5 files changed, 159 insertions, 126 deletions

diff --git a/arch/powerpc/include/asm/signal.h b/arch/powerpc/include/asm/signal.h
index 9322c28aebd2..5ff77722a52d 100644
--- a/arch/powerpc/include/asm/signal.h
+++ b/arch/powerpc/include/asm/signal.h
@@ -5,6 +5,4 @@
 #include <uapi/asm/signal.h>
 #include <uapi/asm/ptrace.h>
 
-extern unsigned long get_tm_stackpointer(struct pt_regs *regs);
-
 #endif /* _ASM_POWERPC_SIGNAL_H */
diff --git a/arch/powerpc/kernel/signal.c b/arch/powerpc/kernel/signal.c
index cb64d6feb45a..bbe77aed198d 100644
--- a/arch/powerpc/kernel/signal.c
+++ b/arch/powerpc/kernel/signal.c
@@ -99,22 +99,24 @@ static void check_syscall_restart(struct pt_regs *regs, struct k_sigaction *ka,
         }
 }
 
-static void do_signal(struct pt_regs *regs)
+static void do_signal(struct task_struct *tsk)
 {
         sigset_t *oldset = sigmask_to_save();
         struct ksignal ksig;
         int ret;
         int is32 = is_32bit_task();
 
+        BUG_ON(tsk != current);
+
         get_signal(&ksig);
 
         /* Is there any syscall restart business here ? */
-        check_syscall_restart(regs, &ksig.ka, ksig.sig > 0);
+        check_syscall_restart(tsk->thread.regs, &ksig.ka, ksig.sig > 0);
 
         if (ksig.sig <= 0) {
                 /* No signal to deliver -- put the saved sigmask back */
                 restore_saved_sigmask();
-                regs->trap = 0;
+                tsk->thread.regs->trap = 0;
                 return;               /* no signals delivered */
         }
 
@@ -124,23 +126,22 @@ static void do_signal(struct pt_regs *regs)
          * user space. The DABR will have been cleared if it
          * triggered inside the kernel.
          */
-        if (current->thread.hw_brk.address &&
-                current->thread.hw_brk.type)
-                __set_breakpoint(&current->thread.hw_brk);
+        if (tsk->thread.hw_brk.address && tsk->thread.hw_brk.type)
+                __set_breakpoint(&tsk->thread.hw_brk);
 #endif
         /* Re-enable the breakpoints for the signal stack */
-        thread_change_pc(current, regs);
+        thread_change_pc(tsk, tsk->thread.regs);
 
         if (is32) {
                 if (ksig.ka.sa.sa_flags & SA_SIGINFO)
-                        ret = handle_rt_signal32(&ksig, oldset, regs);
+                        ret = handle_rt_signal32(&ksig, oldset, tsk);
                 else
-                        ret = handle_signal32(&ksig, oldset, regs);
+                        ret = handle_signal32(&ksig, oldset, tsk);
         } else {
-                ret = handle_rt_signal64(&ksig, oldset, regs);
+                ret = handle_rt_signal64(&ksig, oldset, tsk);
         }
 
-        regs->trap = 0;
+        tsk->thread.regs->trap = 0;
         signal_setup_done(ret, &ksig, test_thread_flag(TIF_SINGLESTEP));
 }
 
@@ -151,8 +152,10 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
         if (thread_info_flags & _TIF_UPROBE)
                 uprobe_notify_resume(regs);
 
-        if (thread_info_flags & _TIF_SIGPENDING)
-                do_signal(regs);
+        if (thread_info_flags & _TIF_SIGPENDING) {
+                BUG_ON(regs != current->thread.regs);
+                do_signal(current);
+        }
 
         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
                 clear_thread_flag(TIF_NOTIFY_RESUME);
@@ -162,7 +165,7 @@ void do_notify_resume(struct pt_regs *regs, unsigned long thread_info_flags)
         user_enter();
 }
 
