diff options
Diffstat (limited to 'arch/x86/kernel/doublefault_32.c')
| -rw-r--r-- | arch/x86/kernel/doublefault_32.c | 58 |
1 files changed, 39 insertions, 19 deletions
diff --git a/arch/x86/kernel/doublefault_32.c b/arch/x86/kernel/doublefault_32.c index 61c707ca8a09..4eecfe4825ed 100644 --- a/arch/x86/kernel/doublefault_32.c +++ b/arch/x86/kernel/doublefault_32.c @@ -10,10 +10,6 @@ #include <asm/processor.h> #include <asm/desc.h> -#define DOUBLEFAULT_STACKSIZE (1024) -static unsigned long doublefault_stack[DOUBLEFAULT_STACKSIZE]; -#define STACK_START (unsigned long)(doublefault_stack+DOUBLEFAULT_STACKSIZE) - #define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + MAXMEM) static void doublefault_fn(void) @@ -21,6 +17,8 @@ static void doublefault_fn(void) struct desc_ptr gdt_desc = {0, 0}; unsigned long gdt, tss; + BUILD_BUG_ON(sizeof(struct doublefault_stack) != PAGE_SIZE); + native_store_gdt(&gdt_desc); gdt = gdt_desc.address; @@ -48,24 +46,46 @@ static void doublefault_fn(void) cpu_relax(); } -struct x86_hw_tss doublefault_tss __cacheline_aligned = { - .sp0 = STACK_START, - .ss0 = __KERNEL_DS, - .ldt = 0, +DEFINE_PER_CPU_PAGE_ALIGNED(struct doublefault_stack, doublefault_stack) = { + .tss = { + /* + * No sp0 or ss0 -- we never run CPL != 0 with this TSS + * active. sp is filled in later. + */ + .ldt = 0, .io_bitmap_base = IO_BITMAP_OFFSET_INVALID, - .ip = (unsigned long) doublefault_fn, - /* 0x2 bit is always set */ - .flags = X86_EFLAGS_SF | 0x2, - .sp = STACK_START, - .es = __USER_DS, - .cs = __KERNEL_CS, - .ss = __KERNEL_DS, - .ds = __USER_DS, - .fs = __KERNEL_PERCPU, + .ip = (unsigned long) doublefault_fn, + /* 0x2 bit is always set */ + .flags = X86_EFLAGS_SF | 0x2, + .es = __USER_DS, + .cs = __KERNEL_CS, + .ss = __KERNEL_DS, + .ds = __USER_DS, + .fs = __KERNEL_PERCPU, #ifndef CONFIG_X86_32_LAZY_GS - .gs = __KERNEL_STACK_CANARY, + .gs = __KERNEL_STACK_CANARY, #endif - .__cr3 = __pa_nodebug(swapper_pg_dir), + .__cr3 = __pa_nodebug(swapper_pg_dir), + }, }; + +void doublefault_init_cpu_tss(void) +{ + unsigned int cpu = smp_processor_id(); + struct cpu_entry_area *cea = get_cpu_entry_area(cpu); + + /* + * The linker isn't smart enough to initialize percpu variables that + * point to other places in percpu space. + */ + this_cpu_write(doublefault_stack.tss.sp, + (unsigned long)&cea->doublefault_stack.stack + + sizeof(doublefault_stack.stack)); + + /* Set up doublefault TSS pointer in the GDT */ + __set_tss_desc(cpu, GDT_ENTRY_DOUBLEFAULT_TSS, + &get_cpu_entry_area(cpu)->doublefault_stack.tss); + +} |