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Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c133
1 files changed, 103 insertions, 30 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index e7548dee636b..aeae5b11b62e 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -37,7 +37,6 @@
#include <linux/swap.h>
#include <linux/syscalls.h>
#include <linux/jiffies.h>
-#include <linux/tracehook.h>
#include <linux/futex.h>
#include <linux/compat.h>
#include <linux/kthread.h>
@@ -59,7 +58,6 @@
#include <linux/taskstats_kern.h>
#include <linux/random.h>
#include <linux/tty.h>
-#include <linux/proc_fs.h>
#include <linux/blkdev.h>
#include <linux/fs_struct.h>
#include <linux/magic.h>
@@ -383,15 +381,14 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
get_file(file);
if (tmp->vm_flags & VM_DENYWRITE)
atomic_dec(&inode->i_writecount);
- spin_lock(&mapping->i_mmap_lock);
+ mutex_lock(&mapping->i_mmap_mutex);
if (tmp->vm_flags & VM_SHARED)
mapping->i_mmap_writable++;
- tmp->vm_truncate_count = mpnt->vm_truncate_count;
flush_dcache_mmap_lock(mapping);
/* insert tmp into the share list, just after mpnt */
vma_prio_tree_add(tmp, mpnt);
flush_dcache_mmap_unlock(mapping);
- spin_unlock(&mapping->i_mmap_lock);
+ mutex_unlock(&mapping->i_mmap_mutex);
}
/*
@@ -522,11 +519,12 @@ struct mm_struct * mm_alloc(void)
struct mm_struct * mm;
mm = allocate_mm();
- if (mm) {
- memset(mm, 0, sizeof(*mm));
- mm = mm_init(mm, current);
- }
- return mm;
+ if (!mm)
+ return NULL;
+
+ memset(mm, 0, sizeof(*mm));
+ mm_init_cpumask(mm);
+ return mm_init(mm, current);
}
/*
@@ -573,6 +571,57 @@ void mmput(struct mm_struct *mm)
}
EXPORT_SYMBOL_GPL(mmput);
+/*
+ * We added or removed a vma mapping the executable. The vmas are only mapped
+ * during exec and are not mapped with the mmap system call.
+ * Callers must hold down_write() on the mm's mmap_sem for these
+ */
+void added_exe_file_vma(struct mm_struct *mm)
+{
+ mm->num_exe_file_vmas++;
+}
+
+void removed_exe_file_vma(struct mm_struct *mm)
+{
+ mm->num_exe_file_vmas--;
+ if ((mm->num_exe_file_vmas == 0) && mm->exe_file){
+ fput(mm->exe_file);
+ mm->exe_file = NULL;
+ }
+
+}
+
+void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file)
+{
+ if (new_exe_file)
+ get_file(new_exe_file);
+ if (mm->exe_file)
+ fput(mm->exe_file);
+ mm->exe_file = new_exe_file;
+ mm->num_exe_file_vmas = 0;
+}
+
+struct file *get_mm_exe_file(struct mm_struct *mm)
+{
+ struct file *exe_file;
+
+ /* We need mmap_sem to protect against races with removal of
+ * VM_EXECUTABLE vmas */
+ down_read(&mm->mmap_sem);
+ exe_file = mm->exe_file;
+ if (exe_file)
+ get_file(exe_file);
+ up_read(&mm->mmap_sem);
+ return exe_file;
+}
+
+static void dup_mm_exe_file(struct mm_struct *oldmm, struct mm_struct *newmm)
+{
+ /* It's safe to write the exe_file pointer without exe_file_lock because
+ * this is called during fork when the task is not yet in /proc */
+ newmm->exe_file = get_mm_exe_file(oldmm);
+}
+
/**
* get_task_mm - acquire a reference to the task's mm
*
@@ -679,6 +728,7 @@ struct mm_struct *dup_mm(struct task_struct *tsk)
goto fail_nomem;
memcpy(mm, oldmm, sizeof(*mm));
+ mm_init_cpumask(mm);
/* Initializing for Swap token stuff */
mm->token_priority = 0;
@@ -927,6 +977,10 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
tty_audit_fork(sig);
sched_autogroup_fork(sig);
+#ifdef CONFIG_CGROUPS
+ init_rwsem(&sig->threadgroup_fork_lock);
+#endif
+
sig->oom_adj = current->signal->oom_adj;
sig->oom_score_adj = current->signal->oom_score_adj;
sig->oom_score_adj_min = current->signal->oom_score_adj_min;
@@ -958,7 +1012,7 @@ static void rt_mutex_init_task(struct task_struct *p)
{
raw_spin_lock_init(&p->pi_lock);
#ifdef CONFIG_RT_MUTEXES
- plist_head_init_raw(&p->pi_waiters, &p->pi_lock);
+ plist_head_init(&p->pi_waiters);
p->pi_blocked_on = NULL;
#endif
}
@@ -1103,12 +1157,13 @@ static struct task_struct *copy_process(unsigned long clone_flags,
posix_cpu_timers_init(p);
- p->lock_depth = -1; /* -1 = no lock */
do_posix_clock_monotonic_gettime(&p->start_time);
p->real_start_time = p->start_time;
monotonic_to_bootbased(&p->real_start_time);
p->io_context = NULL;
p->audit_context = NULL;
+ if (clone_flags & CLONE_THREAD)
+ threadgroup_fork_read_lock(current);
cgroup_fork(p);
#ifdef CONFIG_NUMA
p->mempolicy = mpol_dup(p->mempolicy);
@@ -1153,7 +1208,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
#endif
/* Perform scheduler related setup. Assign this task to a CPU. */
- sched_fork(p, clone_flags);
+ sched_fork(p);
retval = perf_event_init_task(p);
if (retval)
@@ -1194,12 +1249,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (clone_flags & CLONE_THREAD)
p->tgid = current->tgid;
- if (current->nsproxy != p->nsproxy) {
- retval = ns_cgroup_clone(p, pid);
- if (retval)
- goto bad_fork_free_pid;
- }
-
p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
/*
* Clear TID on mm_release()?
