1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /*---------------------------------------------------------------------------+ 3 | fpu_system.h | 4 | | 5 | Copyright (C) 1992,1994,1997 | 6 | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | 7 | Australia. E-mail billm@suburbia.net | 8 | | 9 +---------------------------------------------------------------------------*/ 10 11 #ifndef _FPU_SYSTEM_H 12 #define _FPU_SYSTEM_H 13 14 /* system dependent definitions */ 15 16 #include <linux/sched.h> 17 #include <linux/kernel.h> 18 #include <linux/mm.h> 19 20 #include <asm/desc.h> 21 #include <asm/mmu_context.h> 22 23 static inline struct desc_struct FPU_get_ldt_descriptor(unsigned seg) 24 { 25 static struct desc_struct zero_desc; 26 struct desc_struct ret = zero_desc; 27 28 #ifdef CONFIG_MODIFY_LDT_SYSCALL 29 seg >>= 3; 30 mutex_lock(¤t->mm->context.lock); 31 if (current->mm->context.ldt && seg < current->mm->context.ldt->nr_entries) 32 ret = current->mm->context.ldt->entries[seg]; 33 mutex_unlock(¤t->mm->context.lock); 34 #endif 35 return ret; 36 } 37 38 #define SEG_TYPE_WRITABLE (1U << 1) 39 #define SEG_TYPE_EXPANDS_DOWN (1U << 2) 40 #define SEG_TYPE_EXECUTE (1U << 3) 41 #define SEG_TYPE_EXPAND_MASK (SEG_TYPE_EXPANDS_DOWN | SEG_TYPE_EXECUTE) 42 #define SEG_TYPE_EXECUTE_MASK (SEG_TYPE_WRITABLE | SEG_TYPE_EXECUTE) 43 44 static inline unsigned long seg_get_base(struct desc_struct *d) 45 { 46 unsigned long base = (unsigned long)d->base2 << 24; 47 48 return base | ((unsigned long)d->base1 << 16) | d->base0; 49 } 50 51 static inline unsigned long seg_get_limit(struct desc_struct *d) 52 { 53 return ((unsigned long)d->limit1 << 16) | d->limit0; 54 } 55 56 static inline unsigned long seg_get_granularity(struct desc_struct *d) 57 { 58 return d->g ? 4096 : 1; 59 } 60 61 static inline bool seg_expands_down(struct desc_struct *d) 62 { 63 return (d->type & SEG_TYPE_EXPAND_MASK) == SEG_TYPE_EXPANDS_DOWN; 64 } 65 66 static inline bool seg_execute_only(struct desc_struct *d) 67 { 68 return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_EXECUTE; 69 } 70 71 static inline bool seg_writable(struct desc_struct *d) 72 { 73 return (d->type & SEG_TYPE_EXECUTE_MASK) == SEG_TYPE_WRITABLE; 74 } 75 76 #define I387 (¤t->thread.fpu.fpstate->regs) 77 #define FPU_info (I387->soft.info) 78 79 #define FPU_CS (*(unsigned short *) &(FPU_info->regs->cs)) 80 #define FPU_SS (*(unsigned short *) &(FPU_info->regs->ss)) 81 #define FPU_DS (*(unsigned short *) &(FPU_info->regs->ds)) 82 #define FPU_EAX (FPU_info->regs->ax) 83 #define FPU_EFLAGS (FPU_info->regs->flags) 84 #define FPU_EIP (FPU_info->regs->ip) 85 #define FPU_ORIG_EIP (FPU_info->___orig_eip) 86 87 #define FPU_lookahead (I387->soft.lookahead) 88 89 /* nz if ip_offset and cs_selector are not to be set for the current 90 instruction. */ 91 #define no_ip_update (*(u_char *)&(I387->soft.no_update)) 92 #define FPU_rm (*(u_char *)&(I387->soft.rm)) 93 94 /* Number of bytes of data which can be legally accessed by the current 95 instruction. This only needs to hold a number <= 108, so a byte will do. */ 96 #define access_limit (*(u_char *)&(I387->soft.alimit)) 97 98 #define partial_status (I387->soft.swd) 99 #define control_word (I387->soft.cwd) 100 #define fpu_tag_word (I387->soft.twd) 101 #define registers (I387->soft.st_space) 102 #define top (I387->soft.ftop) 103 104 #define instruction_address (*(struct address *)&I387->soft.fip) 105 #define operand_address (*(struct address *)&I387->soft.foo) 106 107 #define FPU_access_ok(y,z) if ( !access_ok(y,z) ) \ 108 math_abort(FPU_info,SIGSEGV) 109 #define FPU_abort math_abort(FPU_info, SIGSEGV) 110 #define FPU_copy_from_user(to, from, n) \ 111 do { if (copy_from_user(to, from, n)) FPU_abort; } while (0) 112 113 #undef FPU_IGNORE_CODE_SEGV 114 #ifdef FPU_IGNORE_CODE_SEGV 115 /* access_ok() is very expensive, and causes the emulator to run 116 about 20% slower if applied to the code. Anyway, errors due to bad 117 code addresses should be much rarer than errors due to bad data 118 addresses. */ 119 #define FPU_code_access_ok(z) 120 #else 121 /* A simpler test than access_ok() can probably be done for 122 FPU_code_access_ok() because the only possible error is to step 123 past the upper boundary of a legal code area. */ 124 #define FPU_code_access_ok(z) FPU_access_ok((void __user *)FPU_EIP,z) 125 #endif 126 127 #define FPU_get_user(x,y) do { if (get_user((x),(y))) FPU_abort; } while (0) 128 #define FPU_put_user(x,y) do { if (put_user((x),(y))) FPU_abort; } while (0) 129 130 #endif 131