diff options
Diffstat (limited to 'arch/i386/kernel/kprobes.c')
| -rw-r--r-- | arch/i386/kernel/kprobes.c | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/arch/i386/kernel/kprobes.c b/arch/i386/kernel/kprobes.c index 19edcd5..694a139 100644 --- a/arch/i386/kernel/kprobes.c +++ b/arch/i386/kernel/kprobes.c @@ -58,13 +58,14 @@ static inline int is_IF_modifier(kprobe_opcode_t opcode) int __kprobes arch_prepare_kprobe(struct kprobe *p) { - return 0; -} + /* insn: must be on special executable page on i386. */ + p->ainsn.insn = get_insn_slot(); + if (!p->ainsn.insn) + return -ENOMEM; -void __kprobes arch_copy_kprobe(struct kprobe *p) -{ memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); p->opcode = *p->addr; + return 0; } void __kprobes arch_arm_kprobe(struct kprobe *p) @@ -83,6 +84,9 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p) void __kprobes arch_remove_kprobe(struct kprobe *p) { + down(&kprobe_mutex); + free_insn_slot(p->ainsn.insn); + up(&kprobe_mutex); } static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb) @@ -119,7 +123,7 @@ static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs) if (p->opcode == BREAKPOINT_INSTRUCTION) regs->eip = (unsigned long)p->addr; else - regs->eip = (unsigned long)&p->ainsn.insn; + regs->eip = (unsigned long)p->ainsn.insn; } /* Called with kretprobe_lock held */ @@ -196,6 +200,19 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) kcb->kprobe_status = KPROBE_REENTER; return 1; } else { + if (regs->eflags & VM_MASK) { + /* We are in virtual-8086 mode. Return 0 */ + goto no_kprobe; + } + if (*addr != BREAKPOINT_INSTRUCTION) { + /* The breakpoint instruction was removed by + * another cpu right after we hit, no further + * handling of this interrupt is appropriate + */ + regs->eip -= sizeof(kprobe_opcode_t); + ret = 1; + goto no_kprobe; + } p = __get_cpu_var(current_kprobe); if (p->break_handler && p->break_handler(p, regs)) { goto ss_probe; @@ -346,7 +363,7 @@ static void __kprobes resume_execution(struct kprobe *p, { unsigned long *tos = (unsigned long *)®s->esp; unsigned long next_eip = 0; - unsigned long copy_eip = (unsigned long)&p->ainsn.insn; + unsigned long copy_eip = (unsigned long)p->ainsn.insn; unsigned long orig_eip = (unsigned long)p->addr; switch (p->ainsn.insn[0]) { |