/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_PROCESSOR_H #define _ASM_X86_PROCESSOR_H #include /* Forward declaration, a strange C thing */ struct task_struct; struct mm_struct; struct io_bitmap; struct vm86; #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * We handle most unaligned accesses in hardware. On the other hand * unaligned DMA can be quite expensive on some Nehalem processors. * * Based on this we disable the IP header alignment in network drivers. */ #define NET_IP_ALIGN 0 #define HBP_NUM 4 /* * These alignment constraints are for performance in the vSMP case, * but in the task_struct case we must also meet hardware imposed * alignment requirements of the FPU state: */ #ifdef CONFIG_X86_VSMP # define ARCH_MIN_TASKALIGN (1 << INTERNODE_CACHE_SHIFT) # define ARCH_MIN_MMSTRUCT_ALIGN (1 << INTERNODE_CACHE_SHIFT) #else # define ARCH_MIN_TASKALIGN __alignof__(union fpregs_state) # define ARCH_MIN_MMSTRUCT_ALIGN 0 #endif enum tlb_infos { ENTRIES, NR_INFO }; extern u16 __read_mostly tlb_lli_4k[NR_INFO]; extern u16 __read_mostly tlb_lli_2m[NR_INFO]; extern u16 __read_mostly tlb_lli_4m[NR_INFO]; extern u16 __read_mostly tlb_lld_4k[NR_INFO]; extern u16 __read_mostly tlb_lld_2m[NR_INFO]; extern u16 __read_mostly tlb_lld_4m[NR_INFO]; extern u16 __read_mostly tlb_lld_1g[NR_INFO]; /* * CPU type and hardware bug flags. Kept separately for each CPU. * Members of this structure are referenced in head_32.S, so think twice * before touching them. [mj] */ struct cpuinfo_x86 { __u8 x86; /* CPU family */ __u8 x86_vendor; /* CPU vendor */ __u8 x86_model; __u8 x86_stepping; #ifdef CONFIG_X86_64 /* Number of 4K pages in DTLB/ITLB combined(in pages): */ int x86_tlbsize; #endif __u8 x86_virt_bits; __u8 x86_phys_bits; /* CPUID returned core id bits: */ __u8 x86_coreid_bits; __u8 cu_id; /* Max extended CPUID function supported: */ __u32 extended_cpuid_level; /* Maximum supported CPUID level, -1=no CPUID: */ int cpuid_level; /* * Align to size of unsigned long because the x86_capability array * is passed to bitops which require the alignment. Use unnamed * union to enforce the array is aligned to size of unsigned long. */ union { __u32 x86_capability[NCAPINTS + NBUGINTS]; unsigned long x86_capability_alignment; }; char x86_vendor_id[16]; char x86_model_id[64]; /* in KB - valid for CPUS which support this call: */ unsigned int x86_cache_size; int x86_cache_alignment; /* In bytes */ /* Cache QoS architectural values: */ int x86_cache_max_rmid; /* max index */ int x86_cache_occ_scale; /* scale to bytes */ int x86_power; unsigned long loops_per_jiffy; /* cpuid returned max cores value: */ u16 x86_max_cores; u16 apicid; u16 initial_apicid; u16 x86_clflush_size; /* number of cores as seen by the OS: */ u16 booted_cores; /* Physical processor id: */ u16 phys_proc_id; /* Logical processor id: */ u16 logical_proc_id; /* Core id: */ u16 cpu_core_id; u16 cpu_die_id; u16 logical_die_id; /* Index into per_cpu list: */ u16 cpu_index; u32 microcode; /* Address space bits used by the cache internally */ u8 x86_cache_bits; unsigned initialized : 1; } __randomize_layout; struct cpuid_regs { u32 eax, ebx, ecx, edx; }; enum cpuid_regs_idx { CPUID_EAX = 0, CPUID_EBX, CPUID_ECX, CPUID_EDX, }; #define X86_VENDOR_INTEL 0 #define X86_VENDOR_CYRIX 1 #define X86_VENDOR_AMD 2 #define X86_VENDOR_UMC 3 #define X86_VENDOR_CENTAUR 5 #define X86_VENDOR_TRANSMETA 7 #define X86_VENDOR_NSC 8 #define X86_VENDOR_HYGON 9 #define X86_VENDOR_ZHAOXIN 10 #define X86_VENDOR_NUM 11 #define X86_VENDOR_UNKNOWN 0xff /* * capabilities of CPUs */ extern struct cpuinfo_x86 boot_cpu_data; extern struct cpuinfo_x86 new_cpu_data; extern struct x86_hw_tss doublefault_tss; extern __u32 cpu_caps_cleared[NCAPINTS + NBUGINTS]; extern __u32 cpu_caps_set[NCAPINTS + NBUGINTS]; #ifdef CONFIG_SMP DECLARE_PER_CPU_READ_MOSTLY(struct cpuinfo_x86, cpu_info); #define cpu_data(cpu) per_cpu(cpu_info, cpu) #else #define cpu_info boot_cpu_data #define cpu_data(cpu) boot_cpu_data #endif extern const struct seq_operations cpuinfo_op; #define cache_line_size() (boot_cpu_data.x86_cache_alignment) extern void cpu_detect(struct cpuinfo_x86 *c); static inline unsigned long long l1tf_pfn_limit(void) { return BIT_ULL(boot_cpu_data.x86_cache_bits - 1 - PAGE_SHIFT); } extern void early_cpu_init(void); extern void identify_boot_cpu(void); extern void identify_secondary_cpu(struct cpuinfo_x86 *); extern void print_cpu_info(struct cpuinfo_x86 *); void print_cpu_msr(struct cpuinfo_x86 *); #ifdef CONFIG_X86_32 extern int have_cpuid_p(void); #else static inline int have_cpuid_p(void) { return 1; } #endif static inline void native_cpuid(unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx) { /* ecx is often an input as well as an output. */ asm volatile("cpuid" : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx) : "0" (*eax), "2" (*ecx) : "memory"); } #define native_cpuid_reg(reg) \ static inline unsigned int native_cpuid_##reg(unsigned int op) \ { \ unsigned int eax = op, ebx, ecx = 0, edx; \ \ native_cpuid(&eax, &ebx, &ecx, &edx); \ \ return reg; \ } /* * Native CPUID functions returning a single datum. */ native_cpuid_reg(eax) native_cpuid_reg(ebx) native_cpuid_reg(ecx) native_cpuid_reg(edx) /* * Friendlier CR3 helpers. */ static inline unsigned long read_cr3_pa(void) { return __read_cr3() & CR3_ADDR_MASK; } static inline unsigned long native_read_cr3_pa(void) { return __native_read_cr3() & CR3_ADDR_MASK; } static inline void load_cr3(pgd_t *pgdir) { write_cr3(__sme_pa(pgdir)); } /* * Note that while the legacy 'TSS' name comes from 'Task State Segment', * on modern x86 CPUs the TSS also holds information important to 64-bit mode, * unrelated to the task-switch mechanism: */ #ifdef CONFIG_X86_32 /* This is the TSS defined by the hardware. */ struct x86_hw_tss { unsigned short back_link, __blh; unsigned long sp0; unsigned short ss0, __ss0h; unsigned long sp1; /* * We don't use ring 1, so ss1 is a convenient scratch space in * the same cacheline as sp0. We use ss1 to cache the value in * MSR_IA32_SYSENTER_CS. When we context switch * MSR_IA32_SYSENTER_CS, we first check if the new value being * written matches ss1, and, if it's not, then we wrmsr the new * value and update ss1. * * The only reason we context switch MSR_IA32_SYSENTER_CS is * that we set it to zero in vm86 tasks to avoid corrupting the * stack if we were to go through the sysenter path from vm86 * mode. */ unsigned short ss1; /* MSR_IA32_SYSENTER_CS */ unsigned short __ss1h; unsigned long sp2; unsigned short ss2, __ss2h; unsigned long __cr3; unsigned long ip; unsigned long flags; unsigned long ax; unsigned long cx; unsigned long dx; unsigned long bx; unsigned long sp; unsigned long bp; unsigned long si; unsigned long di; unsigned short es, __esh; unsigned short cs, __csh; unsigned short ss, __ssh; unsigned short ds, __dsh; unsigned short fs, __fsh; unsigned short gs, __gsh; unsigned short ldt, __ldth; unsigned short trace; unsigned short io_bitmap_base; } __attribute__((packed)); #else struct x86_hw_tss { u32 reserved1; u64 sp0; /* * We store cpu_current_top_of_stack in sp1 so it's always