linux-stable/net
Yonghong Song 97a19caf1b bpf: net: Emit anonymous enum with BPF_TCP_CLOSE value explicitly
The selftest failed to compile with clang-built bpf-next.
Adding LLVM=1 to your vmlinux and selftest build will use clang.
The error message is:
  progs/test_sk_storage_tracing.c:38:18: error: use of undeclared identifier 'BPF_TCP_CLOSE'
          if (newstate == BPF_TCP_CLOSE)
                          ^
  1 error generated.
  make: *** [Makefile:423: /bpf-next/tools/testing/selftests/bpf/test_sk_storage_tracing.o] Error 1

The reason for the failure is that BPF_TCP_CLOSE, a value of
an anonymous enum defined in uapi bpf.h, is not defined in
vmlinux.h. gcc does not have this problem. Since vmlinux.h
is derived from BTF which is derived from vmlinux DWARF,
that means gcc-produced vmlinux DWARF has BPF_TCP_CLOSE
while llvm-produced vmlinux DWARF does not have.

BPF_TCP_CLOSE is referenced in net/ipv4/tcp.c as
  BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE);
The following test mimics the above BUILD_BUG_ON, preprocessed
with clang compiler, and shows gcc DWARF contains BPF_TCP_CLOSE while
llvm DWARF does not.

  $ cat t.c
  enum {
    BPF_TCP_ESTABLISHED = 1,
    BPF_TCP_CLOSE = 7,
  };
  enum {
    TCP_ESTABLISHED = 1,
    TCP_CLOSE = 7,
  };

  int test() {
    do {
      extern void __compiletime_assert_767(void) ;
      if ((int)BPF_TCP_CLOSE != (int)TCP_CLOSE) __compiletime_assert_767();
    } while (0);
    return 0;
  }
  $ clang t.c -O2 -c -g && llvm-dwarfdump t.o | grep BPF_TCP_CLOSE
  $ gcc t.c -O2 -c -g && llvm-dwarfdump t.o | grep BPF_TCP_CLOSE
                    DW_AT_name    ("BPF_TCP_CLOSE")

Further checking clang code find clang actually tried to
evaluate condition at compile time. If it is definitely
true/false, it will perform optimization and the whole if condition
will be removed before generating IR/debuginfo.

