1 files changed, 45 insertions, 107 deletions

diff --git a/arch/sparc/kernel/process_32.c b/arch/sparc/kernel/process_32.c
index 487bffb36f5e..bf4c6addce7b 100644
--- a/arch/sparc/kernel/process_32.c
+++ b/arch/sparc/kernel/process_32.c
@@ -316,9 +316,10 @@ asmlinkage int sparc_do_fork(unsigned long clone_flags,
  * XXX See comment above sys_vfork in sparc64. todo.
  */
 extern void ret_from_fork(void);
+extern void ret_from_kernel_thread(void);
 
 int copy_thread(unsigned long clone_flags, unsigned long sp,
-                unsigned long unused,
+                unsigned long arg,
                 struct task_struct *p, struct pt_regs *regs)
 {
         struct thread_info *ti = task_thread_info(p);
@@ -336,16 +337,13 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
         }
 
         /*
-         *  p->thread_info         new_stack   childregs
-         *  !                      !           !             {if(PSR_PS) }
-         *  V                      V (stk.fr.) V  (pt_regs)  { (stk.fr.) }
-         *  +----- - - - - - ------+===========+============={+==========}+
+         *  p->thread_info         new_stack   childregs stack bottom
+         *  !                      !           !             !
+         *  V                      V (stk.fr.) V  (pt_regs)  V
+         *  +----- - - - - - ------+===========+=============+
          */
         new_stack = task_stack_page(p) + THREAD_SIZE;
-        if (regs->psr & PSR_PS)
-                new_stack -= STACKFRAME_SZ;
         new_stack -= STACKFRAME_SZ + TRACEREG_SZ;
-        memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
         childregs = (struct pt_regs *) (new_stack + STACKFRAME_SZ);
 
         /*
@@ -356,55 +354,58 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
          * Thus, kpsr|=PSR_PIL.
          */
         ti->ksp = (unsigned long) new_stack;
+        p->thread.kregs = childregs;
+
+        if (unlikely(p->flags & PF_KTHREAD)) {
+                extern int nwindows;
+                unsigned long psr;
+                memset(new_stack, 0, STACKFRAME_SZ + TRACEREG_SZ);
+                p->thread.flags |= SPARC_FLAG_KTHREAD;
+                p->thread.current_ds = KERNEL_DS;
+                ti->kpc = (((unsigned long) ret_from_kernel_thread) - 0x8);
+                childregs->u_regs[UREG_G1] = sp; /* function */
+                childregs->u_regs[UREG_G2] = arg;
+                psr = childregs->psr = get_psr();
+                ti->kpsr = psr | PSR_PIL;
+                ti->kwim = 1 << (((psr & PSR_CWP) + 1) % nwindows);
+                return 0;
+        }
+        memcpy(new_stack, (char *)regs - STACKFRAME_SZ, STACKFRAME_SZ + TRACEREG_SZ);
+        childregs->u_regs[UREG_FP] = sp;
+        p->thread.flags &= ~SPARC_FLAG_KTHREAD;
+        p->thread.current_ds = USER_DS;
         ti->kpc = (((unsigned long) ret_from_fork) - 0x8);
         ti->kpsr = current->thread.fork_kpsr | PSR_PIL;
         ti->kwim = current->thread.fork_kwim;
 
-        if(regs->psr & PSR_PS) {
-                extern struct pt_regs fake_swapper_regs;
+        if (sp != regs->u_regs[UREG_FP]) {
+                struct sparc_stackf __user *childstack;
+                struct sparc_stackf __user *parentstack;
 
-                p->thread.kregs = &fake_swapper_regs;
-                new_stack += STACKFRAME_SZ + TRACEREG_SZ;
-                childregs->u_regs[UREG_FP] = (unsigned long) new_stack;
-                p->thread.flags |= SPARC_FLAG_KTHREAD;
-                p->thread.current_ds = KERNEL_DS;
-                memcpy(new_stack, (void *)regs->u_regs[UREG_FP], STACKFRAME_SZ);
-                childregs->u_regs[UREG_G6] = (unsigned long) ti;
-        } else {
-                p->thread.kregs = childregs;
-                childregs->u_regs[UREG_FP] = sp;
-                p->thread.flags &= ~SPARC_FLAG_KTHREAD;
-                p->thread.current_ds = USER_DS;
-
-                if (sp != regs->u_regs[UREG_FP]) {
-                        struct sparc_stackf __user *childstack;
-                        struct sparc_stackf __user *parentstack;
-
-                        /*
-                         * This is a clone() call with supplied user stack.
-                         * Set some valid stack frames to give to the child.
-                         */
-                        childstack = (struct sparc_stackf __user *)
-                                (sp & ~0xfUL);
-                        parentstack = (struct sparc_stackf __user *)
-                                regs->u_regs[UREG_FP];
+                /*
+                 * This is a clone() call with supplied user stack.
+                 * Set some valid stack frames to give to the child.
+                 */
+                childstack = (struct sparc_stackf __user *)
+                        (sp & ~0xfUL);
+                parentstack = (struct sparc_stackf __user *)
+                        regs->u_regs[UREG_FP];
 
