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_set_nr(struct task_struct *task,
  28                                   struct pt_regs *regs,
  29                                   int nr)
  30 {
  31         /*
  32          * Unlike syscall_get_nr(), syscall_set_nr() can be called only when
  33          * the target task is stopped for tracing on entering syscall, so
  34          * there is no need to have the same check syscall_get_nr() has.
  35          */
  36         regs->int_code = (regs->int_code & ~0xffff) | (nr & 0xffff);
  37 }
  38
  39 static inline void syscall_rollback(struct task_struct *task,
  40                                     struct pt_regs *regs)
  41 {
  42         regs->gprs[2] = regs->orig_gpr2;
  43 }
  44
  45 static inline long syscall_get_error(struct task_struct *task,
  46                                      struct pt_regs *regs)
  47 {
  48         unsigned long error = regs->gprs[2];
  49 #ifdef CONFIG_COMPAT
  50         if (test_tsk_thread_flag(task, TIF_31BIT)) {
  51                 /*
  52                  * Sign-extend the value so (int)-EFOO becomes (long)-EFOO
  53                  * and will match correctly in comparisons.
  54                  */
  55                 error = (long)(int)error;
  56         }
  57 #endif
  58         return IS_ERR_VALUE(error) ? error : 0;
  59 }
  60
  61 static inline long syscall_get_return_value(struct task_struct *task,
  62                                             struct pt_regs *regs)
  63 {
  64         return regs->gprs[2];
  65 }
  66
  67 static inline void syscall_set_return_value(struct task_struct *task,
  68                                             struct pt_regs *regs,
  69                                             int error, long val)
  70 {
  71         set_pt_regs_flag(regs, PIF_SYSCALL_RET_SET);
  72         regs->gprs[2] = error ? error : val;
  73 }
  74
  75 static inline void syscall_get_arguments(struct task_struct *task,
  76                                          struct pt_regs *regs,
  77                                          unsigned long *args)
  78 {
  79         unsigned long mask = -1UL;
  80
  81 #ifdef CONFIG_COMPAT
  82         if (test_tsk_thread_flag(task, TIF_31BIT))
  83                 mask = 0xffffffff;
  84 #endif
  85         for (int i = 1; i < 6; i++)
  86                 args[i] = regs->gprs[2 + i] & mask;
  87
  88         args[0] = regs->orig_gpr2 & mask;
  89 }
  90
  91 static inline void syscall_set_arguments(struct task_struct *task,
  92                                          struct pt_regs *regs,
  93                                          const unsigned long *args)
  94 {
  95         regs->orig_gpr2 = args[0];
  96         for (int n = 1; n < 6; n++)
  97                 regs->gprs[2 + n] = args[n];
  98 }
  99
 100 static inline int syscall_get_arch(struct task_struct *task)
 101 {
 102 #ifdef CONFIG_COMPAT
 103         if (test_tsk_thread_flag(task, TIF_31BIT))
 104                 return AUDIT_ARCH_S390;
 105 #endif
 106         return AUDIT_ARCH_S390X;
 107 }
 108
 109 static inline bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs)
 110 {
 111         return false;
 112 }
 113
 114 #define SYSCALL_FMT_0
 115 #define SYSCALL_FMT_1 , "0" (r2)
 116 #define SYSCALL_FMT_2 , "d" (r3) SYSCALL_FMT_1
 117 #define SYSCALL_FMT_3 , "d" (r4) SYSCALL_FMT_2
 118 #define SYSCALL_FMT_4 , "d" (r5) SYSCALL_FMT_3
 119 #define SYSCALL_FMT_5 , "d" (r6) SYSCALL_FMT_4
 120 #define SYSCALL_FMT_6 , "d" (r7) SYSCALL_FMT_5
 121
 122 #define SYSCALL_PARM_0
 123 #define SYSCALL_PARM_1 , long arg1
 124 #define SYSCALL_PARM_2 SYSCALL_PARM_1, long arg2
 125 #define SYSCALL_PARM_3 SYSCALL_PARM_2, long arg3
 126 #define SYSCALL_PARM_4 SYSCALL_PARM_3, long arg4
 127 #define SYSCALL_PARM_5 SYSCALL_PARM_4, long arg5
 128 #define SYSCALL_PARM_6 SYSCALL_PARM_5, long arg6
 129
 130 #define SYSCALL_REGS_0
 131 #define SYSCALL_REGS_1                                                  \
 132         register long r2 asm("2") = arg1
 133 #define SYSCALL_REGS_2                                                  \
 134         SYSCALL_REGS_1;                                                 \
 135         register long r3 asm("3") = arg2
 136 #define SYSCALL_REGS_3                                                  \
 137         SYSCALL_REGS_2;                                                 \
 138         register long r4 asm("4") = arg3
 139 #define SYSCALL_REGS_4                                                  \
 140         SYSCALL_REGS_3;                                                 \
 141         register long r5 asm("5") = arg4
 142 #define SYSCALL_REGS_5                                                  \
 143         SYSCALL_REGS_4;                                                 \
 144         register long r6 asm("6") = arg5
 145 #define SYSCALL_REGS_6                                                  \
 146         SYSCALL_REGS_5;                                                 \
 147         register long r7 asm("7") = arg6
 148
 149 #define GENERATE_SYSCALL_FUNC(nr)                                       \
 150 static __always_inline                                                  \
 151 long syscall##nr(unsigned long syscall SYSCALL_PARM_##nr)               \
 152 {                                                                       \
 153         register unsigned long r1 asm ("1") = syscall;                  \
 154         register long rc asm ("2");                                     \
 155         SYSCALL_REGS_##nr;                                              \
 156                                                                         \
 157         asm volatile (                                                  \
 158                 "       svc     0\n"                                    \
 159                 : "=d" (rc)                                             \
 160                 : "d" (r1) SYSCALL_FMT_##nr                             \
 161                 : "memory");                                            \
 162         return rc;                                                      \
 163 }
 164
 165 GENERATE_SYSCALL_FUNC(0)
 166 GENERATE_SYSCALL_FUNC(1)
 167 GENERATE_SYSCALL_FUNC(2)
 168 GENERATE_SYSCALL_FUNC(3)
 169 GENERATE_SYSCALL_FUNC(4)
 170 GENERATE_SYSCALL_FUNC(5)
 171 GENERATE_SYSCALL_FUNC(6)
 172
 173 #endif  /* _ASM_SYSCALL_H */