diff options
Diffstat (limited to 'arch/s390/kernel/syscall.c')
| -rw-r--r-- | arch/s390/kernel/syscall.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/arch/s390/kernel/syscall.c b/arch/s390/kernel/syscall.c new file mode 100644 index 000000000..dc2355c62 --- /dev/null +++ b/arch/s390/kernel/syscall.c @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * S390 version + * Copyright IBM Corp. 1999, 2000 + * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), + * Thomas Spatzier (tspat@de.ibm.com) + * + * Derived from "arch/i386/kernel/sys_i386.c" + * + * This file contains various random system calls that + * have a non-standard calling sequence on the Linux/s390 + * platform. + */ + +#include <linux/errno.h> +#include <linux/sched.h> +#include <linux/mm.h> +#include <linux/fs.h> +#include <linux/smp.h> +#include <linux/sem.h> +#include <linux/msg.h> +#include <linux/shm.h> +#include <linux/stat.h> +#include <linux/syscalls.h> +#include <linux/mman.h> +#include <linux/file.h> +#include <linux/utsname.h> +#include <linux/personality.h> +#include <linux/unistd.h> +#include <linux/ipc.h> +#include <linux/uaccess.h> +#include <linux/string.h> +#include <linux/thread_info.h> +#include <linux/entry-common.h> + +#include <asm/ptrace.h> +#include <asm/vtime.h> + +#include "entry.h" + +/* + * Perform the mmap() system call. Linux for S/390 isn't able to handle more + * than 5 system call parameters, so this system call uses a memory block + * for parameter passing. + */ + +struct s390_mmap_arg_struct { + unsigned long addr; + unsigned long len; + unsigned long prot; + unsigned long flags; + unsigned long fd; + unsigned long offset; +}; + +SYSCALL_DEFINE1(mmap2, struct s390_mmap_arg_struct __user *, arg) +{ + struct s390_mmap_arg_struct a; + int error = -EFAULT; + + if (copy_from_user(&a, arg, sizeof(a))) + goto out; + error = ksys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset); +out: + return error; +} + +#ifdef CONFIG_SYSVIPC +/* + * sys_ipc() is the de-multiplexer for the SysV IPC calls. + */ +SYSCALL_DEFINE5(s390_ipc, uint, call, int, first, unsigned long, second, + unsigned long, third, void __user *, ptr) +{ + if (call >> 16) + return -EINVAL; + /* The s390 sys_ipc variant has only five parameters instead of six + * like the generic variant. The only difference is the handling of + * the SEMTIMEDOP subcall where on s390 the third parameter is used + * as a pointer to a struct timespec where the generic variant uses + * the fifth parameter. + * Therefore we can call the generic variant by simply passing the + * third parameter also as fifth parameter. + */ + return ksys_ipc(call, first, second, third, ptr, third); +} +#endif /* CONFIG_SYSVIPC */ + +SYSCALL_DEFINE1(s390_personality, unsigned int, personality) +{ + unsigned int ret = current->personality; + + if (personality(current->personality) == PER_LINUX32 && + personality(personality) == PER_LINUX) + personality |= PER_LINUX32; + + if (personality != 0xffffffff) + set_personality(personality); + + if (personality(ret) == PER_LINUX32) + ret &= ~PER_LINUX32; + + return ret; +} + +SYSCALL_DEFINE0(ni_syscall) +{ + return -ENOSYS; +} + +static void do_syscall(struct pt_regs *regs) +{ + unsigned long nr; + + nr = regs->int_code & 0xffff; + if (!nr) { + nr = regs->gprs[1] & 0xffff; + regs->int_code &= ~0xffffUL; + regs->int_code |= nr; + } + + regs->gprs[2] = nr; + + if (nr == __NR_restart_syscall && !(current->restart_block.arch_data & 1)) { + regs->psw.addr = current->restart_block.arch_data; + current->restart_block.arch_data = 1; + } + nr = syscall_enter_from_user_mode_work(regs, nr); + + /* + * In the s390 ptrace ABI, both the syscall number and the return value + * use gpr2. However, userspace puts the syscall number either in the + * svc instruction itself, or uses gpr1. To make at least skipping syscalls + * work, the ptrace code sets PIF_SYSCALL_RET_SET, which is checked here + * and if set, the syscall will be skipped. + */ + + if (unlikely(test_and_clear_pt_regs_flag(regs, PIF_SYSCALL_RET_SET))) + goto out; + regs->gprs[2] = -ENOSYS; + if (likely(nr >= NR_syscalls)) + goto out; + do { + regs->gprs[2] = current->thread.sys_call_table[nr](regs); + } while (test_and_clear_pt_regs_flag(regs, PIF_EXECVE_PGSTE_RESTART)); +out: + syscall_exit_to_user_mode_work(regs); +} + +void noinstr __do_syscall(struct pt_regs *regs, int per_trap) +{ + add_random_kstack_offset(); + enter_from_user_mode(regs); + regs->psw = S390_lowcore.svc_old_psw; + regs->int_code = S390_lowcore.svc_int_code; + update_timer_sys(); + if (static_branch_likely(&cpu_has_bear)) + current->thread.last_break = regs->last_break; + + local_irq_enable(); + regs->orig_gpr2 = regs->gprs[2]; + + if (per_trap) + set_thread_flag(TIF_PER_TRAP); + + regs->flags = 0; + set_pt_regs_flag(regs, PIF_SYSCALL); + do_syscall(regs); + exit_to_user_mode(); +} |