1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Macros for Flexible Return and Event Delivery (FRED) 4 */ 5 6 #ifndef ASM_X86_FRED_H 7 #define ASM_X86_FRED_H 8 9 #include <linux/const.h> 10 11 #include <asm/asm.h> 12 #include <asm/trapnr.h> 13 14 /* 15 * FRED event return instruction opcodes for ERET{S,U}; supported in 16 * binutils >= 2.41. 17 */ 18 #define ERETS _ASM_BYTES(0xf2,0x0f,0x01,0xca) 19 #define ERETU _ASM_BYTES(0xf3,0x0f,0x01,0xca) 20 21 /* 22 * RSP is aligned to a 64-byte boundary before used to push a new stack frame 23 */ 24 #define FRED_STACK_FRAME_RSP_MASK _AT(unsigned long, (~0x3f)) 25 26 /* 27 * Used for the return address for call emulation during code patching, 28 * and measured in 64-byte cache lines. 29 */ 30 #define FRED_CONFIG_REDZONE_AMOUNT 1 31 #define FRED_CONFIG_REDZONE (_AT(unsigned long, FRED_CONFIG_REDZONE_AMOUNT) << 6) 32 #define FRED_CONFIG_INT_STKLVL(l) (_AT(unsigned long, l) << 9) 33 #define FRED_CONFIG_ENTRYPOINT(p) _AT(unsigned long, (p)) 34 35 #ifndef __ASSEMBLY__ 36 37 #ifdef CONFIG_X86_FRED 38 #include <linux/kernel.h> 39 #include <linux/sched/task_stack.h> 40 41 #include <asm/ptrace.h> 42 43 struct fred_info { 44 /* Event data: CR2, DR6, ... */ 45 unsigned long edata; 46 unsigned long resv; 47 }; 48 49 /* Full format of the FRED stack frame */ 50 struct fred_frame { 51 struct pt_regs regs; 52 struct fred_info info; 53 }; 54 55 static __always_inline struct fred_info *fred_info(struct pt_regs *regs) 56 { 57 return &container_of(regs, struct fred_frame, regs)->info; 58 } 59 60 static __always_inline unsigned long fred_event_data(struct pt_regs *regs) 61 { 62 return fred_info(regs)->edata; 63 } 64 65 void asm_fred_entrypoint_user(void); 66 void asm_fred_entrypoint_kernel(void); 67 void asm_fred_entry_from_kvm(struct fred_ss); 68 69 __visible void fred_entry_from_user(struct pt_regs *regs); 70 __visible void fred_entry_from_kernel(struct pt_regs *regs); 71 __visible void __fred_entry_from_kvm(struct pt_regs *regs); 72 73 /* Can be called from noinstr code, thus __always_inline */ 74 static __always_inline void fred_entry_from_kvm(unsigned int type, unsigned int vector) 75 { 76 struct fred_ss ss = { 77 .ss =__KERNEL_DS, 78 .type = type, 79 .vector = vector, 80 .nmi = type == EVENT_TYPE_NMI, 81 .lm = 1, 82 }; 83 84 asm_fred_entry_from_kvm(ss); 85 } 86 87 void cpu_init_fred_exceptions(void); 88 void cpu_init_fred_rsps(void); 89 void fred_complete_exception_setup(void); 90 91 DECLARE_PER_CPU(unsigned long, fred_rsp0); 92 93 static __always_inline void fred_sync_rsp0(unsigned long rsp0) 94 { 95 __this_cpu_write(fred_rsp0, rsp0); 96 } 97 98 static __always_inline void fred_update_rsp0(void) 99 { 100 unsigned long rsp0 = (unsigned long) task_stack_page(current) + THREAD_SIZE; 101 102 if (cpu_feature_enabled(X86_FEATURE_FRED) && (__this_cpu_read(fred_rsp0) != rsp0)) { 103 wrmsrns(MSR_IA32_FRED_RSP0, rsp0); 104 __this_cpu_write(fred_rsp0, rsp0); 105 } 106 } 107 #else /* CONFIG_X86_FRED */ 108 static __always_inline unsigned long fred_event_data(struct pt_regs *regs) { return 0; } 109 static inline void cpu_init_fred_exceptions(void) { } 110 static inline void cpu_init_fred_rsps(void) { } 111 static inline void fred_complete_exception_setup(void) { } 112 static inline void fred_entry_from_kvm(unsigned int type, unsigned int vector) { } 113 static inline void fred_sync_rsp0(unsigned long rsp0) { } 114 static inline void fred_update_rsp0(void) { } 115 #endif /* CONFIG_X86_FRED */ 116 #endif /* !__ASSEMBLY__ */ 117 118 #endif /* ASM_X86_FRED_H */ 119