xref: /openbmc/linux/arch/powerpc/kernel/syscalls.c (revision a36954f5)
1 /*
2  *  Implementation of various system calls for Linux/PowerPC
3  *
4  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5  *
6  * Derived from "arch/i386/kernel/sys_i386.c"
7  * Adapted from the i386 version by Gary Thomas
8  * Modified by Cort Dougan (cort@cs.nmt.edu)
9  * and Paul Mackerras (paulus@cs.anu.edu.au).
10  *
11  * This file contains various random system calls that
12  * have a non-standard calling sequence on the Linux/PPC
13  * platform.
14  *
15  *  This program is free software; you can redistribute it and/or
16  *  modify it under the terms of the GNU General Public License
17  *  as published by the Free Software Foundation; either version
18  *  2 of the License, or (at your option) any later version.
19  *
20  */
21 
22 #include <linux/errno.h>
23 #include <linux/sched.h>
24 #include <linux/syscalls.h>
25 #include <linux/mm.h>
26 #include <linux/fs.h>
27 #include <linux/smp.h>
28 #include <linux/sem.h>
29 #include <linux/msg.h>
30 #include <linux/shm.h>
31 #include <linux/stat.h>
32 #include <linux/mman.h>
33 #include <linux/sys.h>
34 #include <linux/ipc.h>
35 #include <linux/utsname.h>
36 #include <linux/file.h>
37 #include <linux/personality.h>
38 
39 #include <linux/uaccess.h>
40 #include <asm/syscalls.h>
41 #include <asm/time.h>
42 #include <asm/unistd.h>
43 #include <asm/asm-prototypes.h>
44 
45 static inline long do_mmap2(unsigned long addr, size_t len,
46 			unsigned long prot, unsigned long flags,
47 			unsigned long fd, unsigned long off, int shift)
48 {
49 	long ret = -EINVAL;
50 
51 	if (!arch_validate_prot(prot))
52 		goto out;
53 
54 	if (shift) {
55 		if (off & ((1 << shift) - 1))
56 			goto out;
57 		off >>= shift;
58 	}
59 
60 	ret = sys_mmap_pgoff(addr, len, prot, flags, fd, off);
61 out:
62 	return ret;
63 }
64 
65 SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
66 		unsigned long, prot, unsigned long, flags,
67 		unsigned long, fd, unsigned long, pgoff)
68 {
69 	return do_mmap2(addr, len, prot, flags, fd, pgoff, PAGE_SHIFT-12);
70 }
71 
72 SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
73 		unsigned long, prot, unsigned long, flags,
74 		unsigned long, fd, off_t, offset)
75 {
76 	return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
77 }
78 
79 #ifdef CONFIG_PPC32
80 /*
81  * Due to some executables calling the wrong select we sometimes
82  * get wrong args.  This determines how the args are being passed
83  * (a single ptr to them all args passed) then calls
84  * sys_select() with the appropriate args. -- Cort
85  */
86 int
87 ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct timeval __user *tvp)
88 {
89 	if ( (unsigned long)n >= 4096 )
90 	{
91 		unsigned long __user *buffer = (unsigned long __user *)n;
92 		if (!access_ok(VERIFY_READ, buffer, 5*sizeof(unsigned long))
93 		    || __get_user(n, buffer)
94 		    || __get_user(inp, ((fd_set __user * __user *)(buffer+1)))
95 		    || __get_user(outp, ((fd_set  __user * __user *)(buffer+2)))
96 		    || __get_user(exp, ((fd_set  __user * __user *)(buffer+3)))
97 		    || __get_user(tvp, ((struct timeval  __user * __user *)(buffer+4))))
98 			return -EFAULT;
99 	}
100 	return sys_select(n, inp, outp, exp, tvp);
101 }
102 #endif
103 
104 #ifdef CONFIG_PPC64
105 long ppc64_personality(unsigned long personality)
106 {
107 	long ret;
108 
109 	if (personality(current->personality) == PER_LINUX32
110 	    && personality(personality) == PER_LINUX)
111 		personality = (personality & ~PER_MASK) | PER_LINUX32;
112 	ret = sys_personality(personality);
113 	if (personality(ret) == PER_LINUX32)
114 		ret = (ret & ~PER_MASK) | PER_LINUX;
115 	return ret;
116 }
117 #endif
118 
119 long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
120 		      u32 len_high, u32 len_low)
121 {
122 	return sys_fadvise64(fd, (u64)offset_high << 32 | offset_low,
123 			     (u64)len_high << 32 | len_low, advice);
124 }
125 
126 long sys_switch_endian(void)
127 {
128 	struct thread_info *ti;
129 
130 	current->thread.regs->msr ^= MSR_LE;
131 
132 	/*
133 	 * Set TIF_RESTOREALL so that r3 isn't clobbered on return to
134 	 * userspace. That also has the effect of restoring the non-volatile
135 	 * GPRs, so we saved them on the way in here.
136 	 */
137 	ti = current_thread_info();
138 	ti->flags |= _TIF_RESTOREALL;
139 
140 	return 0;
141 }
142