xref: /linux/arch/powerpc/kernel/syscalls.c (revision d206cef03c4827984e6ac88a9472b70c41f5b28d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Implementation of various system calls for Linux/PowerPC
4  *
5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6  *
7  * Derived from "arch/i386/kernel/sys_i386.c"
8  * Adapted from the i386 version by Gary Thomas
9  * Modified by Cort Dougan (cort@cs.nmt.edu)
10  * and Paul Mackerras (paulus@cs.anu.edu.au).
11  *
12  * This file contains various random system calls that
13  * have a non-standard calling sequence on the Linux/PPC
14  * platform.
15  */
16 
17 #include <linux/errno.h>
18 #include <linux/sched.h>
19 #include <linux/syscalls.h>
20 #include <linux/mm.h>
21 #include <linux/fs.h>
22 #include <linux/smp.h>
23 #include <linux/sem.h>
24 #include <linux/msg.h>
25 #include <linux/shm.h>
26 #include <linux/stat.h>
27 #include <linux/mman.h>
28 #include <linux/sys.h>
29 #include <linux/ipc.h>
30 #include <linux/utsname.h>
31 #include <linux/file.h>
32 #include <linux/personality.h>
33 
34 #include <linux/uaccess.h>
35 #include <asm/syscalls.h>
36 #include <asm/time.h>
37 #include <asm/unistd.h>
38 
39 static inline long do_mmap2(unsigned long addr, size_t len,
40 			unsigned long prot, unsigned long flags,
41 			unsigned long fd, unsigned long off, int shift)
42 {
43 	if (!arch_validate_prot(prot, addr))
44 		return -EINVAL;
45 
46 	if (!IS_ALIGNED(off, 1 << shift))
47 		return -EINVAL;
48 
49 	return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> shift);
50 }
51 
52 SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
53 		unsigned long, prot, unsigned long, flags,
54 		unsigned long, fd, unsigned long, pgoff)
55 {
56 	return do_mmap2(addr, len, prot, flags, fd, pgoff, PAGE_SHIFT-12);
57 }
58 
59 SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
60 		unsigned long, prot, unsigned long, flags,
61 		unsigned long, fd, off_t, offset)
62 {
63 	return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
64 }
65 
66 #ifdef CONFIG_PPC32
67 /*
68  * Due to some executables calling the wrong select we sometimes
69  * get wrong args.  This determines how the args are being passed
70  * (a single ptr to them all args passed) then calls
71  * sys_select() with the appropriate args. -- Cort
72  */
73 int
74 ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct __kernel_old_timeval __user *tvp)
75 {
76 	if ((unsigned long)n >= 4096)
77 		return sys_old_select((void __user *)n);
78 
79 	return sys_select(n, inp, outp, exp, tvp);
80 }
81 #endif
82 
83 #ifdef CONFIG_PPC64
84 long ppc64_personality(unsigned long personality)
85 {
86 	long ret;
87 
88 	if (personality(current->personality) == PER_LINUX32
89 	    && personality(personality) == PER_LINUX)
90 		personality = (personality & ~PER_MASK) | PER_LINUX32;
91 	ret = sys_personality(personality);
92 	if (personality(ret) == PER_LINUX32)
93 		ret = (ret & ~PER_MASK) | PER_LINUX;
94 	return ret;
95 }
96 #endif
97 
98 long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
99 		      u32 len_high, u32 len_low)
100 {
101 	return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,
102 				 (u64)len_high << 32 | len_low, advice);
103 }
104 
105 SYSCALL_DEFINE0(switch_endian)
106 {
107 	struct thread_info *ti;
108 
109 	regs_set_return_msr(current->thread.regs,
110 				current->thread.regs->msr ^ MSR_LE);
111 
112 	/*
113 	 * Set TIF_RESTOREALL so that r3 isn't clobbered on return to
114 	 * userspace. That also has the effect of restoring the non-volatile
115 	 * GPRs, so we saved them on the way in here.
116 	 */
117 	ti = current_thread_info();
118 	ti->flags |= _TIF_RESTOREALL;
119 
120 	return 0;
121 }
122