1 files changed, 35 insertions, 66 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index b99d73e971a4..7ce2ebe84796 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -27,6 +27,7 @@
 #include <linux/key.h>
 #include <linux/binfmts.h>
 #include <linux/mman.h>
+#include <linux/mmu_notifier.h>
 #include <linux/fs.h>
 #include <linux/nsproxy.h>
 #include <linux/capability.h>
@@ -37,6 +38,7 @@
 #include <linux/swap.h>
 #include <linux/syscalls.h>
 #include <linux/jiffies.h>
+#include <linux/tracehook.h>
 #include <linux/futex.h>
 #include <linux/task_io_accounting_ops.h>
 #include <linux/rcupdate.h>
@@ -413,6 +415,7 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
 
         if (likely(!mm_alloc_pgd(mm))) {
                 mm->def_flags = 0;
+                mmu_notifier_mm_init(mm);
                 return mm;
         }
 
@@ -445,6 +448,7 @@ void __mmdrop(struct mm_struct *mm)
         BUG_ON(mm == &init_mm);
         mm_free_pgd(mm);
         destroy_context(mm);
+        mmu_notifier_mm_destroy(mm);
         free_mm(mm);
 }
 EXPORT_SYMBOL_GPL(__mmdrop);
@@ -656,13 +660,6 @@ static struct fs_struct *__copy_fs_struct(struct fs_struct *old)
                 path_get(&old->root);
                 fs->pwd = old->pwd;
                 path_get(&old->pwd);
-                if (old->altroot.dentry) {
-                        fs->altroot = old->altroot;
-                        path_get(&old->altroot);
-                } else {
-                        fs->altroot.mnt = NULL;
-                        fs->altroot.dentry = NULL;
-                }
                 read_unlock(&old->lock);
         }
         return fs;
@@ -812,12 +809,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
         sig->nvcsw = sig->nivcsw = sig->cnvcsw = sig->cnivcsw = 0;
         sig->min_flt = sig->maj_flt = sig->cmin_flt = sig->cmaj_flt = 0;
         sig->inblock = sig->oublock = sig->cinblock = sig->coublock = 0;
-#ifdef CONFIG_TASK_XACCT
-        sig->rchar = sig->wchar = sig->syscr = sig->syscw = 0;
-#endif
-#ifdef CONFIG_TASK_IO_ACCOUNTING
-        memset(&sig->ioac, 0, sizeof(sig->ioac));
-#endif
+        task_io_accounting_init(&sig->ioac);
         sig->sum_sched_runtime = 0;
         INIT_LIST_HEAD(&sig->cpu_timers[0]);
         INIT_LIST_HEAD(&sig->cpu_timers[1]);
@@ -865,8 +857,7 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p)
 
         new_flags &= ~PF_SUPERPRIV;
         new_flags |= PF_FORKNOEXEC;
-        if (!(clone_flags & CLONE_PTRACE))
-                p->ptrace = 0;
+        new_flags |= PF_STARTING;
         p->flags = new_flags;
         clear_freeze_flag(p);
 }
@@ -907,7 +898,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                                         struct pt_regs *regs,
                                         unsigned long stack_size,
                                         int __user *child_tidptr,
-                                        struct pid *pid)
+                                        struct pid *pid,
+                                        int trace)
 {
         int retval;
         struct task_struct *p;
@@ -1000,13 +992,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
         p->last_switch_timestamp = 0;
 #endif
 
-#ifdef CONFIG_TASK_XACCT
-        p->rchar = 0;           /* I/O counter: bytes read */
-        p->wchar = 0;           /* I/O counter: bytes written */
-        p->syscr = 0;           /* I/O counter: read syscalls */
-        p->syscw = 0;           /* I/O counter: write syscalls */
-#endif
-        task_io_accounting_init(p);
+        task_io_accounting_init(&p->ioac);
         acct_clear_integrals(p);
 
         p->it_virt_expires = cputime_zero;
@@ -1163,8 +1149,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
          */
         p->group_leader = p;
         INIT_LIST_HEAD(&p->thread_group);
-        INIT_LIST_HEAD(&p->ptrace_entry);
-        INIT_LIST_HEAD(&p->ptraced);
 
         /* Now that the task is set up, run cgroup callbacks if
          * necessary. We need to run them before the task is visible
@@ -1195,7 +1179,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                 p->real_parent = current->real_parent;
         else
                 p->real_parent = current;
-        p->parent = p->real_parent;
 
         spin_lock(&current->sighand->siglock);
 
