[CRIU] [PATCH] restore: Parse self maps via bfd

[Andrei Vagin]

Accepted, thanks!

On Fri, Apr 14, 2017 at 07:56:58PM +0300, Pavel Emelyanov wrote:
> When injecting the restorer blob criu parses /proc/self/maps
> file to find out the hole for the blob itself. It happens
> every time and the maps file for criu is now HUGE (~12k),
> so it's much more efficient to use bfd for it rather than
> glibc's fopen.
> 
> Signed-off-by: Pavel Emelyanov <xemul at virtuozzo.com>
> ---
>  criu/proc_parse.c | 30 +++++++++++++++++++++---------
>  1 file changed, 21 insertions(+), 9 deletions(-)
> 
> diff --git a/criu/proc_parse.c b/criu/proc_parse.c
> index 5e9780a..19a010e 100644
> --- a/criu/proc_parse.c
> +++ b/criu/proc_parse.c
> @@ -422,20 +422,30 @@ static int vma_get_mapfile(const char *fname, struct vma_area *vma, DIR *mfd,
>  
>  int parse_self_maps_lite(struct vm_area_list *vms)
>  {
> -	FILE *maps;
>  	struct vma_area *prev = NULL;
> +	struct bfd maps;
> +	char *buf;
>  
>  	vm_area_list_init(vms);
>  
> -	maps = fopen_proc(PROC_SELF, "maps");
> -	if (maps == NULL)
> +	maps.fd = open_proc(PROC_SELF, "maps");
> +	if (maps.fd < 0)
>  		return -1;
>  
> -	while (fgets(buf, BUF_SIZE, maps) != NULL) {
> +	if (bfdopenr(&maps))
> +		return -1;
> +
> +	while (1) {
>  		struct vma_area *vma;
>  		char *end;
>  		unsigned long s, e;
>  
> +		buf = breadline(&maps);
> +		if (!buf)
> +			break;
> +		if (IS_ERR(buf))
> +			goto err;
> +
>  		s = strtoul(buf, &end, 16);
>  		e = strtoul(end + 1, NULL, 16);
>  
> @@ -448,10 +458,8 @@ int parse_self_maps_lite(struct vm_area_list *vms)
>  			prev->e->end = e;
>  		else {
>  			vma = alloc_vma_area();
> -			if (!vma) {
> -				fclose(maps);
> -				return -1;
> -			}
> +			if (!vma)
> +				goto err;
>  
>  			vma->e->start = s;
>  			vma->e->end = e;
> @@ -463,8 +471,12 @@ int parse_self_maps_lite(struct vm_area_list *vms)
>  		pr_debug("Parsed %"PRIx64"-%"PRIx64" vma\n", prev->e->start, prev->e->end);
>  	}
>  
> -	fclose(maps);
> +	bclose(&maps);
>  	return 0;
> +
> +err:
> +	bclose(&maps);
> +	return -1;
>  }
>  
>  #ifdef CONFIG_VDSO
> -- 
> 2.5.5
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