 #if 0
-                        printk("clone: parent stack:\n");
-                        show_stackframe(parentstack);
+                printk("clone: parent stack:\n");
+                show_stackframe(parentstack);
 #endif
 
-                        childstack = clone_stackframe(childstack, parentstack);
-                        if (!childstack)
-                                return -EFAULT;
+                childstack = clone_stackframe(childstack, parentstack);
+                if (!childstack)
+                        return -EFAULT;
 
 #if 0
-                        printk("clone: child stack:\n");
-                        show_stackframe(childstack);
+                printk("clone: child stack:\n");
+                show_stackframe(childstack);
 #endif
 
-                        childregs->u_regs[UREG_FP] = (unsigned long)childstack;
-                }
+                childregs->u_regs[UREG_FP] = (unsigned long)childstack;
         }
 
 #ifdef CONFIG_SMP
@@ -475,69 +476,6 @@ int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
         return 1;
 }
 
-/*
- * sparc_execve() executes a new program after the asm stub has set
- * things up for us.  This should basically do what I want it to.
- */
-asmlinkage int sparc_execve(struct pt_regs *regs)
-{
-        int error, base = 0;
-        struct filename *filename;
-
-        /* Check for indirect call. */
-        if(regs->u_regs[UREG_G1] == 0)
-                base = 1;
-
-        filename = getname((char __user *)regs->u_regs[base + UREG_I0]);
-        error = PTR_ERR(filename);
-        if(IS_ERR(filename))
-                goto out;
-        error = do_execve(filename->name,
-                          (const char __user *const  __user *)
-                          regs->u_regs[base + UREG_I1],
-                          (const char __user *const  __user *)
-                          regs->u_regs[base + UREG_I2],
-                          regs);
-        putname(filename);
-out:
-        return error;
-}
-
-/*
- * This is the mechanism for creating a new kernel thread.
- *
- * NOTE! Only a kernel-only process(ie the swapper or direct descendants
- * who haven't done an "execve()") should use this: it will work within
- * a system call from a "real" process, but the process memory space will
- * not be freed until both the parent and the child have exited.
- */
-pid_t kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
-        long retval;
-
-        __asm__ __volatile__("mov %4, %%g2\n\t"    /* Set aside fn ptr... */
-                             "mov %5, %%g3\n\t"    /* and arg. */
-                             "mov %1, %%g1\n\t"
-                             "mov %2, %%o0\n\t"    /* Clone flags. */
-                             "mov 0, %%o1\n\t"     /* usp arg == 0 */
-                             "t 0x10\n\t"          /* Linux/Sparc clone(). */
-                             "cmp %%o1, 0\n\t"
-                             "be 1f\n\t"           /* The parent, just return. */
-                             " nop\n\t"            /* Delay slot. */
-                             "jmpl %%g2, %%o7\n\t" /* Call the function. */
-                             " mov %%g3, %%o0\n\t" /* Get back the arg in delay. */
-                             "mov %3, %%g1\n\t"
-                             "t 0x10\n\t"          /* Linux/Sparc exit(). */
-                             /* Notreached by child. */
-                             "1: mov %%o0, %0\n\t" :
-                             "=r" (retval) :
-                             "i" (__NR_clone), "r" (flags | CLONE_VM | CLONE_UNTRACED),
-                             "i" (__NR_exit),  "r" (fn), "r" (arg) :
-                             "g1", "g2", "g3", "o0", "o1", "memory", "cc");
-        return retval;
-}
-EXPORT_SYMBOL(kernel_thread);
-
 unsigned long get_wchan(struct task_struct *task)
 {
         unsigned long pc, fp, bias = 0;