xref: /openbmc/linux/arch/powerpc/kernel/syscalls.c (revision ac73d4bf)
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 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 #ifdef CONFIG_COMPAT
60 COMPAT_SYSCALL_DEFINE6(mmap2,
61 		       unsigned long, addr, size_t, len,
62 		       unsigned long, prot, unsigned long, flags,
63 		       unsigned long, fd, unsigned long, off_4k)
64 {
65 	return do_mmap2(addr, len, prot, flags, fd, off_4k, PAGE_SHIFT-12);
66 }
67 #endif
68 
69 SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
70 		unsigned long, prot, unsigned long, flags,
71 		unsigned long, fd, off_t, offset)
72 {
73 	return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
74 }
75 
76 #ifdef CONFIG_PPC64
77 static long do_ppc64_personality(unsigned long personality)
78 {
79 	long ret;
80 
81 	if (personality(current->personality) == PER_LINUX32
82 	    && personality(personality) == PER_LINUX)
83 		personality = (personality & ~PER_MASK) | PER_LINUX32;
84 	ret = ksys_personality(personality);
85 	if (personality(ret) == PER_LINUX32)
86 		ret = (ret & ~PER_MASK) | PER_LINUX;
87 	return ret;
88 }
89 
90 SYSCALL_DEFINE1(ppc64_personality, unsigned long, personality)
91 {
92 	return do_ppc64_personality(personality);
93 }
94 
95 #ifdef CONFIG_COMPAT
96 COMPAT_SYSCALL_DEFINE1(ppc64_personality, unsigned long, personality)
97 {
98 	return do_ppc64_personality(personality);
99 }
100 #endif /* CONFIG_COMPAT */
101 #endif /* CONFIG_PPC64 */
102 
103 SYSCALL_DEFINE6(ppc_fadvise64_64,
104 		int, fd, int, advice, u32, offset_high, u32, offset_low,
105 		u32, len_high, u32, len_low)
106 {
107 	return ksys_fadvise64_64(fd, merge_64(offset_high, offset_low),
108 				 merge_64(len_high, len_low), advice);
109 }
110 
111 SYSCALL_DEFINE0(switch_endian)
112 {
113 	struct thread_info *ti;
114 
115 	regs_set_return_msr(current->thread.regs,
116 				current->thread.regs->msr ^ MSR_LE);
117 
118 	/*
119 	 * Set TIF_RESTOREALL so that r3 isn't clobbered on return to
120 	 * userspace. That also has the effect of restoring the non-volatile
121 	 * GPRs, so we saved them on the way in here.
122 	 */
123 	ti = current_thread_info();
124 	ti->flags |= _TIF_RESTOREALL;
125 
126 	return 0;
127 }
128