xref: /openbmc/linux/arch/powerpc/kernel/syscalls.c (revision a44e4f3a)
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 #include <asm/asm-prototypes.h>
39 
40 static inline long do_mmap2(unsigned long addr, size_t len,
41 			unsigned long prot, unsigned long flags,
42 			unsigned long fd, unsigned long off, int shift)
43 {
44 	long ret = -EINVAL;
45 
46 	if (!arch_validate_prot(prot, addr))
47 		goto out;
48 
49 	if (shift) {
50 		if (off & ((1 << shift) - 1))
51 			goto out;
52 		off >>= shift;
53 	}
54 
55 	ret = ksys_mmap_pgoff(addr, len, prot, flags, fd, off);
56 out:
57 	return ret;
58 }
59 
60 SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
61 		unsigned long, prot, unsigned long, flags,
62 		unsigned long, fd, unsigned long, pgoff)
63 {
64 	return do_mmap2(addr, len, prot, flags, fd, pgoff, PAGE_SHIFT-12);
65 }
66 
67 SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
68 		unsigned long, prot, unsigned long, flags,
69 		unsigned long, fd, off_t, offset)
70 {
71 	return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
72 }
73 
74 #ifdef CONFIG_PPC32
75 /*
76  * Due to some executables calling the wrong select we sometimes
77  * get wrong args.  This determines how the args are being passed
78  * (a single ptr to them all args passed) then calls
79  * sys_select() with the appropriate args. -- Cort
80  */
81 int
82 ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct timeval __user *tvp)
83 {
84 	if ( (unsigned long)n >= 4096 )
85 	{
86 		unsigned long __user *buffer = (unsigned long __user *)n;
87 		if (!access_ok(buffer, 5*sizeof(unsigned long))
88 		    || __get_user(n, buffer)
89 		    || __get_user(inp, ((fd_set __user * __user *)(buffer+1)))
90 		    || __get_user(outp, ((fd_set  __user * __user *)(buffer+2)))
91 		    || __get_user(exp, ((fd_set  __user * __user *)(buffer+3)))
92 		    || __get_user(tvp, ((struct timeval  __user * __user *)(buffer+4))))
93 			return -EFAULT;
94 	}
95 	return sys_select(n, inp, outp, exp, tvp);
96 }
97 #endif
98 
99 #ifdef CONFIG_PPC64
100 long ppc64_personality(unsigned long personality)
101 {
102 	long ret;
103 
104 	if (personality(current->personality) == PER_LINUX32
105 	    && personality(personality) == PER_LINUX)
106 		personality = (personality & ~PER_MASK) | PER_LINUX32;
107 	ret = sys_personality(personality);
108 	if (personality(ret) == PER_LINUX32)
109 		ret = (ret & ~PER_MASK) | PER_LINUX;
110 	return ret;
111 }
112 #endif
113 
114 long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
115 		      u32 len_high, u32 len_low)
116 {
117 	return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,
118 				 (u64)len_high << 32 | len_low, advice);
119 }
120 
121 SYSCALL_DEFINE0(switch_endian)
122 {
123 	struct thread_info *ti;
124 
125 	current->thread.regs->msr ^= MSR_LE;
126 
127 	/*
128 	 * Set TIF_RESTOREALL so that r3 isn't clobbered on return to
129 	 * userspace. That also has the effect of restoring the non-volatile
130 	 * GPRs, so we saved them on the way in here.
131 	 */
132 	ti = current_thread_info();
133 	ti->flags |= _TIF_RESTOREALL;
134 
135 	return 0;
136 }
137