[CRIU] [PATCH 08/12] crtools: restore pending signals

[Pavel Emelyanov]

> @@ -1596,6 +1645,9 @@ static int sigreturn_restore(pid_t pid, CoreEntry *core)
>  
>  	struct task_restore_core_args *task_args;
>  	struct thread_restore_args *thread_args;
> +	siginfo_t *siginfo_chunk;
> +	int siginfo_nr = 0;
> +	unsigned long siginfo_size = PAGE_SIZE;

A question. Why do we restore pending signals in restorer, not in generic code?

>  	LIST_HEAD(self_vma_list);
>  	int i;
> @@ -1644,12 +1696,55 @@ static int sigreturn_restore(pid_t pid, CoreEntry *core)
>  	task_args	= mem;
>  	thread_args	= mem + restore_task_vma_len;
>  
> +	siginfo_chunk = mmap(NULL, siginfo_size, PROT_READ | PROT_WRITE,
> +						MAP_PRIVATE | MAP_ANON, 0, 0);
> +	if (mem == MAP_FAILED) {
> +		pr_err("Can't allocate memory for siginfo-s\n");
> +		goto err;
> +	}

This first mmap looks ugly. Re-mplement remapping in open_signal_image to
hide one.

> +
> +	ret = open_signal_image(CR_FD_SIGNAL, pid, &siginfo_chunk,
> +					&siginfo_size, &siginfo_nr);
> +	if (ret < 0) {
> +		if (errno != ENOENT) /* backward compatiblity */
> +			goto err;
> +		ret = 0;
> +	}
> +	task_args->siginfo_nr = ret;
> +
> +	ret = open_signal_image(CR_FD_PSIGNAL, pid, &siginfo_chunk,
> +					&siginfo_size, &siginfo_nr);
> +	if (ret < 0) {
> +		if (errno != ENOENT) /* backward compatiblity */
> +			goto err;
> +		ret = 0;
> +	}
> +	task_args->t.siginfo_nr = ret;
> +
> +	for (i = 0; i < current->nr_threads; i++) {

We have already a loop that initialized thread restore data. This siginfos
read-in should be there.

> +		thread_args[i].pid = current->threads[i].virt;
> +		/* skip self */
> +		if (thread_args[i].pid == pid)
> +			continue;
> +
> +		ret = open_signal_image(CR_FD_PSIGNAL,
> +					thread_args[i].pid, &siginfo_chunk,
> +					&siginfo_size, &siginfo_nr);
> +		if (ret < 0) {
> +			if (errno != ENOENT) /* backward compatiblity */
> +				goto err;
> +			ret = 0;
> +		}
> +		thread_args[i].siginfo_nr = ret;
> +	}
> +
>  	restore_bootstrap_len = restorer_len +
>  				restore_task_vma_len +
>  				restore_thread_vma_len +
>  				SHMEMS_SIZE + TASK_ENTRIES_SIZE +
>  				self_vmas_len + vmas_len +
> -				rst_tcp_socks_size;
> +				rst_tcp_socks_size +
> +				siginfo_size;
>  
>  	/*
>  	 * Restorer is a blob (code + args) that will get mapped in some
> diff --git a/include/restorer.h b/include/restorer.h
> index 2309a3d..f7a762d 100644
> --- a/include/restorer.h
> +++ b/include/restorer.h
> @@ -79,6 +79,9 @@ struct thread_restore_args {
>  	struct rst_sched_param		sp;
>  
>  	struct task_restore_core_args	*ta;
> +
> +	siginfo_t			*siginfo;
> +	unsigned int			siginfo_nr;
>  } __aligned(sizeof(long));
>  
>  struct task_restore_core_args {
> @@ -98,6 +101,9 @@ struct task_restore_core_args {
>  	struct task_entries		*task_entries;
>  	VmaEntry			*self_vmas;
>  	VmaEntry			*tgt_vmas;
> +	siginfo_t			*siginfo;
> +	unsigned int			siginfo_nr;
> +	unsigned long			siginfo_size;

What for? Master thread's siginfos are in respective thread-info.

>  	unsigned int			nr_vmas;
>  	unsigned long			premmapped_addr;
>  	unsigned long			premmapped_len;