vserver 2.0 rc7

[linux-2.6.git] / arch / i386 / kernel / kprobes.c

diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c
index f74b755..59ff9b4 100644 (file)
--- a/arch/i386/kernel/kprobes.c
+++ b/arch/i386/kernel/kprobes.c
@@ -84,7 +84,11 @@ static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
 {
        regs->eflags |= TF_MASK;
        regs->eflags &= ~IF_MASK;
-       regs->eip = (unsigned long)&p->ainsn.insn;
+       /*single step inline if the instruction is an int3*/
+       if (p->opcode == BREAKPOINT_INSTRUCTION)
+               regs->eip = (unsigned long)p->addr;
+       else
+               regs->eip = (unsigned long)&p->ainsn.insn;
 }
 
 /*
@@ -117,6 +121,12 @@ static int kprobe_handler(struct pt_regs *regs)
                   Disarm the probe we just hit, and ignore it. */
                p = get_kprobe(addr);
                if (p) {
+                       if (kprobe_status == KPROBE_HIT_SS) {
+                               regs->eflags &= ~TF_MASK;
+                               regs->eflags |= kprobe_saved_eflags;
+                               unlock_kprobes();
+                               goto no_kprobe;
+                       }
                        disarm_kprobe(p, regs);
                        ret = 1;
                } else {
@@ -159,17 +169,16 @@ static int kprobe_handler(struct pt_regs *regs)
        if (is_IF_modifier(p->opcode))
                kprobe_saved_eflags &= ~IF_MASK;
 
-       if (p->pre_handler(p, regs)) {
+       if (p->pre_handler && p->pre_handler(p, regs))
                /* handler has already set things up, so skip ss setup */
                return 1;
-       }
 
-      ss_probe:
+ss_probe:
        prepare_singlestep(p, regs);
        kprobe_status = KPROBE_HIT_SS;
        return 1;
 
-      no_kprobe:
+no_kprobe:
        preempt_enable_no_resched();
        return ret;
 }
@@ -208,6 +217,13 @@ static void resume_execution(struct kprobe *p, struct pt_regs *regs)
                *tos &= ~(TF_MASK | IF_MASK);
                *tos |= kprobe_old_eflags;
                break;
+       case 0xc3:              /* ret/lret */
+       case 0xcb:
+       case 0xc2:
+       case 0xca:
+               regs->eflags &= ~TF_MASK;
+               /* eip is already adjusted, no more changes required*/
+               return;
        case 0xe8:              /* call relative - Fix return addr */
                *tos = orig_eip + (*tos - copy_eip);
                break;