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author | 2019-07-02 14:34:43 -0300 | |
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committer | 2019-07-02 14:34:43 -0300 | |
commit | 9ec3f4cb35bc8278f0582fed9f9229c9315c2ffb (patch) | |
tree | 3ff6a17a33913268a2ed06e7d9a1a95e29eeee97 /kernel/fork.c | |
parent | mm/swap: fix release_pages() when releasing devmap pages (diff) | |
parent | Linux 5.2-rc7 (diff) | |
download | linux-9ec3f4cb35bc8278f0582fed9f9229c9315c2ffb.tar.gz linux-9ec3f4cb35bc8278f0582fed9f9229c9315c2ffb.tar.bz2 linux-9ec3f4cb35bc8278f0582fed9f9229c9315c2ffb.zip |
Merge tag 'v5.2-rc7' into rdma.git hmm
Required for dependencies in the next patches.
Diffstat (limited to 'kernel/fork.c')
-rw-r--r-- | kernel/fork.c | 64 |
1 files changed, 23 insertions, 41 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index c704c3cedee7..129de589599c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -248,7 +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 } @@ -1711,31 +1715,6 @@ 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 +1752,7 @@ 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 +1801,6 @@ 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 +1811,6 @@ 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); } /* @@ -2057,11 +2025,20 @@ 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); + 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; @@ -2179,6 +2156,9 @@ 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 +2225,10 @@ 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); |