mirror of
https://github.com/hardkernel/kernel_common_drivers.git
synced 2026-06-25 12:03:48 +09:00
Hanjie Lin
3fcef5de34
PD#SWPL-121806 Problem: ret handler running in origin task context with preempt_disable it's not safe for interrupt and may cause nested kprobe and miss Solution: disable irq in ret handler add AMLOGIC_BGKI_KPROBES Verify: sc2 Change-Id: I143e874336d87b143d1607b8e9a7588f84d7bc55 Signed-off-by: Hanjie Lin <hanjie.lin@amlogic.com>
104 lines
2.6 KiB
C
104 lines
2.6 KiB
C
// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
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/*
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* Copyright (c) 2019 Amlogic, Inc. All rights reserved.
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*/
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#include <linux/irqflags.h>
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#include <linux/moduleparam.h>
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#include <linux/module.h>
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#include <linux/kprobes.h>
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#include <linux/stop_machine.h>
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#ifdef CONFIG_ARM64
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#include <asm/daifflags.h>
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#endif
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static DEFINE_PER_CPU(unsigned long, kprobe_busy_flags);
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static int kprobe_busy_disable_irq;
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module_param(kprobe_busy_disable_irq, int, 0644);
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static int __nocfi __kprobes kprobe_busy_begin_pre_handler(struct kprobe *p, struct pt_regs *regs)
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{
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if (kprobe_busy_disable_irq) {
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#ifdef CONFIG_ARM64
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//save and disable irq
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__this_cpu_write(kprobe_busy_flags, regs->pstate & DAIF_MASK);
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regs->pstate |= DAIF_MASK;
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//directly return to lr (eg: kretprobe_trampoline_handler)
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instruction_pointer_set(regs, regs->regs[30]);
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#endif
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#ifdef CONFIG_ARM
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//save and disable irq
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__this_cpu_write(kprobe_busy_flags, regs->ARM_cpsr & PSR_I_BIT);
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regs->ARM_cpsr |= PSR_I_BIT;
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//directly return to lr (eg: kretprobe_trampoline_handler)
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instruction_pointer_set(regs, regs->ARM_lr);
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#endif
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//no need continue do single-step
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return 1;
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}
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//if kprobe_busy_disable_irq not enable, continue origin function
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return 0;
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}
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static struct kprobe kp_kprobe_busy_begin = {
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.symbol_name = "kprobe_busy_begin",
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.pre_handler = kprobe_busy_begin_pre_handler,
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};
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static int __nocfi __kprobes kprobe_busy_end_pre_handler(struct kprobe *p, struct pt_regs *regs)
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{
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if (kprobe_busy_disable_irq) {
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unsigned long flags = __this_cpu_read(kprobe_busy_flags);
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#ifdef CONFIG_ARM64
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//restore irq
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regs->pstate &= ~DAIF_MASK;
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regs->pstate |= flags;
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//directly return to lr (eg: kretprobe_trampoline_handler)
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instruction_pointer_set(regs, regs->regs[30]);
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#endif
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#ifdef CONFIG_ARM
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//restore irq
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regs->ARM_cpsr &= ~PSR_I_BIT;
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regs->ARM_cpsr |= flags;
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//directly return to lr (eg: kretprobe_trampoline_handler)
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instruction_pointer_set(regs, regs->ARM_lr);
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#endif
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//no need continue do single-step
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return 1;
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}
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//if kprobe_busy_disable_irq not enable, continue origin function
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return 0;
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}
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static struct kprobe kp_kprobe_busy_end = {
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.symbol_name = "kprobe_busy_end",
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.pre_handler = kprobe_busy_end_pre_handler,
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};
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int aml_kprobes_init(void)
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{
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int ret;
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ret = register_kprobe(&kp_kprobe_busy_begin);
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if (ret) {
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pr_err("register_kprobe: kp_kprobe_busy_begin failed:%d\n", ret);
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return 1;
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}
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ret = register_kprobe(&kp_kprobe_busy_end);
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if (ret) {
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pr_err("register_kprobe: kp_kprobe_busy_end failed:%d\n", ret);
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unregister_kprobe(&kp_kprobe_busy_begin);
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return 1;
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}
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kprobe_busy_disable_irq = 1;
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return 0;
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}
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