| 1 | /* |
| 2 | * linux/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 | * |
| 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 file contains various random system calls that |
| 12 | * have a non-standard calling sequence on the Linux/arm |
| 13 | * platform. |
| 14 | */ |
| 15 | #include <linux/module.h> |
| 16 | #include <linux/errno.h> |
| 17 | #include <linux/sched.h> |
| 18 | #include <linux/mm.h> |
| 19 | #include <linux/sem.h> |
| 20 | #include <linux/msg.h> |
| 21 | #include <linux/shm.h> |
| 22 | #include <linux/stat.h> |
| 23 | #include <linux/syscalls.h> |
| 24 | #include <linux/mman.h> |
| 25 | #include <linux/fs.h> |
| 26 | #include <linux/file.h> |
| 27 | #include <linux/ipc.h> |
| 28 | #include <linux/uaccess.h> |
| 29 | #include <linux/slab.h> |
| 30 | |
| 31 | /* Fork a new task - this creates a new program thread. |
| 32 | * This is called indirectly via a small wrapper |
| 33 | */ |
| 34 | asmlinkage int sys_fork(struct pt_regs *regs) |
| 35 | { |
| 36 | #ifdef CONFIG_MMU |
| 37 | return do_fork(SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL); |
| 38 | #else |
| 39 | /* can not support in nommu mode */ |
| 40 | return(-EINVAL); |
| 41 | #endif |
| 42 | } |
| 43 | |
| 44 | /* Clone a task - this clones the calling program thread. |
| 45 | * This is called indirectly via a small wrapper |
| 46 | */ |
| 47 | asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp, |
| 48 | int __user *parent_tidptr, int tls_val, |
| 49 | int __user *child_tidptr, struct pt_regs *regs) |
| 50 | { |
| 51 | if (!newsp) |
| 52 | newsp = regs->ARM_sp; |
| 53 | |
| 54 | return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr); |
| 55 | } |
| 56 | |
| 57 | asmlinkage int sys_vfork(struct pt_regs *regs) |
| 58 | { |
| 59 | return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL); |
| 60 | } |
| 61 | |
| 62 | /* sys_execve() executes a new program. |
| 63 | * This is called indirectly via a small wrapper |
| 64 | */ |
| 65 | asmlinkage int sys_execve(const char __user *filenamei, |
| 66 | const char __user *const __user *argv, |
| 67 | const char __user *const __user *envp, struct pt_regs *regs) |
| 68 | { |
| 69 | int error; |
| 70 | char * filename; |
| 71 | |
| 72 | filename = getname(filenamei); |
| 73 | error = PTR_ERR(filename); |
| 74 | if (IS_ERR(filename)) |
| 75 | goto out; |
| 76 | error = do_execve(filename, argv, envp, regs); |
| 77 | putname(filename); |
| 78 | out: |
| 79 | return error; |
| 80 | } |
| 81 | |
| 82 | int kernel_execve(const char *filename, |
| 83 | const char *const argv[], |
| 84 | const char *const envp[]) |
| 85 | { |
| 86 | struct pt_regs regs; |
| 87 | int ret; |
| 88 | |
| 89 | memset(®s, 0, sizeof(struct pt_regs)); |
| 90 | ret = do_execve(filename, |
| 91 | (const char __user *const __user *)argv, |
| 92 | (const char __user *const __user *)envp, ®s); |
| 93 | if (ret < 0) |
| 94 | goto out; |
| 95 | |
| 96 | /* |
| 97 | * Save argc to the register structure for userspace. |
| 98 | */ |
| 99 | regs.ARM_r0 = ret; |
| 100 | |
| 101 | /* |
| 102 | * We were successful. We won't be returning to our caller, but |
| 103 | * instead to user space by manipulating the kernel stack. |
| 104 | */ |
| 105 | asm( "add r0, %0, %1\n\t" |
| 106 | "mov r1, %2\n\t" |
| 107 | "mov r2, %3\n\t" |
| 108 | "bl memmove\n\t" /* copy regs to top of stack */ |
| 109 | "mov r8, #0\n\t" /* not a syscall */ |
| 110 | "mov r9, %0\n\t" /* thread structure */ |
| 111 | "mov sp, r0\n\t" /* reposition stack pointer */ |
| 112 | "b ret_to_user" |
| 113 | : |
| 114 | : "r" (current_thread_info()), |
| 115 | "Ir" (THREAD_START_SP - sizeof(regs)), |
| 116 | "r" (®s), |
| 117 | "Ir" (sizeof(regs)) |
| 118 | : "r0", "r1", "r2", "r3", "ip", "lr", "memory"); |
| 119 | |
| 120 | out: |
| 121 | return ret; |
| 122 | } |
| 123 | EXPORT_SYMBOL(kernel_execve); |
| 124 | |
| 125 | /* |
| 126 | * Since loff_t is a 64 bit type we avoid a lot of ABI hassle |
| 127 | * with a different argument ordering. |
| 128 | */ |
| 129 | asmlinkage long sys_arm_fadvise64_64(int fd, int advice, |
| 130 | loff_t offset, loff_t len) |
| 131 | { |
| 132 | return sys_fadvise64_64(fd, offset, len, advice); |
| 133 | } |