xref: /openbmc/linux/arch/powerpc/kernel/syscalls.c (revision faa16bc4)
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, addr))
52 		goto out;
53 
54 	if (shift) {
55 		if (off & ((1 << shift) - 1))
56 			goto out;
57 		off >>= shift;
58 	}
59 
60 	ret = ksys_mmap_pgoff(addr, len, prot, flags, fd, off);
61 out:
62 	return ret;
63 }
64 
65 #pragma GCC diagnostic push
66 #pragma GCC diagnostic ignored "-Wpragmas"
67 #pragma GCC diagnostic ignored "-Wattribute-alias"
68 SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
69 		unsigned long, prot, unsigned long, flags,
70 		unsigned long, fd, unsigned long, pgoff)
71 {
72 	return do_mmap2(addr, len, prot, flags, fd, pgoff, PAGE_SHIFT-12);
73 }
74 
75 SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
76 		unsigned long, prot, unsigned long, flags,
77 		unsigned long, fd, off_t, offset)
78 {
79 	return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
80 }
81 #pragma GCC diagnostic pop
82 
83 #ifdef CONFIG_PPC32
84 /*
85  * Due to some executables calling the wrong select we sometimes
86  * get wrong args.  This determines how the args are being passed
87  * (a single ptr to them all args passed) then calls
88  * sys_select() with the appropriate args. -- Cort
89  */
90 int
91 ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct timeval __user *tvp)
92 {
93 	if ( (unsigned long)n >= 4096 )
94 	{
95 		unsigned long __user *buffer = (unsigned long __user *)n;
96 		if (!access_ok(VERIFY_READ, buffer, 5*sizeof(unsigned long))
97 		    || __get_user(n, buffer)
98 		    || __get_user(inp, ((fd_set __user * __user *)(buffer+1)))
99 		    || __get_user(outp, ((fd_set  __user * __user *)(buffer+2)))
100 		    || __get_user(exp, ((fd_set  __user * __user *)(buffer+3)))
101 		    || __get_user(tvp, ((struct timeval  __user * __user *)(buffer+4))))
102 			return -EFAULT;
103 	}
104 	return sys_select(n, inp, outp, exp, tvp);
105 }
106 #endif
107 
108 #ifdef CONFIG_PPC64
109 long ppc64_personality(unsigned long personality)
110 {
111 	long ret;
112 
113 	if (personality(current->personality) == PER_LINUX32
114 	    && personality(personality) == PER_LINUX)
115 		personality = (personality & ~PER_MASK) | PER_LINUX32;
116 	ret = sys_personality(personality);
117 	if (personality(ret) == PER_LINUX32)
118 		ret = (ret & ~PER_MASK) | PER_LINUX;
119 	return ret;
120 }
121 #endif
122 
123 long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
124 		      u32 len_high, u32 len_low)
125 {
126 	return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,
127 				 (u64)len_high << 32 | len_low, advice);
128 }
129 
130 long sys_switch_endian(void)
131 {
132 	struct thread_info *ti;
133 
134 	current->thread.regs->msr ^= MSR_LE;
135 
136 	/*
137 	 * Set TIF_RESTOREALL so that r3 isn't clobbered on return to
138 	 * userspace. That also has the effect of restoring the non-volatile
139 	 * GPRs, so we saved them on the way in here.
140 	 */
141 	ti = current_thread_info();
142 	ti->flags |= _TIF_RESTOREALL;
143 
144 	return 0;
145 }
146