@@ -1290,7 +1339,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
}
if (likely(p->pid)) {
- tracehook_finish_clone(p, clone_flags, trace);
+ ptrace_init_task(p, (clone_flags & CLONE_PTRACE) || trace);
if (thread_group_leader(p)) {
if (is_child_reaper(pid))
@@ -1313,6 +1362,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
write_unlock_irq(&tasklist_lock);
proc_fork_connector(p);
cgroup_post_fork(p);
+ if (clone_flags & CLONE_THREAD)
+ threadgroup_fork_read_unlock(current);
perf_event_fork(p);
return p;
@@ -1351,6 +1402,8 @@ bad_fork_cleanup_policy:
mpol_put(p->mempolicy);
bad_fork_cleanup_cgroup:
#endif
+ if (clone_flags & CLONE_THREAD)
+ threadgroup_fork_read_unlock(current);
cgroup_exit(p, cgroup_callbacks_done);
delayacct_tsk_free(p);
module_put(task_thread_info(p)->exec_domain->module);
@@ -1427,10 +1480,22 @@ long do_fork(unsigned long clone_flags,
}
/*
- * When called from kernel_thread, don't do user tracing stuff.
+ * Determine whether and which event to report to ptracer. When
+ * called from kernel_thread or CLONE_UNTRACED is explicitly
+ * requested, no event is reported; otherwise, report if the event
+ * for the type of forking is enabled.
*/
- if (likely(user_mode(regs)))
- trace = tracehook_prepare_clone(clone_flags);
+ if (likely(user_mode(regs)) && !(clone_flags & CLONE_UNTRACED)) {
+ if (clone_flags & CLONE_VFORK)
+ trace = PTRACE_EVENT_VFORK;
+ else if ((clone_flags & CSIGNAL) != SIGCHLD)
+ trace = PTRACE_EVENT_CLONE;
+ else
+ trace = PTRACE_EVENT_FORK;
+
+ if (likely(!ptrace_event_enabled(current, trace)))
+ trace = 0;
+ }
p = copy_process(clone_flags, stack_start, regs, stack_size,
child_tidptr, NULL, trace);
@@ -1454,26 +1519,26 @@ long do_fork(unsigned long clone_flags,
}
audit_finish_fork(p);
- tracehook_report_clone(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.
+ * hasn't finished SIGSTOP raising yet. Now we clear it
+ * and set the child going.
*/
p->flags &= ~PF_STARTING;
- wake_up_new_task(p, clone_flags);
+ wake_up_new_task(p);
- tracehook_report_clone_complete(trace, regs,
- clone_flags, nr, p);
+ /* forking complete and child started to run, tell ptracer */
+ if (unlikely(trace))
+ ptrace_event(trace, nr);
if (clone_flags & CLONE_VFORK) {
freezer_do_not_count();
wait_for_completion(&vfork);
freezer_count();
- tracehook_report_vfork_done(p, nr);
+ ptrace_event(PTRACE_EVENT_VFORK_DONE, nr);
}
} else {
nr = PTR_ERR(p);
@@ -1508,11 +1573,19 @@ void __init proc_caches_init(void)
fs_cachep = kmem_cache_create("fs_cache",
sizeof(struct fs_struct), 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
+ /*
+ * FIXME! The "sizeof(struct mm_struct)" currently includes the
+ * whole struct cpumask for the OFFSTACK case. We could change
+ * this to *only* allocate as much of it as required by the
+ * maximum number of CPU's we can ever have. The cpumask_allocation
+ * is at the end of the structure, exactly for that reason.
+ */
mm_cachep = kmem_cache_create("mm_struct",
sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_NOTRACK, NULL);
vm_area_cachep = KMEM_CACHE(vm_area_struct, SLAB_PANIC);
mmap_init();
+ nsproxy_cache_init();
}
/*
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-31 01:51:16 +0000