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Commit 2affc857 authored by Paul Mundt's avatar Paul Mundt Committed by Linus Torvalds
Browse files

[PATCH] SH vdso: use install_special_mapping() 



Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c13e4ca2

arch/sh/kernel/vsyscall/vsyscall.c

+9 −49
Original line number Diff line number Diff line
@@ -37,11 +37,12 @@ __setup("vdso=", vdso_setup); 
 * of the ELF DSO images included therein.

 */

extern const char vsyscall_trapa_start, vsyscall_trapa_end;

static void *syscall_page;

static struct page *syscall_pages[1];



int __init vsyscall_init(void)

{

	syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);

	void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);

	syscall_pages[0] = virt_to_page(syscall_page);



	/*

	 * XXX: Map this page to a fixmap entry if we get around
@@ -55,37 +56,10 @@ int __init vsyscall_init(void) 
	return 0;

}



static struct page *syscall_vma_nopage(struct vm_area_struct *vma,

				       unsigned long address, int *type)

{

	unsigned long offset = address - vma->vm_start;

	struct page *page;



	if (address < vma->vm_start || address > vma->vm_end)

		return NOPAGE_SIGBUS;



	page = virt_to_page(syscall_page + offset);



	get_page(page);



	return page;

}



/* Prevent VMA merging */

static void syscall_vma_close(struct vm_area_struct *vma)

{

}



static struct vm_operations_struct syscall_vm_ops = {

	.nopage	= syscall_vma_nopage,

	.close	= syscall_vma_close,

};



/* Setup a VMA at program startup for the vsyscall page */

int arch_setup_additional_pages(struct linux_binprm *bprm,

				int executable_stack)

{

	struct vm_area_struct *vma;

	struct mm_struct *mm = current->mm;

	unsigned long addr;

	int ret;
@@ -97,30 +71,16 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, 
		goto up_fail;

	}



	vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);

	if (!vma) {

		ret = -ENOMEM;

	ret = install_special_mapping(mm, addr, PAGE_SIZE,

				      VM_READ | VM_EXEC |

				      VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC |

				      VM_ALWAYSDUMP,

				      syscall_pages);

	if (unlikely(ret))

		goto up_fail;

	}



	vma->vm_start = addr;

	vma->vm_end = addr + PAGE_SIZE;

	/* MAYWRITE to allow gdb to COW and set breakpoints */

	vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE;

	vma->vm_flags |= mm->def_flags;

	vma->vm_page_prot = protection_map[vma->vm_flags & 7];

	vma->vm_ops = &syscall_vm_ops;

	vma->vm_mm = mm;



	ret = insert_vm_struct(mm, vma);

	if (unlikely(ret)) {

		kmem_cache_free(vm_area_cachep, vma);

		goto up_fail;

	}



	current->mm->context.vdso = (void *)addr;



	mm->total_vm++;

up_fail:

	up_write(&mm->mmap_sem);

	return ret;