From 3185bd26188223195dc2e659a3d00219cad71a0f Mon Sep 17 00:00:00 2001
From: Al Viro <viro@ZenIV.linux.org.uk>
Date: Sat, 20 Oct 2012 15:52:23 +0100
Subject: alpha: separate thread-synchronous flags

... and fix the race in updating unaligned control ones

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/alpha/kernel/osf_sys.c | 25 ++++++++++---------------
 arch/alpha/kernel/process.c |  2 +-
 arch/alpha/kernel/traps.c   |  6 +++---
 3 files changed, 14 insertions(+), 19 deletions(-)

(limited to 'arch/alpha/kernel')

diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index 9eb090582cf1..1e6956a90608 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -793,8 +793,7 @@ SYSCALL_DEFINE5(osf_getsysinfo, unsigned long, op, void __user *, buffer,
  	case GSI_UACPROC:
 		if (nbytes < sizeof(unsigned int))
 			return -EINVAL;
-		w = (current_thread_info()->flags >> ALPHA_UAC_SHIFT) &
-			UAC_BITMASK;
+		w = current_thread_info()->status & UAC_BITMASK;
 		if (put_user(w, (unsigned int __user *)buffer))
 			return -EFAULT;
  		return 1;
@@ -904,24 +903,20 @@ SYSCALL_DEFINE5(osf_setsysinfo, unsigned long, op, void __user *, buffer,
 		break;
 
  	case SSI_NVPAIRS: {
-		unsigned long v, w, i;
-		unsigned int old, new;
+		unsigned __user *p = buffer;
+		unsigned i;
 		
- 		for (i = 0; i < nbytes; ++i) {
+		for (i = 0, p = buffer; i < nbytes; ++i, p += 2) {
+			unsigned v, w, status;
 
- 			if (get_user(v, 2*i + (unsigned int __user *)buffer))
- 				return -EFAULT;
- 			if (get_user(w, 2*i + 1 + (unsigned int __user *)buffer))
+			if (get_user(v, p) || get_user(w, p + 1))
  				return -EFAULT;
  			switch (v) {
  			case SSIN_UACPROC:
-			again:
-				old = current_thread_info()->flags;
-				new = old & ~(UAC_BITMASK << ALPHA_UAC_SHIFT);
-				new = new | (w & UAC_BITMASK) << ALPHA_UAC_SHIFT;
-				if (cmpxchg(&current_thread_info()->flags,
-					    old, new) != old)
-					goto again;
+				w &= UAC_BITMASK;
+				status = current_thread_info()->status;
+				status = (status & ~UAC_BITMASK) | w;
+				current_thread_info()->status = status;
  				break;
  
  			default:
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 4054e0ffe2b2..51987dcf79b8 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -49,7 +49,7 @@ EXPORT_SYMBOL(pm_power_off);
 void
 cpu_idle(void)
 {
-	set_thread_flag(TIF_POLLING_NRFLAG);
+	current_thread_info()->status |= TS_POLLING;
 
 	while (1) {
 		/* FIXME -- EV6 and LCA45 know how to power down
diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c
index 80d987c0e9aa..272666d006df 100644
--- a/arch/alpha/kernel/traps.c
+++ b/arch/alpha/kernel/traps.c
@@ -780,17 +780,17 @@ do_entUnaUser(void __user * va, unsigned long opcode,
 	/* Check the UAC bits to decide what the user wants us to do
 	   with the unaliged access.  */
 
-	if (!test_thread_flag (TIF_UAC_NOPRINT)) {
+	if (!(current_thread_info()->status & TS_UAC_NOPRINT)) {
 		if (__ratelimit(&ratelimit)) {
 			printk("%s(%d): unaligned trap at %016lx: %p %lx %ld\n",
 			       current->comm, task_pid_nr(current),
 			       regs->pc - 4, va, opcode, reg);
 		}
 	}
-	if (test_thread_flag (TIF_UAC_SIGBUS))
+	if ((current_thread_info()->status & TS_UAC_SIGBUS))
 		goto give_sigbus;
 	/* Not sure why you'd want to use this, but... */
-	if (test_thread_flag (TIF_UAC_NOFIX))
+	if ((current_thread_info()->status & TS_UAC_NOFIX))
 		return;
 
 	/* Don't bother reading ds in the access check since we already
-- 
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