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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

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Pull big execve/kernel_thread/fork unification series from Al Viro:
 "All architectures are converted to new model.  Quite a bit of that
  stuff is actually shared with architecture trees; in such cases it's
  literally shared branch pulled by both, not a cherry-pick.

  A lot of ugliness and black magic is gone (-3KLoC total in this one):

   - kernel_thread()/kernel_execve()/sys_execve() redesign.

     We don't do syscalls from kernel anymore for either kernel_thread()
     or kernel_execve():

     kernel_thread() is essentially clone(2) with callback run before we
     return to userland, the callbacks either never return or do
     successful do_execve() before returning.

     kernel_execve() is a wrapper for do_execve() - it doesn't need to
     do transition to user mode anymore.

     As a result kernel_thread() and kernel_execve() are
     arch-independent now - they live in kernel/fork.c and fs/exec.c
     resp.  sys_execve() is also in fs/exec.c and it's completely
     architecture-independent.

   - daemonize() is gone, along with its parts in fs/*.c

   - struct pt_regs * is no longer passed to do_fork/copy_process/
     copy_thread/do_execve/search_binary_handler/->load_binary/do_coredump.

   - sys_fork()/sys_vfork()/sys_clone() unified; some architectures
     still need wrappers (ones with callee-saved registers not saved in
     pt_regs on syscall entry), but the main part of those suckers is in
     kernel/fork.c now."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (113 commits)
  do_coredump(): get rid of pt_regs argument
  print_fatal_signal(): get rid of pt_regs argument
  ptrace_signal(): get rid of unused arguments
  get rid of ptrace_signal_deliver() arguments
  new helper: signal_pt_regs()
  unify default ptrace_signal_deliver
  flagday: kill pt_regs argument of do_fork()
  death to idle_regs()
  don't pass regs to copy_process()
  flagday: don't pass regs to copy_thread()
  bfin: switch to generic vfork, get rid of pointless wrappers
  xtensa: switch to generic clone()
  openrisc: switch to use of generic fork and clone
  unicore32: switch to generic clone(2)
  score: switch to generic fork/vfork/clone
  c6x: sanitize copy_thread(), get rid of clone(2) wrapper, switch to generic clone()
  take sys_fork/sys_vfork/sys_clone prototypes to linux/syscalls.h
  mn10300: switch to generic fork/vfork/clone
  h8300: switch to generic fork/vfork/clone
  tile: switch to generic clone()
  ...

Conflicts:
	arch/microblaze/include/asm/Kbuild
This commit is contained in:
Linus Torvalds 2012-12-12 12:22:13 -08:00
commit 9977d9b379
273 changed files with 1385 additions and 4231 deletions
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92
kernel/exit.c
View file

@ -322,43 +322,6 @@ kill_orphaned_pgrp(struct task_struct *tsk, struct task_struct *parent)
}
}
/**
* reparent_to_kthreadd - Reparent the calling kernel thread to kthreadd
*
* If a kernel thread is launched as a result of a system call, or if
* it ever exits, it should generally reparent itself to kthreadd so it
* isn't in the way of other processes and is correctly cleaned up on exit.
*
* The various task state such as scheduling policy and priority may have
* been inherited from a user process, so we reset them to sane values here.
*
* NOTE that reparent_to_kthreadd() gives the caller full capabilities.
*/
static void reparent_to_kthreadd(void)
{
write_lock_irq(&tasklist_lock);
ptrace_unlink(current);
/* Reparent to init */
current->real_parent = current->parent = kthreadd_task;
list_move_tail(&current->sibling, &current->real_parent->children);
/* Set the exit signal to SIGCHLD so we signal init on exit */
current->exit_signal = SIGCHLD;
if (task_nice(current) < 0)
set_user_nice(current, 0);
/* cpus_allowed? */
/* rt_priority? */
/* signals? */
memcpy(current->signal->rlim, init_task.signal->rlim,
sizeof(current->signal->rlim));
atomic_inc(&init_cred.usage);
commit_creds(&init_cred);
write_unlock_irq(&tasklist_lock);
}
void __set_special_pids(struct pid *pid)
{
struct task_struct *curr = current->group_leader;
@ -370,13 +333,6 @@ void __set_special_pids(struct pid *pid)
change_pid(curr, PIDTYPE_PGID, pid);
}
static void set_special_pids(struct pid *pid)
{
write_lock_irq(&tasklist_lock);
__set_special_pids(pid);
write_unlock_irq(&tasklist_lock);
}
/*
* Let kernel threads use this to say that they allow a certain signal.
* Must not be used if kthread was cloned with CLONE_SIGHAND.
@ -416,54 +372,6 @@ int disallow_signal(int sig)
EXPORT_SYMBOL(disallow_signal);
/*
* Put all the gunge required to become a kernel thread without
* attached user resources in one place where it belongs.
*/
void daemonize(const char *name, ...)
{
va_list args;
sigset_t blocked;
va_start(args, name);
vsnprintf(current->comm, sizeof(current->comm), name, args);
va_end(args);
/*
* If we were started as result of loading a module, close all of the
* user space pages. We don't need them, and if we didn't close them
* they would be locked into memory.
*/
exit_mm(current);
/*
* We don't want to get frozen, in case system-wide hibernation
* or suspend transition begins right now.
*/
current->flags |= (PF_NOFREEZE | PF_KTHREAD);
if (current->nsproxy != &init_nsproxy) {
get_nsproxy(&init_nsproxy);
switch_task_namespaces(current, &init_nsproxy);
}
set_special_pids(&init_struct_pid);
proc_clear_tty(current);
/* Block and flush all signals */
sigfillset(&blocked);
sigprocmask(SIG_BLOCK, &blocked, NULL);
flush_signals(current);
/* Become as one with the init task */
daemonize_fs_struct();
daemonize_descriptors();
reparent_to_kthreadd();
}
EXPORT_SYMBOL(daemonize);
#ifdef CONFIG_MM_OWNER
/*
* A task is exiting. If it owned this mm, find a new owner for the mm.