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authorEric Dumazet <eric.dumazet@gmail.com>2010-11-23 17:09:15 +0300
committerDavid S. Miller <davem@davemloft.net>2010-11-24 22:16:43 +0300
commitbba14de98753cb6599a2dae0e520714b2153522d (patch)
treeb771ef780aa0808d3eb7827d527920c07215c4fa
parent456b61bca8ee324ab6c18b065e632c9a8c88aa39 (diff)
downloadlinux-bba14de98753cb6599a2dae0e520714b2153522d.tar.xz
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: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/scm.h5
-rw-r--r--net/core/scm.c10
2 files changed, 9 insertions, 6 deletions
diff --git a/include/net/scm.h b/include/net/scm.h
index 31656506d967..745460fa2f02 100644
--- a/include/net/scm.h
+++ b/include/net/scm.h
@@ -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];
};
diff --git a/net/core/scm.c b/net/core/scm.c
index 413cab89017d..bbe454450801 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -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;
}