Now we can dump all task or children, threads of a specified task. It's an example how this interface can be expanded for different use-cases.
v2: Fixes from David Ahern Add missing break in iter_stop Fix 8-byte alignment issues Cc: David Ahern <[email protected]> Signed-off-by: Andrey Vagin <[email protected]> --- fs/proc/task_diag.c | 93 ++++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/task_diag.h | 7 +++- 2 files changed, 98 insertions(+), 2 deletions(-) diff --git a/fs/proc/task_diag.c b/fs/proc/task_diag.c index 9c1ed45..e0f0b03 100644 --- a/fs/proc/task_diag.c +++ b/fs/proc/task_diag.c @@ -479,6 +479,12 @@ static void iter_stop(struct task_iter *iter) case TASK_DIAG_DUMP_ALL: task = iter->tgid.task; break; + case TASK_DIAG_DUMP_ALL_THREAD: + /* release both tgid task and thread task */ + if (iter->task) + put_task_struct(iter->task); + task = iter->tgid.task; + break; default: task = iter->task; } @@ -486,6 +492,23 @@ static void iter_stop(struct task_iter *iter) put_task_struct(task); } +static struct task_struct * +task_diag_next_child(struct task_struct *parent, + struct task_struct *prev, unsigned int pos) +{ + struct task_struct *task; + + read_lock(&tasklist_lock); + task = task_next_child(parent, prev, pos); + if (prev) + put_task_struct(prev); + if (task) + get_task_struct(task); + read_unlock(&tasklist_lock); + + return task; +} + static struct task_struct *iter_start(struct task_iter *iter) { if (iter->req.pid > 0) { @@ -508,11 +531,48 @@ static struct task_struct *iter_start(struct task_iter *iter) iter->task = NULL; return iter->task; + case TASK_DIAG_DUMP_THREAD: + if (iter->parent == NULL) + return ERR_PTR(-ESRCH); + + iter->pos = iter->cb->pos; + iter->task = task_first_tid(task_pid(iter->parent), + iter->cb->pid,iter->pos, iter->ns); + return iter->task; + + case TASK_DIAG_DUMP_CHILDREN: + if (iter->parent == NULL) + return ERR_PTR(-ESRCH); + + iter->pos = iter->cb->pos; + iter->task = task_diag_next_child(iter->parent, NULL, iter->pos); + return iter->task; + case TASK_DIAG_DUMP_ALL: iter->tgid.tgid = iter->cb->pid; iter->tgid.task = NULL; iter->tgid = next_tgid(iter->ns, iter->tgid); return iter->tgid.task; + + case TASK_DIAG_DUMP_ALL_THREAD: + iter->pos = iter->cb->pos; + iter->tgid.tgid = iter->cb->pid; + iter->tgid.task = NULL; + iter->tgid = next_tgid(iter->ns, iter->tgid); + if (!iter->tgid.task) + return NULL; + + iter->task = task_first_tid(task_pid(iter->tgid.task), + 0, iter->pos, iter->ns); + if (!iter->task) { + iter->pos = 0; + iter->tgid.tgid += 1; + iter->tgid = next_tgid(iter->ns, iter->tgid); + iter->task = iter->tgid.task; + if (iter->task) + get_task_struct(iter->task); + } + return iter->task; } return ERR_PTR(-EINVAL); @@ -529,11 +589,44 @@ static struct task_struct *iter_next(struct task_iter *iter) iter->task = NULL; return NULL; + case TASK_DIAG_DUMP_THREAD: + iter->pos++; + iter->task = task_next_tid(iter->task); + iter->cb->pos = iter->pos; + if (iter->task) + iter->cb->pid = task_pid_nr_ns(iter->task, iter->ns); + else + iter->cb->pid = -1; + return iter->task; + case TASK_DIAG_DUMP_CHILDREN: + iter->pos++; + iter->task = task_diag_next_child(iter->parent, iter->task, iter->pos); + iter->cb->pos = iter->pos; + return iter->task; + case TASK_DIAG_DUMP_ALL: iter->tgid.tgid += 1; iter->tgid = next_tgid(iter->ns, iter->tgid); iter->cb->pid = iter->tgid.tgid; return iter->tgid.task; + + case TASK_DIAG_DUMP_ALL_THREAD: + iter->pos++; + iter->task = task_next_tid(iter->task); + if (!iter->task) { + iter->pos = 0; + iter->tgid.tgid += 1; + iter->tgid = next_tgid(iter->ns, iter->tgid); + iter->task = iter->tgid.task; + if (iter->task) + get_task_struct(iter->task); + } + + /* save current position */ + iter->cb->pid = iter->tgid.tgid; + iter->cb->pos = iter->pos; + + return iter->task; } return NULL; diff --git a/include/uapi/linux/task_diag.h b/include/uapi/linux/task_diag.h index 3486f2f..8bccd02 100644 --- a/include/uapi/linux/task_diag.h +++ b/include/uapi/linux/task_diag.h @@ -151,8 +151,11 @@ struct task_diag_vma_stat *task_diag_vma_stat(struct task_diag_vma *vma) (void *) vma < nla_data(attr) + nla_len(attr); \ vma = (void *) vma + vma->vma_len) -#define TASK_DIAG_DUMP_ALL 0 -#define TASK_DIAG_DUMP_ONE 1 +#define TASK_DIAG_DUMP_ALL 0 +#define TASK_DIAG_DUMP_ONE 1 +#define TASK_DIAG_DUMP_ALL_THREAD 2 +#define TASK_DIAG_DUMP_CHILDREN 3 +#define TASK_DIAG_DUMP_THREAD 4 struct task_diag_pid { __u64 show_flags; -- 2.5.5
