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- /*
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 2009, 2010 Cavium Networks, Inc.
- */
- #include <linux/kernel.h>
- #include <linux/err.h>
- #include <linux/sched.h>
- #include <linux/mm.h>
- #include <linux/init.h>
- #include <linux/binfmts.h>
- #include <linux/elf.h>
- #include <linux/vmalloc.h>
- #include <linux/unistd.h>
- #include <linux/random.h>
- #include <asm/vdso.h>
- #include <asm/uasm.h>
- #include <asm/processor.h>
- /*
- * Including <asm/unistd.h> would give use the 64-bit syscall numbers ...
- */
- #define __NR_O32_sigreturn 4119
- #define __NR_O32_rt_sigreturn 4193
- #define __NR_N32_rt_sigreturn 6211
- static struct page *vdso_page;
- static void __init install_trampoline(u32 *tramp, unsigned int sigreturn)
- {
- uasm_i_addiu(&tramp, 2, 0, sigreturn); /* li v0, sigreturn */
- uasm_i_syscall(&tramp, 0);
- }
- static int __init init_vdso(void)
- {
- struct mips_vdso *vdso;
- vdso_page = alloc_page(GFP_KERNEL);
- if (!vdso_page)
- panic("Cannot allocate vdso");
- vdso = vmap(&vdso_page, 1, 0, PAGE_KERNEL);
- if (!vdso)
- panic("Cannot map vdso");
- clear_page(vdso);
- install_trampoline(vdso->rt_signal_trampoline, __NR_rt_sigreturn);
- #ifdef CONFIG_32BIT
- install_trampoline(vdso->signal_trampoline, __NR_sigreturn);
- #else
- install_trampoline(vdso->n32_rt_signal_trampoline,
- __NR_N32_rt_sigreturn);
- install_trampoline(vdso->o32_signal_trampoline, __NR_O32_sigreturn);
- install_trampoline(vdso->o32_rt_signal_trampoline,
- __NR_O32_rt_sigreturn);
- #endif
- vunmap(vdso);
- return 0;
- }
- subsys_initcall(init_vdso);
- static unsigned long vdso_addr(unsigned long start)
- {
- unsigned long offset = 0UL;
- if (current->flags & PF_RANDOMIZE) {
- offset = get_random_int();
- offset <<= PAGE_SHIFT;
- if (TASK_IS_32BIT_ADDR)
- offset &= 0xfffffful;
- else
- offset &= 0xffffffful;
- }
- return STACK_TOP + offset;
- }
- int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
- {
- int ret;
- unsigned long addr;
- struct mm_struct *mm = current->mm;
- down_write(&mm->mmap_sem);
- addr = vdso_addr(mm->start_stack);
- addr = get_unmapped_area(NULL, addr, PAGE_SIZE, 0, 0);
- if (IS_ERR_VALUE(addr)) {
- ret = addr;
- goto up_fail;
- }
- ret = install_special_mapping(mm, addr, PAGE_SIZE,
- VM_READ|VM_EXEC|
- VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
- &vdso_page);
- if (ret)
- goto up_fail;
- mm->context.vdso = (void *)addr;
- up_fail:
- up_write(&mm->mmap_sem);
- return ret;
- }
- const char *arch_vma_name(struct vm_area_struct *vma)
- {
- if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
- return "[vdso]";
- return NULL;
- }
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