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Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c102
1 files changed, 55 insertions, 47 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index fbd3497b221..9b7d746d6d6 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -294,11 +294,18 @@ int __weak arch_dup_task_struct(struct task_struct *dst,
return 0;
}
+void set_task_stack_end_magic(struct task_struct *tsk)
+{
+ unsigned long *stackend;
+
+ stackend = end_of_stack(tsk);
+ *stackend = STACK_END_MAGIC; /* for overflow detection */
+}
+
static struct task_struct *dup_task_struct(struct task_struct *orig)
{
struct task_struct *tsk;
struct thread_info *ti;
- unsigned long *stackend;
int node = tsk_fork_get_node(orig);
int err;
@@ -328,8 +335,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
clear_tsk_need_resched(tsk);
- stackend = end_of_stack(tsk);
- *stackend = STACK_END_MAGIC; /* for overflow detection */
+ set_task_stack_end_magic(tsk);
#ifdef CONFIG_CC_STACKPROTECTOR
tsk->stack_canary = get_random_int();
@@ -374,12 +380,11 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
*/
down_write_nested(&mm->mmap_sem, SINGLE_DEPTH_NESTING);
- mm->locked_vm = 0;
- mm->mmap = NULL;
- mm->vmacache_seqnum = 0;
- mm->map_count = 0;
- cpumask_clear(mm_cpumask(mm));
- mm->mm_rb = RB_ROOT;
+ mm->total_vm = oldmm->total_vm;
+ mm->shared_vm = oldmm->shared_vm;
+ mm->exec_vm = oldmm->exec_vm;
+ mm->stack_vm = oldmm->stack_vm;
+
rb_link = &mm->mm_rb.rb_node;
rb_parent = NULL;
pprev = &mm->mmap;
@@ -430,7 +435,7 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
atomic_dec(&inode->i_writecount);
mutex_lock(&mapping->i_mmap_mutex);
if (tmp->vm_flags & VM_SHARED)
- mapping->i_mmap_writable++;
+ atomic_inc(&mapping->i_mmap_writable);
flush_dcache_mmap_lock(mapping);
/* insert tmp into the share list, just after mpnt */
if (unlikely(tmp->vm_flags & VM_NONLINEAR))
@@ -536,19 +541,37 @@ static void mm_init_aio(struct mm_struct *mm)
#endif
}
+static void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
+{
+#ifdef CONFIG_MEMCG
+ mm->owner = p;
+#endif
+}
+
static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
{
+ mm->mmap = NULL;
+ mm->mm_rb = RB_ROOT;
+ mm->vmacache_seqnum = 0;
atomic_set(&mm->mm_users, 1);
atomic_set(&mm->mm_count, 1);
init_rwsem(&mm->mmap_sem);
INIT_LIST_HEAD(&mm->mmlist);
mm->core_state = NULL;
atomic_long_set(&mm->nr_ptes, 0);
+ mm->map_count = 0;
+ mm->locked_vm = 0;
+ mm->pinned_vm = 0;
memset(&mm->rss_stat, 0, sizeof(mm->rss_stat));
spin_lock_init(&mm->page_table_lock);
+ mm_init_cpumask(mm);
mm_init_aio(mm);
mm_init_owner(mm, p);
+ mmu_notifier_mm_init(mm);
clear_tlb_flush_pending(mm);
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
+ mm->pmd_huge_pte = NULL;
+#endif
if (current->mm) {
mm->flags = current->mm->flags & MMF_INIT_MASK;
@@ -558,11 +581,17 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p)
mm->def_flags = 0;
}
- if (likely(!mm_alloc_pgd(mm))) {
- mmu_notifier_mm_init(mm);
- return mm;
- }
+ if (mm_alloc_pgd(mm))
+ goto fail_nopgd;
+ if (init_new_context(p, mm))
+ goto fail_nocontext;
+
+ return mm;
+
+fail_nocontext:
+ mm_free_pgd(mm);
+fail_nopgd:
free_mm(mm);
return NULL;
}
@@ -578,9 +607,8 @@ static void check_mm(struct mm_struct *mm)
printk(KERN_ALERT "BUG: Bad rss-counter state "
