10 files changed, 30 insertions, 13 deletions

diff --git a/include/asm-arm/thread_info.h b/include/asm-arm/thread_info.h
index d9b8bddc8732..5014794f9eb3 100644
--- a/include/asm-arm/thread_info.h
+++ b/include/asm-arm/thread_info.h
@@ -147,6 +147,7 @@ extern void iwmmxt_task_switch(struct thread_info *);
 #define TIF_POLLING_NRFLAG      16
 #define TIF_USING_IWMMXT        17
 #define TIF_MEMDIE              18
+#define TIF_FREEZE              19
 
 #define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
 #define _TIF_SIGPENDING         (1 << TIF_SIGPENDING)
@@ -154,6 +155,7 @@ extern void iwmmxt_task_switch(struct thread_info *);
 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
 #define _TIF_POLLING_NRFLAG     (1 << TIF_POLLING_NRFLAG)
 #define _TIF_USING_IWMMXT       (1 << TIF_USING_IWMMXT)
+#define _TIF_FREEZE             (1 << TIF_FREEZE)
 
 /*
  * Change these and you break ASM code in entry-common.S
diff --git a/include/asm-frv/thread_info.h b/include/asm-frv/thread_info.h
index d66c48e6ef14..d881f518e6a9 100644
--- a/include/asm-frv/thread_info.h
+++ b/include/asm-frv/thread_info.h
@@ -116,6 +116,7 @@ register struct thread_info *__current_thread_info asm("gr15");
 #define TIF_RESTORE_SIGMASK     6       /* restore signal mask in do_signal() */
 #define TIF_POLLING_NRFLAG      16      /* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE              17      /* OOM killer killed process */
+#define TIF_FREEZE              18      /* freezing for suspend */
 
 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
 #define _TIF_NOTIFY_RESUME      (1 << TIF_NOTIFY_RESUME)
@@ -125,6 +126,7 @@ register struct thread_info *__current_thread_info asm("gr15");
 #define _TIF_IRET               (1 << TIF_IRET)
 #define _TIF_RESTORE_SIGMASK    (1 << TIF_RESTORE_SIGMASK)
 #define _TIF_POLLING_NRFLAG     (1 << TIF_POLLING_NRFLAG)
+#define _TIF_FREEZE             (1 << TIF_FREEZE)
 
 #define _TIF_WORK_MASK          0x0000FFFE      /* work to do on interrupt/exception return */
 #define _TIF_ALLWORK_MASK       0x0000FFFF      /* work to do on any return to u-space */
diff --git a/include/asm-i386/thread_info.h b/include/asm-i386/thread_info.h
index 46d32ad92082..4b187bb377b4 100644
--- a/include/asm-i386/thread_info.h
+++ b/include/asm-i386/thread_info.h
@@ -134,6 +134,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_MEMDIE              16
 #define TIF_DEBUG               17      /* uses debug registers */
 #define TIF_IO_BITMAP           18      /* uses I/O bitmap */
+#define TIF_FREEZE              19      /* is freezing for suspend */
 
 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
@@ -147,6 +148,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
 #define _TIF_DEBUG              (1<<TIF_DEBUG)
 #define _TIF_IO_BITMAP          (1<<TIF_IO_BITMAP)
+#define _TIF_FREEZE             (1<<TIF_FREEZE)
 
 /* work to do on interrupt/exception return */
 #define _TIF_WORK_MASK \
diff --git a/include/asm-ia64/thread_info.h b/include/asm-ia64/thread_info.h
index 8adcde0934ca..9b505b25544f 100644
--- a/include/asm-ia64/thread_info.h
+++ b/include/asm-ia64/thread_info.h
@@ -88,6 +88,7 @@ struct thread_info {
 #define TIF_MEMDIE              17
 #define TIF_MCA_INIT            18      /* this task is processing MCA or INIT */
 #define TIF_DB_DISABLED         19      /* debug trap disabled for fsyscall */
+#define TIF_FREEZE              20      /* is freezing for suspend */
 
 #define _TIF_SYSCALL_TRACE      (1 << TIF_SYSCALL_TRACE)
 #define _TIF_SYSCALL_AUDIT      (1 << TIF_SYSCALL_AUDIT)
@@ -98,6 +99,7 @@ struct thread_info {
 #define _TIF_POLLING_NRFLAG     (1 << TIF_POLLING_NRFLAG)
 #define _TIF_MCA_INIT           (1 << TIF_MCA_INIT)
 #define _TIF_DB_DISABLED        (1 << TIF_DB_DISABLED)
+#define _TIF_FREEZE             (1 << TIF_FREEZE)
 
 /* "work to do on user-return" bits */
 #define TIF_ALLWORK_MASK        (_TIF_NOTIFY_RESUME|_TIF_SIGPENDING|_TIF_NEED_RESCHED|_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
diff --git a/include/asm-powerpc/thread_info.h b/include/asm-powerpc/thread_info.h
index d339e2e88b11..3f32ca8bfec9 100644
--- a/include/asm-powerpc/thread_info.h
+++ b/include/asm-powerpc/thread_info.h
@@ -122,6 +122,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_RESTOREALL          12      /* Restore all regs (implies NOERROR) */
 #define TIF_NOERROR             14      /* Force successful syscall return */
 #define TIF_RESTORE_SIGMASK     15      /* Restore signal mask in do_signal */
+#define TIF_FREEZE              16      /* Freezing for suspend */
 
 /* as above, but as bit values */
 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
@@ -138,6 +139,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_RESTOREALL         (1<<TIF_RESTOREALL)
 #define _TIF_NOERROR            (1<<TIF_NOERROR)
 #define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
+#define _TIF_FREEZE             (1<<TIF_FREEZE)
 #define _TIF_SYSCALL_T_OR_A     (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP)
 
