1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Access to user system call parameters and results 4 * 5 * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved. 6 * 7 * See asm-generic/syscall.h for descriptions of what we must do here. 8 */ 9 10 #ifndef _ASM_X86_SYSCALL_H 11 #define _ASM_X86_SYSCALL_H 12 13 #include <uapi/linux/audit.h> 14 #include <linux/sched.h> 15 #include <linux/err.h> 16 #include <asm/asm-offsets.h> /* For NR_syscalls */ 17 #include <asm/thread_info.h> /* for TS_COMPAT */ 18 #include <asm/unistd.h> 19 20 #ifdef CONFIG_X86_64 21 typedef asmlinkage long (*sys_call_ptr_t)(const struct pt_regs *); 22 #else 23 typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long, 24 unsigned long, unsigned long, 25 unsigned long, unsigned long); 26 #endif /* CONFIG_X86_64 */ 27 extern const sys_call_ptr_t sys_call_table[]; 28 29 #if defined(CONFIG_X86_32) 30 #define ia32_sys_call_table sys_call_table 31 #define __NR_syscall_compat_max __NR_syscall_max 32 #define IA32_NR_syscalls NR_syscalls 33 #endif 34 35 #if defined(CONFIG_IA32_EMULATION) 36 extern const sys_call_ptr_t ia32_sys_call_table[]; 37 #endif 38 39 #ifdef CONFIG_X86_X32_ABI 40 extern const sys_call_ptr_t x32_sys_call_table[]; 41 #endif 42 43 /* 44 * Only the low 32 bits of orig_ax are meaningful, so we return int. 45 * This importantly ignores the high bits on 64-bit, so comparisons 46 * sign-extend the low 32 bits. 47 */ 48 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) 49 { 50 return regs->orig_ax; 51 } 52 53 static inline void syscall_rollback(struct task_struct *task, 54 struct pt_regs *regs) 55 { 56 regs->ax = regs->orig_ax; 57 } 58 59 static inline long syscall_get_error(struct task_struct *task, 60 struct pt_regs *regs) 61 { 62 unsigned long error = regs->ax; 63 #ifdef CONFIG_IA32_EMULATION 64 /* 65 * TS_COMPAT is set for 32-bit syscall entries and then 66 * remains set until we return to user mode. 67 */ 68 if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED)) 69 /* 70 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO 71 * and will match correctly in comparisons. 72 */ 73 error = (long) (int) error; 74 #endif 75 return IS_ERR_VALUE(error) ? error : 0; 76 } 77 78 static inline long syscall_get_return_value(struct task_struct *task, 79 struct pt_regs *regs) 80 { 81 return regs->ax; 82 } 83 84 static inline void syscall_set_return_value(struct task_struct *task, 85 struct pt_regs *regs, 86 int error, long val) 87 { 88 regs->ax = (long) error ?: val; 89 } 90 91 #ifdef CONFIG_X86_32 92 93 static inline void syscall_get_arguments(struct task_struct *task, 94 struct pt_regs *regs, 95 unsigned long *args) 96 { 97 memcpy(args, ®s->bx, 6 * sizeof(args[0])); 98 } 99 100 static inline void syscall_set_arguments(struct task_struct *task, 101 struct pt_regs *regs, 102 unsigned int i, unsigned int n, 103 const unsigned long *args) 104 { 105 BUG_ON(i + n > 6); 106 memcpy(®s->bx + i, args, n * sizeof(args[0])); 107 } 108 109 static inline int syscall_get_arch(struct task_struct *task) 110 { 111 return AUDIT_ARCH_I386; 112 } 113 114 #else /* CONFIG_X86_64 */ 115 116 static inline void syscall_get_arguments(struct task_struct *task, 117 struct pt_regs *regs, 118 unsigned long *args) 119 { 120 # ifdef CONFIG_IA32_EMULATION 121 if (task->thread_info.status & TS_COMPAT) { 122 *args++ = regs->bx; 123 *args++ = regs->cx; 124 *args++ = regs->dx; 125 *args++ = regs->si; 126 *args++ = regs->di; 127 *args = regs->bp; 128 } else 129 # endif 130 { 131 *args++ = regs->di; 132 *args++ = regs->si; 133 *args++ = regs->dx; 134 *args++ = regs->r10; 135 *args++ = regs->r8; 136 *args = regs->r9; 137 } 138 } 139 140 static inline void syscall_set_arguments(struct task_struct *task, 141 struct pt_regs *regs, 142 const unsigned long *args) 143 { 144 # ifdef CONFIG_IA32_EMULATION 145 if (task->thread_info.status & TS_COMPAT) { 146 regs->bx = *args++; 147 regs->cx = *args++; 148 regs->dx = *args++; 149 regs->si = *args++; 150 regs->di = *args++; 151 regs->bp = *args; 152 } else 153 # endif 154 { 155 regs->di = *args++; 156 regs->si = *args++; 157 regs->dx = *args++; 158 regs->r10 = *args++; 159 regs->r8 = *args++; 160 regs->r9 = *args; 161 } 162 } 163 164 static inline int syscall_get_arch(struct task_struct *task) 165 { 166 /* x32 tasks should be considered AUDIT_ARCH_X86_64. */ 167 return (IS_ENABLED(CONFIG_IA32_EMULATION) && 168 task->thread_info.status & TS_COMPAT) 169 ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64; 170 } 171 #endif /* CONFIG_X86_32 */ 172 173 #endif /* _ASM_X86_SYSCALL_H */ 174