diff --git a/drivers/android/binder.c b/drivers/android/binder.c index 89b590c95..08f6b7b01 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -2232,10 +2232,12 @@ static void binder_deferred_fd_close(int fd) return; init_task_work(&twcb->twork, binder_do_fd_close); __close_fd_get_file(fd, &twcb->file); - if (twcb->file) + if (twcb->file) { + filp_close(twcb->file, current->files); task_work_add(current, &twcb->twork, true); - else + } else { kfree(twcb); + } } static void binder_transaction_buffer_release(struct binder_proc *proc, diff --git a/fs/file.c b/fs/file.c index e5d328335..759f4a534 100644 --- a/fs/file.c +++ b/fs/file.c @@ -642,7 +642,9 @@ out_unlock: EXPORT_SYMBOL(__close_fd); /* for ksys_close() */ /* - * variant of __close_fd that gets a ref on the file for later fput + * variant of __close_fd that gets a ref on the file for later fput. + * The caller must ensure that filp_close() called on the file, and then + * an fput(). */ int __close_fd_get_file(unsigned int fd, struct file **res) { @@ -662,7 +664,7 @@ int __close_fd_get_file(unsigned int fd, struct file **res) spin_unlock(&files->file_lock); get_file(file); *res = file; - return filp_close(file, files); + return 0; out_unlock: spin_unlock(&files->file_lock); @@ -706,29 +708,79 @@ void do_close_on_exec(struct files_struct *files) spin_unlock(&files->file_lock); } -static struct file *__fget(unsigned int fd, fmode_t mask, unsigned int refs) +static inline struct file *__fget_files_rcu(struct files_struct *files, + unsigned int fd, fmode_t mask, unsigned int refs) +{ + for (;;) { + struct file *file; + struct fdtable *fdt = rcu_dereference_raw(files->fdt); + struct file __rcu **fdentry; + + if (unlikely(fd >= fdt->max_fds)) + return NULL; + + fdentry = fdt->fd + array_index_nospec(fd, fdt->max_fds); + file = rcu_dereference_raw(*fdentry); + if (unlikely(!file)) + return NULL; + + if (unlikely(file->f_mode & mask)) + return NULL; + + /* + * Ok, we have a file pointer. However, because we do + * this all locklessly under RCU, we may be racing with + * that file being closed. + * + * Such a race can take two forms: + * + * (a) the file ref already went down to zero, + * and get_file_rcu_many() fails. Just try + * again: + */ + if (unlikely(!get_file_rcu_many(file, refs))) + continue; + + /* + * (b) the file table entry has changed under us. + * Note that we don't need to re-check the 'fdt->fd' + * pointer having changed, because it always goes + * hand-in-hand with 'fdt'. + * + * If so, we need to put our refs and try again. + */ + if (unlikely(rcu_dereference_raw(files->fdt) != fdt) || + unlikely(rcu_dereference_raw(*fdentry) != file)) { + fput_many(file, refs); + continue; + } + + /* + * Ok, we have a ref to the file, and checked that it + * still exists. + */ + return file; + } +} + +static struct file *__fget_files(struct files_struct *files, unsigned int fd, + fmode_t mask, unsigned int refs) { - struct files_struct *files = current->files; struct file *file; rcu_read_lock(); -loop: - file = fcheck_files(files, fd); - if (file) { - /* File object ref couldn't be taken. - * dup2() atomicity guarantee is the reason - * we loop to catch the new file (or NULL pointer) - */ - if (file->f_mode & mask) - file = NULL; - else if (!get_file_rcu_many(file, refs)) - goto loop; - } + file = __fget_files_rcu(files, fd, mask, refs); rcu_read_unlock(); return file; } +static inline struct file *__fget(unsigned int fd, fmode_t mask, + unsigned int refs) +{ + return __fget_files(current->files, fd, mask, refs); +} + struct file *fget_many(unsigned int fd, unsigned int refs) { return __fget(fd, FMODE_PATH, refs); @@ -746,6 +798,18 @@ struct file *fget_raw(unsigned int fd) } EXPORT_SYMBOL(fget_raw); +struct file *fget_task(struct task_struct *task, unsigned int fd) +{ + struct file *file = NULL; + + task_lock(task); + if (task->files) + file = __fget_files(task->files, fd, 0, 1); + task_unlock(task); + + return file; +} + /* * Lightweight file lookup - no refcnt increment if fd table isn't shared. * diff --git a/include/linux/file.h b/include/linux/file.h index 3fcddff56..c6c7b24ea 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -16,6 +16,7 @@ extern void fput(struct file *); extern void fput_many(struct file *, unsigned int); struct file_operations; +struct task_struct; struct vfsmount; struct dentry; struct inode; @@ -47,6 +48,7 @@ static inline void fdput(struct fd fd) extern struct file *fget(unsigned int fd); extern struct file *fget_many(unsigned int fd, unsigned int refs); extern struct file *fget_raw(unsigned int fd); +extern struct file *fget_task(struct task_struct *task, unsigned int fd); extern unsigned long __fdget(unsigned int fd); extern unsigned long __fdget_raw(unsigned int fd); extern unsigned long __fdget_pos(unsigned int fd); diff --git a/mm/slub.c b/mm/slub.c index 52ded855b..06726e181 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -282,7 +282,7 @@ static inline void *get_freepointer(struct kmem_cache *s, void *object) static void prefetch_freepointer(const struct kmem_cache *s, void *object) { - prefetch(object + s->offset); + prefetchw(object + s->offset); } static inline void *get_freepointer_safe(struct kmem_cache *s, void *object) diff --git a/package/default/config.default b/package/default/config.default index 943c7700e..220c013fb 100644 --- a/package/default/config.default +++ b/package/default/config.default @@ -700,7 +700,8 @@ CONFIG_OPROFILE_EVENT_MULTIPLEX=y CONFIG_HAVE_OPROFILE=y CONFIG_OPROFILE_NMI_TIMER=y CONFIG_KPROBES=y -# CONFIG_JUMP_LABEL is not set +CONFIG_JUMP_LABEL=y +# CONFIG_STATIC_KEYS_SELFTEST is not set CONFIG_OPTPROBES=y CONFIG_KPROBES_ON_FTRACE=y CONFIG_UPROBES=y @@ -4995,7 +4996,7 @@ CONFIG_RCU_CPU_STALL_TIMEOUT=60 # CONFIG_NOTIFIER_ERROR_INJECTION is not set CONFIG_FUNCTION_ERROR_INJECTION=y # CONFIG_FAULT_INJECTION is not set -CONFIG_LATENCYTOP=y +# CONFIG_LATENCYTOP is not set CONFIG_USER_STACKTRACE_SUPPORT=y CONFIG_NOP_TRACER=y CONFIG_HAVE_FUNCTION_TRACER=y