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Date: Sat, 13 Jan 2007 21:37:26 -0800 (PST)
From: Roland McGrath <roland@...hat.com>
To: Linus Torvalds <torvalds@...l.org>, Andrew Morton <akpm@...l.org>
Cc: linux-kernel@...r.kernel.org
Subject: [PATCH 10/11] 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: Roland McGrath <roland@...hat.com>
---
arch/x86_64/ia32/syscall32.c | 75 ++++++++++++------------------------------
include/asm-x86_64/proto.h | 1 -
2 files changed, 21 insertions(+), 55 deletions(-)
diff --git a/arch/x86_64/ia32/syscall32.c b/arch/x86_64/ia32/syscall32.c
index 59f1fa1..3939f10 100644
--- a/arch/x86_64/ia32/syscall32.c
+++ b/arch/x86_64/ia32/syscall32.c
@@ -18,68 +18,34 @@ extern unsigned char syscall32_syscall[]
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
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);
diff --git a/include/asm-x86_64/proto.h b/include/asm-x86_64/proto.h
index 6d324b8..a6d2ff5 100644
--- a/include/asm-x86_64/proto.h
+++ b/include/asm-x86_64/proto.h
@@ -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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