@@ -1237,8 +1220,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
         if (likely(p->pid)) {
                 list_add_tail(&p->sibling, &p->real_parent->children);
-                if (unlikely(p->ptrace & PT_PTRACED))
-                        __ptrace_link(p, current->parent);
+                tracehook_finish_clone(p, clone_flags, trace);
 
                 if (thread_group_leader(p)) {
                         if (clone_flags & CLONE_NEWPID)
@@ -1323,29 +1305,13 @@ struct task_struct * __cpuinit fork_idle(int cpu)
         struct pt_regs regs;
 
         task = copy_process(CLONE_VM, 0, idle_regs(&regs), 0, NULL,
-                                &init_struct_pid);
+                            &init_struct_pid, 0);
         if (!IS_ERR(task))
                 init_idle(task, cpu);
 
         return task;
 }
 
-static int fork_traceflag(unsigned clone_flags)
-{
-        if (clone_flags & CLONE_UNTRACED)
-                return 0;
-        else if (clone_flags & CLONE_VFORK) {
-                if (current->ptrace & PT_TRACE_VFORK)
-                        return PTRACE_EVENT_VFORK;
-        } else if ((clone_flags & CSIGNAL) != SIGCHLD) {
-                if (current->ptrace & PT_TRACE_CLONE)
-                        return PTRACE_EVENT_CLONE;
-        } else if (current->ptrace & PT_TRACE_FORK)
-                return PTRACE_EVENT_FORK;
-
-        return 0;
-}
-
 /*
  *  Ok, this is the main fork-routine.
  *
@@ -1380,14 +1346,14 @@ long do_fork(unsigned long clone_flags,
                 }
         }
 
-        if (unlikely(current->ptrace)) {
-                trace = fork_traceflag (clone_flags);
-                if (trace)
-                        clone_flags |= CLONE_PTRACE;
-        }
+        /*
+         * When called from kernel_thread, don't do user tracing stuff.
+         */
+        if (likely(user_mode(regs)))
+                trace = tracehook_prepare_clone(clone_flags);
 
         p = copy_process(clone_flags, stack_start, regs, stack_size,
-                        child_tidptr, NULL);
+                         child_tidptr, NULL, trace);
         /*
          * Do this prior waking up the new thread - the thread pointer
          * might get invalid after that point, if the thread exits quickly.
@@ -1405,32 +1371,35 @@ long do_fork(unsigned long clone_flags,
                         init_completion(&vfork);
                 }
 
-                if ((p->ptrace & PT_PTRACED) || (clone_flags & CLONE_STOPPED)) {
+                tracehook_report_clone(trace, regs, clone_flags, nr, p);
+
+                /*
+                 * We set PF_STARTING at creation in case tracing wants to
+                 * use this to distinguish a fully live task from one that
+                 * hasn't gotten to tracehook_report_clone() yet.  Now we
+                 * clear it and set the child going.
+                 */
+                p->flags &= ~PF_STARTING;
+
+                if (unlikely(clone_flags & CLONE_STOPPED)) {
                         /*
                          * We'll start up with an immediate SIGSTOP.
                          */
                         sigaddset(&p->pending.signal, SIGSTOP);
                         set_tsk_thread_flag(p, TIF_SIGPENDING);
-                }
-
-                if (!(clone_flags & CLONE_STOPPED))
-                        wake_up_new_task(p, clone_flags);
-                else
                         __set_task_state(p, TASK_STOPPED);
-
-                if (unlikely (trace)) {
-                        current->ptrace_message = nr;
-                        ptrace_notify ((trace << 8) | SIGTRAP);
+                } else {
+                        wake_up_new_task(p, clone_flags);
                 }
 
+                tracehook_report_clone_complete(trace, regs,
+                                                clone_flags, nr, p);
+
                 if (clone_flags & CLONE_VFORK) {
                         freezer_do_not_count();
                         wait_for_completion(&vfork);
                         freezer_count();
-                        if (unlikely (current->ptrace & PT_TRACE_VFORK_DONE)) {
-                                current->ptrace_message = nr;
-                                ptrace_notify ((PTRACE_EVENT_VFORK_DONE << 8) | SIGTRAP);
-                        }
+                        tracehook_report_vfork_done(p, nr);
                 }
         } else {
                 nr = PTR_ERR(p);
@@ -1442,7 +1411,7 @@ long do_fork(unsigned long clone_flags,
 #define ARCH_MIN_MMSTRUCT_ALIGN 0
 #endif
 
-static void sighand_ctor(struct kmem_cache *cachep, void *data)
+static void sighand_ctor(void *data)
 {
         struct sighand_struct *sighand = data;