-unsigned long get_tm_stackpointer(struct pt_regs *regs)
+unsigned long get_tm_stackpointer(struct task_struct *tsk)
 {
         /* When in an active transaction that takes a signal, we need to be
          * careful with the stack.  It's possible that the stack has moved back
@@ -187,11 +190,13 @@ unsigned long get_tm_stackpointer(struct pt_regs *regs)
          */
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-        if (MSR_TM_ACTIVE(regs->msr)) {
+        BUG_ON(tsk != current);
+
+        if (MSR_TM_ACTIVE(tsk->thread.regs->msr)) {
                 tm_reclaim_current(TM_CAUSE_SIGNAL);
-                if (MSR_TM_TRANSACTIONAL(regs->msr))
-                        return current->thread.ckpt_regs.gpr[1];
+                if (MSR_TM_TRANSACTIONAL(tsk->thread.regs->msr))
+                        return tsk->thread.ckpt_regs.gpr[1];
         }
 #endif
-        return regs->gpr[1];
+        return tsk->thread.regs->gpr[1];
 }
diff --git a/arch/powerpc/kernel/signal.h b/arch/powerpc/kernel/signal.h
index be305c858e51..254ca074504f 100644
--- a/arch/powerpc/kernel/signal.h
+++ b/arch/powerpc/kernel/signal.h
@@ -16,10 +16,10 @@ extern void __user *get_sigframe(struct ksignal *ksig, unsigned long sp,
                                   size_t frame_size, int is_32);
 
 extern int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
-                           struct pt_regs *regs);
+                           struct task_struct *tsk);
 
 extern int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
-                              struct pt_regs *regs);
+                              struct task_struct *tsk);
 
 extern unsigned long copy_fpr_to_user(void __user *to,
                                       struct task_struct *task);
@@ -29,6 +29,8 @@ extern unsigned long copy_fpr_from_user(struct task_struct *task,
                                         void __user *from);
 extern unsigned long copy_transact_fpr_from_user(struct task_struct *task,
                                                  void __user *from);
+extern unsigned long get_tm_stackpointer(struct task_struct *tsk);
+
 #ifdef CONFIG_VSX
 extern unsigned long copy_vsx_to_user(void __user *to,
                                       struct task_struct *task);
@@ -43,12 +45,12 @@ extern unsigned long copy_transact_vsx_from_user(struct task_struct *task,
 #ifdef CONFIG_PPC64
 
 extern int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
-                              struct pt_regs *regs);
+                              struct task_struct *tsk);
 
 #else /* CONFIG_PPC64 */
 
 static inline int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
-                                     struct pt_regs *regs)
+                                     struct task_struct *tsk)
 {
         return -EFAULT;
 }
diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
index d2745375f27e..9637f8eb5204 100644
--- a/arch/powerpc/kernel/signal_32.c
+++ b/arch/powerpc/kernel/signal_32.c
@@ -978,7 +978,7 @@ int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
  * (one which gets siginfo).
  */
 int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
-                       struct pt_regs *regs)
+                       struct task_struct *tsk)
 {
         struct rt_sigframe __user *rt_sf;
         struct mcontext __user *frame;
@@ -987,10 +987,13 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
         unsigned long newsp = 0;
         int sigret;
         unsigned long tramp;
+        struct pt_regs *regs = tsk->thread.regs;
+
+        BUG_ON(tsk != current);
 
         /* Set up Signal Frame */
         /* Put a Real Time Context onto stack */
-        rt_sf = get_sigframe(ksig, get_tm_stackpointer(regs), sizeof(*rt_sf), 1);
+        rt_sf = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*rt_sf), 1);
         addr = rt_sf;
         if (unlikely(rt_sf == NULL))
                 goto badframe;
@@ -1007,9 +1010,9 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
         /* Save user registers on the stack */
         frame = &rt_sf->uc.uc_mcontext;
         addr = frame;
-        if (vdso32_rt_sigtramp && current->mm->context.vdso_base) {
+        if (vdso32_rt_sigtramp && tsk->mm->context.vdso_base) {
                 sigret = 0;
-                tramp = current->mm->context.vdso_base + vdso32_rt_sigtramp;
+                tramp = tsk->mm->context.vdso_base + vdso32_rt_sigtramp;
         } else {
                 sigret = __NR_rt_sigreturn;
                 tramp = (unsigned long) frame->tramp;
@@ -1036,7 +1039,7 @@ int handle_rt_signal32(struct ksignal *ksig, sigset_t *oldset,
         }
         regs->link = tramp;
 
-        current->thread.fp_state.fpscr = 0;     /* turn off all fp exceptions */
+        tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
 
