Commit 81287ad6 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Dave Hansen
Browse files

x86/apic: Sanitize APIC address setup 



Convert places which just write mp_lapic_addr and let them register the
local APIC address directly instead of relying on magic other code to do
so.

Add a WARN_ON() into register_lapic_address() which is raised when
register_lapic_address() is invoked more than once during boot.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: default avatarMichael Kelley <mikelley@microsoft.com>
Tested-by: default avatarSohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)
parent 5a88f354

arch/x86/include/asm/mpspec.h

+0 −1
Original line number Diff line number Diff line
@@ -41,7 +41,6 @@ extern DECLARE_BITMAP(mp_bus_not_pci, MAX_MP_BUSSES); 


extern unsigned int boot_cpu_physical_apicid;

extern u8 boot_cpu_apic_version;

extern unsigned long mp_lapic_addr;



#ifdef CONFIG_X86_LOCAL_APIC

extern int smp_found_config;

arch/x86/kernel/apic/apic.c

+10 −19
Original line number Diff line number Diff line
@@ -172,7 +172,7 @@ static __init int setup_apicpmtimer(char *s) 
__setup("apicpmtimer", setup_apicpmtimer);

#endif



unsigned long mp_lapic_addr __ro_after_init;

static unsigned long mp_lapic_addr __ro_after_init;

bool apic_is_disabled __ro_after_init;

/* Disable local APIC timer from the kernel commandline or via dmi quirk */

static int disable_apic_timer __initdata;
@@ -2009,12 +2009,12 @@ static bool __init detect_init_APIC(void) 
		return false;

	}



	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;

	register_lapic_address(APIC_DEFAULT_PHYS_BASE);

	return true;

}

#else



static bool __init apic_verify(void)

static bool __init apic_verify(unsigned long addr)

{

	u32 features, h, l;
@@ -2028,15 +2028,15 @@ static bool __init apic_verify(void) 
		return false;

	}

	set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);

	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;



	/* The BIOS may have set up the APIC at some other address */

	if (boot_cpu_data.x86 >= 6) {

		rdmsr(MSR_IA32_APICBASE, l, h);

		if (l & MSR_IA32_APICBASE_ENABLE)

			mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;

			addr = l & MSR_IA32_APICBASE_BASE;

	}



	register_lapic_address(addr);

	pr_info("Found and enabled local APIC!\n");

	return true;

}
@@ -2063,7 +2063,7 @@ bool __init apic_force_enable(unsigned long addr) 
			enabled_via_apicbase = 1;

		}

	}

	return apic_verify();

	return apic_verify(addr);

}



/*
@@ -2105,7 +2105,7 @@ static bool __init detect_init_APIC(void) 
		if (!apic_force_enable(APIC_DEFAULT_PHYS_BASE))

			return false;

	} else {

		if (!apic_verify())

		if (!apic_verify(APIC_DEFAULT_PHYS_BASE))

			return false;

	}
@@ -2130,27 +2130,16 @@ void __init init_apic_mappings(void) 
	if (x2apic_mode)

		return;



	/* If no local APIC can be found return early */

	if (!smp_found_config && !detect_init_APIC()) {

		/* lets NOP'ify apic operations */

		pr_info("APIC: disable apic facility\n");

		apic_disable();

	} else {

		apic_phys = mp_lapic_addr;



		/*

		 * If the system has ACPI MADT tables or MP info, the LAPIC

		 * address is already registered.

		 */

		if (!acpi_lapic && !smp_found_config)

			register_lapic_address(apic_phys);

	}

}



static __init void apic_set_fixmap(void)

{

	set_fixmap_nocache(FIX_APIC_BASE, mp_lapic_addr);

	apic_mmio_base = APIC_BASE;

	apic_phys = apic_mmio_base = APIC_BASE;

	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",

		    apic_mmio_base, mp_lapic_addr);

	apic_read_boot_cpu_id(false);
@@ -2158,6 +2147,8 @@ static __init void apic_set_fixmap(void) 


void __init register_lapic_address(unsigned long address)

{

	/* This should only happen once */

	WARN_ON_ONCE(mp_lapic_addr);

	mp_lapic_addr = address;



	if (!x2apic_mode)

arch/x86/kernel/mpparse.c

+2 −9
Original line number Diff line number Diff line
@@ -374,11 +374,6 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type) 
	int linttypes[2] = { mp_ExtINT, mp_NMI };

	int i;



	/*

	 * local APIC has default address

	 */

	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;



	/*

	 * 2 CPUs, numbered 0 & 1.

	 */
@@ -520,10 +515,8 @@ void __init default_get_smp_config(unsigned int early) 
	 */

	if (mpf->feature1) {

		if (early) {

			/*

			 * local APIC has default address

			 */

			mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;

			/* Local APIC has default address */

			register_lapic_address(APIC_DEFAULT_PHYS_BASE);

			goto out;

		}