[CRIU] [PATCH 6/6] restore: restore signals from core->tc->signals, othrewise -- from signal_p/s*.img

[Pavel Emelyanov]

On 08/05/2014 12:36 PM, Ruslan Kuprieiev wrote:

This is not bisect-safe. Once I apply the 5th patch, but not the 6th criu 
would stop working.

> Signed-off-by: Ruslan Kuprieiev <kupruser at gmail.com>
> ---
>  cr-restore.c | 79 ++++++++++++++++++++++++++++++++++++++++++++----------------
>  1 file changed, 58 insertions(+), 21 deletions(-)
> 
> diff --git a/cr-restore.c b/cr-restore.c
> index c2515bf..b47e4c0 100644
> --- a/cr-restore.c
> +++ b/cr-restore.c
> @@ -89,7 +89,7 @@ static int sigreturn_restore(pid_t pid, CoreEntry *core);
>  static int prepare_restorer_blob(void);
>  static int prepare_rlimits(int pid, CoreEntry *core);
>  static int prepare_posix_timers(int pid, CoreEntry *core);
> -static int prepare_signals(int pid);
> +static int prepare_signals(int pid, SignalsEntry *signals);
>  
>  static int shmem_remap(void *old_addr, void *new_addr, unsigned long size)
>  {
> @@ -721,7 +721,7 @@ static int restore_one_alive_task(int pid, CoreEntry *core)
>  	if (open_vmas(pid))
>  		return -1;
>  
> -	if (prepare_signals(pid))
> +	if (prepare_signals(pid, core->tc->signals))
>  		return -1;
>  
>  	if (prepare_posix_timers(pid, core))
> @@ -2264,22 +2264,44 @@ static int prepare_rlimits(int pid, CoreEntry *core)
>  	return 0;
>  }
>  
> -static int open_signal_image(int type, pid_t pid, unsigned int *nr)
> +static int signals_to_mem(SignalQueueEntry *sqe)
> +{
> +	int i;
> +	siginfo_t *info, *t;
> +
> +	for (i = 0; i < sqe->n_signals; i++) {
> +		info = (siginfo_t *) sqe->signals[i]->siginfo.data;
> +		t = rst_mem_alloc(sizeof(siginfo_t), RM_PRIVATE);
> +		if (!t)
> +			return -1;
> +
> +		memcpy(t, info, sizeof(*info));
> +	}
> +
> +	return 0;
> +}
> +
> +static SignalQueueEntry *open_signal_image(int type, pid_t pid)
>  {
>  	int fd, ret;
> +	SignalQueueEntry *sqe = NULL;
> +
> +	sqe = xmalloc(sizeof(*sqe));
> +	if (!sqe)
> +		return NULL;
> +
> +	signal_queue_entry__init(sqe);
>  
>  	fd = open_image(type, O_RSTR | O_OPT, pid);
>  	if (fd < 0) {
>  		if (fd == -ENOENT) /* backward compatibility */
> -			return 0;
> +			return sqe;
>  		else
> -			return -1;
> +			return NULL;
>  	}
>  
> -	*nr = 0;
>  	while (1) {
>  		SiginfoEntry *sie;
> -		siginfo_t *info, *t;
>  
>  		ret = pb_read_one_eof(fd, &sie, PB_SIGINFO);
>  		if (ret <= 0)
> @@ -2289,43 +2311,58 @@ static int open_signal_image(int type, pid_t pid, unsigned int *nr)
>  			ret = -1;
>  			break;
>  		}
> -		info = (siginfo_t *) sie->siginfo.data;
> -		t = rst_mem_alloc(sizeof(siginfo_t), RM_PRIVATE);
> -		if (!t) {
> +
> +		sqe->n_signals++;
> +		sqe->signals = xrealloc(sqe->signals, sizeof(*sqe->signals) * sqe->n_signals);
> +		if (!sqe->signals) {
>  			ret = -1;
>  			break;
>  		}
>  
> -		memcpy(t, info, sizeof(*info));
> -		(*nr)++;
> -
> -		siginfo_entry__free_unpacked(sie, NULL);
> +		sqe->signals[sqe->n_signals - 1] = sie;
>  	}
>  
>  	close(fd);
> -
> -	return ret ? : 0;
> +	return ret ? NULL : sqe;
>  }
>  
>  static unsigned long siginfo_cpos;
>  static unsigned int siginfo_nr, *siginfo_priv_nr;
>  
> -static int prepare_signals(int pid)
> +static int prepare_signals(int pid, SignalsEntry *signals)
>  {
>  	int ret = -1, i;
> +	SignalQueueEntry *queue = NULL;
>  
>  	siginfo_cpos = rst_mem_cpos(RM_PRIVATE);
>  	siginfo_priv_nr = xmalloc(sizeof(int) * current->nr_threads);
>  	if (siginfo_priv_nr == NULL)
>  		goto out;
>  
> -	ret = open_signal_image(CR_FD_SIGNAL, pid, &siginfo_nr);
> -	if (ret < 0)
> +	if (!signals) { /* backward compatibility */
> +		queue = open_signal_image(CR_FD_SIGNAL, pid);
> +		if (!queue)
> +			goto out;
> +	} else
> +		queue = signals->shared;
> +
> +	siginfo_nr = queue->n_signals;
> +	ret = signals_to_mem(queue);
> +	if (ret)
>  		goto out;
>  
>  	for (i = 0; i < current->nr_threads; i++) {
> -		ret = open_signal_image(CR_FD_PSIGNAL,
> -				current->threads[i].virt, &siginfo_priv_nr[i]);
> +		if (!signals) { /* backward compatibility */
> +			queue = open_signal_image(CR_FD_PSIGNAL, current->threads[i].virt);
> +			if (!queue)
> +				goto out;
> +		} else {
> +			queue = signals->private_[i];
> +			BUG_ON(signals->n_private_ != current->nr_threads);
> +		}
> +
> +		siginfo_priv_nr[i] = queue->n_signals;
> +		ret = signals_to_mem(queue);
>  		if (ret < 0)
>  			goto out;
>  	}
>