         /* create a stack frame for the caller of the handler */
         newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
@@ -1061,7 +1064,7 @@ badframe:
                 printk_ratelimited(KERN_INFO
                                    "%s[%d]: bad frame in handle_rt_signal32: "
                                    "%p nip %08lx lr %08lx\n",
-                                   current->comm, current->pid,
+                                   tsk->comm, tsk->pid,
                                    addr, regs->nip, regs->link);
 
         return 1;
@@ -1417,7 +1420,8 @@ int sys_debug_setcontext(struct ucontext __user *ctx,
 /*
  * OK, we're invoking a handler
  */
-int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs)
+int handle_signal32(struct ksignal *ksig, sigset_t *oldset,
+                struct task_struct *tsk)
 {
         struct sigcontext __user *sc;
         struct sigframe __user *frame;
@@ -1425,9 +1429,12 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs
         unsigned long newsp = 0;
         int sigret;
         unsigned long tramp;
+        struct pt_regs *regs = tsk->thread.regs;
+
+        BUG_ON(tsk != current);
 
         /* Set up Signal Frame */
-        frame = get_sigframe(ksig, get_tm_stackpointer(regs), sizeof(*frame), 1);
+        frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 1);
         if (unlikely(frame == NULL))
                 goto badframe;
         sc = (struct sigcontext __user *) &frame->sctx;
@@ -1446,9 +1453,9 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs
             || __put_user(ksig->sig, &sc->signal))
                 goto badframe;
 
-        if (vdso32_sigtramp && current->mm->context.vdso_base) {
+        if (vdso32_sigtramp && tsk->mm->context.vdso_base) {
                 sigret = 0;
-                tramp = current->mm->context.vdso_base + vdso32_sigtramp;
+                tramp = tsk->mm->context.vdso_base + vdso32_sigtramp;
         } else {
                 sigret = __NR_sigreturn;
                 tramp = (unsigned long) frame->mctx.tramp;
@@ -1470,7 +1477,7 @@ int handle_signal32(struct ksignal *ksig, sigset_t *oldset, struct pt_regs *regs
 
         regs->link = tramp;
 
-        current->thread.fp_state.fpscr = 0;     /* turn off all fp exceptions */
+        tsk->thread.fp_state.fpscr = 0; /* turn off all fp exceptions */
 
         /* create a stack frame for the caller of the handler */
         newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
@@ -1490,7 +1497,7 @@ badframe:
                 printk_ratelimited(KERN_INFO
                                    "%s[%d]: bad frame in handle_signal32: "
                                    "%p nip %08lx lr %08lx\n",
-                                   current->comm, current->pid,
+                                   tsk->comm, tsk->pid,
                                    frame, regs->nip, regs->link);
 
         return 1;
diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index 6faa8240b7c9..befa10af0c17 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -91,9 +91,9 @@ static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
  * Set up the sigcontext for the signal frame.
  */
 
-static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
-                 int signr, sigset_t *set, unsigned long handler,
-                 int ctx_has_vsx_region)
+static long setup_sigcontext(struct sigcontext __user *sc,
+                struct task_struct *tsk, int signr, sigset_t *set,
+                unsigned long handler, int ctx_has_vsx_region)
 {
         /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
          * process never used altivec yet (MSR_VEC is zero in pt_regs of
@@ -107,17 +107,20 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
         elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
         unsigned long vrsave;
 #endif
+        struct pt_regs *regs = tsk->thread.regs;
         unsigned long msr = regs->msr;
         long err = 0;
 
+        BUG_ON(tsk != current);
+
 #ifdef CONFIG_ALTIVEC
         err |= __put_user(v_regs, &sc->v_regs);
 
         /* save altivec registers */
-        if (current->thread.used_vr) {
-                flush_altivec_to_thread(current);
+        if (tsk->thread.used_vr) {
+                flush_altivec_to_thread(tsk);
                 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
-                err |= __copy_to_user(v_regs, &current->thread.vr_state,
+                err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
                                       33 * sizeof(vector128));
                 /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
                  * contains valid data.
@@ -130,16 +133,16 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
         vrsave = 0;
         if (cpu_has_feature(CPU_FTR_ALTIVEC)) {
                 vrsave = mfspr(SPRN_VRSAVE);
-                current->thread.vrsave = vrsave;
+                tsk->thread.vrsave = vrsave;
         }
 
         err |= __put_user(vrsave, (u32 __user *)&v_regs[33]);
 #else /* CONFIG_ALTIVEC */
         err |= __put_user(0, &sc->v_regs);
 #endif /* CONFIG_ALTIVEC */
-        flush_fp_to_thread(current);
+        flush_fp_to_thread(tsk);
         /* copy fpr regs and fpscr */
-        err |= copy_fpr_to_user(&sc->fp_regs, current);
+        err |= copy_fpr_to_user(&sc->fp_regs, tsk);
 
