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Commit 8ea6e345 authored by Li RongQing's avatar Li RongQing Committed by David S. Miller
Browse files

net: filter: fix the comments 



1. sk_run_filter has been renamed, sk_filter() is using SK_RUN_FILTER.
2. Remove wrong comments about storing intermediate value.
3. replace sk_run_filter with __bpf_prog_run for check_load_and_stores's
comments

Cc: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: default avatarLi RongQing <roy.qing.li@gmail.com>
Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1a9525f6

net/core/filter.c

+3 −6
Original line number Diff line number Diff line
@@ -51,9 +51,9 @@ 
 *	@skb: buffer to filter

 *

 * Run the filter code and then cut skb->data to correct size returned by

 * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller

 * SK_RUN_FILTER. If pkt_len is 0 we toss packet. If skb->len is smaller

 * than pkt_len we keep whole skb->data. This is the socket level

 * wrapper to sk_run_filter. It returns 0 if the packet should

 * wrapper to SK_RUN_FILTER. It returns 0 if the packet should

 * be accepted or -EPERM if the packet should be tossed.

 *

 */
@@ -565,12 +565,9 @@ int bpf_convert_filter(struct sock_filter *prog, int len, 
}



/* Security:

 *

 * A BPF program is able to use 16 cells of memory to store intermediate

 * values (check u32 mem[BPF_MEMWORDS] in sk_run_filter()).

 *

 * As we dont want to clear mem[] array for each packet going through

 * sk_run_filter(), we check that filter loaded by user never try to read

 * __bpf_prog_run(), we check that filter loaded by user never try to read

 * a cell if not previously written, and we check all branches to be sure

 * a malicious user doesn't try to abuse us.

 */