accessible. * Linux does not use ring 1, so sp1 is not otherwise needed. */ u64 sp1; /* * Since Linux does not use ring 2, the 'sp2' slot is unused by * hardware. entry_SYSCALL_64 uses it as scratch space to stash * the user RSP value. */ u64 sp2; u64 reserved2; u64 ist[7]; u32 reserved3; u32 reserved4; u16 reserved5; u16 io_bitmap_base; } __attribute__((packed)); #endif /* * IO-bitmap sizes: */ #define IO_BITMAP_BITS 65536 #define IO_BITMAP_BYTES (IO_BITMAP_BITS / BITS_PER_BYTE) #define IO_BITMAP_LONGS (IO_BITMAP_BYTES / sizeof(long)) #define IO_BITMAP_OFFSET_VALID_MAP \ (offsetof(struct tss_struct, io_bitmap.bitmap) - \ offsetof(struct tss_struct, x86_tss)) #define IO_BITMAP_OFFSET_VALID_ALL \ (offsetof(struct tss_struct, io_bitmap.mapall) - \ offsetof(struct tss_struct, x86_tss)) #ifdef CONFIG_X86_IOPL_IOPERM /* * sizeof(unsigned long) coming from an extra "long" at the end of the * iobitmap. The limit is inclusive, i.e. the last valid byte. */ # define __KERNEL_TSS_LIMIT \ (IO_BITMAP_OFFSET_VALID_ALL + IO_BITMAP_BYTES + \ sizeof(unsigned long) - 1) #else # define __KERNEL_TSS_LIMIT \ (offsetof(struct tss_struct, x86_tss) + sizeof(struct x86_hw_tss) - 1) #endif /* Base offset outside of TSS_LIMIT so unpriviledged IO causes #GP */ #define IO_BITMAP_OFFSET_INVALID (__KERNEL_TSS_LIMIT + 1) struct entry_stack { unsigned long words[64]; }; struct entry_stack_page { struct entry_stack stack; } __aligned(PAGE_SIZE); /* * All IO bitmap related data stored in the TSS: */ struct x86_io_bitmap { /* The sequence number of the last active bitmap. */ u64 prev_sequence; /* * Store the dirty size of the last io bitmap offender. The next * one will have to do the cleanup as the switch out to a non io * bitmap user will just set x86_tss.io_bitmap_base to a value * outside of the TSS limit. So for sane tasks there is no need to * actually touch the io_bitmap at all. */ unsigned int prev_max; /* * The extra 1 is there because the CPU will access an * additional byte beyond the end of the IO permission * bitmap. The extra byte must be all 1 bits, and must * be within the limit. */ unsigned long bitmap[IO_BITMAP_LONGS + 1]; /* * Special I/O bitmap to emulate IOPL(3). All bytes zero, * except the additional byte at the end. */ unsigned long mapall[IO_BITMAP_LONGS + 1]; }; struct tss_struct { /* * The fixed hardware portion. This must not cross a page boundary * at risk of violating the SDM's advice and potentially triggering * errata. */ struct x86_hw_tss x86_tss; struct x86_io_bitmap io_bitmap; } __aligned(PAGE_SIZE); DECLARE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw); /* Per CPU interrupt stacks */ struct irq_stack { char stack[IRQ_STACK_SIZE]; } __aligned(IRQ_STACK_SIZE); DECLARE_PER_CPU(struct irq_stack *, hardirq_stack_ptr); #ifdef CONFIG_X86_32 DECLARE_PER_CPU(unsigned long, cpu_current_top_of_stack); #else /* The RO copy can't be accessed with this_cpu_xyz(), so use the RW copy. */ #define cpu_current_top_of_stack cpu_tss_rw.x86_tss.sp1 #endif #ifdef CONFIG_X86_64 struct fixed_percpu_data { /* * GCC hardcodes the stack canary as %gs:40. Since the * irq_stack is the object at %gs:0, we reserve the bottom * 48 bytes of the irq stack for the canary. */ char gs_base[40]; unsigned long stack_canary; }; DECLARE_PER_CPU_FIRST(struct fixed_percpu_data, fixed_percpu_data) __visible; DECLARE_INIT_PER_CPU(fixed_percpu_data); static inline unsigned long cpu_kernelmode_gs_base(int cpu) { return (unsigned long)per_cpu(fixed_percpu_data.gs_base, cpu); } DECLARE_PER_CPU(unsigned int, irq_count); extern asmlinkage