David Daney | c52d0d3 | 2010-02-18 16:13:04 -0800 | [diff] [blame] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | * |
| 6 | * Copyright (C) 2009, 2010 Cavium Networks, Inc. |
| 7 | */ |
| 8 | |
| 9 | |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/err.h> |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/mm.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/binfmts.h> |
| 16 | #include <linux/elf.h> |
| 17 | #include <linux/vmalloc.h> |
| 18 | #include <linux/unistd.h> |
| 19 | |
| 20 | #include <asm/vdso.h> |
| 21 | #include <asm/uasm.h> |
| 22 | |
| 23 | /* |
| 24 | * Including <asm/unistd.h> would give use the 64-bit syscall numbers ... |
| 25 | */ |
| 26 | #define __NR_O32_sigreturn 4119 |
| 27 | #define __NR_O32_rt_sigreturn 4193 |
| 28 | #define __NR_N32_rt_sigreturn 6211 |
| 29 | |
| 30 | static struct page *vdso_page; |
| 31 | |
| 32 | static void __init install_trampoline(u32 *tramp, unsigned int sigreturn) |
| 33 | { |
| 34 | uasm_i_addiu(&tramp, 2, 0, sigreturn); /* li v0, sigreturn */ |
| 35 | uasm_i_syscall(&tramp, 0); |
| 36 | } |
| 37 | |
| 38 | static int __init init_vdso(void) |
| 39 | { |
| 40 | struct mips_vdso *vdso; |
| 41 | |
| 42 | vdso_page = alloc_page(GFP_KERNEL); |
| 43 | if (!vdso_page) |
| 44 | panic("Cannot allocate vdso"); |
| 45 | |
| 46 | vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL); |
| 47 | if (!vdso) |
| 48 | panic("Cannot map vdso"); |
| 49 | clear_page(vdso); |
| 50 | |
| 51 | install_trampoline(vdso->rt_signal_trampoline, __NR_rt_sigreturn); |
| 52 | #ifdef CONFIG_32BIT |
| 53 | install_trampoline(vdso->signal_trampoline, __NR_sigreturn); |
| 54 | #else |
| 55 | install_trampoline(vdso->n32_rt_signal_trampoline, |
| 56 | __NR_N32_rt_sigreturn); |
| 57 | install_trampoline(vdso->o32_signal_trampoline, __NR_O32_sigreturn); |
| 58 | install_trampoline(vdso->o32_rt_signal_trampoline, |
| 59 | __NR_O32_rt_sigreturn); |
| 60 | #endif |
| 61 | |
| 62 | vunmap(vdso); |
| 63 | |
David Daney | c52d0d3 | 2010-02-18 16:13:04 -0800 | [diff] [blame] | 64 | return 0; |
| 65 | } |
David Daney | 1ed8453 | 2010-06-16 15:00:28 -0700 | [diff] [blame] | 66 | subsys_initcall(init_vdso); |
David Daney | c52d0d3 | 2010-02-18 16:13:04 -0800 | [diff] [blame] | 67 | |
| 68 | static unsigned long vdso_addr(unsigned long start) |
| 69 | { |
| 70 | return STACK_TOP; |
| 71 | } |
| 72 | |
| 73 | int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp) |
| 74 | { |
| 75 | int ret; |
| 76 | unsigned long addr; |
| 77 | struct mm_struct *mm = current->mm; |
| 78 | |
| 79 | down_write(&mm->mmap_sem); |
| 80 | |
| 81 | addr = vdso_addr(mm->start_stack); |
| 82 | |
| 83 | addr = get_unmapped_area(NULL, addr, PAGE_SIZE, 0, 0); |
| 84 | if (IS_ERR_VALUE(addr)) { |
| 85 | ret = addr; |
| 86 | goto up_fail; |
| 87 | } |
| 88 | |
| 89 | ret = install_special_mapping(mm, addr, PAGE_SIZE, |
| 90 | VM_READ|VM_EXEC| |
| 91 | VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC| |
| 92 | VM_ALWAYSDUMP, |
| 93 | &vdso_page); |
| 94 | |
| 95 | if (ret) |
| 96 | goto up_fail; |
| 97 | |
| 98 | mm->context.vdso = (void *)addr; |
| 99 | |
| 100 | up_fail: |
| 101 | up_write(&mm->mmap_sem); |
| 102 | return ret; |
| 103 | } |
| 104 | |
| 105 | const char *arch_vma_name(struct vm_area_struct *vma) |
| 106 | { |
| 107 | if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) |
| 108 | return "[vdso]"; |
| 109 | return NULL; |
| 110 | } |