Message ID | 20170816170202.456851-3-equinox@diac24.net |
---|---|
State | Changes Requested, archived |
Delegated to: | David Miller |
Headers | show |
Hi David, [auto build test WARNING on net-next/master] [also build test WARNING on next-20170817] [cannot apply to v4.13-rc5] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/David-Lamparter/bridge-learn-dst-metadata-in-FDB/20170820-001849 config: s390-allmodconfig (attached as .config) compiler: s390x-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705 reproduce: wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree make.cross ARCH=s390 Note: it may well be a FALSE warning. FWIW you are at least aware of it now. http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings All warnings (new ones prefixed by >>): In file included from include/uapi/linux/stddef.h:1:0, from include/linux/stddef.h:4, from include/uapi/linux/posix_types.h:4, from include/uapi/linux/types.h:13, from include/linux/types.h:5, from net/mpls/af_mpls.c:1: net/mpls/af_mpls.c: In function 'mpls_rt_xmit': >> include/linux/compiler.h:239:26: warning: 'out_dev' may be used uninitialized in this function [-Wmaybe-uninitialized] case 8: *(__u64 *)res = *(volatile __u64 *)p; break; \ ^ net/mpls/af_mpls.c:384:21: note: 'out_dev' was declared here struct net_device *out_dev; ^~~~~~~ -- In file included from include/uapi/linux/stddef.h:1:0, from include/linux/stddef.h:4, from include/uapi/linux/posix_types.h:4, from include/uapi/linux/types.h:13, from include/linux/types.h:5, from net//mpls/af_mpls.c:1: net//mpls/af_mpls.c: In function 'mpls_rt_xmit': >> include/linux/compiler.h:239:26: warning: 'out_dev' may be used uninitialized in this function [-Wmaybe-uninitialized] case 8: *(__u64 *)res = *(volatile __u64 *)p; break; \ ^ net//mpls/af_mpls.c:384:21: note: 'out_dev' was declared here struct net_device *out_dev; ^~~~~~~ vim +/out_dev +239 include/linux/compiler.h 230fa253 Christian Borntraeger 2014-11-25 232 d976441f Andrey Ryabinin 2015-10-19 233 #define __READ_ONCE_SIZE \ d976441f Andrey Ryabinin 2015-10-19 234 ({ \ d976441f Andrey Ryabinin 2015-10-19 235 switch (size) { \ d976441f Andrey Ryabinin 2015-10-19 236 case 1: *(__u8 *)res = *(volatile __u8 *)p; break; \ d976441f Andrey Ryabinin 2015-10-19 237 case 2: *(__u16 *)res = *(volatile __u16 *)p; break; \ d976441f Andrey Ryabinin 2015-10-19 238 case 4: *(__u32 *)res = *(volatile __u32 *)p; break; \ d976441f Andrey Ryabinin 2015-10-19 @239 case 8: *(__u64 *)res = *(volatile __u64 *)p; break; \ d976441f Andrey Ryabinin 2015-10-19 240 default: \ d976441f Andrey Ryabinin 2015-10-19 241 barrier(); \ d976441f Andrey Ryabinin 2015-10-19 242 __builtin_memcpy((void *)res, (const void *)p, size); \ d976441f Andrey Ryabinin 2015-10-19 243 barrier(); \ d976441f Andrey Ryabinin 2015-10-19 244 } \ d976441f Andrey Ryabinin 2015-10-19 245 }) d976441f Andrey Ryabinin 2015-10-19 246 :::::: The code at line 239 was first introduced by commit :::::: d976441f44bc5d48635d081d277aa76556ffbf8b compiler, atomics, kasan: Provide READ_ONCE_NOCHECK() :::::: TO: Andrey Ryabinin <aryabinin@virtuozzo.com> :::::: CC: Ingo Molnar <mingo@kernel.org> --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
Hi David,
[auto build test WARNING on net-next/master]
[also build test WARNING on next-20170817]
[cannot apply to v4.13-rc5]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/David-Lamparter/bridge-learn-dst-metadata-in-FDB/20170820-001849
config: xtensa-allmodconfig (attached as .config)
compiler: xtensa-linux-gcc (GCC) 4.9.0
reproduce:
wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=xtensa
Note: it may well be a FALSE warning. FWIW you are at least aware of it now.
