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Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c136
1 files changed, 82 insertions, 54 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index f6083561dfe..bf0cef8bbdf 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -40,12 +40,14 @@
#include <linux/jiffies.h>
#include <linux/tracehook.h>
#include <linux/futex.h>
+#include <linux/compat.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/rcupdate.h>
#include <linux/ptrace.h>
#include <linux/mount.h>
#include <linux/audit.h>
#include <linux/memcontrol.h>
+#include <linux/ftrace.h>
#include <linux/profile.h>
#include <linux/rmap.h>
#include <linux/acct.h>
@@ -79,6 +81,8 @@ DEFINE_PER_CPU(unsigned long, process_counts) = 0;
__cacheline_aligned DEFINE_RWLOCK(tasklist_lock); /* outer */
+DEFINE_TRACE(sched_process_fork);
+
int nr_processes(void)
{
int cpu;
@@ -136,6 +140,7 @@ void free_task(struct task_struct *tsk)
prop_local_destroy_single(&tsk->dirties);
free_thread_info(tsk->stack);
rt_mutex_debug_task_free(tsk);
+ ftrace_graph_exit_task(tsk);
free_task_struct(tsk);
}
EXPORT_SYMBOL(free_task);
@@ -146,9 +151,8 @@ void __put_task_struct(struct task_struct *tsk)
WARN_ON(atomic_read(&tsk->usage));
WARN_ON(tsk == current);
- security_task_free(tsk);
- free_uid(tsk->user);
- put_group_info(tsk->group_info);
+ put_cred(tsk->real_cred);
+ put_cred(tsk->cred);
delayacct_tsk_free(tsk);
if (!profile_handoff_task(tsk))
@@ -314,17 +318,20 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
file = tmp->vm_file;
if (file) {
struct inode *inode = file->f_path.dentry->d_inode;
+ struct address_space *mapping = file->f_mapping;
+
get_file(file);
if (tmp->vm_flags & VM_DENYWRITE)
atomic_dec(&inode->i_writecount);
-
- /* insert tmp into the share list, just after mpnt */
- spin_lock(&file->f_mapping->i_mmap_lock);
+ spin_lock(&mapping->i_mmap_lock);
+ if (tmp->vm_flags & VM_SHARED)
+ mapping->i_mmap_writable++;
tmp->vm_truncate_count = mpnt->vm_truncate_count;
- flush_dcache_mmap_lock(file->f_mapping);
+ flush_dcache_mmap_lock(mapping);
+ /* insert tmp into the share list, just after mpnt */
vma_prio_tree_add(tmp, mpnt);
- flush_dcache_mmap_unlock(file->f_mapping);
- spin_unlock(&file->f_mapping->i_mmap_lock);
+ flush_dcache_mmap_unlock(mapping);
+ spin_unlock(&mapping->i_mmap_lock);
}
/*
@@ -393,6 +400,18 @@ __cacheline_aligned_in_smp DEFINE_SPINLOCK(mmlist_lock);
#define allocate_mm() (kmem_cache_alloc(mm_cachep, GFP_KERNEL))
#define free_mm(mm) (kmem_cache_free(mm_cachep, (mm)))
+static unsigned long default_dump_filter = MMF_DUMP_FILTER_DEFAULT;
+
+static int __init coredump_filter_setup(char *s)
+{
+ default_dump_filter =
+ (simple_strtoul(s, NULL, 0) << MMF_DUMP_FILTER_SHIFT) &
+ MMF_DUMP_FILTER_MASK;
+ return 1;
+}
+
+__setup("coredump_filter=", coredump_filter_setup);
+
#include <linux/init_task.h>
static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
@@ -401,15 +420,14 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
atomic_set(&mm->mm_count, 1);
init_rwsem(&mm->mmap_sem);
INIT_LIST_HEAD(&mm->mmlist);
- mm->flags = (current->mm) ? current->mm->flags
- : MMF_DUMP_FILTER_DEFAULT;
+ mm->flags = (current->mm) ? current->mm->flags : default_dump_filter;
mm->core_state = NULL;
mm->nr_ptes = 0;
set_mm_counter(mm, file_rss, 0);
set_mm_counter(mm, anon_rss, 0);
spin_lock_init(&mm->page_table_lock);
- rwlock_init(&mm->ioctx_list_lock);
- mm->ioctx_list = NULL;
+ spin_lock_init(&mm->ioctx_lock);
+ INIT_HLIST_HEAD(&mm->ioctx_list);
mm->free_area_cache = TASK_UNMAPPED_BASE;
mm->cached_hole_size = ~0UL;
mm_init_owner(mm, p);
@@ -519,6 +537,16 @@ void mm_release(struct task_struct *tsk, struct mm_struct *mm)
{
struct completion *vfork_done = tsk->vfork_done;