 #define _TIF_USER_WORK_MASK     (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | \
diff --git a/include/asm-sh/thread_info.h b/include/asm-sh/thread_info.h
index 0c01dc550819..879f741105db 100644
--- a/include/asm-sh/thread_info.h
+++ b/include/asm-sh/thread_info.h
@@ -106,6 +106,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_USEDFPU             16      /* FPU was used by this task this quantum (SMP) */
 #define TIF_POLLING_NRFLAG      17      /* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE              18
+#define TIF_FREEZE              19
 
 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
@@ -114,6 +115,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_RESTORE_SIGMASK    (1<<TIF_RESTORE_SIGMASK)
 #define _TIF_USEDFPU            (1<<TIF_USEDFPU)
 #define _TIF_POLLING_NRFLAG     (1<<TIF_POLLING_NRFLAG)
+#define _TIF_FREEZE             (1<<TIF_FREEZE)
 
 #define _TIF_WORK_MASK          0x000000FE      /* work to do on interrupt/exception return */
 #define _TIF_ALLWORK_MASK       0x000000FF      /* work to do on any return to u-space */
diff --git a/include/asm-x86_64/thread_info.h b/include/asm-x86_64/thread_info.h
index 787a08114b48..74a6c74397f7 100644
--- a/include/asm-x86_64/thread_info.h
+++ b/include/asm-x86_64/thread_info.h
@@ -122,6 +122,7 @@ static inline struct thread_info *stack_thread_info(void)
 #define TIF_MEMDIE              20
 #define TIF_DEBUG               21      /* uses debug registers */
 #define TIF_IO_BITMAP           22      /* uses I/O bitmap */
+#define TIF_FREEZE              23      /* is freezing for suspend */
 
 #define _TIF_SYSCALL_TRACE      (1<<TIF_SYSCALL_TRACE)
 #define _TIF_NOTIFY_RESUME      (1<<TIF_NOTIFY_RESUME)
@@ -137,6 +138,7 @@ static inline struct thread_info *stack_thread_info(void)
 #define _TIF_ABI_PENDING        (1<<TIF_ABI_PENDING)
 #define _TIF_DEBUG              (1<<TIF_DEBUG)
 #define _TIF_IO_BITMAP          (1<<TIF_IO_BITMAP)
+#define _TIF_FREEZE             (1<<TIF_FREEZE)
 
 /* work to do on interrupt/exception return */
 #define _TIF_WORK_MASK \
diff --git a/include/linux/freezer.h b/include/linux/freezer.h
index 393063096134..5e75e26d4787 100644
--- a/include/linux/freezer.h
+++ b/include/linux/freezer.h
@@ -16,16 +16,15 @@ static inline int frozen(struct task_struct *p)
  */
 static inline int freezing(struct task_struct *p)
 {
-        return p->flags & PF_FREEZE;
+        return test_tsk_thread_flag(p, TIF_FREEZE);
 }
 
 /*
  * Request that a process be frozen
- * FIXME: SMP problem. We may not modify other process' flags!
  */
 static inline void freeze(struct task_struct *p)
 {
-        p->flags |= PF_FREEZE;
+        set_tsk_thread_flag(p, TIF_FREEZE);
 }
 
 /*
@@ -33,7 +32,7 @@ static inline void freeze(struct task_struct *p)
  */
 static inline void do_not_freeze(struct task_struct *p)
 {
-        p->flags &= ~PF_FREEZE;
+        clear_tsk_thread_flag(p, TIF_FREEZE);
 }
 
 /*
@@ -54,7 +53,9 @@ static inline int thaw_process(struct task_struct *p)
  */
 static inline void frozen_process(struct task_struct *p)
 {
-        p->flags = (p->flags & ~PF_FREEZE) | PF_FROZEN;
+        p->flags |= PF_FROZEN;
+        wmb();
+        clear_tsk_thread_flag(p, TIF_FREEZE);
 }
 
 extern void refrigerator(void);
diff --git a/include/linux/sched.h b/include/linux/sched.h
index ea92e5c89089..446373535190 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1144,7 +1144,6 @@ static inline void put_task_struct(struct task_struct *t)
 #define PF_MEMALLOC     0x00000800      /* Allocating memory */
 #define PF_FLUSHER      0x00001000      /* responsible for disk writeback */
 #define PF_USED_MATH    0x00002000      /* if unset the fpu must be initialized before use */
-#define PF_FREEZE       0x00004000      /* this task is being frozen for suspend now */
 #define PF_NOFREEZE     0x00008000      /* this thread should not be frozen */
 #define PF_FROZEN       0x00010000      /* frozen for system suspend */
 #define PF_FSTRANS      0x00020000      /* inside a filesystem transaction */
diff --git a/kernel/power/process.c b/kernel/power/process.c
index b9a32860bef3..6d566bf7085c 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -60,13 +60,16 @@ static inline void freeze_process(struct task_struct *p)
         unsigned long flags;
 
         if (!freezing(p)) {
-                if (p->state == TASK_STOPPED)
-                        force_sig_specific(SIGSTOP, p);
-
-                freeze(p);
-                spin_lock_irqsave(&p->sighand->siglock, flags);
-                signal_wake_up(p, p->state == TASK_STOPPED);
-                spin_unlock_irqrestore(&p->sighand->siglock, flags);
+                rmb();
+                if (!frozen(p)) {
+                        if (p->state == TASK_STOPPED)
+                                force_sig_specific(SIGSTOP, p);
+
+                        freeze(p);
+                        spin_lock_irqsave(&p->sighand->siglock, flags);
+                        signal_wake_up(p, p->state == TASK_STOPPED);
+                        spin_unlock_irqrestore(&p->sighand->siglock, flags);
+                }
         }
 }