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Commit 6444b40e authored by Sean Christopherson's avatar Sean Christopherson Committed by Thomas Gleixner
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x86/apic: Annotate global config variables as "read-only after init" 



Mark the APIC's global config variables that are constant after boot as
__ro_after_init to help document that the majority of the APIC config is
not changed at runtime, and to harden the kernel a smidge.

Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20190805212134.12001-1-sean.j.christopherson@intel.com
parent 43931d35

arch/x86/kernel/apic/apic.c

+13 −13
Original line number Diff line number Diff line
@@ -65,10 +65,10 @@ unsigned int num_processors; 
unsigned disabled_cpus;



/* Processor that is doing the boot up */

unsigned int boot_cpu_physical_apicid = -1U;

unsigned int boot_cpu_physical_apicid __ro_after_init = -1U;

EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);



u8 boot_cpu_apic_version;

u8 boot_cpu_apic_version __ro_after_init;



/*

 * The highest APIC ID seen during enumeration.
@@ -85,13 +85,13 @@ physid_mask_t phys_cpu_present_map; 
 * disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to

 * avoid undefined behaviour caused by sending INIT from AP to BSP.

 */

static unsigned int disabled_cpu_apicid __read_mostly = BAD_APICID;

static unsigned int disabled_cpu_apicid __ro_after_init = BAD_APICID;



/*

 * This variable controls which CPUs receive external NMIs.  By default,

 * external NMIs are delivered only to the BSP.

 */

static int apic_extnmi = APIC_EXTNMI_BSP;

static int apic_extnmi __ro_after_init = APIC_EXTNMI_BSP;



/*

 * Map cpu index to physical APIC ID
@@ -114,7 +114,7 @@ EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_acpiid); 
DEFINE_EARLY_PER_CPU_READ_MOSTLY(int, x86_cpu_to_logical_apicid, BAD_APICID);



/* Local APIC was disabled by the BIOS and enabled by the kernel */

static int enabled_via_apicbase;

static int enabled_via_apicbase __ro_after_init;



/*

 * Handle interrupt mode configuration register (IMCR).
@@ -172,23 +172,23 @@ static __init int setup_apicpmtimer(char *s) 
__setup("apicpmtimer", setup_apicpmtimer);

#endif



unsigned long mp_lapic_addr;

int disable_apic;

unsigned long mp_lapic_addr __ro_after_init;

int disable_apic __ro_after_init;

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

static int disable_apic_timer __initdata;

/* Local APIC timer works in C2 */

int local_apic_timer_c2_ok;

int local_apic_timer_c2_ok __ro_after_init;

EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);



/*

 * Debug level, exported for io_apic.c

 */

int apic_verbosity;

int apic_verbosity __ro_after_init;



int pic_mode;

int pic_mode __ro_after_init;



/* Have we found an MP table */

int smp_found_config;

int smp_found_config __ro_after_init;



static struct resource lapic_resource = {

	.name = "Local APIC",
@@ -199,7 +199,7 @@ unsigned int lapic_timer_period = 0; 


static void apic_pm_activate(void);



static unsigned long apic_phys;

static unsigned long apic_phys __ro_after_init;



/*

 * Get the LAPIC version
@@ -1278,7 +1278,7 @@ void __init sync_Arb_IDs(void) 
			APIC_INT_LEVELTRIG | APIC_DM_INIT);

}



enum apic_intr_mode_id apic_intr_mode;

enum apic_intr_mode_id apic_intr_mode __ro_after_init;



static int __init apic_intr_mode_select(void)

{