void ignore_sysret(void); #if IS_ENABLED(CONFIG_KVM) /* Save actual FS/GS selectors and bases to current->thread */ void save_fsgs_for_kvm(void); #endif #else /* X86_64 */ #ifdef CONFIG_STACKPROTECTOR /* * Make sure stack canary segment base is cached-aligned: * "For Intel Atom processors, avoid non zero segment base address * that is not aligned to cache line boundary at all cost." * (Optim Ref Manual Assembly/Compiler Coding Rule 15.) */ struct stack_canary { char __pad[20]; /* canary at %gs:20 */ unsigned long canary; }; DECLARE_PER_CPU_ALIGNED(struct stack_canary, stack_canary); #endif /* Per CPU softirq stack pointer */ DECLARE_PER_CPU(struct irq_stack *, softirq_stack_ptr); #endif /* X86_64 */ extern unsigned int fpu_kernel_xstate_size; extern unsigned int fpu_user_xstate_size; struct perf_event; typedef struct { unsigned long seg; } mm_segment_t; struct thread_struct { /* Cached TLS descriptors: */ struct desc_struct tls_array[GDT_ENTRY_TLS_ENTRIES]; #ifdef CONFIG_X86_32 unsigned long sp0; #endif unsigned long sp; #ifdef CONFIG_X86_32 unsigned long sysenter_cs; #else unsigned short es; unsigned short ds; unsigned short fsindex; unsigned short gsindex; #endif #ifdef CONFIG_X86_64 unsigned long fsbase; unsigned long gsbase; #else /* * XXX: this could presumably be unsigned short. Alternatively, * 32-bit kernels could be taught to use fsindex instead. */ unsigned long fs; unsigned long gs; #endif /* Save middle states of ptrace breakpoints */ struct perf_event *ptrace_bps[HBP_NUM]; /* Debug status used for traps, single steps, etc... */ unsigned long debugreg6; /* Keep track of the exact dr7 value set by the user */ unsigned long ptrace_dr7; /* Fault info: */ unsigned long cr2; unsigned long trap_nr; unsigned long error_code; #ifdef CONFIG_VM86 /* Virtual 86 mode info */ struct vm86 *vm86; #endif /* IO permissions: */ struct io_bitmap *io_bitmap; /* * IOPL. Priviledge level dependent I/O permission which is * emulated via the I/O bitmap to prevent user space from disabling * interrupts. */ unsigned long iopl_emul; mm_segment_t addr_limit; unsigned int sig_on_uaccess_err:1; unsigned int uaccess_err:1; /* uaccess failed */ /* Floating point and extended processor state */ struct fpu fpu; /* * WARNING: 'fpu' is dynamically-sized. It *MUST* be at * the end. */ }; /* Whitelist the FPU state from the task_struct for hardened usercopy. */ static inline void arch_thread_struct_whitelist(unsigned long *offset, unsigned long *size) { *offset = offsetof(struct thread_struct, fpu.state); *size = fpu_kernel_xstate_size; } /* * Thread-synchronous status. * * This is different from the flags in that nobody else * ever touches our thread-synchronous status, so we don't * have to worry about atomic accesses. */ #define TS_COMPAT 0x0002 /* 32bit syscall active (64BIT)*/ static inline void native_load_sp0(unsigned long sp0) { this_cpu_write(cpu_tss_rw.x86_tss.sp0, sp0); } static inline void native_swapgs(void) { #ifdef CONFIG_X86_64 asm volatile("swapgs" ::: "memory"); #endif } static inline unsigned long current_top_of_stack(void) { /* * We can't read directly from tss.sp0: sp0 on x86_32 is special in * and around vm86 mode and sp0 on x86_64 is special because of the * entry trampoline. */ return this_cpu_read_stable(cpu_current_top_of_stack); } static inline bool on_thread_stack(void) { return (unsigned long)(current_top_of_stack() - current_stack_pointer) < THREAD_SIZE; } #ifdef CONFIG_PARAVIRT_XXL #include #else #define __cpuid native_cpuid static inline void load_sp0(unsigned long sp0) { native_load_sp0(sp0); } #endif /* CONFIG_PARAVIRT_XXL */ /* Free all resources held by a thread. */ extern void release_thread(struct task_struct *); unsigned long get_wchan(struct task_struct *p); /* * Generic CPUID function * clear %ecx since some cpus (Cyrix MII) do not set or clear %ecx * resulting in stale register contents being returned. */ static inline void cpuid(unsigned int op, unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx) { *eax = op; *ecx = 0; __cpuid(eax, ebx, ecx, edx); } /* Some CPUID calls want 'count' to be placed in ecx */ static inline void cpuid_count(unsigned int op, int count, unsigned int *eax, unsigned int *ebx, unsigned int *ecx, unsigned int *edx) { *eax = op; *ecx = count; __cpuid(eax, ebx, ecx, edx); } /* * CPUID functions returning a single datum */ static inline unsigned int cpuid_eax(unsigned int op) { unsigned int eax, ebx, ecx, edx; cpuid(op, &eax, &ebx, &ecx, &edx); return eax; } static inline unsigned int cpuid_ebx(unsigned int op) { unsigned int eax, ebx, ecx, edx; cpuid(op, &eax, &ebx, &ecx, &edx); return ebx; } static inline unsigned int cpuid_ecx(unsigned int op) { unsigned int eax, ebx, ecx, edx; cpuid(op, &eax, &ebx, &ecx, &edx); return ecx; } static inline unsigned int cpuid_edx(unsigned int op) { unsigned int eax, ebx, ecx, edx; cpuid(op, &eax, &ebx, &ecx, &edx); return edx; } /* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */ static __always_inline void rep_nop(void) { asm volatile("rep; nop" ::: "memory"); } static __always_inline void cpu_relax(void) { rep_nop(); } /* * This function forces the icache and prefetched instruction stream to * catch up with reality in two very specific cases: * * a) Text was modified using one virtual address and is about to be executed * from the same physical page at a different virtual address. * * b) Text was modified on a different CPU, may subsequently be * executed on this CPU, and you want to make sure the new version * gets executed. This generally means you're calling this in a IPI. * * If you're calling this for a different reason, you're probably doing * it wrong. */ static inline void sync_core(void) { /* * There are quite a few ways to do this. IRET-to-self is nice * because it works on every CPU, at any CPL (so it's compatible * with paravirtualization), and it never exits to a hypervisor. * The only down sides are that it's a bit slow (it seems to be * a bit more than 2x slower than the fastest options) and that * it unmasks NMIs. The "push %cs" is needed because, in * paravirtual environments, __KERNEL_CS may not be a valid CS * value when we do IRET directly. * * In case NMI unmasking or performance ever becomes a problem, * the next best option appears to be MOV-to-CR2 and an * unconditional jump. That sequence also works on all CPUs, * but it will fault at CPL3 (i.e. Xen PV). * * CPUID is the conventional way, but it's nasty: it doesn't * exist on some 486-like CPUs, and it usually exits to a * hypervisor. * * Like all of Linux's memory ordering operations, this is a * compiler barrier as well. */ #ifdef CONFIG_X86_32 asm volatile ( "pushfl\n\t" "pushl %%cs\n\t" "pushl $1f\n\t" "iret\n\t" "1:" : ASM_CALL_CONSTRAINT : : "memory"); #else unsigned int tmp; asm volatile ( UNWIND_HINT_SAVE "mov %%ss, %0\n\t" "pushq %q0\n\t" "pushq %%rsp\n\t" "addq $8, (%%rsp)\n\t" "pushfq\n\t" "mov %%cs, %0\n\t" "pushq %q0\n\t" "pushq $1f\n\t" "iretq\n\t" UNWIND_HINT_RESTORE "1:" : "=&r" (tmp), ASM_CALL_CONSTRAINT : : "cc", "memory"); #endif } extern void select_idle_routine(const struct cpuinfo_x86 *c); extern