diff options
| -rw-r--r-- | arch/um/sys-i386/ldt.c | 36 |
1 files changed, 24 insertions, 12 deletions
diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c index 5db7737df0ff..4a8b4202ef9e 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 +387,33 @@ 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; + struct ldt_entry * ldt, *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 +437,13 @@ 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 +493,7 @@ 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 +572,6 @@ 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); } |