+ /* Get rid of any futexes when releasing the mm */
+#ifdef CONFIG_FUTEX
+ if (unlikely(tsk->robust_list))
+ exit_robust_list(tsk);
+#ifdef CONFIG_COMPAT
+ if (unlikely(tsk->compat_robust_list))
+ compat_exit_robust_list(tsk);
+#endif
+#endif
+
/* Get rid of any cached register state */
deactivate_mm(tsk, mm);
@@ -741,7 +769,7 @@ static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk)
{
struct sighand_struct *sig;
- if (clone_flags & (CLONE_SIGHAND | CLONE_THREAD)) {
+ if (clone_flags & CLONE_SIGHAND) {
atomic_inc(&current->sighand->count);
return 0;
}
@@ -804,12 +832,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
if (!sig)
return -ENOMEM;
- ret = copy_thread_group_keys(tsk);
- if (ret < 0) {
- kmem_cache_free(signal_cachep, sig);
- return ret;
- }
-
atomic_set(&sig->count, 1);
atomic_set(&sig->live, 1);
init_waitqueue_head(&sig->wait_chldexit);
@@ -854,7 +876,6 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk)
void __cleanup_signal(struct signal_struct *sig)
{
thread_group_cputime_free(sig);
- exit_thread_group_keys(sig);
tty_kref_put(sig->tty);
kmem_cache_free(signal_cachep, sig);
}
@@ -880,7 +901,7 @@ static void copy_flags(unsigned long clone_flags, struct task_struct *p)
clear_freeze_flag(p);
}
-asmlinkage long sys_set_tid_address(int __user *tidptr)
+SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr)
{
current->clear_child_tid = tidptr;
@@ -970,16 +991,16 @@ static struct task_struct *copy_process(unsigned long clone_flags,
DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
#endif
retval = -EAGAIN;
- if (atomic_read(&p->user->processes) >=
+ if (atomic_read(&p->real_cred->user->processes) >=
p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
- p->user != current->nsproxy->user_ns->root_user)
+ p->real_cred->user != INIT_USER)
goto bad_fork_free;
}
- atomic_inc(&p->user->__count);
- atomic_inc(&p->user->processes);
- get_group_info(p->group_info);
+ retval = copy_creds(p, clone_flags);
+ if (retval < 0)
+ goto bad_fork_free;
/*
* If multiple threads are within copy_process(), then this check
@@ -1034,10 +1055,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
do_posix_clock_monotonic_gettime(&p->start_time);
p->real_start_time = p->start_time;
monotonic_to_bootbased(&p->real_start_time);
-#ifdef CONFIG_SECURITY
- p->security = NULL;
-#endif
- p->cap_bset = current->cap_bset;
p->io_context = NULL;
p->audit_context = NULL;
cgroup_fork(p);
@@ -1078,14 +1095,14 @@ static struct task_struct *copy_process(unsigned long clone_flags,
#ifdef CONFIG_DEBUG_MUTEXES
p->blocked_on = NULL; /* not blocked yet */
#endif
+ if (unlikely(ptrace_reparented(current)))
+ ptrace_fork(p, clone_flags);
/* Perform scheduler related setup. Assign this task to a CPU. */
sched_fork(p, clone_flags);
- if ((retval = security_task_alloc(p)))
- goto bad_fork_cleanup_policy;
if ((retval = audit_alloc(p)))
- goto bad_fork_cleanup_security;
+ goto bad_fork_cleanup_policy;
/* copy all the process information */
if ((retval = copy_semundo(clone_flags, p)))
goto bad_fork_cleanup_audit;
@@ -1099,10 +1116,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
goto bad_fork_cleanup_sighand;
if ((retval = copy_mm(clone_flags, p)))
goto bad_fork_cleanup_signal;
- if ((retval = copy_keys(clone_flags, p)))
- goto bad_fork_cleanup_mm;
if ((retval = copy_namespaces(clone_flags, p)))
- goto bad_fork_cleanup_keys;
+ goto bad_fork_cleanup_mm;
if ((retval = copy_io(clone_flags, p)))
goto bad_fork_cleanup_namespaces;
retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
@@ -1111,17 +1126,19 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (pid != &init_struct_pid) {
retval = -ENOMEM;
- pid = alloc_pid(task_active_pid_ns(p));
+ pid = alloc_pid(p->nsproxy->pid_ns);
if (!pid)
goto bad_fork_cleanup_io;
if (clone_flags & CLONE_NEWPID) {
