arch/sh/include/asm/syscall_32.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ASM_SH_SYSCALL_32_H
   3 #define __ASM_SH_SYSCALL_32_H
   4
   5 #include <uapi/linux/audit.h>
   6 #include <linux/kernel.h>
   7 #include <linux/sched.h>
   8 #include <linux/err.h>
   9 #include <asm/ptrace.h>
  10
  11 /* The system call number is given by the user in R3 */
  12 static inline long syscall_get_nr(struct task_struct *task,
  13                                   struct pt_regs *regs)
  14 {
  15         return (regs->tra >= 0) ? regs->regs[3] : -1L;
  16 }
  17
  18 static inline void syscall_rollback(struct task_struct *task,
  19                                     struct pt_regs *regs)
  20 {
  21         /*
  22          * XXX: This needs some thought. On SH we don't
  23          * save away the original r0 value anywhere.
  24          */
  25 }
  26
  27 static inline long syscall_get_error(struct task_struct *task,
  28                                      struct pt_regs *regs)
  29 {
  30         return IS_ERR_VALUE(regs->regs[0]) ? regs->regs[0] : 0;
  31 }
  32
  33 static inline long syscall_get_return_value(struct task_struct *task,
  34                                             struct pt_regs *regs)
  35 {
  36         return regs->regs[0];
  37 }
  38
  39 static inline void syscall_set_return_value(struct task_struct *task,
  40                                             struct pt_regs *regs,
  41                                             int error, long val)
  42 {
  43         if (error)
  44                 regs->regs[0] = -error;
  45         else
  46                 regs->regs[0] = val;
  47 }
  48
  49 static inline void syscall_get_arguments(struct task_struct *task,
  50                                          struct pt_regs *regs,
  51                                          unsigned int i, unsigned int n,
  52                                          unsigned long *args)
  53 {
  54         /*
  55          * Do this simply for now. If we need to start supporting
  56          * fetching arguments from arbitrary indices, this will need some
  57          * extra logic. Presently there are no in-tree users that depend
  58          * on this behaviour.
  59          */
  60         BUG_ON(i);
  61
  62         /* Argument pattern is: R4, R5, R6, R7, R0, R1 */
  63         switch (n) {
  64         case 6: args[5] = regs->regs[1];
  65         case 5: args[4] = regs->regs[0];
  66         case 4: args[3] = regs->regs[7];
  67         case 3: args[2] = regs->regs[6];
  68         case 2: args[1] = regs->regs[5];
  69         case 1: args[0] = regs->regs[4];
  70         case 0:
  71                 break;
  72         default:
  73                 BUG();
  74         }
  75 }
  76
  77 static inline void syscall_set_arguments(struct task_struct *task,
  78                                          struct pt_regs *regs,
  79                                          unsigned int i, unsigned int n,
  80                                          const unsigned long *args)
  81 {
  82         /* Same note as above applies */
  83         BUG_ON(i);
  84
  85         switch (n) {
  86         case 6: regs->regs[1] = args[5];
  87         case 5: regs->regs[0] = args[4];
  88         case 4: regs->regs[7] = args[3];
  89         case 3: regs->regs[6] = args[2];
  90         case 2: regs->regs[5] = args[1];
  91         case 1: regs->regs[4] = args[0];
  92                 break;
  93         default:
  94                 BUG();
  95         }
  96 }
  97
  98 static inline int syscall_get_arch(void)
  99 {
 100         int arch = AUDIT_ARCH_SH;
 101
 102 #ifdef CONFIG_CPU_LITTLE_ENDIAN
 103         arch |= __AUDIT_ARCH_LE;
 104 #endif
 105         return arch;
 106 }
 107 #endif /* __ASM_SH_SYSCALL_32_H */