Commit dc5882b2 authored by Roland McGrath's avatar Roland McGrath Committed by Linus Torvalds
Browse files

[PATCH] x86_64 ia32 vDSO: use install_special_mapping



This patch uses install_special_mapping for the ia32 vDSO setup, consolidating
duplicated code.
Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7d91d531
......@@ -18,68 +18,34 @@ extern unsigned char syscall32_syscall[], syscall32_syscall_end[];
extern unsigned char syscall32_sysenter[], syscall32_sysenter_end[];
extern int sysctl_vsyscall32;
char *syscall32_page;
static struct page *syscall32_pages[1];
static int use_sysenter = -1;
static struct page *
syscall32_nopage(struct vm_area_struct *vma, unsigned long adr, int *type)
{
struct page *p = virt_to_page(adr - vma->vm_start + syscall32_page);
get_page(p);
return p;
}
/* Prevent VMA merging */
static void syscall32_vma_close(struct vm_area_struct *vma)
{
}
static struct vm_operations_struct syscall32_vm_ops = {
.close = syscall32_vma_close,
.nopage = syscall32_nopage,
};
struct linux_binprm;
/* Setup a VMA at program startup for the vsyscall page */
int syscall32_setup_pages(struct linux_binprm *bprm, int exstack)
{
int npages = (VSYSCALL32_END - VSYSCALL32_BASE) >> PAGE_SHIFT;
struct vm_area_struct *vma;
struct mm_struct *mm = current->mm;
int ret;
vma = kmem_cache_alloc(vm_area_cachep, GFP_KERNEL);
if (!vma)
return -ENOMEM;
memset(vma, 0, sizeof(struct vm_area_struct));
/* Could randomize here */
vma->vm_start = VSYSCALL32_BASE;
vma->vm_end = VSYSCALL32_END;
/* MAYWRITE to allow gdb to COW and set breakpoints */
vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE;
down_write(&mm->mmap_sem);
/*
* MAYWRITE to allow gdb to COW and set breakpoints
*
* Make sure the vDSO gets into every core dump.
* Dumping its contents makes post-mortem fully interpretable later
* without matching up the same kernel and hardware config to see
* what PC values meant.
*/
vma->vm_flags |= VM_ALWAYSDUMP;
vma->vm_flags |= mm->def_flags;
vma->vm_page_prot = protection_map[vma->vm_flags & 7];
vma->vm_ops = &syscall32_vm_ops;
vma->vm_mm = mm;
down_write(&mm->mmap_sem);
if ((ret = insert_vm_struct(mm, vma))) {
up_write(&mm->mmap_sem);
kmem_cache_free(vm_area_cachep, vma);
return ret;
}
mm->total_vm += npages;
/* Could randomize here */
ret = install_special_mapping(mm, VSYSCALL32_BASE, PAGE_SIZE,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
VM_ALWAYSDUMP,
syscall32_pages);
up_write(&mm->mmap_sem);
return 0;
return ret;
}
const char *arch_vma_name(struct vm_area_struct *vma)
......@@ -92,9 +58,10 @@ const char *arch_vma_name(struct vm_area_struct *vma)
static int __init init_syscall32(void)
{
syscall32_page = (void *)get_zeroed_page(GFP_KERNEL);
char *syscall32_page = (void *)get_zeroed_page(GFP_KERNEL);
if (!syscall32_page)
panic("Cannot allocate syscall32 page");
syscall32_pages[0] = virt_to_page(syscall32_page);
if (use_sysenter > 0) {
memcpy(syscall32_page, syscall32_sysenter,
syscall32_sysenter_end - syscall32_sysenter);
......
......@@ -81,7 +81,6 @@ extern void swap_low_mappings(void);
extern void __show_regs(struct pt_regs * regs);
extern void show_regs(struct pt_regs * regs);
extern char *syscall32_page;
extern void syscall32_cpu_init(void);
extern void setup_node_bootmem(int nodeid, unsigned long start, unsigned long end);
......
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