Catalin Marinas | 7992d60 | 2012-03-05 11:49:31 +0000 | [diff] [blame] | 1 | /* |
| 2 | * AArch64-specific system calls implementation |
| 3 | * |
| 4 | * Copyright (C) 2012 ARM Ltd. |
| 5 | * Author: Catalin Marinas <catalin.marinas@arm.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 18 | */ |
| 19 | |
| 20 | #include <linux/compiler.h> |
| 21 | #include <linux/errno.h> |
| 22 | #include <linux/fs.h> |
| 23 | #include <linux/mm.h> |
| 24 | #include <linux/export.h> |
| 25 | #include <linux/sched.h> |
| 26 | #include <linux/slab.h> |
| 27 | #include <linux/syscalls.h> |
| 28 | |
| 29 | /* |
| 30 | * Clone a task - this clones the calling program thread. |
| 31 | */ |
| 32 | asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp, |
| 33 | int __user *parent_tidptr, unsigned long tls_val, |
| 34 | int __user *child_tidptr, struct pt_regs *regs) |
| 35 | { |
| 36 | if (!newsp) |
| 37 | newsp = regs->sp; |
| 38 | /* 16-byte aligned stack mandatory on AArch64 */ |
| 39 | if (newsp & 15) |
| 40 | return -EINVAL; |
| 41 | return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr); |
| 42 | } |
| 43 | |
| 44 | /* |
| 45 | * sys_execve() executes a new program. |
| 46 | */ |
| 47 | asmlinkage long sys_execve(const char __user *filenamei, |
| 48 | const char __user *const __user *argv, |
| 49 | const char __user *const __user *envp, |
| 50 | struct pt_regs *regs) |
| 51 | { |
| 52 | long error; |
Jeff Layton | 91a27b2 | 2012-10-10 15:25:28 -0400 | [diff] [blame] | 53 | struct filename *filename; |
Catalin Marinas | 7992d60 | 2012-03-05 11:49:31 +0000 | [diff] [blame] | 54 | |
| 55 | filename = getname(filenamei); |
| 56 | error = PTR_ERR(filename); |
| 57 | if (IS_ERR(filename)) |
| 58 | goto out; |
Jeff Layton | 91a27b2 | 2012-10-10 15:25:28 -0400 | [diff] [blame] | 59 | error = do_execve(filename->name, argv, envp, regs); |
Catalin Marinas | 7992d60 | 2012-03-05 11:49:31 +0000 | [diff] [blame] | 60 | putname(filename); |
| 61 | out: |
| 62 | return error; |
| 63 | } |
| 64 | |
| 65 | int kernel_execve(const char *filename, |
| 66 | const char *const argv[], |
| 67 | const char *const envp[]) |
| 68 | { |
| 69 | struct pt_regs regs; |
| 70 | int ret; |
| 71 | |
| 72 | memset(®s, 0, sizeof(struct pt_regs)); |
| 73 | ret = do_execve(filename, |
| 74 | (const char __user *const __user *)argv, |
| 75 | (const char __user *const __user *)envp, ®s); |
| 76 | if (ret < 0) |
| 77 | goto out; |
| 78 | |
| 79 | /* |
| 80 | * Save argc to the register structure for userspace. |
| 81 | */ |
| 82 | regs.regs[0] = ret; |
| 83 | |
| 84 | /* |
| 85 | * We were successful. We won't be returning to our caller, but |
| 86 | * instead to user space by manipulating the kernel stack. |
| 87 | */ |
| 88 | asm( "add x0, %0, %1\n\t" |
| 89 | "mov x1, %2\n\t" |
| 90 | "mov x2, %3\n\t" |
| 91 | "bl memmove\n\t" /* copy regs to top of stack */ |
| 92 | "mov x27, #0\n\t" /* not a syscall */ |
| 93 | "mov x28, %0\n\t" /* thread structure */ |
| 94 | "mov sp, x0\n\t" /* reposition stack pointer */ |
| 95 | "b ret_to_user" |
| 96 | : |
| 97 | : "r" (current_thread_info()), |
| 98 | "Ir" (THREAD_START_SP - sizeof(regs)), |
| 99 | "r" (®s), |
| 100 | "Ir" (sizeof(regs)) |
| 101 | : "x0", "x1", "x2", "x27", "x28", "x30", "memory"); |
| 102 | |
| 103 | out: |
| 104 | return ret; |
| 105 | } |
| 106 | EXPORT_SYMBOL(kernel_execve); |
| 107 | |
| 108 | asmlinkage long sys_mmap(unsigned long addr, unsigned long len, |
| 109 | unsigned long prot, unsigned long flags, |
| 110 | unsigned long fd, off_t off) |
| 111 | { |
| 112 | if (offset_in_page(off) != 0) |
| 113 | return -EINVAL; |
| 114 | |
| 115 | return sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT); |
| 116 | } |
| 117 | |
| 118 | /* |
| 119 | * Wrappers to pass the pt_regs argument. |
| 120 | */ |
| 121 | #define sys_execve sys_execve_wrapper |
| 122 | #define sys_clone sys_clone_wrapper |
| 123 | #define sys_rt_sigreturn sys_rt_sigreturn_wrapper |
| 124 | #define sys_sigaltstack sys_sigaltstack_wrapper |
| 125 | |
| 126 | #include <asm/syscalls.h> |
| 127 | |
| 128 | #undef __SYSCALL |
| 129 | #define __SYSCALL(nr, sym) [nr] = sym, |
| 130 | |
| 131 | /* |
| 132 | * The sys_call_table array must be 4K aligned to be accessible from |
| 133 | * kernel/entry.S. |
| 134 | */ |
| 135 | void *sys_call_table[__NR_syscalls] __aligned(4096) = { |
| 136 | [0 ... __NR_syscalls - 1] = sys_ni_syscall, |
| 137 | #include <asm/unistd.h> |
| 138 | }; |