Commit bba14de9 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

scm: lower SCM_MAX_FD 



Lower SCM_MAX_FD from 255 to 253 so that allocations for scm_fp_list are
halved. (commit f8d570a4 added two pointers in this structure)

scm_fp_dup() should not copy whole structure (and trigger kmemcheck
warnings), but only the used part. While we are at it, only allocate
needed size.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 456b61bc

include/net/scm.h

+3 −2
Original line number Diff line number Diff line
@@ -10,11 +10,12 @@ 
/* Well, we should have at least one descriptor open

 * to accept passed FDs 8)

 */

#define SCM_MAX_FD	255

#define SCM_MAX_FD	253



struct scm_fp_list {

	struct list_head	list;

	int			count;

	short			count;

	short			max;

	struct file		*fp[SCM_MAX_FD];

};

net/core/scm.c

+6 −4
Original line number Diff line number Diff line
@@ -79,10 +79,11 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp) 
			return -ENOMEM;

		*fplp = fpl;

		fpl->count = 0;

		fpl->max = SCM_MAX_FD;

	}

	fpp = &fpl->fp[fpl->count];



	if (fpl->count + num > SCM_MAX_FD)

	if (fpl->count + num > fpl->max)

		return -EINVAL;



	/*
@@ -331,11 +332,12 @@ struct scm_fp_list *scm_fp_dup(struct scm_fp_list *fpl) 
	if (!fpl)

		return NULL;



	new_fpl = kmalloc(sizeof(*fpl), GFP_KERNEL);

	new_fpl = kmemdup(fpl, offsetof(struct scm_fp_list, fp[fpl->count]),

			  GFP_KERNEL);

	if (new_fpl) {

		for (i=fpl->count-1; i>=0; i--)

		for (i = 0; i < fpl->count; i++)

			get_file(fpl->fp[i]);

		memcpy(new_fpl, fpl, sizeof(*fpl));

		new_fpl->max = new_fpl->count;

	}

	return new_fpl;

}

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