This patch explicited add an expression after the
above mentioned BUILD_BUG_ON in net/ipv4/tcp.c like
  (void)BPF_TCP_ESTABLISHED
to enable generation of debuginfo for the anonymous
enum which also includes BPF_TCP_CLOSE.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210317174132.589276-1-yhs@fb.com
2021-03-17 18:45:40 -07:00
..
6lowpan
9p net: 9p: advance iov on empty read 2021-03-03 16:57:59 -08:00
802
8021q Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-01-14 18:34:50 -08:00
appletalk appletalk: Fix skb allocation size in loopback case 2021-02-12 16:40:28 -08:00
atm net: atm: pppoatm: use new API for wakeup tasklet 2021-01-29 18:24:05 -08:00
ax25
batman-adv This feature/cleanup patchset is an updated version of the pull request 2021-02-08 11:32:40 -08:00
bluetooth Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kern 2021-02-11 14:59:01 -08:00
bpf bpf: Add PROG_TEST_RUN support for sk_lookup programs 2021-03-04 19:11:29 -08:00
bpfilter net: remove redundant 'depends on NET' 2021-01-27 17:04:12 -08:00
bridge bridge: mrp: Update br_mrp to use new return values of br_mrp_switchdev 2021-02-16 14:47:46 -08:00
caif net: caif: Use netif_rx_any_context(). 2021-02-15 13:21:48 -08:00
can net: introduce CAN specific pointer in the struct net_device 2021-02-24 14:32:15 -08:00
ceph libceph: remove osdtimeout option entirely 2021-02-16 12:09:52 +01:00
core bpf: Add getter and setter for SO_REUSEPORT through bpf_{g,s}etsockopt 2021-03-15 17:22:22 +01:00
dcb net: dcb: use obj-$(CONFIG_DCB) form in net/Makefile 2021-01-27 17:03:52 -08:00
dccp dccp: Return the correct errno code 2021-02-06 11:15:28 -08:00
decnet net: decnet: fix netdev refcount leaking on error path 2021-01-27 17:33:46 -08:00
dns_resolver net: remove redundant 'depends on NET' 2021-01-27 17:04:12 -08:00
dsa net: dsa: fix switchdev objects on bridge master mistakenly being applied on ports 2021-03-08 11:59:00 -08:00
ethernet net: datagram: fix some kernel-doc markups 2020-11-17 14:15:03 -08:00
ethtool ethtool: fix the check logic of at least one channel for RX/TX 2021-02-28 11:49:07 -08:00
hsr net: hsr: add support for EntryForgetTime 2021-02-25 09:41:51 -08:00
ieee802154 treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
ife net: remove redundant 'depends on NET' 2021-01-27 17:04:12 -08:00
ipv4 bpf: net: Emit anonymous enum with BPF_TCP_CLOSE value explicitly 2021-03-17 18:45:40 -07:00
ipv6 Merge git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2021-03-09 17:15:56 -08:00
iucv net/af_iucv: build SG skbs for TRANS_HIPER sockets 2021-01-28 20:36:22 -08:00
kcm net: group skb_shinfo zerocopy related bits together. 2021-01-07 16:08:37 -08:00
key af_key: relax availability checks for skb size calculation 2021-01-04 10:05:50 +01:00
l2tp net: l2tp: reduce log level of messages in receive path, add counter instead 2021-03-03 16:55:02 -08:00
l3mdev net: l3mdev: use obj-$(CONFIG_NET_L3_MASTER_DEV) form in net/Makefile 2021-01-27 17:03:52 -08:00
lapb net: lapb: Copy the skb before sending a packet 2021-02-02 08:40:48 -08:00
llc net: remove redundant 'depends on NET' 2021-01-27 17:04:12 -08:00
mac80211 cfg80211/mac80211: Support disabling HE mode 2021-02-12 09:33:34 +01:00
mac802154 net: mac802154: convert tasklets to use new tasklet_setup() API 2020-11-07 10:40:56 -08:00
mpls net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0 2021-03-09 16:12:20 -08:00
mptcp mptcp: fix length of ADD_ADDR with port sub-option 2021-03-08 15:02:03 -08:00
ncsi net/ncsi: Use real net-device for response handler 2020-12-23 12:22:23 -08:00
netfilter netfilter: nftables: bogus check for netlink portID with table owner 2021-03-04 04:02:54 +01:00
netlabel cipso,calipso: resolve a number of problems with the DOI refcounts 2021-03-04 15:26:57 -08:00
netlink mptcp: avoid lock_fast usage in accept path 2021-02-12 16:31:46 -08:00
netrom
nfc TTY/Serial driver changes for 5.12-rc1 2021-02-20 21:28:04 -08:00
nsh
openvswitch net: openvswitch: add log message for error case 2021-01-14 16:32:14 -08:00
packet net/packet: Improve the comment about LL header visibility criteria 2021-02-06 14:59:28 -08:00
phonet
psample net: psample: Fix netlink skb length with tunnel info 2021-02-25 09:49:46 -08:00
qrtr net: qrtr: fix error return code of qrtr_sendmsg() 2021-03-08 15:02:53 -08:00
rds net/rds: restrict iovecs length for RDS_CMSG_RDMA_ARGS 2021-02-02 08:44:08 -08:00
rfkill rfkill: add a reason to the HW rfkill state 2020-12-11 12:47:17 +01:00
rose rose: Fix Null pointer dereference in rose_send_frame() 2020-11-20 10:04:58 -08:00
rxrpc rxrpc: Fix dependency on IPv6 in udp tunnel config 2021-02-12 16:42:05 -08:00
sched net: sched: avoid duplicates in classes dump 2021-03-04 14:27:47 -08:00
sctp net: sctp: trivial: fix typo in comment 2021-03-04 13:48:32 -08:00
smc net/smc: use memcpy instead of snprintf to avoid out of bounds read 2021-01-12 20:22:01 -08:00
strparser
sunrpc NFS Client Updates for Linux 5.12 2021-02-26 09:17:24 -08:00
switchdev net: bridge: propagate extack through switchdev_port_attr_set 2021-02-14 17:38:11 -08:00
tipc tipc: remove duplicated code in tipc_msg_create 2021-01-27 18:50:07 -08:00
tls net/tls: Select SOCK_RX_QUEUE_MAPPING from TLS_DEVICE 2021-02-11 19:08:06 -08:00
unix af_unix: handle idmapped mounts 2021-01-24 14:27:18 +01:00
vmw_vsock vsock: fix locking in vsock_shutdown() 2021-02-09 15:31:22 -08:00
wireless cfg80211/mac80211: Support disabling HE mode 2021-02-12 09:33:34 +01:00
x25 net: x25: Remove unimplemented X.25-over-LLC code stubs 2020-12-12 17:15:33 -08:00
xdp bpf, xdp: Restructure redirect actions 2021-03-10 01:06:34 +01:00
xfrm Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2021-02-09 11:23:41 -08:00
compat.c
devres.c
Kconfig bpf: Clean up sockmap related Kconfigs 2021-02-26 12:28:03 -08:00
Makefile net: l3mdev: use obj-$(CONFIG_NET_L3_MASTER_DEV) form in net/Makefile 2021-01-27 17:03:52 -08:00
socket.c io_uring-worker.v3-2021-02-25 2021-02-27 08:29:02 -08:00
sysctl_net.c