         /*
          * Clear the MSR VSX bit to indicate there is no valid state attached
@@ -152,10 +155,10 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
          * then out to userspace.  Update v_regs to point after the
          * VMX data.
          */
-        if (current->thread.used_vsr && ctx_has_vsx_region) {
-                flush_vsx_to_thread(current);
+        if (tsk->thread.used_vsr && ctx_has_vsx_region) {
+                flush_vsx_to_thread(tsk);
                 v_regs += ELF_NVRREG;
-                err |= copy_vsx_to_user(v_regs, current);
+                err |= copy_vsx_to_user(v_regs, tsk);
                 /* set MSR_VSX in the MSR value in the frame to
                  * indicate that sc->vs_reg) contains valid data.
                  */
@@ -188,7 +191,7 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
  */
 static long setup_tm_sigcontexts(struct sigcontext __user *sc,
                                  struct sigcontext __user *tm_sc,
-                                 struct pt_regs *regs,
+                                 struct task_struct *tsk,
                                  int signr, sigset_t *set, unsigned long handler)
 {
         /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
@@ -203,9 +206,12 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
         elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
         elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
 #endif
-        unsigned long msr = regs->msr;
+        struct pt_regs *regs = tsk->thread.regs;
+        unsigned long msr = tsk->thread.ckpt_regs.msr;
         long err = 0;
 
+        BUG_ON(tsk != current);
+
         BUG_ON(!MSR_TM_ACTIVE(regs->msr));
 
         /* Remove TM bits from thread's MSR.  The MSR in the sigcontext
@@ -215,28 +221,28 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
          */
         regs->msr &= ~MSR_TS_MASK;
 
-        flush_fp_to_thread(current);
+        flush_fp_to_thread(tsk);
 
 #ifdef CONFIG_ALTIVEC
         err |= __put_user(v_regs, &sc->v_regs);
         err |= __put_user(tm_v_regs, &tm_sc->v_regs);
 
         /* save altivec registers */
-        if (current->thread.used_vr) {
-                flush_altivec_to_thread(current);
+        if (tsk->thread.used_vr) {
+                flush_altivec_to_thread(tsk);
                 /* Copy 33 vec registers (vr0..31 and vscr) to the stack */
-                err |= __copy_to_user(v_regs, &current->thread.vr_state,
+                err |= __copy_to_user(v_regs, &tsk->thread.vr_state,
                                       33 * sizeof(vector128));
                 /* If VEC was enabled there are transactional VRs valid too,
                  * else they're a copy of the checkpointed VRs.
                  */
                 if (msr & MSR_VEC)
                         err |= __copy_to_user(tm_v_regs,
-                                              &current->thread.transact_vr,
+                                              &tsk->thread.transact_vr,
                                               33 * sizeof(vector128));
                 else
                         err |= __copy_to_user(tm_v_regs,
-                                              &current->thread.vr_state,
+                                              &tsk->thread.vr_state,
                                               33 * sizeof(vector128));
 
                 /* set MSR_VEC in the MSR value in the frame to indicate
@@ -248,13 +254,13 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
          * use altivec.
          */
         if (cpu_has_feature(CPU_FTR_ALTIVEC))
-                current->thread.vrsave = mfspr(SPRN_VRSAVE);
-        err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
+                tsk->thread.vrsave = mfspr(SPRN_VRSAVE);
+        err |= __put_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
         if (msr & MSR_VEC)
-                err |= __put_user(current->thread.transact_vrsave,
+                err |= __put_user(tsk->thread.transact_vrsave,
                                   (u32 __user *)&tm_v_regs[33]);
         else
-                err |= __put_user(current->thread.vrsave,
+                err |= __put_user(tsk->thread.vrsave,
                                   (u32 __user *)&tm_v_regs[33]);
 
 #else /* CONFIG_ALTIVEC */
@@ -263,11 +269,11 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
 #endif /* CONFIG_ALTIVEC */
 
