x86-64, vdso: Do not allocate memory for the vDSO
We can map the vDSO straight from kernel data, saving a few page
allocations. As an added bonus, the deleted code contained a memory
leak.
Signed-off-by: Andy Lutomirski <luto@mit.edu>
Link: http://lkml.kernel.org/r/2c4ed5c2c2e93603790229e0c3403ae506ccc0cb.1311277573.git.luto@mit.edu
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index c39938d..316fbca 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -14,13 +14,14 @@
#include <asm/vgtod.h>
#include <asm/proto.h>
#include <asm/vdso.h>
+#include <asm/page.h>
unsigned int __read_mostly vdso_enabled = 1;
extern char vdso_start[], vdso_end[];
extern unsigned short vdso_sync_cpuid;
-static struct page **vdso_pages;
+extern struct page *vdso_pages[];
static unsigned vdso_size;
static void __init patch_vdso(void *vdso, size_t len)
@@ -54,7 +55,7 @@
apply_alternatives(alt_data, alt_data + alt_sec->sh_size);
}
-static int __init init_vdso_vars(void)
+static int __init init_vdso(void)
{
int npages = (vdso_end - vdso_start + PAGE_SIZE - 1) / PAGE_SIZE;
int i;
@@ -62,26 +63,12 @@
patch_vdso(vdso_start, vdso_end - vdso_start);
vdso_size = npages << PAGE_SHIFT;
- vdso_pages = kmalloc(sizeof(struct page *) * npages, GFP_KERNEL);
- if (!vdso_pages)
- goto oom;
- for (i = 0; i < npages; i++) {
- struct page *p;
- p = alloc_page(GFP_KERNEL);
- if (!p)
- goto oom;
- vdso_pages[i] = p;
- copy_page(page_address(p), vdso_start + i*PAGE_SIZE);
- }
+ for (i = 0; i < npages; i++)
+ vdso_pages[i] = virt_to_page(vdso_start + i*PAGE_SIZE);
return 0;
-
- oom:
- printk("Cannot allocate vdso\n");
- vdso_enabled = 0;
- return -ENOMEM;
}
-subsys_initcall(init_vdso_vars);
+subsys_initcall(init_vdso);
struct linux_binprm;