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Patch "bpf: move fixup_bpf_calls() function" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 1 message Jan 13, 2018

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This is a note to let you know that I've just added the patch titled

bpf: move fixup_bpf_calls() function

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
bpf-move-fixup_bpf_calls-function.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From e245c5c6a5656e4d61aa7bb08e9694fd6e5b2b9d Mon Sep 17 00:00:00 2001

From: Alexei Starovoitov <[email protected]>
Date: Wed, 15 Mar 2017 18:26:39 -0700
Subject: bpf: move fixup_bpf_calls() function

From: Alexei Starovoitov <[email protected]>

commit e245c5c6a5656e4d61aa7bb08e9694fd6e5b2b9d upstream.

no functional change.
move fixup_bpf_calls() to verifier.c
it's being refactored in the next patch

Signed-off-by Alexei Starovoitov <[email protected]>
Acked-by Daniel Borkmann <[email protected]>
Signed-off-by David S. Miller <[email protected]>
Signed-off-by Jiri Slaby <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 kernel/bpf/syscall.c  |   54 -------------------------------------------------
 kernel/bpf/verifier.c |   55 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 54 deletions(-)
kernel/bpf/syscall.c +0 -54
@@ -447,57 +447,6 @@ void bpf_register_prog_type(struct bpf_p
 	list_add(&tl->list_node, &bpf_prog_types);
 }
 
-/* fixup insn->imm field of bpf_call instructions:
- * if (insn->imm == BPF_FUNC_map_lookup_elem)
- *      insn->imm = bpf_map_lookup_elem - __bpf_call_base;
- * else if (insn->imm == BPF_FUNC_map_update_elem)
- *      insn->imm = bpf_map_update_elem - __bpf_call_base;
- * else ...
- *
- * this function is called after eBPF program passed verification
- */
-static void fixup_bpf_calls(struct bpf_prog *prog)
-{
-	const struct bpf_func_proto *fn;
-	int i;
-
-	for (i = 0; i < prog->len; i++) {
-		struct bpf_insn *insn = &prog->insnsi[i];
-
-		if (insn->code == (BPF_JMP | BPF_CALL)) {
-			/* we reach here when program has bpf_call instructions
-			 * and it passed bpf_check(), means that
-			 * ops->get_func_proto must have been supplied, check it
-			 */
-			BUG_ON(!prog->aux->ops->get_func_proto);
-
-			if (insn->imm == BPF_FUNC_get_route_realm)
-				prog->dst_needed = 1;
-			if (insn->imm == BPF_FUNC_get_prandom_u32)
-				bpf_user_rnd_init_once();
-			if (insn->imm == BPF_FUNC_tail_call) {
-				/* mark bpf_tail_call as different opcode
-				 * to avoid conditional branch in
-				 * interpeter for every normal call
-				 * and to prevent accidental JITing by
-				 * JIT compiler that doesn't support
-				 * bpf_tail_call yet
-				 */
-				insn->imm = 0;
-				insn->code |= BPF_X;
-				continue;
-			}
-
-			fn = prog->aux->ops->get_func_proto(insn->imm);
-			/* all functions that have prototype and verifier allowed
-			 * programs to call them, must be real in-kernel functions
-			 */
-			BUG_ON(!fn->func);
-			insn->imm = fn->func - __bpf_call_base;
-		}
-	}
-}
-
 /* drop refcnt on maps used by eBPF program and free auxilary data */
 static void free_used_maps(struct bpf_prog_aux *aux)
 {

@@ -680,9 +629,6 @@ static int bpf_prog_load(union bpf_attr
 	if (err < 0)
 		goto free_used_maps;
 
-	/* fixup BPF_CALL->imm field */
-	fixup_bpf_calls(prog);
-
 	/* eBPF program is ready to be JITed */
 	err = bpf_prog_select_runtime(prog);
 	if (err < 0)
kernel/bpf/verifier.c +55 -0

67 lines not on this page · raw message

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/bpf-adjust-insn_aux_data-when-patching-insns.patch queue-4.4/bpf-refactor-fixup_bpf_calls.patch queue-4.4/bpf-move-fixup_bpf_calls-function.patch