         /* copy fpr regs and fpscr */
-        err |= copy_fpr_to_user(&sc->fp_regs, current);
+        err |= copy_fpr_to_user(&sc->fp_regs, tsk);
         if (msr & MSR_FP)
-                err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, current);
+                err |= copy_transact_fpr_to_user(&tm_sc->fp_regs, tsk);
         else
-                err |= copy_fpr_to_user(&tm_sc->fp_regs, current);
+                err |= copy_fpr_to_user(&tm_sc->fp_regs, tsk);
 
 #ifdef CONFIG_VSX
         /*
@@ -275,17 +281,17 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
          * then out to userspace.  Update v_regs to point after the
          * VMX data.
          */
-        if (current->thread.used_vsr) {
-                flush_vsx_to_thread(current);
+        if (tsk->thread.used_vsr) {
+                flush_vsx_to_thread(tsk);
                 v_regs += ELF_NVRREG;
                 tm_v_regs += ELF_NVRREG;
 
-                err |= copy_vsx_to_user(v_regs, current);
+                err |= copy_vsx_to_user(v_regs, tsk);
 
                 if (msr & MSR_VSX)
-                        err |= copy_transact_vsx_to_user(tm_v_regs, current);
+                        err |= copy_transact_vsx_to_user(tm_v_regs, tsk);
                 else
-                        err |= copy_vsx_to_user(tm_v_regs, current);
+                        err |= copy_vsx_to_user(tm_v_regs, tsk);
 
                 /* set MSR_VSX in the MSR value in the frame to
                  * indicate that sc->vs_reg) contains valid data.
@@ -299,7 +305,7 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
         WARN_ON(!FULL_REGS(regs));
         err |= __copy_to_user(&tm_sc->gp_regs, regs, GP_REGS_SIZE);
         err |= __copy_to_user(&sc->gp_regs,
-                              &current->thread.ckpt_regs, GP_REGS_SIZE);
+                              &tsk->thread.ckpt_regs, GP_REGS_SIZE);
         err |= __put_user(msr, &tm_sc->gp_regs[PT_MSR]);
         err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
         err |= __put_user(signr, &sc->signal);
@@ -315,7 +321,7 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
  * Restore the sigcontext from the signal frame.
  */
 
-static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
+static long restore_sigcontext(struct task_struct *tsk, sigset_t *set, int sig,
                               struct sigcontext __user *sc)
 {
 #ifdef CONFIG_ALTIVEC
@@ -324,10 +330,13 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
         unsigned long err = 0;
         unsigned long save_r13 = 0;
         unsigned long msr;
+        struct pt_regs *regs = tsk->thread.regs;
 #ifdef CONFIG_VSX
         int i;
 #endif
 
+        BUG_ON(tsk != current);
+
         /* If this is not a signal return, we preserve the TLS in r13 */
         if (!sig)
                 save_r13 = regs->gpr[13];
@@ -357,7 +366,7 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
 
         /*
          * Force reload of FP/VEC.
-         * This has to be done before copying stuff into current->thread.fpr/vr
+         * This has to be done before copying stuff into tsk->thread.fpr/vr
          * for the reasons explained in the previous comment.
          */
         regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
@@ -370,22 +379,22 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
                 return -EFAULT;
         /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
         if (v_regs != NULL && (msr & MSR_VEC) != 0) {
-                err |= __copy_from_user(&current->thread.vr_state, v_regs,
+                err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
                                         33 * sizeof(vector128));
-                current->thread.used_vr = true;
+                tsk->thread.used_vr = true;
+        } else if (tsk->thread.used_vr) {
+                memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
         }
-        else if (current->thread.used_vr)
-                memset(&current->thread.vr_state, 0, 33 * sizeof(vector128));
         /* Always get VRSAVE back */
         if (v_regs != NULL)
-                err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
+                err |= __get_user(tsk->thread.vrsave, (u32 __user *)&v_regs[33]);
         else
-                current->thread.vrsave = 0;
+                tsk->thread.vrsave = 0;
         if (cpu_has_feature(CPU_FTR_ALTIVEC))
-                mtspr(SPRN_VRSAVE, current->thread.vrsave);
+                mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
 #endif /* CONFIG_ALTIVEC */
         /* restore floating point */
-        err |= copy_fpr_from_user(current, &sc->fp_regs);
+        err |= copy_fpr_from_user(tsk, &sc->fp_regs);
 #ifdef CONFIG_VSX
         /*
          * Get additional VSX data. Update v_regs to point after the
@@ -394,11 +403,12 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
          */
         v_regs += ELF_NVRREG;
         if ((msr & MSR_VSX) != 0) {
-                err |= copy_vsx_from_user(current, v_regs);
-                current->thread.used_vsr = true;
-        } else
+                err |= copy_vsx_from_user(tsk, v_regs);
+                tsk->thread.used_vsr = true;
+        } else {
                 for (i = 0; i < 32 ; i++)
-                        current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
+                        tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
+        }
 #endif
         return err;
 }
@@ -408,7 +418,7 @@ static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
  * Restore the two sigcontexts from the frame of a transactional processes.
  */
 
