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| author | Al Viro <viro@zeniv.linux.org.uk> | 2012-10-21 15:52:04 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-11-28 21:49:04 -0500 |
| commit | 25906730ec01be664534c9439d7cf5a373e8a4e4 (patch) | |
| tree | 0fc3a2d0a08e5bdd815d61371b52ea2ccdc8cfa2 /arch | |
| parent | b960f303448969c6cb76b4df9291e9e6213e2b9f (diff) | |
| download | linux-3.10-25906730ec01be664534c9439d7cf5a373e8a4e4.tar.gz linux-3.10-25906730ec01be664534c9439d7cf5a373e8a4e4.tar.bz2 linux-3.10-25906730ec01be664534c9439d7cf5a373e8a4e4.zip | |
alpha: reorganize copy_process(), prepare to saner fork_idle()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/alpha/kernel/process.c | 35 |
1 files changed, 14 insertions, 21 deletions
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c index ad86c099b6f..a4dc79ba030 100644 --- a/arch/alpha/kernel/process.c +++ b/arch/alpha/kernel/process.c @@ -266,18 +266,22 @@ alpha_vfork(void) int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg, - struct task_struct * p, struct pt_regs * regs) + struct task_struct *p, struct pt_regs *wontuse) { 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 = task_pt_regs(p); + struct pt_regs *regs = current_pt_regs(); struct switch_stack *childstack, *stack; unsigned long settls; childstack = ((struct switch_stack *) childregs) - 1; - if (unlikely(!regs)) { + childti->pcb.ksp = (unsigned long) childstack; + childti->pcb.flags = 1; /* set FEN, clear everything else */ + + if (unlikely(p->flags & PF_KTHREAD)) { /* kernel thread */ memset(childstack, 0, sizeof(struct switch_stack) + sizeof(struct pt_regs)); @@ -286,12 +290,17 @@ copy_thread(unsigned long clone_flags, unsigned long usp, 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; } + /* Note: if CLONE_SETTLS is not set, then we must inherit the + value from the parent, which will have been set by the block + copy in dup_task_struct. This is non-intuitive, but is + required for proper operation in the case of a threaded + application calling fork. */ + if (clone_flags & CLONE_SETTLS) + childti->pcb.unique = regs->r20; + childti->pcb.usp = usp ?: rdusp(); *childregs = *regs; - settls = regs->r20; childregs->r0 = 0; childregs->r19 = 0; childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */ @@ -299,22 +308,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp, stack = ((struct switch_stack *) regs) - 1; *childstack = *stack; childstack->r26 = (unsigned long) ret_from_fork; - childti->pcb.usp = usp ?: rdusp(); - childti->pcb.ksp = (unsigned long) childstack; - childti->pcb.flags = 1; /* set FEN, clear everything else */ - - /* Set a new TLS for the child thread? Peek back into the - syscall arguments that we saved on syscall entry. Oops, - except we'd have clobbered it with the parent/child set - of r20. Read the saved copy. */ - /* Note: if CLONE_SETTLS is not set, then we must inherit the - value from the parent, which will have been set by the block - copy in dup_task_struct. This is non-intuitive, but is - required for proper operation in the case of a threaded - application calling fork. */ - if (clone_flags & CLONE_SETTLS) - childti->pcb.unique = settls; - return 0; } |