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Diffstat (limited to 'arch/um/sys-i386/ldt.c')
-rw-r--r--arch/um/sys-i386/ldt.c35
1 files changed, 24 insertions, 11 deletions
diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c
index 5db7737df0f..a939a7ef022 100644
--- a/arch/um/sys-i386/ldt.c
+++ b/arch/um/sys-i386/ldt.c
@@ -7,6 +7,7 @@
#include "linux/slab.h"
#include "linux/types.h"
#include "linux/errno.h"
+#include "linux/spinlock.h"
#include "asm/uaccess.h"
#include "asm/smp.h"
#include "asm/ldt.h"
@@ -386,23 +387,34 @@ static long do_modify_ldt_skas(int func, void __user *ptr,
return ret;
}
-short dummy_list[9] = {0, -1};
-short * host_ldt_entries = NULL;
+static DEFINE_SPINLOCK(host_ldt_lock);
+static short dummy_list[9] = {0, -1};
+static short * host_ldt_entries = NULL;
-void ldt_get_host_info(void)
+static void ldt_get_host_info(void)
{
long ret;
struct ldt_entry * ldt;
+ short *tmp;
int i, size, k, order;
+ spin_lock(&host_ldt_lock);
+
+ if(host_ldt_entries != NULL){
+ spin_unlock(&host_ldt_lock);
+ return;
+ }
host_ldt_entries = dummy_list+1;
+ spin_unlock(&host_ldt_lock);
+
for(i = LDT_PAGES_MAX-1, order=0; i; i>>=1, order++);
ldt = (struct ldt_entry *)
__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
if(ldt == NULL) {
- printk("ldt_get_host_info: couldn't allocate buffer for host ldt\n");
+ printk("ldt_get_host_info: couldn't allocate buffer for host "
+ "ldt\n");
return;
}
@@ -426,11 +438,13 @@ void ldt_get_host_info(void)
host_ldt_entries = dummy_list;
else {
size = (size + 1) * sizeof(dummy_list[0]);
- host_ldt_entries = kmalloc(size, GFP_KERNEL);
- if(host_ldt_entries == NULL) {
- printk("ldt_get_host_info: couldn't allocate host ldt list\n");
+ tmp = kmalloc(size, GFP_KERNEL);
+ if(tmp == NULL) {
+ printk("ldt_get_host_info: couldn't allocate host ldt "
+ "list\n");
goto out_free;
}
+ host_ldt_entries = tmp;
}
for(i=0, k=0; i<ret/LDT_ENTRY_SIZE; i++){
@@ -480,8 +494,7 @@ long init_new_ldt(struct mmu_context_skas * new_mm,
* inherited from the host. All ldt-entries found
* will be reset in the following loop
*/
- if(host_ldt_entries == NULL)
- ldt_get_host_info();
+ ldt_get_host_info();
for(num_p=host_ldt_entries; *num_p != -1; num_p++){
desc.entry_number = *num_p;
err = write_ldt_entry(&new_mm->id, 1, &desc,
@@ -560,6 +573,6 @@ void free_ldt(struct mmu_context_skas * mm)
int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
{
- return(CHOOSE_MODE_PROC(do_modify_ldt_tt, do_modify_ldt_skas, func,
- ptr, bytecount));
+ return CHOOSE_MODE_PROC(do_modify_ldt_tt, do_modify_ldt_skas, func,
+ ptr, bytecount);
}