Subject: [PATCH] Fix getxpid on alpha to use getpid and getppid.
From: Eric W. Biederman <ebiederman@lnxi.com>
Date: 1129752689 -0600

The code was wrong for threaded programs even without put my pspace work.

---

 arch/alpha/kernel/entry.S   |   21 +++++++--------------
 arch/alpha/kernel/process.c |   11 +++++++++++
 kernel/timer.c              |   14 +++++++-------
 3 files changed, 25 insertions(+), 21 deletions(-)

6c6ee86578ba876ab0b85cb2089794da5e06c86a
diff --git a/arch/alpha/kernel/entry.S b/arch/alpha/kernel/entry.S
index e38671c..780cb93 100644
--- a/arch/alpha/kernel/entry.S
+++ b/arch/alpha/kernel/entry.S
@@ -874,22 +874,15 @@ sys_getxgid:
 	.globl	sys_getxpid
 	.ent	sys_getxpid
 sys_getxpid:
+	lda	$sp, -16($sp)
+	stq	$26, 0($sp)
 	.prologue 0
-	ldq	$2, TI_TASK($8)
 
-	/* See linux/kernel/timer.c sys_getppid for discussion
-	   about this loop.  */
-	ldq	$3, TASK_REAL_PARENT($2)
-1:	ldl	$1, TASK_TGID($3)
-#ifdef CONFIG_SMP
-	mov	$3, $4
-	mb
-	ldq	$3, TASK_REAL_PARENT($2)
-	cmpeq	$3, $4, $4
-	beq	$4, 1b
-#endif
-	stq	$1, 80($sp)
-	ldl	$0, TASK_TGID($2)
+	lda	$16, 96($sp)
+	jsr	$26, do_getxpid
+	ldq	$26, 0($sp)
+
+	lda	$sp, 16($sp)
 	ret
 .end sys_getxpid
 
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index eb20c3a..dd7baf0 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -31,6 +31,7 @@
 #include <linux/reboot.h>
 #include <linux/tty.h>
 #include <linux/console.h>
+#include <linux/syscall.h>
 
 #include <asm/reg.h>
 #include <asm/uaccess.h>
@@ -527,3 +528,13 @@ get_wchan(struct task_struct *p)
 	}
 	return pc;
 }
+
+asmlinkage long do_getxpid(long *ppid)
+{
+	/* The assembly version as getting out of sync with
+	 * sys_getpid and sys_getppid in timer.c so just call
+	 * them and stop optimizing infrequently called functions.
+	 */
+	*ppid = sys_getppid();
+	return sys_getpid();
+}
diff --git a/kernel/timer.c b/kernel/timer.c
index b56659f..72b5e6d 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -979,13 +979,6 @@ asmlinkage unsigned long sys_alarm(unsig
 
 #endif
 
-#ifndef __alpha__
-
-/*
- * The Alpha uses getxpid, getxuid, and getxgid instead.  Maybe this
- * should be moved into arch/i386 instead?
- */
-
 /**
  * sys_getpid - return the thread group id of the current process
  *
@@ -1044,6 +1037,13 @@ asmlinkage long sys_getppid(void)
 	return pid_to_user(pid);
 }
 
+#ifndef __alpha__
+
+/*
+ * The Alpha uses getxpid, getxuid, and getxgid instead.  
+ * And is suffering bit-rot because of the difference.
+ */
+
 asmlinkage long sys_getuid(void)
 {
 	/* Only we change this so SMP safe */
-- 
1.0.GIT