Merge branch 'bpf-fixes' (acf167f3) · Commits · 戴 / test

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:

David S. Miller <davem@davemloft.net>

kernel/bpf/syscall.c

+8 −0

Original line number	Original line	Diff line number	Diff line
	@@ -617,6 +617,14 @@ static void fixup_bpf_calls(struct bpf_prog *prog)
	if (insn->imm == BPF_FUNC_xdp_adjust_head)		if (insn->imm == BPF_FUNC_xdp_adjust_head)
	prog->xdp_adjust_head = 1;		prog->xdp_adjust_head = 1;
	if (insn->imm == BPF_FUNC_tail_call) {		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		/* mark bpf_tail_call as different opcode
	* to avoid conditional branch in		* to avoid conditional branch in
	* interpeter for every normal call		* interpeter for every normal call

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