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-rw-r--r--arch/s390/kernel/syscall.c170
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 0000000000..dc2355c623
--- /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();
+}