diff options
Diffstat (limited to 'kernel/fork.c')
-rw-r--r-- | kernel/fork.c | 75 |
1 files changed, 29 insertions, 46 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index b4cba953040a..847dd147b068 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * linux/kernel/fork.c * @@ -122,7 +123,7 @@ unsigned long total_forks; /* Handle normal Linux uptimes. */ int nr_threads; /* The idle threads do not count.. */ -int max_threads; /* tunable limit on nr_threads */ +static int max_threads; /* tunable limit on nr_threads */ DEFINE_PER_CPU(unsigned long, process_counts) = 0; @@ -247,7 +248,11 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node) struct page *page = alloc_pages_node(node, THREADINFO_GFP, THREAD_SIZE_ORDER); - return page ? page_address(page) : NULL; + if (likely(page)) { + tsk->stack = page_address(page); + return tsk->stack; + } + return NULL; #endif } @@ -893,6 +898,8 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) #ifdef CONFIG_STACKPROTECTOR tsk->stack_canary = get_random_canary(); #endif + if (orig->cpus_ptr == &orig->cpus_mask) + tsk->cpus_ptr = &tsk->cpus_mask; /* * One for us, one for whoever does the "release_task()" (usually @@ -1711,31 +1718,6 @@ const struct file_operations pidfd_fops = { #endif }; -/** - * pidfd_create() - Create a new pid file descriptor. - * - * @pid: struct pid that the pidfd will reference - * - * This creates a new pid file descriptor with the O_CLOEXEC flag set. - * - * Note, that this function can only be called after the fd table has - * been unshared to avoid leaking the pidfd to the new process. - * - * Return: On success, a cloexec pidfd is returned. - * On error, a negative errno number will be returned. - */ -static int pidfd_create(struct pid *pid) -{ - int fd; - - fd = anon_inode_getfd("[pidfd]", &pidfd_fops, get_pid(pid), - O_RDWR | O_CLOEXEC); - if (fd < 0) - put_pid(pid); - - return fd; -} - static void __delayed_free_task(struct rcu_head *rhp) { struct task_struct *tsk = container_of(rhp, struct task_struct, rcu); @@ -1773,6 +1755,7 @@ static __latent_entropy struct task_struct *copy_process( int pidfd = -1, retval; struct task_struct *p; struct multiprocess_signals delayed; + struct file *pidfile = NULL; /* * Don't allow sharing the root directory with processes in a different @@ -1821,8 +1804,6 @@ static __latent_entropy struct task_struct *copy_process( } if (clone_flags & CLONE_PIDFD) { - int reserved; - /* * - CLONE_PARENT_SETTID is useless for pidfds and also * parent_tidptr is used to return pidfds. @@ -1833,16 +1814,6 @@ static __latent_entropy struct task_struct *copy_process( if (clone_flags & (CLONE_DETACHED | CLONE_PARENT_SETTID | CLONE_THREAD)) return ERR_PTR(-EINVAL); - - /* - * Verify that parent_tidptr is sane so we can potentially - * reuse it later. - */ - if (get_user(reserved, parent_tidptr)) - return ERR_PTR(-EFAULT); - - if (reserved != 0) - return ERR_PTR(-EINVAL); } /* @@ -1983,9 +1954,6 @@ static __latent_entropy struct task_struct *copy_process( p->pagefault_disabled = 0; #ifdef CONFIG_LOCKDEP - p->lockdep_depth = 0; /* no locks held yet */ - p->curr_chain_key = 0; - p->lockdep_recursion = 0; lockdep_init_task(p); #endif @@ -2057,11 +2025,21 @@ static __latent_entropy struct task_struct *copy_process( * if the fd table isn't shared). */ if (clone_flags & CLONE_PIDFD) { - retval = pidfd_create(pid); + retval = get_unused_fd_flags(O_RDWR | O_CLOEXEC); if (retval < 0) goto bad_fork_free_pid; pidfd = retval; + + pidfile = anon_inode_getfile("[pidfd]", &pidfd_fops, pid, + O_RDWR | O_CLOEXEC); + if (IS_ERR(pidfile)) { + put_unused_fd(pidfd); + retval = PTR_ERR(pidfile); + goto bad_fork_free_pid; + } + get_pid(pid); /* held by pidfile now */ + retval = put_user(pidfd, parent_tidptr); if (retval) goto bad_fork_put_pidfd; @@ -2138,7 +2116,7 @@ static __latent_entropy struct task_struct *copy_process( */ p->start_time = ktime_get_ns(); - p->real_start_time = ktime_get_boot_ns(); + p->real_start_time = ktime_get_boottime_ns(); /* * Make it visible to the rest of the system, but dont wake it up yet. @@ -2179,6 +2157,9 @@ static __latent_entropy struct task_struct *copy_process( goto bad_fork_cancel_cgroup; } + /* past the last point of failure */ + if (pidfile) + fd_install(pidfd, pidfile); init_task_pid_links(p); if (likely(p->pid)) { @@ -2245,8 +2226,10 @@ bad_fork_cancel_cgroup: bad_fork_cgroup_threadgroup_change_end: cgroup_threadgroup_change_end(current); bad_fork_put_pidfd: - if (clone_flags & CLONE_PIDFD) - ksys_close(pidfd); + if (clone_flags & CLONE_PIDFD) { + fput(pidfile); + put_unused_fd(pidfd); + } bad_fork_free_pid: if (pid != &init_struct_pid) free_pid(pid); |