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authorTakashi Iwai <tiwai@suse.de>2019-05-06 16:14:09 +0200
committerTakashi Iwai <tiwai@suse.de>2019-05-06 16:14:34 +0200
commitd81645510ce2a140816c4cb37c45b78d810ca63f (patch)
treeedd9464900904d22a23da362bb152669480c5d26 /include/linux/bpf_verifier.h
parent2854cd34fbab5f28a356d3667c26b7856a7b73e2 (diff)
parent378d590c494551a68a824b939c711bb9a280e9ef (diff)
Merge tag 'asoc-v5.2' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
ASoC: Updates for v5.2 This is a pretty huge set of changes, it's been a pretty active release all round but the big thing with this release is the Sound Open Firmware changes from Intel, providing another DSP framework for use with the DSPs in their SoCs. This one works with the firmware of the same name which is free software (unlike the previous DSP firmwares and framework) and there has been some interest in adoption by other systems already so hopefully we will see adoption by other vendors in the future. Other highlights include: - Support for MCLK/sample rate ratio setting in the generic cards. - Support for pin switches in the generic cards. - A big set of improvements to the TLV320AIC32x4 drivers from Annaliese McDermond. - New drivers for Freescale audio mixers, several Intel machines, several Mediatek machines, Meson G12A, Sound Open Firmware and Spreadtrum compressed audio and DMA devices.
Diffstat (limited to 'include/linux/bpf_verifier.h')
-rw-r--r--include/linux/bpf_verifier.h40
1 files changed, 40 insertions, 0 deletions
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 69f7a3449eda..7d8228d1c898 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -66,6 +66,46 @@ struct bpf_reg_state {
* same reference to the socket, to determine proper reference freeing.
*/
u32 id;
+ /* PTR_TO_SOCKET and PTR_TO_TCP_SOCK could be a ptr returned
+ * from a pointer-cast helper, bpf_sk_fullsock() and
+ * bpf_tcp_sock().
+ *
+ * Consider the following where "sk" is a reference counted
+ * pointer returned from "sk = bpf_sk_lookup_tcp();":
+ *
+ * 1: sk = bpf_sk_lookup_tcp();
+ * 2: if (!sk) { return 0; }
+ * 3: fullsock = bpf_sk_fullsock(sk);
+ * 4: if (!fullsock) { bpf_sk_release(sk); return 0; }
+ * 5: tp = bpf_tcp_sock(fullsock);
+ * 6: if (!tp) { bpf_sk_release(sk); return 0; }
+ * 7: bpf_sk_release(sk);
+ * 8: snd_cwnd = tp->snd_cwnd; // verifier will complain
+ *
+ * After bpf_sk_release(sk) at line 7, both "fullsock" ptr and
+ * "tp" ptr should be invalidated also. In order to do that,
+ * the reg holding "fullsock" and "sk" need to remember
+ * the original refcounted ptr id (i.e. sk_reg->id) in ref_obj_id
+ * such that the verifier can reset all regs which have
+ * ref_obj_id matching the sk_reg->id.
+ *
+ * sk_reg->ref_obj_id is set to sk_reg->id at line 1.
+ * sk_reg->id will stay as NULL-marking purpose only.
+ * After NULL-marking is done, sk_reg->id can be reset to 0.
+ *
+ * After "fullsock = bpf_sk_fullsock(sk);" at line 3,
+ * fullsock_reg->ref_obj_id is set to sk_reg->ref_obj_id.
+ *
+ * After "tp = bpf_tcp_sock(fullsock);" at line 5,
+ * tp_reg->ref_obj_id is set to fullsock_reg->ref_obj_id
+ * which is the same as sk_reg->ref_obj_id.
+ *
+ * From the verifier perspective, if sk, fullsock and tp
+ * are not NULL, they are the same ptr with different
+ * reg->type. In particular, bpf_sk_release(tp) is also
+ * allowed and has the same effect as bpf_sk_release(sk).
+ */
+ u32 ref_obj_id;
/* For scalar types (SCALAR_VALUE), this represents our knowledge of
* the actual value.
* For pointer types, this represents the variable part of the offset