diff options
Diffstat (limited to 'arch/alpha/kernel/process.c')
-rw-r--r-- | arch/alpha/kernel/process.c | 79 |
1 files changed, 20 insertions, 59 deletions
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index 83638aa096d5..4054e0ffe2b2 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -263,33 +263,35 @@ alpha_vfork(struct pt_regs *regs) /* * Copy an alpha thread.. - * - * Note the "stack_offset" stuff: when returning to kernel mode, we need - * to have some extra stack-space for the kernel stack that still exists - * after the "ret_from_fork". When returning to user mode, we only want - * the space needed by the syscall stack frame (ie "struct pt_regs"). - * Use the passed "regs" pointer to determine how much space we need - * for a kernel fork(). */ int copy_thread(unsigned long clone_flags, unsigned long usp, - unsigned long unused, + unsigned long arg, struct task_struct * p, struct pt_regs * regs) { extern void ret_from_fork(void); + extern void ret_from_kernel_thread(void); struct thread_info *childti = task_thread_info(p); - struct pt_regs * childregs; - struct switch_stack * childstack, *stack; - unsigned long stack_offset, settls; - - stack_offset = PAGE_SIZE - sizeof(struct pt_regs); - if (!(regs->ps & 8)) - stack_offset = (PAGE_SIZE-1) & (unsigned long) regs; - childregs = (struct pt_regs *) - (stack_offset + PAGE_SIZE + task_stack_page(p)); - + struct pt_regs *childregs = task_pt_regs(p); + struct switch_stack *childstack, *stack; + unsigned long settls; + + childstack = ((struct switch_stack *) childregs) - 1; + if (unlikely(!regs)) { + /* kernel thread */ + memset(childstack, 0, + sizeof(struct switch_stack) + sizeof(struct pt_regs)); + childstack->r26 = (unsigned long) ret_from_kernel_thread; + childstack->r9 = usp; /* function */ + childstack->r10 = arg; + childregs->hae = alpha_mv.hae_cache, + childti->pcb.usp = 0; + childti->pcb.ksp = (unsigned long) childstack; + childti->pcb.flags = 1; /* set FEN, clear everything else */ + return 0; + } *childregs = *regs; settls = regs->r20; childregs->r0 = 0; @@ -297,7 +299,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp, childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */ regs->r20 = 0; stack = ((struct switch_stack *) regs) - 1; - childstack = ((struct switch_stack *) childregs) - 1; *childstack = *stack; childstack->r26 = (unsigned long) ret_from_fork; childti->pcb.usp = usp; @@ -386,27 +387,6 @@ dump_elf_task_fp(elf_fpreg_t *dest, struct task_struct *task) EXPORT_SYMBOL(dump_elf_task_fp); /* - * sys_execve() executes a new program. - */ -asmlinkage int -do_sys_execve(const char __user *ufilename, - const char __user *const __user *argv, - const char __user *const __user *envp, struct pt_regs *regs) -{ - int error; - char *filename; - - filename = getname(ufilename); - error = PTR_ERR(filename); - if (IS_ERR(filename)) - goto out; - error = do_execve(filename, argv, envp, regs); - putname(filename); -out: - return error; -} - -/* * Return saved PC of a blocked thread. This assumes the frame * pointer is the 6th saved long on the kernel stack and that the * saved return address is the first long in the frame. This all @@ -459,22 +439,3 @@ get_wchan(struct task_struct *p) } return pc; } - -int kernel_execve(const char *path, const char *const argv[], const char *const envp[]) -{ - /* Avoid the HAE being gratuitously wrong, which would cause us - to do the whole turn off interrupts thing and restore it. */ - struct pt_regs regs = {.hae = alpha_mv.hae_cache}; - int err = do_execve(path, argv, envp, ®s); - if (!err) { - struct pt_regs *p = current_pt_regs(); - /* copy regs to normal position and off to userland we go... */ - *p = regs; - __asm__ __volatile__ ( - "mov %0, $sp;" - "br $31, ret_from_sys_call" - : : "r"(p)); - } - return err; -} -EXPORT_SYMBOL(kernel_execve); |