diff options
| -rw-r--r-- | arch/x86/include/asm/fixmap.h | 12 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 74 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 3 |
3 files changed, 57 insertions, 32 deletions
diff --git a/arch/x86/include/asm/fixmap.h b/arch/x86/include/asm/fixmap.h index 6a699474c2c7..451da7d9a502 100644 --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -63,10 +63,22 @@ struct cpu_entry_area { struct tss_struct tss; char entry_trampoline[PAGE_SIZE]; + +#ifdef CONFIG_X86_64 + /* + * Exception stacks used for IST entries. + * + * In the future, this should have a separate slot for each stack + * with guard pages between them. + */ + char exception_stacks[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]; +#endif }; #define CPU_ENTRY_AREA_PAGES (sizeof(struct cpu_entry_area) / PAGE_SIZE) +extern void setup_cpu_entry_areas(void); + /* * Here we define all the compile-time 'special' virtual * addresses. The point is to have a constant address at diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 430f950b0b7f..fb01a8e5e9b7 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -466,24 +466,36 @@ void load_percpu_segment(int cpu) load_stack_canary_segment(); } -static void set_percpu_fixmap_pages(int fixmap_index, void *ptr, - int pages, pgprot_t prot) -{ - int i; - - for (i = 0; i < pages; i++) { - __set_fixmap(fixmap_index - i, - per_cpu_ptr_to_phys(ptr + i * PAGE_SIZE), prot); - } -} - #ifdef CONFIG_X86_32 /* The 32-bit entry code needs to find cpu_entry_area. */ DEFINE_PER_CPU(struct cpu_entry_area *, cpu_entry_area); #endif +#ifdef CONFIG_X86_64 +/* + * Special IST stacks which the CPU switches to when it calls + * an IST-marked descriptor entry. Up to 7 stacks (hardware + * limit), all of them are 4K, except the debug stack which + * is 8K. + */ +static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = { + [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ, + [DEBUG_STACK - 1] = DEBUG_STKSZ +}; + +static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks + [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]); +#endif + +static void __init +set_percpu_fixmap_pages(int idx, void *ptr, int pages, pgprot_t prot) +{ + for ( ; pages; pages--, idx--, ptr += PAGE_SIZE) + __set_fixmap(idx, per_cpu_ptr_to_phys(ptr), prot); +} + /* Setup the fixmap mappings only once per-processor */ -static inline void setup_cpu_entry_area(int cpu) +static void __init setup_cpu_entry_area(int cpu) { #ifdef CONFIG_X86_64 extern char _entry_trampoline[]; @@ -532,15 +544,31 @@ static inline void setup_cpu_entry_area(int cpu) PAGE_KERNEL); #ifdef CONFIG_X86_32 - this_cpu_write(cpu_entry_area, get_cpu_entry_area(cpu)); + per_cpu(cpu_entry_area, cpu) = get_cpu_entry_area(cpu); #endif #ifdef CONFIG_X86_64 + BUILD_BUG_ON(sizeof(exception_stacks) % PAGE_SIZE != 0); + BUILD_BUG_ON(sizeof(exception_stacks) != + sizeof(((struct cpu_entry_area *)0)->exception_stacks)); + set_percpu_fixmap_pages(get_cpu_entry_area_index(cpu, exception_stacks), + &per_cpu(exception_stacks, cpu), + sizeof(exception_stacks) / PAGE_SIZE, + PAGE_KERNEL); + __set_fixmap(get_cpu_entry_area_index(cpu, entry_trampoline), __pa_symbol(_entry_trampoline), PAGE_KERNEL_RX); #endif } +void __init setup_cpu_entry_areas(void) +{ + unsigned int cpu; + + for_each_possible_cpu(cpu) + setup_cpu_entry_area(cpu); +} + /* Load the original GDT from the per-cpu structure */ void load_direct_gdt(int cpu) { @@ -1385,20 +1413,6 @@ DEFINE_PER_CPU(unsigned int, irq_count) __visible = -1; DEFINE_PER_CPU(int, __preempt_count) = INIT_PREEMPT_COUNT; EXPORT_PER_CPU_SYMBOL(__preempt_count); -/* - * Special IST stacks which the CPU switches to when it calls - * an IST-marked descriptor entry. Up to 7 stacks (hardware - * limit), all of them are 4K, except the debug stack which - * is 8K. - */ -static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = { - [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ, - [DEBUG_STACK - 1] = DEBUG_STKSZ -}; - -static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks - [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]); - /* May not be marked __init: used by software suspend */ void syscall_init(void) { @@ -1607,7 +1621,7 @@ void cpu_init(void) * set up and load the per-CPU TSS */ if (!oist->ist[0]) { - char *estacks = per_cpu(exception_stacks, cpu); + char *estacks = get_cpu_entry_area(cpu)->exception_stacks; for (v = 0; v < N_EXCEPTION_STACKS; v++) { estacks += exception_stack_sizes[v]; @@ -1633,8 +1647,6 @@ void cpu_init(void) initialize_tlbstate_and_flush(); enter_lazy_tlb(&init_mm, me); - setup_cpu_entry_area(cpu); - /* * Initialize the TSS. sp0 points to the entry trampoline stack * regardless of what task is running. @@ -1694,8 +1706,6 @@ void cpu_init(void) initialize_tlbstate_and_flush(); enter_lazy_tlb(&init_mm, curr); - setup_cpu_entry_area(cpu); - /* * Initialize the TSS. Don't bother initializing sp0, as the initial * task never enters user mode. diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index ee9ca0ad4388..3e29aad5c7cc 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -947,6 +947,9 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) void __init trap_init(void) { + /* Init cpu_entry_area before IST entries are set up */ + setup_cpu_entry_areas(); + idt_setup_traps(); /* |