Commit 46b325c7 authored Apr 12, 2012 by Will Drewry Committed by James Morris Apr 14, 2012

sk_run_filter: add BPF_S_ANC_SECCOMP_LD_W

Introduces a new BPF ancillary instruction that all LD calls will be
mapped through when skb_run_filter() is being used for seccomp BPF.  The
rewriting will be done using a secondary chk_filter function that is run
after skb_chk_filter.

The code change is guarded by CONFIG_SECCOMP_FILTER which is added,
along with the seccomp_bpf_load() function later in this series.

This is based on http://lkml.org/lkml/2012/3/2/141



Suggested-by: Indan Zupancic <indan@nul.nu>
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Eric Paris <eparis@redhat.com>

v18: rebase
...
v15: include seccomp.h explicitly for when seccomp_bpf_load exists.
v14: First cut using a single additional instruction
... v13: made bpf functions generic.
Signed-off-by: James Morris <james.l.morris@oracle.com>

parent c29bceb3

include/linux/filter.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -228,6 +228,7 @@ enum {
		BPF_S_ANC_HATYPE,
		BPF_S_ANC_RXHASH,
		BPF_S_ANC_CPU,
		BPF_S_ANC_SECCOMP_LD_W,
		};

		#endif /* __KERNEL__ */

net/core/filter.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -38,6 +38,7 @@
		#include <linux/filter.h>
		#include <linux/reciprocal_div.h>
		#include <linux/ratelimit.h>
		#include <linux/seccomp.h>

		/* No hurry in this branch
		*
		@@ -352,6 +353,11 @@ load_b:
		A = 0;
		continue;
		}
		#ifdef CONFIG_SECCOMP_FILTER
		case BPF_S_ANC_SECCOMP_LD_W:
		A = seccomp_bpf_load(fentry->k);
		continue;
		#endif
		default:
		WARN_RATELIMIT(1, "Unknown code:%u jt:%u tf:%u k:%u\n",
		fentry->code, fentry->jt,

Admin message