http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings
All warnings (new ones prefixed by >>):
net/mpls/af_mpls.c: In function 'mpls_rt_xmit':
>> net/mpls/af_mpls.c:452:45: warning: 'out_dev' may be used uninitialized in this function [-Wmaybe-uninitialized]
out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
^
vim +/out_dev +452 net/mpls/af_mpls.c
679ee57f David Lamparter 2017-08-16 379
679ee57f David Lamparter 2017-08-16 380 int mpls_rt_xmit(struct sk_buff *skb, struct mpls_route *rt,
679ee57f David Lamparter 2017-08-16 381 struct mpls_entry_decoded dec)
679ee57f David Lamparter 2017-08-16 382 {
679ee57f David Lamparter 2017-08-16 383 struct mpls_nh *nh;
679ee57f David Lamparter 2017-08-16 384 struct net_device *out_dev;
679ee57f David Lamparter 2017-08-16 385 struct mpls_dev *out_mdev;
679ee57f David Lamparter 2017-08-16 386 unsigned int hh_len;
679ee57f David Lamparter 2017-08-16 387 unsigned int new_header_size;
679ee57f David Lamparter 2017-08-16 388 unsigned int mtu;
679ee57f David Lamparter 2017-08-16 389 int err;
679ee57f David Lamparter 2017-08-16 390
679ee57f David Lamparter 2017-08-16 391 nh = mpls_select_multipath(rt, skb);
679ee57f David Lamparter 2017-08-16 392 if (!nh)
679ee57f David Lamparter 2017-08-16 393 goto tx_err;
679ee57f David Lamparter 2017-08-16 394
27d69105 Robert Shearman 2017-01-16 395 /* Find the output device */
27d69105 Robert Shearman 2017-01-16 396 out_dev = rcu_dereference(nh->nh_dev);
27d69105 Robert Shearman 2017-01-16 397 if (!mpls_output_possible(out_dev))
27d69105 Robert Shearman 2017-01-16 398 goto tx_err;
27d69105 Robert Shearman 2017-01-16 399
0189197f Eric W. Biederman 2015-03-03 400 /* Verify the destination can hold the packet */
f8efb73c Roopa Prabhu 2015-10-23 401 new_header_size = mpls_nh_header_size(nh);
0189197f Eric W. Biederman 2015-03-03 402 mtu = mpls_dev_mtu(out_dev);
0189197f Eric W. Biederman 2015-03-03 403 if (mpls_pkt_too_big(skb, mtu - new_header_size))
27d69105 Robert Shearman 2017-01-16 404 goto tx_err;
0189197f Eric W. Biederman 2015-03-03 405
0189197f Eric W. Biederman 2015-03-03 406 hh_len = LL_RESERVED_SPACE(out_dev);
0189197f Eric W. Biederman 2015-03-03 407 if (!out_dev->header_ops)
0189197f Eric W. Biederman 2015-03-03 408 hh_len = 0;
0189197f Eric W. Biederman 2015-03-03 409
0189197f Eric W. Biederman 2015-03-03 410 /* Ensure there is enough space for the headers in the skb */
0189197f Eric W. Biederman 2015-03-03 411 if (skb_cow(skb, hh_len + new_header_size))
27d69105 Robert Shearman 2017-01-16 412 goto tx_err;
0189197f Eric W. Biederman 2015-03-03 413
0189197f Eric W. Biederman 2015-03-03 414 skb->dev = out_dev;
0189197f Eric W. Biederman 2015-03-03 415 skb->protocol = htons(ETH_P_MPLS_UC);
0189197f Eric W. Biederman 2015-03-03 416
0189197f Eric W. Biederman 2015-03-03 417 if (unlikely(!new_header_size && dec.bos)) {
0189197f Eric W. Biederman 2015-03-03 418 /* Penultimate hop popping */
5b441ac8 Robert Shearman 2017-03-10 419 if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
679ee57f David Lamparter 2017-08-16 420 goto tx_err;
0189197f Eric W. Biederman 2015-03-03 421 } else {
679ee57f David Lamparter 2017-08-16 422 struct mpls_shim_hdr *hdr;
0189197f Eric W. Biederman 2015-03-03 423 bool bos;
0189197f Eric W. Biederman 2015-03-03 424 int i;
0189197f Eric W. Biederman 2015-03-03 425 skb_push(skb, new_header_size);
0189197f Eric W. Biederman 2015-03-03 426 skb_reset_network_header(skb);
0189197f Eric W. Biederman 2015-03-03 427 /* Push the new labels */
0189197f Eric W. Biederman 2015-03-03 428 hdr = mpls_hdr(skb);
0189197f Eric W. Biederman 2015-03-03 429 bos = dec.bos;
f8efb73c Roopa Prabhu 2015-10-23 430 for (i = nh->nh_labels - 1; i >= 0; i--) {
f8efb73c Roopa Prabhu 2015-10-23 431 hdr[i] = mpls_entry_encode(nh->nh_label[i],
f8efb73c Roopa Prabhu 2015-10-23 432 dec.ttl, 0, bos);
0189197f Eric W. Biederman 2015-03-03 433 bos = false;
0189197f Eric W. Biederman 2015-03-03 434 }
0189197f Eric W. Biederman 2015-03-03 435 }
0189197f Eric W. Biederman 2015-03-03 436
27d69105 Robert Shearman 2017-01-16 437 mpls_stats_inc_outucastpkts(out_dev, skb);
27d69105 Robert Shearman 2017-01-16 438
eb7809f0 Robert Shearman 2015-12-10 439 /* If via wasn't specified then send out using device address */
eb7809f0 Robert Shearman 2015-12-10 440 if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC)
eb7809f0 Robert Shearman 2015-12-10 441 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev,
