sparc64: Fix kernel thread stack termination.

[pandora-kernel.git] / arch / sparc64 / kernel / process.c

diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c
index 0a0c05f..2084f81 100644 (file)
--- a/arch/sparc64/kernel/process.c
+++ b/arch/sparc64/kernel/process.c
@@ -657,20 +657,39 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
                struct task_struct *p, struct pt_regs *regs)
 {
        struct thread_info *t = task_thread_info(p);
+       struct sparc_stackf *parent_sf;
+       unsigned long child_stack_sz;
        char *child_trap_frame;
+       int kernel_thread;
 
-       /* Calculate offset to stack_frame & pt_regs */
-       child_trap_frame = task_stack_page(p) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
-       memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
+       kernel_thread = (regs->tstate & TSTATE_PRIV) ? 1 : 0;
+       parent_sf = ((struct sparc_stackf *) regs) - 1;
 
-       t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
+       /* Calculate offset to stack_frame & pt_regs */
+       child_stack_sz = ((STACKFRAME_SZ + TRACEREG_SZ) +
+                         (kernel_thread ? STACKFRAME_SZ : 0));
+       child_trap_frame = (task_stack_page(p) +
+                           (THREAD_SIZE - child_stack_sz));
+       memcpy(child_trap_frame, parent_sf, child_stack_sz);
+
+       t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) |
+                                (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
                (((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
        t->new_child = 1;
        t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
-       t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
+       t->kregs = (struct pt_regs *) (child_trap_frame +
+                                      sizeof(struct sparc_stackf));
        t->fpsaved[0] = 0;
 
-       if (regs->tstate & TSTATE_PRIV) {
+       if (kernel_thread) {
+               struct sparc_stackf *child_sf = (struct sparc_stackf *)
+                       (child_trap_frame + (STACKFRAME_SZ + TRACEREG_SZ));
+
+               /* Zero terminate the stack backtrace.  */
+               child_sf->fp = NULL;
+               t->kregs->u_regs[UREG_FP] =
+                 ((unsigned long) child_sf) - STACK_BIAS;
+
                /* Special case, if we are spawning a kernel thread from
                 * a userspace task (via KMOD, NFS, or similar) we must
                 * disable performance counters in the child because the
@@ -681,12 +700,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
                        t->pcr_reg = 0;
                        t->flags &= ~_TIF_PERFCTR;
                }
-               t->kregs->u_regs[UREG_FP] = t->ksp;
                t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
-               flush_register_windows();
-               memcpy((void *)(t->ksp + STACK_BIAS),
-                      (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
-                      sizeof(struct sparc_stackf));
                t->kregs->u_regs[UREG_G6] = (unsigned long) t;
                t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
        } else {