Commit acf167f3 authored by David S. Miller's avatar David S. Miller

Merge branch 'bpf-fixes'

Daniel Borkmann says:

====================
Two BPF fixes

The set fixes cb_access and xdp_adjust_head bits in struct bpf_prog,
that are used for requirement checks on the program rather than f.e.
heuristics. Thus, for tail calls, we cannot make any assumptions and
are forced to set them.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 0aa8c13e c2002f98
......@@ -617,6 +617,14 @@ static void fixup_bpf_calls(struct bpf_prog *prog)
if (insn->imm == BPF_FUNC_xdp_adjust_head)
prog->xdp_adjust_head = 1;
if (insn->imm == BPF_FUNC_tail_call) {
/* If we tail call into other programs, we
* cannot make any assumptions since they
* can be replaced dynamically during runtime
* in the program array.
*/
prog->cb_access = 1;
prog->xdp_adjust_head = 1;
/* mark bpf_tail_call as different opcode
* to avoid conditional branch in
* interpeter for every normal call
......
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