-static long restore_tm_sigcontexts(struct pt_regs *regs,
+static long restore_tm_sigcontexts(struct task_struct *tsk,
                                    struct sigcontext __user *sc,
                                    struct sigcontext __user *tm_sc)
 {
@@ -417,12 +427,16 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
 #endif
         unsigned long err = 0;
         unsigned long msr;
+        struct pt_regs *regs = tsk->thread.regs;
 #ifdef CONFIG_VSX
         int i;
 #endif
+
+        BUG_ON(tsk != current);
+
         /* copy the GPRs */
         err |= __copy_from_user(regs->gpr, tm_sc->gp_regs, sizeof(regs->gpr));
-        err |= __copy_from_user(&current->thread.ckpt_regs, sc->gp_regs,
+        err |= __copy_from_user(&tsk->thread.ckpt_regs, sc->gp_regs,
                                 sizeof(regs->gpr));
 
         /*
@@ -434,7 +448,7 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
          * we don't need to re-copy them here.
          */
         err |= __get_user(regs->nip, &tm_sc->gp_regs[PT_NIP]);
-        err |= __get_user(current->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
+        err |= __get_user(tsk->thread.tm_tfhar, &sc->gp_regs[PT_NIP]);
 
         /* get MSR separately, transfer the LE bit if doing signal return */
         err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
@@ -453,13 +467,13 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
         err |= __get_user(regs->link, &tm_sc->gp_regs[PT_LNK]);
         err |= __get_user(regs->xer, &tm_sc->gp_regs[PT_XER]);
         err |= __get_user(regs->ccr, &tm_sc->gp_regs[PT_CCR]);
-        err |= __get_user(current->thread.ckpt_regs.ctr,
+        err |= __get_user(tsk->thread.ckpt_regs.ctr,
                           &sc->gp_regs[PT_CTR]);
-        err |= __get_user(current->thread.ckpt_regs.link,
+        err |= __get_user(tsk->thread.ckpt_regs.link,
                           &sc->gp_regs[PT_LNK]);
-        err |= __get_user(current->thread.ckpt_regs.xer,
+        err |= __get_user(tsk->thread.ckpt_regs.xer,
                           &sc->gp_regs[PT_XER]);
-        err |= __get_user(current->thread.ckpt_regs.ccr,
+        err |= __get_user(tsk->thread.ckpt_regs.ccr,
                           &sc->gp_regs[PT_CCR]);
 
         /* These regs are not checkpointed; they can go in 'regs'. */
@@ -470,7 +484,7 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
 
