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/thread_info.h> /* for TS_COMPAT */ 17 #include <asm/unistd.h> 18 19 /* This is used purely for kernel/trace/trace_syscalls.c */ 20 typedef long (*sys_call_ptr_t)(const struct pt_regs *); 21 extern const sys_call_ptr_t sys_call_table[]; 22 23 /* 24 * These may not exist, but still put the prototypes in so we 25 * can use IS_ENABLED(). 26 */ 27 extern long ia32_sys_call(const struct pt_regs *, unsigned int nr); 28 extern long x32_sys_call(const struct pt_regs *, unsigned int nr); 29 extern long x64_sys_call(const struct pt_regs *, unsigned int nr); 30 31 /* 32 * Only the low 32 bits of orig_ax are meaningful, so we return int. 33 * This importantly ignores the high bits on 64-bit, so comparisons 34 * sign-extend the low 32 bits. 35 */ 36 static inline int syscall_get_nr(struct task_struct *task, struct pt_regs *regs) 37 { 38 return regs->orig_ax; 39 } 40 41 static inline void syscall_set_nr(struct task_struct *task, 42 struct pt_regs *regs, 43 int nr) 44 { 45 regs->orig_ax = nr; 46 } 47 48 static inline void syscall_rollback(struct task_struct *task, 49 struct pt_regs *regs) 50 { 51 regs->ax = regs->orig_ax; 52 } 53 54 static inline long syscall_get_error(struct task_struct *task, 55 struct pt_regs *regs) 56 { 57 unsigned long error = regs->ax; 58 #ifdef CONFIG_IA32_EMULATION 59 /* 60 * TS_COMPAT is set for 32-bit syscall entries and then 61 * remains set until we return to user mode. 62 */ 63 if (task->thread_info.status & (TS_COMPAT|TS_I386_REGS_POKED)) 64 /* 65 * Sign-extend the value so (int)-EFOO becomes (long)-EFOO 66 * and will match correctly in comparisons. 67 */ 68 error = (long) (int) error; 69 #endif 70 return IS_ERR_VALUE(error) ? error : 0; 71 } 72 73 static inline long syscall_get_return_value(struct task_struct *task, 74 struct pt_regs *regs) 75 { 76 return regs->ax; 77 } 78 79 static inline void syscall_set_return_value(struct task_struct *task, 80 struct pt_regs *regs, 81 int error, long val) 82 { 83 regs->ax = (long) error ?: val; 84 } 85 86 #ifdef CONFIG_X86_32 87 88 static inline void syscall_get_arguments(struct task_struct *task, 89 struct pt_regs *regs, 90 unsigned long *args) 91 { 92 args[0] = regs->bx; 93 args[1] = regs->cx; 94 args[2] = regs->dx; 95 args[3] = regs->si; 96 args[4] = regs->di; 97 args[5] = regs->bp; 98 } 99 100 static inline void syscall_set_arguments(struct task_struct *task, 101 struct pt_regs *regs, 102 const unsigned long *args) 103 { 104 regs->bx = args[0]; 105 regs->cx = args[1]; 106 regs->dx = args[2]; 107 regs->si = args[3]; 108 regs->di = args[4]; 109 regs->bp = args[5]; 110 } 111 112 static inline int syscall_get_arch(struct task_struct *task) 113 { 114 return AUDIT_ARCH_I386; 115 } 116 117 #else /* CONFIG_X86_64 */ 118 119 static inline void syscall_get_arguments(struct task_struct *task, 120 struct pt_regs *regs, 121 unsigned long *args) 122 { 123 # ifdef CONFIG_IA32_EMULATION 124 if (task->thread_info.status & TS_COMPAT) { 125 *args++ = regs->bx; 126 *args++ = regs->cx; 127 *args++ = regs->dx; 128 *args++ = regs->si; 129 *args++ = regs->di; 130 *args = regs->bp; 131 } else 132 # endif 133 { 134 *args++ = regs->di; 135 *args++ = regs->si; 136 *args++ = regs->dx; 137 *args++ = regs->r10; 138 *args++ = regs->r8; 139 *args = regs->r9; 140 } 141 } 142 143 static inline void syscall_set_arguments(struct task_struct *task, 144 struct pt_regs *regs, 145 const unsigned long *args) 146 { 147 # ifdef CONFIG_IA32_EMULATION 148 if (task->thread_info.status & TS_COMPAT) { 149 regs->bx = *args++; 150 regs->cx = *args++; 151 regs->dx = *args++; 152 regs->si = *args++; 153 regs->di = *args++; 154 regs->bp = *args; 155 } else 156 # endif 157 { 158 regs->di = *args++; 159 regs->si = *args++; 160 regs->dx = *args++; 161 regs->r10 = *args++; 162 regs->r8 = *args++; 163 regs->r9 = *args; 164 } 165 } 166 167 static inline int syscall_get_arch(struct task_struct *task) 168 { 169 /* x32 tasks should be considered AUDIT_ARCH_X86_64. */ 170 return (IS_ENABLED(CONFIG_IA32_EMULATION) && 171 task->thread_info.status & TS_COMPAT) 172 ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64; 173 } 174 175 bool do_syscall_64(struct pt_regs *regs, int nr); 176 void do_int80_emulation(struct pt_regs *regs); 177 178 #endif /* CONFIG_X86_32 */ 179 180 void do_int80_syscall_32(struct pt_regs *regs); 181 bool do_fast_syscall_32(struct pt_regs *regs); 182 bool do_SYSENTER_32(struct pt_regs *regs); 183 184 #endif /* _ASM_X86_SYSCALL_H */ 185