[PARISC] Allow overriding personality with sys_personality

And now suddenly, linux32 works on parisc...

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/arch/parisc/kernel/sys_parisc.c b/arch/parisc/kernel/sys_parisc.c
index 8b5df98e2b31..1db5588ceacf 100644
--- a/arch/parisc/kernel/sys_parisc.c
+++ b/arch/parisc/kernel/sys_parisc.c
@@ -31,6 +31,8 @@
 #include <linux/shm.h>
 #include <linux/smp_lock.h>
 #include <linux/syscalls.h>
+#include <linux/utsname.h>
+#include <linux/personality.h>
 
 int sys_pipe(int __user *fildes)
 {
@@ -248,3 +250,46 @@ asmlinkage int sys_free_hugepages(unsigned long addr)
 {
         return -EINVAL;
 }
+
+long parisc_personality(unsigned long personality)
+{
+        long err;
+
+        if (personality(current->personality) == PER_LINUX32
+            && personality == PER_LINUX)
+                personality = PER_LINUX32;
+
+        err = sys_personality(personality);
+        if (err == PER_LINUX32)
+                err = PER_LINUX;
+
+        return err;
+}
+
+static inline int override_machine(char __user *mach) {
+#ifdef CONFIG_COMPAT
+        if (personality(current->personality) == PER_LINUX32) {
+                if (__put_user(0, mach + 6) ||
+                    __put_user(0, mach + 7))
+                        return -EFAULT;
+        }
+
+        return 0;
+#else /*!CONFIG_COMPAT*/
+        return 0;
+#endif /*CONFIG_COMPAT*/
+}
+
+long parisc_newuname(struct new_utsname __user *utsname)
+{
+        int err = 0;
+
+        down_read(&uts_sem);
+        if (copy_to_user(utsname, &system_utsname, sizeof(*utsname)))
+                err = -EFAULT;
+        up_read(&uts_sem);
+
+        err = override_machine(utsname->machine);
+
+        return (long)err;
+}