         /*
          * Force reload of FP/VEC.
-         * This has to be done before copying stuff into current->thread.fpr/vr
+         * This has to be done before copying stuff into tsk->thread.fpr/vr
          * for the reasons explained in the previous comment.
          */
         regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC | MSR_VSX);
@@ -487,33 +501,33 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
                 return -EFAULT;
         /* Copy 33 vec registers (vr0..31 and vscr) from the stack */
         if (v_regs != NULL && tm_v_regs != NULL && (msr & MSR_VEC) != 0) {
-                err |= __copy_from_user(&current->thread.vr_state, v_regs,
+                err |= __copy_from_user(&tsk->thread.vr_state, v_regs,
                                         33 * sizeof(vector128));
-                err |= __copy_from_user(&current->thread.transact_vr, tm_v_regs,
+                err |= __copy_from_user(&tsk->thread.transact_vr, tm_v_regs,
                                         33 * sizeof(vector128));
                 current->thread.used_vr = true;
         }
-        else if (current->thread.used_vr) {
-                memset(&current->thread.vr_state, 0, 33 * sizeof(vector128));
-                memset(&current->thread.transact_vr, 0, 33 * sizeof(vector128));
+        else if (tsk->thread.used_vr) {
+                memset(&tsk->thread.vr_state, 0, 33 * sizeof(vector128));
+                memset(&tsk->thread.transact_vr, 0, 33 * sizeof(vector128));
         }
         /* Always get VRSAVE back */
         if (v_regs != NULL && tm_v_regs != NULL) {
-                err |= __get_user(current->thread.vrsave,
+                err |= __get_user(tsk->thread.vrsave,
                                   (u32 __user *)&v_regs[33]);
-                err |= __get_user(current->thread.transact_vrsave,
+                err |= __get_user(tsk->thread.transact_vrsave,
                                   (u32 __user *)&tm_v_regs[33]);
         }
         else {
-                current->thread.vrsave = 0;
-                current->thread.transact_vrsave = 0;
+                tsk->thread.vrsave = 0;
+                tsk->thread.transact_vrsave = 0;
         }
         if (cpu_has_feature(CPU_FTR_ALTIVEC))
-                mtspr(SPRN_VRSAVE, current->thread.vrsave);
+                mtspr(SPRN_VRSAVE, tsk->thread.vrsave);
 #endif /* CONFIG_ALTIVEC */
         /* restore floating point */
-        err |= copy_fpr_from_user(current, &sc->fp_regs);
-        err |= copy_transact_fpr_from_user(current, &tm_sc->fp_regs);
+        err |= copy_fpr_from_user(tsk, &sc->fp_regs);
+        err |= copy_transact_fpr_from_user(tsk, &tm_sc->fp_regs);
 #ifdef CONFIG_VSX
         /*
          * Get additional VSX data. Update v_regs to point after the
@@ -523,30 +537,30 @@ static long restore_tm_sigcontexts(struct pt_regs *regs,
         if (v_regs && ((msr & MSR_VSX) != 0)) {
                 v_regs += ELF_NVRREG;
                 tm_v_regs += ELF_NVRREG;
-                err |= copy_vsx_from_user(current, v_regs);
-                err |= copy_transact_vsx_from_user(current, tm_v_regs);
-                current->thread.used_vsr = true;
+                err |= copy_vsx_from_user(tsk, v_regs);
+                err |= copy_transact_vsx_from_user(tsk, tm_v_regs);
+                tsk->thread.used_vsr = true;
         } else {
                 for (i = 0; i < 32 ; i++) {
-                        current->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
-                        current->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0;
+                        tsk->thread.fp_state.fpr[i][TS_VSRLOWOFFSET] = 0;
+                        tsk->thread.transact_fp.fpr[i][TS_VSRLOWOFFSET] = 0;
                 }
         }
 #endif
         tm_enable();
         /* Make sure the transaction is marked as failed */
-        current->thread.tm_texasr |= TEXASR_FS;
+        tsk->thread.tm_texasr |= TEXASR_FS;
         /* This loads the checkpointed FP/VEC state, if used */
-        tm_recheckpoint(&current->thread, msr);
+        tm_recheckpoint(&tsk->thread, msr);
 
         /* This loads the speculative FP/VEC state, if used */
         if (msr & MSR_FP) {
-                do_load_up_transact_fpu(&current->thread);
-                regs->msr |= (MSR_FP | current->thread.fpexc_mode);
+                do_load_up_transact_fpu(&tsk->thread);
+                regs->msr |= (MSR_FP | tsk->thread.fpexc_mode);
         }
 #ifdef CONFIG_ALTIVEC
         if (msr & MSR_VEC) {
-                do_load_up_transact_altivec(&current->thread);
+                do_load_up_transact_altivec(&tsk->thread);
                 regs->msr |= MSR_VEC;
         }
 #endif
@@ -600,6 +614,8 @@ int sys_swapcontext(struct ucontext __user *old_ctx,
         unsigned long new_msr = 0;
         int ctx_has_vsx_region = 0;
 
