1 /* 2 * Based on arch/arm/kernel/sys_arm.c 3 * 4 * Copyright (C) People who wrote linux/arch/i386/kernel/sys_i386.c 5 * Copyright (C) 1995, 1996 Russell King. 6 * Copyright (C) 2012 ARM Ltd. 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program. If not, see <http://www.gnu.org/licenses/>. 19 */ 20 21 #include <linux/compat.h> 22 #include <linux/personality.h> 23 #include <linux/sched.h> 24 #include <linux/slab.h> 25 #include <linux/syscalls.h> 26 #include <linux/uaccess.h> 27 28 #include <asm/cacheflush.h> 29 #include <asm/unistd32.h> 30 31 asmlinkage int compat_sys_sched_rr_get_interval(compat_pid_t pid, 32 struct compat_timespec __user *interval) 33 { 34 struct timespec t; 35 int ret; 36 mm_segment_t old_fs = get_fs(); 37 38 set_fs(KERNEL_DS); 39 ret = sys_sched_rr_get_interval(pid, (struct timespec __user *)&t); 40 set_fs(old_fs); 41 if (put_compat_timespec(&t, interval)) 42 return -EFAULT; 43 return ret; 44 } 45 46 static inline void 47 do_compat_cache_op(unsigned long start, unsigned long end, int flags) 48 { 49 struct mm_struct *mm = current->active_mm; 50 struct vm_area_struct *vma; 51 52 if (end < start || flags) 53 return; 54 55 down_read(&mm->mmap_sem); 56 vma = find_vma(mm, start); 57 if (vma && vma->vm_start < end) { 58 if (start < vma->vm_start) 59 start = vma->vm_start; 60 if (end > vma->vm_end) 61 end = vma->vm_end; 62 up_read(&mm->mmap_sem); 63 __flush_cache_user_range(start & PAGE_MASK, PAGE_ALIGN(end)); 64 return; 65 } 66 up_read(&mm->mmap_sem); 67 } 68 69 /* 70 * Handle all unrecognised system calls. 71 */ 72 long compat_arm_syscall(struct pt_regs *regs) 73 { 74 unsigned int no = regs->regs[7]; 75 76 switch (no) { 77 /* 78 * Flush a region from virtual address 'r0' to virtual address 'r1' 79 * _exclusive_. There is no alignment requirement on either address; 80 * user space does not need to know the hardware cache layout. 81 * 82 * r2 contains flags. It should ALWAYS be passed as ZERO until it 83 * is defined to be something else. For now we ignore it, but may 84 * the fires of hell burn in your belly if you break this rule. ;) 85 * 86 * (at a later date, we may want to allow this call to not flush 87 * various aspects of the cache. Passing '0' will guarantee that 88 * everything necessary gets flushed to maintain consistency in 89 * the specified region). 90 */ 91 case __ARM_NR_compat_cacheflush: 92 do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]); 93 return 0; 94 95 case __ARM_NR_compat_set_tls: 96 current->thread.tp_value = regs->regs[0]; 97 asm ("msr tpidrro_el0, %0" : : "r" (regs->regs[0])); 98 return 0; 99 100 default: 101 return -ENOSYS; 102 } 103 } 104