xref: /linux/arch/powerpc/kernel/syscalls.c (revision d1b803f4ca4f25d6f171219d039f9410a10b29ee)
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 	if (!arch_validate_prot(prot, addr))
45 		return -EINVAL;
46 
47 	if (!IS_ALIGNED(off, 1 << shift))
48 		return -EINVAL;
49 
50 	return ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> shift);
51 }
52 
53 SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
54 		unsigned long, prot, unsigned long, flags,
55 		unsigned long, fd, unsigned long, pgoff)
56 {
57 	return do_mmap2(addr, len, prot, flags, fd, pgoff, PAGE_SHIFT-12);
58 }
59 
60 SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
61 		unsigned long, prot, unsigned long, flags,
62 		unsigned long, fd, off_t, offset)
63 {
64 	return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);
65 }
66 
67 #ifdef CONFIG_PPC32
68 /*
69  * Due to some executables calling the wrong select we sometimes
70  * get wrong args.  This determines how the args are being passed
71  * (a single ptr to them all args passed) then calls
72  * sys_select() with the appropriate args. -- Cort
73  */
74 int
75 ppc_select(int n, fd_set __user *inp, fd_set __user *outp, fd_set __user *exp, struct __kernel_old_timeval __user *tvp)
76 {
77 	if ( (unsigned long)n >= 4096 )
78 		return sys_old_select((void __user *)n);
79 
80 	return sys_select(n, inp, outp, exp, tvp);
81 }
82 #endif
83 
84 #ifdef CONFIG_PPC64
85 long ppc64_personality(unsigned long personality)
86 {
87 	long ret;
88 
89 	if (personality(current->personality) == PER_LINUX32
90 	    && personality(personality) == PER_LINUX)
91 		personality = (personality & ~PER_MASK) | PER_LINUX32;
92 	ret = sys_personality(personality);
93 	if (personality(ret) == PER_LINUX32)
94 		ret = (ret & ~PER_MASK) | PER_LINUX;
95 	return ret;
96 }
97 #endif
98 
99 long ppc_fadvise64_64(int fd, int advice, u32 offset_high, u32 offset_low,
100 		      u32 len_high, u32 len_low)
101 {
102 	return ksys_fadvise64_64(fd, (u64)offset_high << 32 | offset_low,
103 				 (u64)len_high << 32 | len_low, advice);
104 }
105 
106 SYSCALL_DEFINE0(switch_endian)
107 {
108 	struct thread_info *ti;
109 
110 	regs_set_return_msr(current->thread.regs,
111 				current->thread.regs->msr ^ MSR_LE);
112 
113 	/*
114 	 * Set TIF_RESTOREALL so that r3 isn't clobbered on return to
115 	 * userspace. That also has the effect of restoring the non-volatile
116 	 * GPRs, so we saved them on the way in here.
117 	 */
118 	ti = current_thread_info();
119 	ti->flags |= _TIF_RESTOREALL;
120 
121 	return 0;
122 }
123