void amd_e400_c1e_apic_setup(void); extern unsigned long boot_option_idle_override; enum idle_boot_override {IDLE_NO_OVERRIDE=0, IDLE_HALT, IDLE_NOMWAIT, IDLE_POLL}; extern void enable_sep_cpu(void); extern int sysenter_setup(void); /* Defined in head.S */ extern struct desc_ptr early_gdt_descr; extern void switch_to_new_gdt(int); extern void load_direct_gdt(int); extern void load_fixmap_gdt(int); extern void load_percpu_segment(int); extern void cpu_init(void); extern void cr4_init(void); static inline unsigned long get_debugctlmsr(void) { unsigned long debugctlmsr = 0; #ifndef CONFIG_X86_DEBUGCTLMSR if (boot_cpu_data.x86 < 6) return 0; #endif rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr); return debugctlmsr; } static inline void update_debugctlmsr(unsigned long debugctlmsr) { #ifndef CONFIG_X86_DEBUGCTLMSR if (boot_cpu_data.x86 < 6) return; #endif wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctlmsr); } extern void set_task_blockstep(struct task_struct *task, bool on); /* Boot loader type from the setup header: */ extern int bootloader_type; extern int bootloader_version; extern char ignore_fpu_irq; #define HAVE_ARCH_PICK_MMAP_LAYOUT 1 #define ARCH_HAS_PREFETCHW #define ARCH_HAS_SPINLOCK_PREFETCH #ifdef CONFIG_X86_32 # define BASE_PREFETCH "" # define ARCH_HAS_PREFETCH #else # define BASE_PREFETCH "prefetcht0 %P1" #endif /* * Prefetch instructions for Pentium III (+) and AMD Athlon (+) * * It's not worth to care about 3dnow prefetches for the K6 * because they are microcoded there and very slow. */ static inline void prefetch(const void *x) { alternative_input(BASE_PREFETCH, "prefetchnta %P1", X86_FEATURE_XMM, "m" (*(const char *)x)); } /* * 3dnow prefetch to get an exclusive cache line. * Useful for spinlocks to avoid one state transition in the * cache coherency protocol: */ static inline void prefetchw(const void *x) { alternative_input(BASE_PREFETCH, "prefetchw %P1", X86_FEATURE_3DNOWPREFETCH, "m" (*(const char *)x)); } static inline void spin_lock_prefetch(const void *x) { prefetchw(x); } #define TOP_OF_INIT_STACK ((unsigned long)&init_stack + sizeof(init_stack) - \ TOP_OF_KERNEL_STACK_PADDING) #define task_top_of_stack(task) ((unsigned long)(task_pt_regs(task) + 1)) #define task_pt_regs(task) \ ({ \ unsigned long __ptr = (unsigned long)task_stack_page(task); \ __ptr += THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING; \ ((struct pt_regs *)__ptr) - 1; \ }) #ifdef CONFIG_X86_32 /* * User space process size: 3GB (default). */ #define IA32_PAGE_OFFSET PAGE_OFFSET #define TASK_SIZE PAGE_OFFSET #define TASK_SIZE_LOW TASK_SIZE #define TASK_SIZE_MAX TASK_SIZE #define DEFAULT_MAP_WINDOW TASK_SIZE #define STACK_TOP TASK_SIZE #define STACK_TOP_MAX STACK_TOP #define INIT_THREAD { \ .sp0 = TOP_OF_INIT_STACK, \ .sysenter_cs = __KERNEL_CS, \ .addr_limit = KERNEL_DS, \ } #define KSTK_ESP(task) (task_pt_regs(task)->sp) #else /* * User space process size. This is the first address outside the user range. * There are a few constraints that determine this: * * On Intel CPUs, if a SYSCALL instruction is at the highest canonical * address, then that syscall will enter the kernel with a * non-canonical return address, and SYSRET will explode dangerously. * We avoid this particular problem by preventing anything executable * from being mapped at the maximum canonical address. * * On AMD CPUs in the Ryzen family, there's a nasty bug in which the * CPUs malfunction if they execute code from the highest canonical page. * They'll speculate right off the end of the canonical space, and * bad things happen. This is worked around in the same way as the * Intel problem. * * With page table isolation enabled, we map the LDT in ... [stay tuned] */ #define TASK_SIZE_MAX ((1UL << __VIRTUAL_MASK_SHIFT) - PAGE_SIZE) #define DEFAULT_MAP_WINDOW ((1UL << 47) - PAGE_SIZE) /* This decides where the kernel will search for a free chunk of vm * space during mmap's. */ #define IA32_PAGE_OFFSET ((current->personality & ADDR_LIMIT_3GB) ? \ 0xc0000000 : 0xFFFFe000) #define TASK_SIZE_LOW (test_thread_flag(TIF_ADDR32) ? \ IA32_PAGE_OFFSET : DEFAULT_MAP_WINDOW) #define TASK_SIZE (test_thread_flag(TIF_ADDR32) ? \ IA32_PAGE_OFFSET : TASK_SIZE_MAX) #define TASK_SIZE_OF(child) ((test_tsk_thread_flag(child, TIF_ADDR32)) ? \ IA32_PAGE_OFFSET : TASK_SIZE_MAX) #define STACK_TOP TASK_SIZE_LOW #define STACK_TOP_MAX TASK_SIZE_MAX #define INIT_THREAD { \ .addr_limit = KERNEL_DS, \ } extern unsigned long KSTK_ESP(struct task_struct *task); #endif /* CONFIG_X86_64 */ extern void start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp); /* * This decides where the kernel will search for a free chunk of vm * space during mmap's. */ #define __TASK_UNMAPPED_BASE(task_size) (PAGE_ALIGN(task_size / 3)) #define TASK_UNMAPPED_BASE __TASK_UNMAPPED_BASE(TASK_SIZE_LOW) #define KSTK_EIP(task) (task_pt_regs(task)->ip) /* Get/set a process' ability to use the timestamp counter instruction */ #define GET_TSC_CTL(adr) get_tsc_mode((adr)) #define SET_TSC_CTL(val) set_tsc_mode((val)) extern int get_tsc_mode(unsigned long adr); extern int set_tsc_mode(unsigned int val); DECLARE_PER_CPU(u64, msr_misc_features_shadow); /* Register/unregister a process' MPX related resource */ #define MPX_ENABLE_MANAGEMENT() mpx_enable_management() #define MPX_DISABLE_MANAGEMENT() mpx_disable_management() #ifdef CONFIG_X86_INTEL_MPX extern int mpx_enable_management(void); extern int mpx_disable_management(void); #else static inline int mpx_enable_management(void) { return -EINVAL; } static inline int mpx_disable_management(void) { return -EINVAL; } #endif /* CONFIG_X86_INTEL_MPX */ #ifdef CONFIG_CPU_SUP_AMD extern u16 amd_get_nb_id(int cpu); extern u32 amd_get_nodes_per_socket(void); #else static inline u16 amd_get_nb_id(int cpu) { return 0; } static inline u32 amd_get_nodes_per_socket(void) { return 0; } #endif static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves) { uint32_t base, eax, signature[3]; for (base = 0x40000000; base < 0x40010000; base += 0x100) { cpuid(base, &eax, &signature[0], &signature[1], &signature[2]); if (!memcmp(sig, signature, 12) && (leaves == 0 || ((eax - base) >= leaves))) return base; } return 0; } extern unsigned long arch_align_stack(unsigned long sp); void free_init_pages(const char *what, unsigned long begin, unsigned long end); extern void free_kernel_image_pages(const char *what, void *begin, void *end); void default_idle(void); #ifdef CONFIG_XEN bool xen_set_default_idle(void); #else #define xen_set_default_idle 0 #endif void stop_this_cpu(void *dummy); void df_debug(struct pt_regs *regs, long error_code); void microcode_check(void); enum l1tf_mitigations { L1TF_MITIGATION_OFF, L1TF_MITIGATION_FLUSH_NOWARN, L1TF_MITIGATION_FLUSH, L1TF_MITIGATION_FLUSH_NOSMT, L1TF_MITIGATION_FULL, L1TF_MITIGATION_FULL_FORCE }; extern enum l1tf_mitigations l1tf_mitigation; enum mds_mitigations { MDS_MITIGATION_OFF, MDS_MITIGATION_FULL, MDS_MITIGATION_VMWERV, }; enum taa_mitigations { TAA_MITIGATION_OFF, TAA_MITIGATION_UCODE_NEEDED, TAA_MITIGATION_VERW, TAA_MITIGATION_TSX_DISABLED, }; #endif /* _ASM_X86_PROCESSOR_H */