summaryrefslogtreecommitdiffstats
path: root/arch/um/sys-i386/ldt.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/um/sys-i386/ldt.c')
-rw-r--r--arch/um/sys-i386/ldt.c114
1 files changed, 62 insertions, 52 deletions
diff --git a/arch/um/sys-i386/ldt.c b/arch/um/sys-i386/ldt.c
index dc755b0b9db..bd3c34aa52e 100644
--- a/arch/um/sys-i386/ldt.c
+++ b/arch/um/sys-i386/ldt.c
@@ -4,96 +4,106 @@
*/
#include "linux/config.h"
+#include "linux/sched.h"
#include "linux/slab.h"
+#include "linux/types.h"
#include "asm/uaccess.h"
#include "asm/ptrace.h"
+#include "asm/smp.h"
+#include "asm/ldt.h"
#include "choose-mode.h"
#include "kern.h"
+#include "mode_kern.h"
#ifdef CONFIG_MODE_TT
-extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
-/* XXX this needs copy_to_user and copy_from_user */
+extern int modify_ldt(int func, void *ptr, unsigned long bytecount);
-int sys_modify_ldt_tt(int func, void __user *ptr, unsigned long bytecount)
+static int do_modify_ldt_tt(int func, void *ptr, unsigned long bytecount)
{
- if (!access_ok(VERIFY_READ, ptr, bytecount))
- return -EFAULT;
-
return modify_ldt(func, ptr, bytecount);
}
+
#endif
#ifdef CONFIG_MODE_SKAS
-extern int userspace_pid[];
+#include "skas.h"
#include "skas_ptrace.h"
-int sys_modify_ldt_skas(int func, void __user *ptr, unsigned long bytecount)
+static int do_modify_ldt_skas(int func, void *ptr, unsigned long bytecount)
{
struct ptrace_ldt ldt;
- void *buf;
- int res, n;
+ u32 cpu;
+ int res;
- buf = kmalloc(bytecount, GFP_KERNEL);
- if(buf == NULL)
- return(-ENOMEM);
+ ldt = ((struct ptrace_ldt) { .func = func,
+ .ptr = ptr,
+ .bytecount = bytecount });
- res = 0;
+ cpu = get_cpu();
+ res = ptrace(PTRACE_LDT, userspace_pid[cpu], 0, (unsigned long) &ldt);
+ put_cpu();
+
+ return res;
+}
+#endif
+
+int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
+{
+ struct user_desc info;
+ int res = 0;
+ void *buf = NULL;
+ void *p = NULL; /* What we pass to host. */
switch(func){
case 1:
- case 0x11:
- res = copy_from_user(buf, ptr, bytecount);
- break;
- }
+ case 0x11: /* write_ldt */
+ /* Do this check now to avoid overflows. */
+ if (bytecount != sizeof(struct user_desc)) {
+ res = -EINVAL;
+ goto out;
+ }
+
+ if(copy_from_user(&info, ptr, sizeof(info))) {
+ res = -EFAULT;
+ goto out;
+ }
- if(res != 0){
- res = -EFAULT;
+ p = &info;
+ break;
+ case 0:
+ case 2: /* read_ldt */
+
+ /* The use of info avoids kmalloc on the write case, not on the
+ * read one. */
+ buf = kmalloc(bytecount, GFP_KERNEL);
+ if (!buf) {
+ res = -ENOMEM;
+ goto out;
+ }
+ p = buf;
+ default:
+ res = -ENOSYS;
goto out;
}
- ldt = ((struct ptrace_ldt) { .func = func,
- .ptr = buf,
- .bytecount = bytecount });
-#warning Need to look up userspace_pid by cpu
- res = ptrace(PTRACE_LDT, userspace_pid[0], 0, (unsigned long) &ldt);
+ res = CHOOSE_MODE_PROC(do_modify_ldt_tt, do_modify_ldt_skas, func,
+ p, bytecount);
if(res < 0)
goto out;
switch(func){
case 0:
case 2:
- n = res;
- res = copy_to_user(ptr, buf, n);
- if(res != 0)
+ /* Modify_ldt was for reading and returned the number of read
+ * bytes.*/
+ if(copy_to_user(ptr, p, res))
res = -EFAULT;
- else
- res = n;
break;
}
- out:
+out:
kfree(buf);
- return(res);
-}
-#endif
-
-int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
-{
- return(CHOOSE_MODE_PROC(sys_modify_ldt_tt, sys_modify_ldt_skas, func,
- ptr, bytecount));
+ return res;
}
-
-
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only. This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */