1 /* 2 * Access to user system call parameters and results 3 * 4 * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved. 5 * 6 * This copyrighted material is made available to anyone wishing to use, 7 * modify, copy, or redistribute it subject to the terms and conditions 8 * of the GNU General Public License v.2. 9 * 10 * See asm-generic/syscall.h for descriptions of what we must do here. 11 */ 12 13 #ifndef _ASM_X86_SYSCALL_H 14 #define _ASM_X86_SYSCALL_H 15 16 #include <uapi/linux/audit.h> 17 #include <linux/sched.h> 18 #include <linux/err.h> 19 #include <asm/asm-offsets.h> /* For NR_syscalls */ 20 #include <asm/thread_info.h> /* for TS_COMPAT */ 21 #include <asm/unistd.h> 22 23 #ifdef CONFIG_X86_64 24 typedef asmlinkage long (*sys_call_ptr_t)(const struct pt_regs *); 25 #else 26 typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long, 27 unsigned long, unsigned long, 28 unsigned long, unsigned long); 29 #endif /* CONFIG_X86_64 */ 30 extern const sys_call_ptr_t sys_call_table[]; 31 32 #if defined(CONFIG_X86_32) 33 #define ia32_sys_call_table sys_call_table 34 #define __NR_syscall_compat_max __NR_syscall_max 35 #define IA32_NR_syscalls NR_syscalls 36 #endif 37 38 #if defined(CONFIG_IA32_EMULATION) 39 extern const sys_call_ptr_t ia32_sys_call_table[]; 40 #endif 41 42 /* 43 * Only the low 32 bits of orig_ax are meaningful, so we return int. 44 * This importantly ignores the high bits on 64-bit, so comparisons 45 * sign-extend the low 32 bits. 46 */ 47 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) 48 { 49 return regs->orig_ax; 50 } 51 52 static inline void syscall_rollback(struct task_struct *task, 53 struct pt_regs *regs) 54 { 55 regs->ax = regs->orig_ax; 56 } 57 58 static inline long syscall_get_error(struct task_struct *task, 59 struct pt_regs *regs) 60 { 61 unsigned long error = regs->ax; 62 #ifdef CONFIG_IA32_EMULATION 63 /* 64 * TS_COMPAT is set for 32-bit syscall entries and then 65 * remains set until we return to user mode. 66 */ 67 if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED)) 68 /* 69 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO 70 * and will match correctly in comparisons. 71 */ 72 error = (long) (int) error; 73 #endif 74 return IS_ERR_VALUE(error) ? error : 0; 75 } 76 77 static inline long syscall_get_return_value(struct task_struct *task, 78 struct pt_regs *regs) 79 { 80 return regs->ax; 81 } 82 83 static inline void syscall_set_return_value(struct task_struct *task, 84 struct pt_regs *regs, 85 int error, long val) 86 { 87 regs->ax = (long) error ?: val; 88 } 89 90 #ifdef CONFIG_X86_32 91 92 static inline void syscall_get_arguments(struct task_struct *task, 93 struct pt_regs *regs, 94 unsigned int i, unsigned int n, 95 unsigned long *args) 96 { 97 BUG_ON(i + n > 6); 98 memcpy(args, ®s->bx + i, n * sizeof(args[0])); 99 } 100 101 static inline void syscall_set_arguments(struct task_struct *task, 102 struct pt_regs *regs, 103 unsigned int i, unsigned int n, 104 const unsigned long *args) 105 { 106 BUG_ON(i + n > 6); 107 memcpy(®s->bx + i, args, n * sizeof(args[0])); 108 } 109 110 static inline int syscall_get_arch(void) 111 { 112 return AUDIT_ARCH_I386; 113 } 114 115 #else /* CONFIG_X86_64 */ 116 117 static inline void syscall_get_arguments(struct task_struct *task, 118 struct pt_regs *regs, 119 unsigned int i, unsigned int n, 120 unsigned long *args) 121 { 122 # ifdef CONFIG_IA32_EMULATION 123 if (task->thread_info.status & TS_COMPAT) 124 switch (i) { 125 case 0: 126 if (!n--) break; 127 *args++ = regs->bx; 128 case 1: 129 if (!n--) break; 130 *args++ = regs->cx; 131 case 2: 132 if (!n--) break; 133 *args++ = regs->dx; 134 case 3: 135 if (!n--) break; 136 *args++ = regs->si; 137 case 4: 138 if (!n--) break; 139 *args++ = regs->di; 140 case 5: 141 if (!n--) break; 142 *args++ = regs->bp; 143 case 6: 144 if (!n--) break; 145 default: 146 BUG(); 147 break; 148 } 149 else 150 # endif 151 switch (i) { 152 case 0: 153 if (!n--) break; 154 *args++ = regs->di; 155 case 1: 156 if (!n--) break; 157 *args++ = regs->si; 158 case 2: 159 if (!n--) break; 160 *args++ = regs->dx; 161 case 3: 162 if (!n--) break; 163 *args++ = regs->r10; 164 case 4: 165 if (!n--) break; 166 *args++ = regs->r8; 167 case 5: 168 if (!n--) break; 169 *args++ = regs->r9; 170 case 6: 171 if (!n--) break; 172 default: 173 BUG(); 174 break; 175 } 176 } 177 178 static inline void syscall_set_arguments(struct task_struct *task, 179 struct pt_regs *regs, 180 unsigned int i, unsigned int n, 181 const unsigned long *args) 182 { 183 # ifdef CONFIG_IA32_EMULATION 184 if (task->thread_info.status & TS_COMPAT) 185 switch (i) { 186 case 0: 187 if (!n--) break; 188 regs->bx = *args++; 189 case 1: 190 if (!n--) break; 191 regs->cx = *args++; 192 case 2: 193 if (!n--) break; 194 regs->dx = *args++; 195 case 3: 196 if (!n--) break; 197 regs->si = *args++; 198 case 4: 199 if (!n--) break; 200 regs->di = *args++; 201 case 5: 202 if (!n--) break; 203 regs->bp = *args++; 204 case 6: 205 if (!n--) break; 206 default: 207 BUG(); 208 break; 209 } 210 else 211 # endif 212 switch (i) { 213 case 0: 214 if (!n--) break; 215 regs->di = *args++; 216 case 1: 217 if (!n--) break; 218 regs->si = *args++; 219 case 2: 220 if (!n--) break; 221 regs->dx = *args++; 222 case 3: 223 if (!n--) break; 224 regs->r10 = *args++; 225 case 4: 226 if (!n--) break; 227 regs->r8 = *args++; 228 case 5: 229 if (!n--) break; 230 regs->r9 = *args++; 231 case 6: 232 if (!n--) break; 233 default: 234 BUG(); 235 break; 236 } 237 } 238 239 static inline int syscall_get_arch(void) 240 { 241 /* x32 tasks should be considered AUDIT_ARCH_X86_64. */ 242 return in_ia32_syscall() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64; 243 } 244 #endif /* CONFIG_X86_32 */ 245 246 #endif /* _ASM_X86_SYSCALL_H */ 247