x86/mce/amd: Sanitize thresholding device creation hotplug path (6e7a41c6) · Commits · 戴 / test

arch/x86/kernel/cpu/mce/amd.c

+16 −41

Original line number	Diff line number	Diff line
		@@ -1474,12 +1474,22 @@ int mce_threshold_remove_device(unsigned int cpu)
		return 0;
		}

		/* create dir/files for all valid threshold banks */
		/**
		* mce_threshold_create_device - Create the per-CPU MCE threshold device
		* @cpu: The plugged in CPU
		*
		* Create directories and files for all valid threshold banks.
		*
		* This is invoked from the CPU hotplug callback which was installed in
		* mcheck_init_device(). The invocation happens in context of the hotplug
		* thread running on @cpu. The callback is invoked on all CPUs which are
		* online when the callback is installed or during a real hotplug event.
		*/
		int mce_threshold_create_device(unsigned int cpu)
		{
		unsigned int bank;
		struct threshold_bank **bp;
		int err = 0;
		int err;

		if (!mce_flags.amd_threshold)
		return 0;
		@@ -1500,49 +1510,14 @@ int mce_threshold_create_device(unsigned int cpu)
		continue;
		err = threshold_create_bank(cpu, bank);
		if (err)
		goto err;
		}
		return err;
		err:
		mce_threshold_remove_device(cpu);
		return err;
		}

		static __init int threshold_init_device(void)
		{
		unsigned lcpu = 0;

		/* to hit CPUs online before the notifier is up */
		for_each_online_cpu(lcpu) {
		int err = mce_threshold_create_device(lcpu);

		if (err)
		return err;
		goto out_err;
		}

		if (thresholding_irq_en)
		mce_threshold_vector = amd_threshold_interrupt;

		return 0;
		out_err:
		mce_threshold_remove_device(cpu);
		return err;
		}
		/*
		* there are 3 funcs which need to be _initcalled in a logic sequence:
		* 1. xen_late_init_mcelog
		* 2. mcheck_init_device
		* 3. threshold_init_device
		*
		* xen_late_init_mcelog must register xen_mce_chrdev_device before
		* native mce_chrdev_device registration if running under xen platform;
		*
		* mcheck_init_device should be inited before threshold_init_device to
		* initialize mce_device, otherwise a NULL ptr dereference will cause panic.
		*
		* so we use following _initcalls
		* 1. device_initcall(xen_late_init_mcelog);
		* 2. device_initcall_sync(mcheck_init_device);
		* 3. late_initcall(threshold_init_device);
		*
		* when running under xen, the initcall order is 1,2,3;
		* on baremetal, we skip 1 and we do only 2 and 3.
		*/
		late_initcall(threshold_init_device);

arch/x86/kernel/cpu/mce/core.c

+11 −0

Original line number	Diff line number	Diff line
		@@ -2481,6 +2481,13 @@ static __init void mce_init_banks(void)
		}
		}

		/*
		* When running on XEN, this initcall is ordered against the XEN mcelog
		* initcall:
		*
		* device_initcall(xen_late_init_mcelog);
		* device_initcall_sync(mcheck_init_device);
		*/
		static __init int mcheck_init_device(void)
		{
		int err;
		@@ -2512,6 +2519,10 @@ static __init int mcheck_init_device(void)
		if (err)
		goto err_out_mem;

		/*
		* Invokes mce_cpu_online() on all CPUs which are online when
		* the state is installed.
		*/
		err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/mce:online",
		mce_cpu_online, mce_cpu_pre_down);
		if (err < 0)

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