lkml.org 
[lkml]   [2014]   [Mar]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v23 13/13] x86, vdso32: handle 32 bit vDSO larger one page
Date
This patch enables 32 bit vDSO which are larger than a page.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
---
arch/x86/vdso/vdso32-setup.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)

diff --git a/arch/x86/vdso/vdso32-setup.c b/arch/x86/vdso/vdso32-setup.c
index e10abdf..0bc363a 100644
--- a/arch/x86/vdso/vdso32-setup.c
+++ b/arch/x86/vdso/vdso32-setup.c
@@ -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);
--
1.9.0


\
 
 \ /
  Last update: 2014-03-18 00:21    [W:0.147 / U:3.284 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site