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[PATCH] powerpc vDSO: use install_special_mapping 

This patch uses install_special_mapping for the powerpc vDSO setup,
consolidating duplicated code.

Signed-off-by: Roland 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Roland McGrath 2007-02-08 14:20:43 -08:00 committed by Linus Torvalds
parent dc5882b20a
commit c13e4ca247
1 changed files with 27 additions and 77 deletions
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104
arch/powerpc/kernel/vdso.c
View File

@ -49,9 +49,13 @@
/* Max supported size for symbol names */
#define MAX_SYMNAME 64
#define VDSO32_MAXPAGES (((0x3000 + PAGE_MASK) >> PAGE_SHIFT) + 2)
#define VDSO64_MAXPAGES (((0x3000 + PAGE_MASK) >> PAGE_SHIFT) + 2)
extern char vdso32_start, vdso32_end;
static void *vdso32_kbase = &vdso32_start;
unsigned int vdso32_pages;
static struct page *vdso32_pagelist[VDSO32_MAXPAGES];
unsigned long vdso32_sigtramp;
unsigned long vdso32_rt_sigtramp;
@ -59,6 +63,7 @@ unsigned long vdso32_rt_sigtramp;
extern char vdso64_start, vdso64_end;
static void *vdso64_kbase = &vdso64_start;
unsigned int vdso64_pages;
static struct page *vdso64_pagelist[VDSO64_MAXPAGES];
unsigned long vdso64_rt_sigtramp;
#endif /* CONFIG_PPC64 */
@ -164,55 +169,6 @@ static void dump_vdso_pages(struct vm_area_struct * vma)
}
#endif /* DEBUG */
/*
* Keep a dummy vma_close for now, it will prevent VMA merging.
*/
static void vdso_vma_close(struct vm_area_struct * vma)
{
}
/*
* Our nopage() function, maps in the actual vDSO kernel pages, they will
* be mapped read-only by do_no_page(), and eventually COW'ed, either
* right away for an initial write access, or by do_wp_page().
*/
static struct page * vdso_vma_nopage(struct vm_area_struct * vma,
unsigned long address, int *type)
{
unsigned long offset = address - vma->vm_start;
struct page *pg;
#ifdef CONFIG_PPC64
void *vbase = (vma->vm_mm->task_size > TASK_SIZE_USER32) ?
vdso64_kbase : vdso32_kbase;
#else
void *vbase = vdso32_kbase;
#endif
DBG("vdso_vma_nopage(current: %s, address: %016lx, off: %lx)\n",
current->comm, address, offset);
if (address < vma->vm_start || address > vma->vm_end)
return NOPAGE_SIGBUS;
/*
* Last page is systemcfg.
*/
if ((vma->vm_end - address) <= PAGE_SIZE)
pg = virt_to_page(vdso_data);
else
pg = virt_to_page(vbase + offset);
get_page(pg);
DBG(" ->page count: %d\n", page_count(pg));
return pg;
}
static struct vm_operations_struct vdso_vmops = {
.close = vdso_vma_close,
.nopage = vdso_vma_nopage,
};
/*
* This is called from binfmt_elf, we create the special vma for the
* vDSO and insert it into the mm struct tree
@ -221,20 +177,23 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
int executable_stack)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
struct page **vdso_pagelist;
unsigned long vdso_pages;
unsigned long vdso_base;
int rc;
#ifdef CONFIG_PPC64
if (test_thread_flag(TIF_32BIT)) {
vdso_pagelist = vdso32_pagelist;
vdso_pages = vdso32_pages;
vdso_base = VDSO32_MBASE;
} else {
vdso_pagelist = vdso64_pagelist;
vdso_pages = vdso64_pages;
vdso_base = VDSO64_MBASE;
}
#else
vdso_pagelist = vdso32_pagelist;
vdso_pages = vdso32_pages;
vdso_base = VDSO32_MBASE;
#endif
@ -262,17 +221,6 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
goto fail_mmapsem;
}
/* Allocate a VMA structure and fill it up */
vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
if (vma == NULL) {
rc = -ENOMEM;
goto fail_mmapsem;
}
vma->vm_mm = mm;
vma->vm_start = vdso_base;
vma->vm_end = vma->vm_start + (vdso_pages << PAGE_SHIFT);
/*
* our vma flags don't have VM_WRITE so by default, the process isn't
* allowed to write those pages.
@ -282,32 +230,26 @@ int arch_setup_additional_pages(struct linux_binprm *bprm,
* and your nice userland gettimeofday will be totally dead.
* It's fine to use that for setting breakpoints in the vDSO code
* pages though
*/
vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC;
/*
*
* 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 & 0x7];
vma->vm_ops = &vdso_vmops;
/* Insert new VMA */
rc = insert_vm_struct(mm, vma);
rc = install_special_mapping(mm, vdso_base, vdso_pages << PAGE_SHIFT,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
VM_ALWAYSDUMP,
vdso_pagelist);
if (rc)
goto fail_vma;
goto fail_mmapsem;
/* Put vDSO base into mm struct and account for memory usage */
/* Put vDSO base into mm struct */
current->mm->context.vdso_base = vdso_base;
mm->total_vm += (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
up_write(&mm->mmap_sem);
return 0;
fail_vma:
kmem_cache_free(vm_area_cachep, vma);
fail_mmapsem:
up_write(&mm->mmap_sem);
return rc;
@ -778,18 +720,26 @@ void __init vdso_init(void)
}
/* Make sure pages are in the correct state */
BUG_ON(vdso32_pages + 2 > VDSO32_MAXPAGES);
for (i = 0; i < vdso32_pages; i++) {
struct page *pg = virt_to_page(vdso32_kbase + i*PAGE_SIZE);
ClearPageReserved(pg);
get_page(pg);
vdso32_pagelist[i] = pg;
}
vdso32_pagelist[i++] = virt_to_page(vdso_data);
vdso32_pagelist[i] = NULL;
#ifdef CONFIG_PPC64
BUG_ON(vdso64_pages + 2 > VDSO64_MAXPAGES);
for (i = 0; i < vdso64_pages; i++) {
struct page *pg = virt_to_page(vdso64_kbase + i*PAGE_SIZE);
ClearPageReserved(pg);
get_page(pg);
vdso64_pagelist[i] = pg;
}
vdso64_pagelist[i++] = virt_to_page(vdso_data);
vdso64_pagelist[i] = NULL;
#endif /* CONFIG_PPC64 */
get_page(virt_to_page(vdso_data));