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bpf: convert relevant helper args to ARG_PTR_TO_RAW_STACK

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This patch converts all helpers that can use ARG_PTR_TO_RAW_STACK as argument
type. For tc programs this is bpf_skb_load_bytes(), bpf_skb_get_tunnel_key(),
bpf_skb_get_tunnel_opt(). For tracing, this optimizes bpf_get_current_comm()
and bpf_probe_read(). The check in bpf_skb_load_bytes() for MAX_BPF_STACK can
also be removed since the verifier already makes sure we stay within bounds
on stack buffers.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Borkmann
2016-04-13 00:10:52 +02:00
committed by David S. Miller
parent 435faee1aa
commit 074f528eed
3 changed files with 60 additions and 24 deletions
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10
kernel/trace/bpf_trace.c
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@@ -62,17 +62,21 @@ EXPORT_SYMBOL_GPL(trace_call_bpf);
static u64 bpf_probe_read(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
{
void *dst = (void *) (long) r1;
int size = (int) r2;
int ret, size = (int) r2;
void *unsafe_ptr = (void *) (long) r3;
return probe_kernel_read(dst, unsafe_ptr, size);
ret = probe_kernel_read(dst, unsafe_ptr, size);
if (unlikely(ret < 0))
memset(dst, 0, size);
return ret;
}
static const struct bpf_func_proto bpf_probe_read_proto = {
.func = bpf_probe_read,
.gpl_only = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_PTR_TO_STACK,
.arg1_type = ARG_PTR_TO_RAW_STACK,
.arg2_type = ARG_CONST_STACK_SIZE,
.arg3_type = ARG_ANYTHING,
};