[CRIU] [PATCH 7/7] dump: dump signals into core->thread_core->signals

[Pavel Emelyanov]

On 08/14/2014 06:33 AM, Ruslan Kuprieiev wrote:
> Every thread has it's own private signals and leader thread has also shared
> signals.

This patch lacks the hunk that moves CR_FD_SIGNAL from inside _CR_FD_TASK_XXX
into outside, so that empty signals files are not even created.

> Signed-off-by: Ruslan Kuprieiev <kupruser at gmail.com>
> ---
>  cr-dump.c | 81 ++++++++++++++++++++++++++++++++++++---------------------------
>  1 file changed, 46 insertions(+), 35 deletions(-)
> 
> diff --git a/cr-dump.c b/cr-dump.c
> index 74a8b4c..a3a0aa9 100644
> --- a/cr-dump.c
> +++ b/cr-dump.c
> @@ -1168,11 +1168,12 @@ err:
>  	return ret;
>  }
>  
> -static int dump_signal_queue(pid_t tid, int fd, bool group)
> +static int dump_signal_queue(pid_t tid, SignalQueueEntry **sqe, bool group)
>  {
>  	struct ptrace_peeksiginfo_args arg;
>  	siginfo_t siginfo[32]; /* One page or all non-rt signals */
>  	int ret, i = 0, j, nr;
> +	SignalQueueEntry *queue = NULL;
>  
>  	pr_debug("Dump %s signals of %d\n", group ? "shared" : "private", tid);
>  
> @@ -1181,6 +1182,12 @@ static int dump_signal_queue(pid_t tid, int fd, bool group)
>  	if (group)
>  		arg.flags |= PTRACE_PEEKSIGINFO_SHARED;
>  
> +	queue = xmalloc(sizeof(*queue));
> +	if (!queue)
> +		return -1;
> +
> +	signal_queue_entry__init(queue);
> +
>  	for (; ; ) {
>  		arg.off = i;
>  
> @@ -1198,50 +1205,54 @@ static int dump_signal_queue(pid_t tid, int fd, bool group)
>  			break;
>  		nr = ret;
>  
> -		for (j = 0; j < nr; j++) {
> -			SiginfoEntry sie = SIGINFO_ENTRY__INIT;
> +		queue->n_signals += nr;
> +		queue->signals = xrealloc(queue->signals, sizeof(*queue->signals) * queue->n_signals);
> +		if (!queue->signals) {
> +			ret = -1;
> +			break;
> +		}
>  
> -			sie.siginfo.len = sizeof(siginfo_t);
> -			sie.siginfo.data = (void *) (siginfo + j);
> +		for (j = queue->n_signals - nr; j < queue->n_signals; j++) {
> +			queue->signals[j]->siginfo.len = sizeof(siginfo_t);
> +			queue->signals[j]->siginfo.data = (void *) (siginfo + j);
>  
> -			ret = pb_write_one(fd, &sie, PB_SIGINFO);
> -			if (ret < 0)
> -				break;
>  			i++;
>  		}
>  	}
>  
> +	*sqe = queue;
> +
>  	return ret;
>  }
>  
> -static int dump_thread_signals(struct pid *tid)
> +static int dump_task_signals(pid_t pid, struct pstree_item *item)
>  {
> -	int fd, ret;
> +	int i, ret;
> +	SignalsEntry *signals = NULL;
>  
> -	fd = open_image(CR_FD_PSIGNAL, O_DUMP, tid->virt);
> -	if (fd < 0)
> -		return -1;
> -	ret = dump_signal_queue(tid->real, fd, false);
> -	close(fd);
> +	/* Dump private signals for each thread */
> +	for (i = 0; i < item->nr_threads; i++) {
> +		signals = xmalloc(sizeof(*signals));
> +		if (!signals)
> +			return -1;
>  
> -	return ret;
> -}
> +		signals_entry__init(signals);
>  
> -static int dump_task_signals(pid_t pid, struct pstree_item *item,
> -		struct cr_fdset *cr_fdset)
> -{
> -	int i, ret;
> +		ret = dump_signal_queue(item->threads[i].real, &signals->p, false);
> +		if (ret) {
> +			pr_err("Can't dump private signals for thread %d\n", item->threads[i].real);
> +			return -1;
> +		}
>  
> -	ret = dump_signal_queue(pid, fdset_fd(cr_fdset, CR_FD_SIGNAL), true);
> -	if (ret) {
> -		pr_err("Can't dump pending signals (pid: %d)\n", pid);
> -		return -1;
> +		item->core[i]->thread_core->signals = signals;
>  	}
>  
> -	for (i = 0; i < item->nr_threads; i++) {
> -		ret = dump_thread_signals(&item->threads[i]);
> -		if (ret)
> -			return -1;
> +	/* Dump shared signals */
> +	signals = item->core[0]->thread_core->signals;
> +	ret = dump_signal_queue(pid, &signals->s, true);
> +	if (ret) {
> +		pr_err("Can't dump shared signals (pid: %d)\n", pid);
> +		return -1;
>  	}
>  
>  	return 0;
> @@ -1501,6 +1512,12 @@ static int dump_one_task(struct pstree_item *item)
>  		goto err;
>  	}
>  
> +	ret = dump_task_signals(pid, item);
> +	if (ret) {
> +		pr_err("Dump %d signals failed %d\n", pid, ret);
> +		goto err;
> +	}
> +
>  	ret = -1;
>  	parasite_ctl = parasite_infect_seized(pid, item, &vmas, dfds, proc_args.timer_n);
>  	if (!parasite_ctl) {
> @@ -1635,12 +1652,6 @@ static int dump_one_task(struct pstree_item *item)
>  		goto err;
>  	}
>  
> -	ret = dump_task_signals(pid, item, cr_fdset);
> -	if (ret) {
> -		pr_err("Dump %d signals failed %d\n", pid, ret);
> -		goto err;
> -	}
> -
>  	close_cr_fdset(&cr_fdset);
>  err:
>  	close_pid_proc();
>