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 int syscall_get_arch(struct task_struct *task)
  82 {
  83 #ifdef CONFIG_COMPAT
  84         if (test_tsk_thread_flag(task, TIF_31BIT))
  85                 return AUDIT_ARCH_S390;
  86 #endif
  87         return AUDIT_ARCH_S390X;
  88 }
  89
  90 static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
  91 {
  92         return false;
  93 }
  94
  95 #define SYSCALL_FMT_0
  96 #define SYSCALL_FMT_1 , "0" (r2)
  97 #define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1
  98 #define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2
  99 #define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3
 100 #define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4
 101 #define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5
 102
 103 #define SYSCALL_PARM_0
 104 #define SYSCALL_PARM_1 , long arg1
 105 #define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2
 106 #define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3
 107 #define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4
 108 #define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5
 109 #define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6
 110
 111 #define SYSCALL_REGS_0
 112 #define SYSCALL_REGS_1                                                  \
 113         register long r2 asm("2") = arg1
 114 #define SYSCALL_REGS_2                                                  \
 115         SYSCALL_REGS_1;                                                 \
 116         register long r3 asm("3") = arg2
 117 #define SYSCALL_REGS_3                                                  \
 118         SYSCALL_REGS_2;                                                 \
 119         register long r4 asm("4") = arg3
 120 #define SYSCALL_REGS_4                                                  \
 121         SYSCALL_REGS_3;                                                 \
 122         register long r5 asm("5") = arg4
 123 #define SYSCALL_REGS_5                                                  \
 124         SYSCALL_REGS_4;                                                 \
 125         register long r6 asm("6") = arg5
 126 #define SYSCALL_REGS_6                                                  \
 127         SYSCALL_REGS_5;                                                 \
 128         register long r7 asm("7") = arg6
 129
 130 #define GENERATE_SYSCALL_FUNC(nr)                                       \
 131 static __always_inline                                                  \
 132 long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr)               \
 133 {                                                                       \
 134         register unsigned long r1 asm ("1") = syscall;                  \
 135         register long rc asm ("2");                                     \
 136         SYSCALL_REGS_##nr;                                              \
 137                                                                         \
 138         asm volatile (                                                  \
 139                 "       svc     0\n"                                    \
 140                 : "=d" (rc)                                             \
 141                 : "d" (r1) SYSCALL_FMT_##nr                             \
 142                 : "memory");                                            \
 143         return rc;                                                      \
 144 }
 145
 146 GENERATE_SYSCALL_FUNC(0)
 147 GENERATE_SYSCALL_FUNC(1)
 148 GENERATE_SYSCALL_FUNC(2)
 149 GENERATE_SYSCALL_FUNC(3)
 150 GENERATE_SYSCALL_FUNC(4)
 151 GENERATE_SYSCALL_FUNC(5)
 152 GENERATE_SYSCALL_FUNC(6)
 153
 154 #endif  /* _ASM_SYSCALL_H */