+        BUG_ON(regs != current->thread.regs);
+
         if (new_ctx &&
             get_user(new_msr, &new_ctx->uc_mcontext.gp_regs[PT_MSR]))
                 return -EFAULT;
@@ -622,7 +638,7 @@ int sys_swapcontext(struct ucontext __user *old_ctx,
 
         if (old_ctx != NULL) {
                 if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
-                    || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0,
+                    || setup_sigcontext(&old_ctx->uc_mcontext, current, 0, NULL, 0,
                                         ctx_has_vsx_region)
                     || __copy_to_user(&old_ctx->uc_sigmask,
                                       &current->blocked, sizeof(sigset_t)))
@@ -650,7 +666,7 @@ int sys_swapcontext(struct ucontext __user *old_ctx,
         if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
                 do_exit(SIGSEGV);
         set_current_blocked(&set);
-        if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
+        if (restore_sigcontext(current, NULL, 0, &new_ctx->uc_mcontext))
                 do_exit(SIGSEGV);
 
         /* This returns like rt_sigreturn */
@@ -673,6 +689,8 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
         unsigned long msr;
 #endif
 
+        BUG_ON(current->thread.regs != regs);
+
         /* Always make any pending restarted system calls return -EINTR */
         current->restart_block.fn = do_no_restart_syscall;
 
@@ -704,14 +722,14 @@ int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
                 struct ucontext __user *uc_transact;
                 if (__get_user(uc_transact, &uc->uc_link))
                         goto badframe;
-                if (restore_tm_sigcontexts(regs, &uc->uc_mcontext,
+                if (restore_tm_sigcontexts(current, &uc->uc_mcontext,
                                            &uc_transact->uc_mcontext))
                         goto badframe;
         }
         else
         /* Fall through, for non-TM restore */
 #endif
-        if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
+        if (restore_sigcontext(current, NULL, 1, &uc->uc_mcontext))
                 goto badframe;
 
         if (restore_altstack(&uc->uc_stack))
@@ -730,13 +748,17 @@ badframe:
         return 0;
 }
 
-int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
+int handle_rt_signal64(struct ksignal *ksig, sigset_t *set,
+                struct task_struct *tsk)
 {
         struct rt_sigframe __user *frame;
         unsigned long newsp = 0;
         long err = 0;
+        struct pt_regs *regs = tsk->thread.regs;
+
+        BUG_ON(tsk != current);
 
-        frame = get_sigframe(ksig, get_tm_stackpointer(regs), sizeof(*frame), 0);
+        frame = get_sigframe(ksig, get_tm_stackpointer(tsk), sizeof(*frame), 0);
         if (unlikely(frame == NULL))
                 goto badframe;
 
@@ -757,14 +779,13 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs
                 err |= __put_user(&frame->uc_transact, &frame->uc.uc_link);
                 err |= setup_tm_sigcontexts(&frame->uc.uc_mcontext,
                                             &frame->uc_transact.uc_mcontext,
-                                            regs, ksig->sig,
-                                            NULL,
+                                            tsk, ksig->sig, NULL,
                                             (unsigned long)ksig->ka.sa.sa_handler);
         } else
 #endif
         {
                 err |= __put_user(0, &frame->uc.uc_link);
-                err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, ksig->sig,
+                err |= setup_sigcontext(&frame->uc.uc_mcontext, tsk, ksig->sig,
                                         NULL, (unsigned long)ksig->ka.sa.sa_handler,
                                         1);
         }
@@ -773,11 +794,11 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs
                 goto badframe;
 
         /* Make sure signal handler doesn't get spurious FP exceptions */
-        current->thread.fp_state.fpscr = 0;
+        tsk->thread.fp_state.fpscr = 0;
 
         /* Set up to return from userspace. */
-        if (vdso64_rt_sigtramp && current->mm->context.vdso_base) {
-                regs->link = current->mm->context.vdso_base + vdso64_rt_sigtramp;
+        if (vdso64_rt_sigtramp && tsk->mm->context.vdso_base) {
+                regs->link = tsk->mm->context.vdso_base + vdso64_rt_sigtramp;
         } else {
                 err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
                 if (err)
@@ -827,7 +848,7 @@ int handle_rt_signal64(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs
 badframe:
         if (show_unhandled_signals)
                 printk_ratelimited(regs->msr & MSR_64BIT ? fmt64 : fmt32,
-                                   current->comm, current->pid, "setup_rt_frame",
+                                   tsk->comm, tsk->pid, "setup_rt_frame",
                                    (long)frame, regs->nip, regs->link);
 
         return 1;