs)->ri = ((unsigned long)cur->addr) & 0xf;
+               if (kcb->kprobe_status == KPROBE_REENTER)
+                       restore_previous_kprobe(kcb);
+               else
+                       reset_current_kprobe();
                preempt_enable_no_resched();
+               break;
+       case KPROBE_HIT_ACTIVE:
+       case KPROBE_HIT_SSDONE:
+               /*
+                * We increment the nmissed count for accounting,
+                * we can also use npre/npostfault count for accouting
+                * these specific fault cases.
+                */
+               kprobes_inc_nmissed_count(cur);
+
+               /*
+                * We come here because instructions in the pre/post
+                * handler caused the page_fault, this could happen
+                * if handler tries to access user space by
+                * copy_from_user(), get_user() etc. Let the
+                * user-specified handler try to fix it first.
+                */
+               if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
+                       return 1;
+
+               /*
+                * Let ia64_do_page_fault() fix it.
+                */
+               break;
+       default:
+               break;
        }
 
        return 0;
@@ -740,6 +778,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
        struct die_args *args = (struct die_args *)data;
        int ret = NOTIFY_DONE;
 
+       if (args->regs && user_mode(args->regs))
+               return ret;
+
        switch(val) {
        case DIE_BREAK:
                /* err is break number from ia64_bad_break() */