arch/s390/include/asm/syscall.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Access to user system call parameters and results
   4  *
   5  *  Copyright IBM Corp. 2008
   6  *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
   7  */
   8
   9 #ifndef _ASM_SYSCALL_H
  10 #define _ASM_SYSCALL_H  1
  11
  12 #include <uapi/linux/audit.h>
  13 #include <linux/sched.h>
  14 #include <linux/err.h>
  15 #include <asm/ptrace.h>
  16
  17 extern const sys_call_ptr_t sys_call_table[];
  18 extern const sys_call_ptr_t sys_call_table_emu[];
  19
  20 static inline long syscall_get_nr(struct task_struct *task,
  21                                   struct pt_regs *regs)
  22 {
  23         return test_pt_regs_flag(regs, PIF_SYSCALL) ?
  24                 (regs->int_code & 0xffff) : -1;
  25 }
  26
  27 static inline void syscall_rollback(struct task_struct *task,
  28                                     struct pt_regs *regs)
  29 {
  30         regs->gprs[2] = regs->orig_gpr2;
  31 }
  32
  33 static inline long syscall_get_error(struct task_struct *task,
  34                                      struct pt_regs *regs)
  35 {
  36         unsigned long error = regs->gprs[2];
  37 #ifdef CONFIG_COMPAT
  38         if (test_tsk_thread_flag(task, TIF_31BIT)) {
  39                 /*
  40                  * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
  41                  * and will match correctly in comparisons.
  42                  */
  43                 error = (long)(int)error;
  44         }
  45 #endif
  46         return IS_ERR_VALUE(error) ? error : 0;
  47 }
  48
  49 static inline long syscall_get_return_value(struct task_struct *task,
  50                                             struct pt_regs *regs)
  51 {
  52         return regs->gprs[2];
  53 }
  54
  55 static inline void syscall_set_return_value(struct task_struct *task,
  56                                             struct pt_regs *regs,
  57                                             int error, long val)
  58 {
  59         set_pt_regs_flag(regs, PIF_SYSCALL_RET_SET);
  60         regs->gprs[2] = error ? error : val;
  61 }
  62
  63 static inline void syscall_get_arguments(struct task_struct *task,
  64                                          struct pt_regs *regs,
  65                                          unsigned long *args)
  66 {
  67         unsigned long mask = -1UL;
  68         unsigned int n = 6;
  69
  70 #ifdef CONFIG_COMPAT
  71         if (test_tsk_thread_flag(task, TIF_31BIT))
  72                 mask = 0xffffffff;
  73 #endif
  74         while (n-- > 0)
  75                 if (n > 0)
  76                         args[n] = regs->gprs[2 + n] & mask;
  77
  78         args[0] = regs->orig_gpr2 & mask;
  79 }
  80
  81 static inline void syscall_set_arguments(struct task_struct *task,
  82                                          struct pt_regs *regs,
  83                                          const unsigned long *args)
  84 {
  85         unsigned int n = 6;
  86
  87         while (n-- > 0)
  88                 if (n > 0)
  89                         regs->gprs[2 + n] = args[n];
  90         regs->orig_gpr2 = args[0];
  91 }
  92
  93 static inline int syscall_get_arch(struct task_struct *task)
  94 {
  95 #ifdef CONFIG_COMPAT
  96         if (test_tsk_thread_flag(task, TIF_31BIT))
  97                 return AUDIT_ARCH_S390;
  98 #endif
  99         return AUDIT_ARCH_S390X;
 100 }
 101
 102 static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
 103 {
 104         return false;
 105 }
 106
 107 #define SYSCALL_FMT_0
 108 #define SYSCALL_FMT_1 , "0" (r2)
 109 #define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1
 110 #define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2
 111 #define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3
 112 #define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4
 113 #define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5
 114
 115 #define SYSCALL_PARM_0
 116 #define SYSCALL_PARM_1 , long arg1
 117 #define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2
 118 #define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3
 119 #define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4
 120 #define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5
 121 #define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6
 122
 123 #define SYSCALL_REGS_0
 124 #define SYSCALL_REGS_1                                                  \
 125         register long r2 asm("2") = arg1
 126 #define SYSCALL_REGS_2                                                  \
 127         SYSCALL_REGS_1;                                                 \
 128         register long r3 asm("3") = arg2
 129 #define SYSCALL_REGS_3                                                  \
 130         SYSCALL_REGS_2;                                                 \
 131         register long r4 asm("4") = arg3
 132 #define SYSCALL_REGS_4                                                  \
 133         SYSCALL_REGS_3;                                                 \
 134         register long r5 asm("5") = arg4
 135 #define SYSCALL_REGS_5                                                  \
 136         SYSCALL_REGS_4;                                                 \
 137         register long r6 asm("6") = arg5
 138 #define SYSCALL_REGS_6                                                  \
 139         SYSCALL_REGS_5;                                                 \
 140         register long r7 asm("7") = arg6
 141
 142 #define GENERATE_SYSCALL_FUNC(nr)                                       \
 143 static __always_inline                                                  \
 144 long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr)               \
 145 {                                                                       \
 146         register unsigned long r1 asm ("1") = syscall;                  \
 147         register long rc asm ("2");                                     \
 148         SYSCALL_REGS_##nr;                                              \
 149                                                                         \
 150         asm volatile (                                                  \
 151                 "       svc     0\n"                                    \
 152                 : "=d" (rc)                                             \
 153                 : "d" (r1) SYSCALL_FMT_##nr                             \
 154                 : "memory");                                            \
 155         return rc;                                                      \
 156 }
 157
 158 GENERATE_SYSCALL_FUNC(0)
 159 GENERATE_SYSCALL_FUNC(1)
 160 GENERATE_SYSCALL_FUNC(2)
 161 GENERATE_SYSCALL_FUNC(3)
 162 GENERATE_SYSCALL_FUNC(4)
 163 GENERATE_SYSCALL_FUNC(5)
 164 GENERATE_SYSCALL_FUNC(6)
 165
 166 #endif  /* _ASM_SYSCALL_H */