| 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/unistd.h> |
| 30 | |
| 31 | static inline void |
| 32 | do_compat_cache_op(unsigned long start, unsigned long end, int flags) |
| 33 | { |
| 34 | struct mm_struct *mm = current->active_mm; |
| 35 | struct vm_area_struct *vma; |
| 36 | |
| 37 | if (end < start || flags) |
| 38 | return; |
| 39 | |
| 40 | down_read(&mm->mmap_sem); |
| 41 | vma = find_vma(mm, start); |
| 42 | if (vma && vma->vm_start < end) { |
| 43 | if (start < vma->vm_start) |
| 44 | start = vma->vm_start; |
| 45 | if (end > vma->vm_end) |
| 46 | end = vma->vm_end; |
| 47 | up_read(&mm->mmap_sem); |
| 48 | __flush_cache_user_range(start & PAGE_MASK, PAGE_ALIGN(end)); |
| 49 | return; |
| 50 | } |
| 51 | up_read(&mm->mmap_sem); |
| 52 | } |
| 53 | |
| 54 | /* |
| 55 | * Handle all unrecognised system calls. |
| 56 | */ |
| 57 | long compat_arm_syscall(struct pt_regs *regs) |
| 58 | { |
| 59 | unsigned int no = regs->regs[7]; |
| 60 | |
| 61 | switch (no) { |
| 62 | /* |
| 63 | * Flush a region from virtual address 'r0' to virtual address 'r1' |
| 64 | * _exclusive_. There is no alignment requirement on either address; |
| 65 | * user space does not need to know the hardware cache layout. |
| 66 | * |
| 67 | * r2 contains flags. It should ALWAYS be passed as ZERO until it |
| 68 | * is defined to be something else. For now we ignore it, but may |
| 69 | * the fires of hell burn in your belly if you break this rule. ;) |
| 70 | * |
| 71 | * (at a later date, we may want to allow this call to not flush |
| 72 | * various aspects of the cache. Passing '0' will guarantee that |
| 73 | * everything necessary gets flushed to maintain consistency in |
| 74 | * the specified region). |
| 75 | */ |
| 76 | case __ARM_NR_compat_cacheflush: |
| 77 | do_compat_cache_op(regs->regs[0], regs->regs[1], regs->regs[2]); |
| 78 | return 0; |
| 79 | |
| 80 | case __ARM_NR_compat_set_tls: |
| 81 | current->thread.tp_value = regs->regs[0]; |
| 82 | asm ("msr tpidrro_el0, %0" : : "r" (regs->regs[0])); |
| 83 | return 0; |
| 84 | |
| 85 | default: |
| 86 | return -ENOSYS; |
| 87 | } |
| 88 | } |