[PATCH] ppc64: Fix PER_LINUX32 behaviour

This patch fixes some bugs in the ppc64 PER_LINUX32 implementation,
noted by Juergen Kreileder:

* uname(2) doesn't respect PER_LINUX32, it returns 'ppc64' instead of 'ppc'
* Child processes of a PER_LINUX32 process don't inherit PER_LINUX32

Along the way I took the opportunity to move things around so that
sys_ppc32.c only has 32-bit syscall emulation functions and to remove
the obsolete "fakeppc" command line option.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 21 insertions, 12 deletions

diff --git a/arch/ppc64/kernel/syscalls.c b/arch/ppc64/kernel/syscalls.c
index f2865ff8d2f..a8cbb202b8c 100644
--- a/arch/ppc64/kernel/syscalls.c
+++ b/arch/ppc64/kernel/syscalls.c
@@ -199,24 +199,33 @@ out:
         return ret;
 }
 
-static int __init set_fakeppc(char *str)
+long ppc64_personality(unsigned long personality)
 {
-        if (*str)
-                return 0;
-        init_task.personality = PER_LINUX32;
-        return 1;
+        long ret;
+
+        if (personality(current->personality) == PER_LINUX32
+            && personality == PER_LINUX)
+                personality = PER_LINUX32;
+        ret = sys_personality(personality);
+        if (ret == PER_LINUX32)
+                ret = PER_LINUX;
+        return ret;
 }
-__setup("fakeppc", set_fakeppc);
 
-asmlinkage int sys_uname(struct old_utsname __user * name)
+long ppc64_newuname(struct new_utsname __user * name)
 {
-        int err = -EFAULT;
-        
+        int err = 0;
+
         down_read(&uts_sem);
-        if (name && !copy_to_user(name, &system_utsname, sizeof (*name)))
-                err = 0;
+        if (copy_to_user(name, &system_utsname, sizeof(*name)))
+                err = -EFAULT;
         up_read(&uts_sem);
-        
+        if (!err && personality(current->personality) == PER_LINUX32) {
+                /* change ppc64 to ppc */
+                if (__put_user(0, name->machine + 3)
+                    || __put_user(0, name->machine + 4))
+                        err = -EFAULT;
+        }
         return err;
 }