eb7809f0 Robert Shearman 2015-12-10 442 out_dev->dev_addr, skb);
eb7809f0 Robert Shearman 2015-12-10 443 else
eb7809f0 Robert Shearman 2015-12-10 444 err = neigh_xmit(nh->nh_via_table, out_dev,
eb7809f0 Robert Shearman 2015-12-10 445 mpls_nh_via(rt, nh), skb);
0189197f Eric W. Biederman 2015-03-03 446 if (err)
0189197f Eric W. Biederman 2015-03-03 447 net_dbg_ratelimited("%s: packet transmission failed: %d\n",
0189197f Eric W. Biederman 2015-03-03 448 __func__, err);
0189197f Eric W. Biederman 2015-03-03 449 return 0;
0189197f Eric W. Biederman 2015-03-03 450
27d69105 Robert Shearman 2017-01-16 451 tx_err:
27d69105 Robert Shearman 2017-01-16 @452 out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
27d69105 Robert Shearman 2017-01-16 453 if (out_mdev)
27d69105 Robert Shearman 2017-01-16 454 MPLS_INC_STATS(out_mdev, tx_errors);
679ee57f David Lamparter 2017-08-16 455 return -1;
0189197f Eric W. Biederman 2015-03-03 456 }
0189197f Eric W. Biederman 2015-03-03 457
:::::: The code at line 452 was first introduced by commit
:::::: 27d691056bde4a6feca5e83fd92b787332c46302 mpls: Packet stats
:::::: TO: Robert Shearman <rshearma@brocade.com>
:::::: CC: David S. Miller <davem@davemloft.net>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c index c5b9ce41d66f..0c5953e5d5bd 100644 --- a/net/mpls/af_mpls.c +++ b/net/mpls/af_mpls.c @@ -43,7 +43,7 @@ static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt, struct nlmsghdr *nlh, struct net *net, u32 portid, unsigned int nlm_flags); -static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index) +struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index) { struct mpls_route *rt = NULL; @@ -313,15 +313,8 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev, struct net *net = dev_net(dev); struct mpls_shim_hdr *hdr; struct mpls_route *rt; - struct mpls_nh *nh; struct mpls_entry_decoded dec; - struct net_device *out_dev; - struct mpls_dev *out_mdev; struct mpls_dev *mdev; - unsigned int hh_len; - unsigned int new_header_size; - unsigned int mtu; - int err; /* Careful this entire function runs inside of an rcu critical section */ @@ -356,9 +349,6 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev, goto drop; } - nh = mpls_select_multipath(rt, skb); - if (!nh) - goto err; /* Pop the label */ skb_pull(skb, sizeof(*hdr)); @@ -376,6 +366,32 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev, goto err; dec.ttl -= 1; + if (mpls_rt_xmit(skb, rt, dec)) + goto drop; + return 0; + +err: + MPLS_INC_STATS(mdev, rx_errors); +drop: + kfree_skb(skb); + return NET_RX_DROP; +} + +int mpls_rt_xmit(struct sk_buff *skb, struct mpls_route *rt, + struct mpls_entry_decoded dec) +{ + struct mpls_nh *nh; + struct net_device *out_dev; + struct mpls_dev *out_mdev; + unsigned int hh_len; + unsigned int new_header_size; + unsigned int mtu; + int err; + + nh = mpls_select_multipath(rt, skb); + if (!nh) + goto tx_err; + /* Find the output device */ out_dev = rcu_dereference(nh->nh_dev); if (!mpls_output_possible(out_dev)) @@ -401,8 +417,9 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev, if (unlikely(!new_header_size && dec.bos)) { /* Penultimate hop popping */ if (!mpls_egress(dev_net(out_dev), rt, skb, dec)) - goto err; + goto tx_err; } else { + struct mpls_shim_hdr *hdr; bool bos; int i; skb_push(skb, new_header_size); @@ -435,12 +452,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev, out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL; if (out_mdev) MPLS_INC_STATS(out_mdev, tx_errors); - goto drop; -err: - MPLS_INC_STATS(mdev, rx_errors); -drop: - kfree_skb(skb); - return NET_RX_DROP; + return -1; } static struct packet_type mpls_packet_type __read_mostly = { diff --git a/net/mpls/internal.h b/net/mpls/internal.h index cf65aec2e551..b70c6663d4f3 100644 --- a/net/mpls/internal.h +++ b/net/mpls/internal.h @@ -210,4 +210,8 @@ bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu); void mpls_stats_inc_outucastpkts(struct net_device *dev, const struct sk_buff *skb); +struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index); +int mpls_rt_xmit(struct sk_buff *skb, struct mpls_route *rt, + struct mpls_entry_decoded dec); + #endif /* MPLS_INTERNAL_H */
This makes mpls_rt_xmit() available for use in upcoming VPLS code. Same for mpls_route_input_rcu(). Signed-off-by: David Lamparter <equinox@diac24.net> --- net/mpls/af_mpls.c | 48 ++++++++++++++++++++++++++++++------------------ net/mpls/internal.h | 4 ++++ 2 files changed, 34 insertions(+), 18 deletions(-)