54 lines
1.4 KiB
C
54 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/kprobes.h>
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/* Ftrace callback handler for kprobes -- called under preepmt disabed */
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void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *ops, struct ftrace_regs *regs)
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{
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struct kprobe *p;
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struct kprobe_ctlblk *kcb;
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p = get_kprobe((kprobe_opcode_t *)ip);
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if (unlikely(!p) || kprobe_disabled(p))
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return;
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kcb = get_kprobe_ctlblk();
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if (kprobe_running()) {
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kprobes_inc_nmissed_count(p);
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} else {
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unsigned long orig_ip = instruction_pointer(&(regs->regs));
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instruction_pointer_set(&(regs->regs), ip);
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__this_cpu_write(current_kprobe, p);
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kcb->kprobe_status = KPROBE_HIT_ACTIVE;
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if (!p->pre_handler || !p->pre_handler(p, &(regs->regs))) {
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/*
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* Emulate singlestep (and also recover regs->pc)
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* as if there is a nop
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*/
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instruction_pointer_set(&(regs->regs),
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(unsigned long)p->addr + MCOUNT_INSN_SIZE);
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if (unlikely(p->post_handler)) {
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kcb->kprobe_status = KPROBE_HIT_SSDONE;
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p->post_handler(p, &(regs->regs), 0);
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}
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instruction_pointer_set(&(regs->regs), orig_ip);
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}
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/*
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* If pre_handler returns !0, it changes regs->pc. We have to
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* skip emulating post_handler.
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*/
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__this_cpu_write(current_kprobe, NULL);
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}
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}
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NOKPROBE_SYMBOL(kprobe_ftrace_handler);
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int arch_prepare_kprobe_ftrace(struct kprobe *p)
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{
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p->ainsn.api.insn = NULL;
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return 0;
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}
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