1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * This file contains various system calls that have different calling 4 * conventions on different platforms. 5 * 6 * Copyright (C) 1999-2000, 2002-2003, 2005 Hewlett-Packard Co 7 * David Mosberger-Tang <davidm@hpl.hp.com> 8 */ 9 #include <linux/errno.h> 10 #include <linux/fs.h> 11 #include <linux/mm.h> 12 #include <linux/mman.h> 13 #include <linux/sched.h> 14 #include <linux/sched/mm.h> 15 #include <linux/sched/task_stack.h> 16 #include <linux/shm.h> 17 #include <linux/file.h> /* doh, must come after sched.h... */ 18 #include <linux/smp.h> 19 #include <linux/syscalls.h> 20 #include <linux/highuid.h> 21 #include <linux/hugetlb.h> 22 23 #include <asm/shmparam.h> 24 #include <linux/uaccess.h> 25 26 unsigned long 27 arch_get_unmapped_area (struct file *filp, unsigned long addr, unsigned long len, 28 unsigned long pgoff, unsigned long flags) 29 { 30 long map_shared = (flags & MAP_SHARED); 31 unsigned long align_mask = 0; 32 struct mm_struct *mm = current->mm; 33 struct vm_unmapped_area_info info; 34 35 if (len > RGN_MAP_LIMIT) 36 return -ENOMEM; 37 38 /* handle fixed mapping: prevent overlap with huge pages */ 39 if (flags & MAP_FIXED) { 40 if (is_hugepage_only_range(mm, addr, len)) 41 return -EINVAL; 42 return addr; 43 } 44 45 #ifdef CONFIG_HUGETLB_PAGE 46 if (REGION_NUMBER(addr) == RGN_HPAGE) 47 addr = 0; 48 #endif 49 if (!addr) 50 addr = TASK_UNMAPPED_BASE; 51 52 if (map_shared && (TASK_SIZE > 0xfffffffful)) 53 /* 54 * For 64-bit tasks, align shared segments to 1MB to avoid potential 55 * performance penalty due to virtual aliasing (see ASDM). For 32-bit 56 * tasks, we prefer to avoid exhausting the address space too quickly by 57 * limiting alignment to a single page. 58 */ 59 align_mask = PAGE_MASK & (SHMLBA - 1); 60 61 info.flags = 0; 62 info.length = len; 63 info.low_limit = addr; 64 info.high_limit = TASK_SIZE; 65 info.align_mask = align_mask; 66 info.align_offset = pgoff << PAGE_SHIFT; 67 return vm_unmapped_area(&info); 68 } 69 70 asmlinkage long 71 ia64_getpriority (int which, int who) 72 { 73 long prio; 74 75 prio = sys_getpriority(which, who); 76 if (prio >= 0) { 77 force_successful_syscall_return(); 78 prio = 20 - prio; 79 } 80 return prio; 81 } 82 83 /* XXX obsolete, but leave it here until the old libc is gone... */ 84 asmlinkage unsigned long 85 sys_getpagesize (void) 86 { 87 return PAGE_SIZE; 88 } 89 90 asmlinkage unsigned long 91 ia64_brk (unsigned long brk) 92 { 93 unsigned long retval = sys_brk(brk); 94 force_successful_syscall_return(); 95 return retval; 96 } 97 98 /* 99 * On IA-64, we return the two file descriptors in ret0 and ret1 (r8 100 * and r9) as this is faster than doing a copy_to_user(). 101 */ 102 asmlinkage long 103 sys_ia64_pipe (void) 104 { 105 struct pt_regs *regs = task_pt_regs(current); 106 int fd[2]; 107 int retval; 108 109 retval = do_pipe_flags(fd, 0); 110 if (retval) 111 goto out; 112 retval = fd[0]; 113 regs->r9 = fd[1]; 114 out: 115 return retval; 116 } 117 118 int ia64_mmap_check(unsigned long addr, unsigned long len, 119 unsigned long flags) 120 { 121 unsigned long roff; 122 123 /* 124 * Don't permit mappings into unmapped space, the virtual page table 125 * of a region, or across a region boundary. Note: RGN_MAP_LIMIT is 126 * equal to 2^n-PAGE_SIZE (for some integer n <= 61) and len > 0. 127 */ 128 roff = REGION_OFFSET(addr); 129 if ((len > RGN_MAP_LIMIT) || (roff > (RGN_MAP_LIMIT - len))) 130 return -EINVAL; 131 return 0; 132 } 133 134 /* 135 * mmap2() is like mmap() except that the offset is expressed in units 136 * of PAGE_SIZE (instead of bytes). This allows to mmap2() (pieces 137 * of) files that are larger than the address space of the CPU. 138 */ 139 asmlinkage unsigned long 140 sys_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, long pgoff) 141 { 142 addr = ksys_mmap_pgoff(addr, len, prot, flags, fd, pgoff); 143 if (!IS_ERR_VALUE(addr)) 144 force_successful_syscall_return(); 145 return addr; 146 } 147 148 asmlinkage unsigned long 149 sys_mmap (unsigned long addr, unsigned long len, int prot, int flags, int fd, long off) 150 { 151 if (offset_in_page(off) != 0) 152 return -EINVAL; 153 154 addr = ksys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT); 155 if (!IS_ERR_VALUE(addr)) 156 force_successful_syscall_return(); 157 return addr; 158 } 159 160 asmlinkage unsigned long 161 ia64_mremap (unsigned long addr, unsigned long old_len, unsigned long new_len, unsigned long flags, 162 unsigned long new_addr) 163 { 164 addr = sys_mremap(addr, old_len, new_len, flags, new_addr); 165 if (!IS_ERR_VALUE(addr)) 166 force_successful_syscall_return(); 167 return addr; 168 } 169 170 asmlinkage long 171 ia64_clock_getres(const clockid_t which_clock, struct __kernel_timespec __user *tp) 172 { 173 struct timespec64 rtn_tp; 174 s64 tick_ns; 175 176 /* 177 * ia64's clock_gettime() syscall is implemented as a vdso call 178 * fsys_clock_gettime(). Currently it handles only 179 * CLOCK_REALTIME and CLOCK_MONOTONIC. Both are based on 180 * 'ar.itc' counter which gets incremented at a constant 181 * frequency. It's usually 400MHz, ~2.5x times slower than CPU 182 * clock frequency. Which is almost a 1ns hrtimer, but not quite. 183 * 184 * Let's special-case these timers to report correct precision 185 * based on ITC frequency and not HZ frequency for supported 186 * clocks. 187 */ 188 switch (which_clock) { 189 case CLOCK_REALTIME: 190 case CLOCK_MONOTONIC: 191 tick_ns = DIV_ROUND_UP(NSEC_PER_SEC, local_cpu_data->itc_freq); 192 rtn_tp = ns_to_timespec64(tick_ns); 193 return put_timespec64(&rtn_tp, tp); 194 } 195 196 return sys_clock_getres(which_clock, tp); 197 } 198