- retval = pid_ns_prepare_proc(task_active_pid_ns(p));
+ retval = pid_ns_prepare_proc(p->nsproxy->pid_ns);
if (retval < 0)
goto bad_fork_free_pid;
}
}
+ ftrace_graph_init_task(p);
+
p->pid = pid_nr(pid);
p->tgid = p->pid;
if (clone_flags & CLONE_THREAD)
@@ -1130,7 +1147,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (current->nsproxy != p->nsproxy) {
retval = ns_cgroup_clone(p, pid);
if (retval)
- goto bad_fork_free_pid;
+ goto bad_fork_free_graph;
}
p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
@@ -1223,7 +1240,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
spin_unlock(&current->sighand->siglock);
write_unlock_irq(&tasklist_lock);
retval = -ERESTARTNOINTR;
- goto bad_fork_free_pid;
+ goto bad_fork_free_graph;
}
if (clone_flags & CLONE_THREAD) {
@@ -1260,6 +1277,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
cgroup_post_fork(p);
return p;
+bad_fork_free_graph:
+ ftrace_graph_exit_task(p);
bad_fork_free_pid:
if (pid != &init_struct_pid)
free_pid(pid);
@@ -1267,8 +1286,6 @@ bad_fork_cleanup_io:
put_io_context(p->io_context);
bad_fork_cleanup_namespaces:
exit_task_namespaces(p);
-bad_fork_cleanup_keys:
- exit_keys(p);
bad_fork_cleanup_mm:
if (p->mm)
mmput(p->mm);
@@ -1284,8 +1301,6 @@ bad_fork_cleanup_semundo:
exit_sem(p);
bad_fork_cleanup_audit:
audit_free(p);
-bad_fork_cleanup_security:
- security_task_free(p);
bad_fork_cleanup_policy:
#ifdef CONFIG_NUMA
mpol_put(p->mempolicy);
@@ -1298,9 +1313,9 @@ bad_fork_cleanup_cgroup:
bad_fork_cleanup_put_domain:
module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
- put_group_info(p->group_info);
- atomic_dec(&p->user->processes);
- free_uid(p->user);
+ atomic_dec(&p->cred->user->processes);
+ put_cred(p->real_cred);
+ put_cred(p->cred);
bad_fork_free:
free_task(p);
fork_out:
@@ -1344,6 +1359,21 @@ long do_fork(unsigned long clone_flags,
long nr;
/*
+ * Do some preliminary argument and permissions checking before we
+ * actually start allocating stuff
+ */
+ if (clone_flags & CLONE_NEWUSER) {
+ if (clone_flags & CLONE_THREAD)
+ return -EINVAL;
+ /* hopefully this check will go away when userns support is
+ * complete
+ */
+ if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SETUID) ||
+ !capable(CAP_SETGID))
+ return -EPERM;
+ }
+
+ /*
* We hope to recycle these flags after 2.6.26
*/
if (unlikely(clone_flags & CLONE_STOPPED)) {
@@ -1387,6 +1417,7 @@ long do_fork(unsigned long clone_flags,
init_completion(&vfork);
}
+ audit_finish_fork(p);
tracehook_report_clone(trace, regs, clone_flags, nr, p);
/*
@@ -1450,12 +1481,10 @@ void __init proc_caches_init(void)
fs_cachep = kmem_cache_create("fs_cache",
sizeof(struct fs_struct), 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
- vm_area_cachep = kmem_cache_create("vm_area_struct",
- sizeof(struct vm_area_struct), 0,
- SLAB_PANIC, NULL);
mm_cachep = kmem_cache_create("mm_struct",
sizeof(struct mm_struct), ARCH_MIN_MMSTRUCT_ALIGN,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+ mmap_init();
}
/*
@@ -1574,7 +1603,7 @@ static int unshare_fd(unsigned long unshare_flags, struct files_struct **new_fdp
* constructed. Here we are modifying the current, active,
* task_struct.
*/
-asmlinkage long sys_unshare(unsigned long unshare_flags)
+SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags)
{
int err = 0;
struct fs_struct *fs, *new_fs = NULL;
@@ -1590,8 +1619,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
err = -EINVAL;
if (unshare_flags & ~(CLONE_THREAD|CLONE_FS|CLONE_NEWNS|CLONE_SIGHAND|
CLONE_VM|CLONE_FILES|CLONE_SYSVSEM|
- CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWUSER|
- CLONE_NEWNET))
+ CLONE_NEWUTS|CLONE_NEWIPC|CLONE_NEWNET))
goto bad_unshare_out;
/*
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-03 22:00:15 +0000