| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame^] | 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 | /* |
| 18 | * The syscall table always contains 32 bit pointers since we know that the |
| 19 | * address of the function to be called is (way) below 4GB. So the "int" |
| 20 | * type here is what we want [need] for both 32 bit and 64 bit systems. |
| 21 | */ |
| 22 | extern const unsigned int sys_call_table[]; |
| 23 | extern const unsigned int sys_call_table_emu[]; |
| 24 | |
| 25 | static inline long syscall_get_nr(struct task_struct *task, |
| 26 | struct pt_regs *regs) |
| 27 | { |
| 28 | return test_pt_regs_flag(regs, PIF_SYSCALL) ? |
| 29 | (regs->int_code & 0xffff) : -1; |
| 30 | } |
| 31 | |
| 32 | static inline void syscall_rollback(struct task_struct *task, |
| 33 | struct pt_regs *regs) |
| 34 | { |
| 35 | regs->gprs[2] = regs->orig_gpr2; |
| 36 | } |
| 37 | |
| 38 | static inline long syscall_get_error(struct task_struct *task, |
| 39 | struct pt_regs *regs) |
| 40 | { |
| 41 | return IS_ERR_VALUE(regs->gprs[2]) ? regs->gprs[2] : 0; |
| 42 | } |
| 43 | |
| 44 | static inline long syscall_get_return_value(struct task_struct *task, |
| 45 | struct pt_regs *regs) |
| 46 | { |
| 47 | return regs->gprs[2]; |
| 48 | } |
| 49 | |
| 50 | static inline void syscall_set_return_value(struct task_struct *task, |
| 51 | struct pt_regs *regs, |
| 52 | int error, long val) |
| 53 | { |
| 54 | regs->gprs[2] = error ? error : val; |
| 55 | } |
| 56 | |
| 57 | static inline void syscall_get_arguments(struct task_struct *task, |
| 58 | struct pt_regs *regs, |
| 59 | unsigned int i, unsigned int n, |
| 60 | unsigned long *args) |
| 61 | { |
| 62 | unsigned long mask = -1UL; |
| 63 | |
| 64 | /* |
| 65 | * No arguments for this syscall, there's nothing to do. |
| 66 | */ |
| 67 | if (!n) |
| 68 | return; |
| 69 | |
| 70 | BUG_ON(i + n > 6); |
| 71 | #ifdef CONFIG_COMPAT |
| 72 | if (test_tsk_thread_flag(task, TIF_31BIT)) |
| 73 | mask = 0xffffffff; |
| 74 | #endif |
| 75 | while (n-- > 0) |
| 76 | if (i + n > 0) |
| 77 | args[n] = regs->gprs[2 + i + n] & mask; |
| 78 | if (i == 0) |
| 79 | args[0] = regs->orig_gpr2 & mask; |
| 80 | } |
| 81 | |
| 82 | static inline void syscall_set_arguments(struct task_struct *task, |
| 83 | struct pt_regs *regs, |
| 84 | unsigned int i, unsigned int n, |
| 85 | const unsigned long *args) |
| 86 | { |
| 87 | BUG_ON(i + n > 6); |
| 88 | while (n-- > 0) |
| 89 | if (i + n > 0) |
| 90 | regs->gprs[2 + i + n] = args[n]; |
| 91 | if (i == 0) |
| 92 | regs->orig_gpr2 = args[0]; |
| 93 | } |
| 94 | |
| 95 | static inline int syscall_get_arch(void) |
| 96 | { |
| 97 | #ifdef CONFIG_COMPAT |
| 98 | if (test_tsk_thread_flag(current, TIF_31BIT)) |
| 99 | return AUDIT_ARCH_S390; |
| 100 | #endif |
| 101 | return AUDIT_ARCH_S390X; |
| 102 | } |
| 103 | #endif /* _ASM_SYSCALL_H */ |