"mm:%p idx:%d val:%ld\n", mm, i, x);
}
-
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
- VM_BUG_ON(mm->pmd_huge_pte);
+ VM_BUG_ON_MM(mm->pmd_huge_pte, mm);
#endif
}
@@ -596,7 +624,6 @@ struct mm_struct *mm_alloc(void)
return NULL;
memset(mm, 0, sizeof(*mm));
- mm_init_cpumask(mm);
return mm_init(mm, current);
}
@@ -828,17 +855,10 @@ static struct mm_struct *dup_mm(struct task_struct *tsk)
goto fail_nomem;
memcpy(mm, oldmm, sizeof(*mm));
- mm_init_cpumask(mm);
-#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
- mm->pmd_huge_pte = NULL;
-#endif
if (!mm_init(mm, tsk))
goto fail_nomem;
- if (init_new_context(tsk, mm))
- goto fail_nocontext;
-
dup_mm_exe_file(oldmm, mm);
err = dup_mmap(mm, oldmm);
@@ -860,15 +880,6 @@ free_pt:
fail_nomem:
return NULL;
-
-fail_nocontext:
- /*
- * If init_new_context() failed, we cannot use mmput() to free the mm
- * because it calls destroy_context()
- */
- mm_free_pgd(mm);
- free_mm(mm);
- return NULL;
}
static int copy_mm(unsigned long clone_flags, struct task_struct *tsk)
@@ -1062,6 +1073,7 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
sig->curr_target = tsk;
init_sigpending(&sig->shared_pending);
INIT_LIST_HEAD(&sig->posix_timers);
+ seqlock_init(&sig->stats_lock);
hrtimer_init(&sig->real_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
sig->real_timer.function = it_real_fn;
@@ -1099,7 +1111,7 @@ static void copy_seccomp(struct task_struct *p)
* needed because this new task is not yet running and cannot
* be racing exec.
*/
- BUG_ON(!spin_is_locked(&current->sighand->siglock));
+ assert_spin_locked(&current->sighand->siglock);
/* Ref-count the new filter user, and assign it. */
get_seccomp_filter(current);
@@ -1140,13 +1152,6 @@ static void rt_mutex_init_task(struct task_struct *p)
#endif
}
-#ifdef CONFIG_MEMCG
-void mm_init_owner(struct mm_struct *mm, struct task_struct *p)
-{
- mm->owner = p;
-}
-#endif /* CONFIG_MEMCG */
-
/*
* Initialize POSIX timer handling for a single task.
*/
@@ -1346,10 +1351,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
#ifdef CONFIG_DEBUG_MUTEXES
p->blocked_on = NULL; /* not blocked yet */
#endif
-#ifdef CONFIG_MEMCG
- p->memcg_batch.do_batch = 0;
- p->memcg_batch.memcg = NULL;
-#endif
#ifdef CONFIG_BCACHE
p->sequential_io = 0;
p->sequential_io_avg = 0;
@@ -1365,8 +1366,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto bad_fork_cleanup_policy;
retval = audit_alloc(p);
if (retval)
- goto bad_fork_cleanup_policy;
+ goto bad_fork_cleanup_perf;
/* copy all the process information */
+ shm_init_task(p);
retval = copy_semundo(clone_flags, p);
if (retval)
goto bad_fork_cleanup_audit;
@@ -1570,8 +1572,9 @@ bad_fork_cleanup_semundo:
exit_sem(p);
bad_fork_cleanup_audit:
audit_free(p);
-bad_fork_cleanup_policy:
+bad_fork_cleanup_perf:
perf_event_free_task(p);
+bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
mpol_put(p->mempolicy);
bad_fork_cleanup_threadgroup_lock:
@@ -1918,6 +1921,11 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
*/
exit_sem(current);
}
+ if (unshare_flags & CLONE_NEWIPC) {
+ /* Orphan segments in old ns (see sem above). */
+ exit_shm(current);
+ shm_init_task(current);
+ }
if (new_nsproxy)
switch_task_namespaces(current, new_nsproxy);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-03-03 09:05:47 +0000