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x86, vdso32: handle 32 bit vDSO larger one page

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This patch enables 32 bit vDSO which are larger than a page.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Link: http://lkml.kernel.org/r/1395094933-14252-14-git-send-email-stefani@seibold.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Stefani Seibold 2014-03-17 23:22:13 +01:00 committed by H. Peter Anvin
parent 008cc907de
commit 4e40112c4f
1 changed files with 15 additions and 7 deletions
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22
arch/x86/vdso/vdso32-setup.c
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@ -16,6 +16,7 @@
#include <linux/mm.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <asm/cpufeature.h>
#include <asm/msr.h>
@ -69,7 +70,8 @@ __setup_param("vdso=", vdso32_setup, vdso_setup, 0);
EXPORT_SYMBOL_GPL(vdso_enabled);
#endif
static struct page *vdso32_pages[1];
static struct page **vdso32_pages;
static unsigned int vdso32_size;
#ifdef CONFIG_X86_64
@ -115,11 +117,10 @@ void enable_sep_cpu(void)
int __init sysenter_setup(void)
{
void *vdso_page = (void *)get_zeroed_page(GFP_ATOMIC);
void *vdso_pages;
const void *vdso;
size_t vdso_len;
vdso32_pages[0] = virt_to_page(vdso_page);
unsigned int i;
if (vdso32_syscall()) {
vdso = &vdso32_syscall_start;
@ -132,8 +133,15 @@ int __init sysenter_setup(void)
vdso_len = &vdso32_int80_end - &vdso32_int80_start;
}
memcpy(vdso_page, vdso, vdso_len);
patch_vdso32(vdso_page, vdso_len);
vdso32_size = (vdso_len + PAGE_SIZE - 1) / PAGE_SIZE;
vdso32_pages = kmalloc(sizeof(*vdso32_pages) * vdso32_size, GFP_ATOMIC);
vdso_pages = kmalloc(VDSO_OFFSET(vdso32_size), GFP_ATOMIC);
for(i = 0; i != vdso32_size; ++i)
vdso32_pages[i] = virt_to_page(vdso_pages + VDSO_OFFSET(i));
memcpy(vdso_pages, vdso, vdso_len);
patch_vdso32(vdso_pages, vdso_len);
return 0;
}
@ -169,7 +177,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
*/
ret = install_special_mapping(mm,
addr,
VDSO_OFFSET(VDSO_PAGES - VDSO_PREV_PAGES),
VDSO_OFFSET(vdso32_size),
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
vdso32_pages);