* Re: [PATCH] net/ipv4: always honour route mtu during forwarding
2020-09-23 4:40 [PATCH] net/ipv4: always honour route mtu during forwarding Maciej Żenczykowski
@ 2020-09-23 4:46 ` Maciej Żenczykowski
2020-09-23 4:51 ` [PATCH v2] " Maciej Żenczykowski
2020-09-23 21:33 ` [PATCH] " kernel test robot
2020-09-24 4:21 ` kernel test robot
2 siblings, 1 reply; 14+ messages in thread
From: Maciej Żenczykowski @ 2020-09-23 4:46 UTC (permalink / raw)
To: Maciej Żenczykowski, David S . Miller
Cc: Linux Network Development Mailing List, Willem de Bruijn,
Lorenzo Colitti, Sunmeet Gill, Vinay Paradkar, Tyler Wear,
David Ahern
On Tue, Sep 22, 2020 at 9:41 PM Maciej Żenczykowski
<zenczykowski@gmail.com> wrote:
>
> From: Maciej Żenczykowski <maze@google.com>
>
> Documentation/networking/ip-sysctl.txt:46 says:
> ip_forward_use_pmtu - BOOLEAN
> By default we don't trust protocol path MTUs while forwarding
> because they could be easily forged and can lead to unwanted
> fragmentation by the router.
> You only need to enable this if you have user-space software
> which tries to discover path mtus by itself and depends on the
> kernel honoring this information. This is normally not the case.
> Default: 0 (disabled)
> Possible values:
> 0 - disabled
> 1 - enabled
>
> Which makes it pretty clear that setting it to 1 is a potential
> security/safety/DoS issue, and yet it is entirely reasonable to want
> forwarded traffic to honour explicitly administrator configured
> route mtus (instead of defaulting to device mtu).
>
> Indeed, I can't think of a single reason why you wouldn't want to.
> Since you configured a route mtu you probably know better...
>
> It is pretty common to have a higher device mtu to allow receiving
> large (jumbo) frames, while having some routes via that interface
> (potentially including the default route to the internet) specify
> a lower mtu.
>
> Note that ipv6 forwarding uses device mtu unless the route is locked
> (in which case it will use the route mtu).
>
> This approach is not usable for IPv4 where an 'mtu lock' on a route
> also has the side effect of disabling TCP path mtu discovery via
> disabling the IPv4 DF (don't frag) bit on all outgoing frames.
>
> I'm not aware of a way to lock a route from an IPv6 RA, so that also
> potentially seems wrong.
>
> Signed-off-by: Maciej Żenczykowski <maze@google.com>
> Cc: Eric Dumazet <maze@google.com>
> Cc: Willem de Bruijn <willemb@google.com>
> Cc: Lorenzo Colitti <lorenzo@google.com>
> Cc: Sunmeet Gill (Sunny) <sgill@quicinc.com>
> Cc: Vinay Paradkar <vparadka@qti.qualcomm.com>
> Cc: Tyler Wear <twear@quicinc.com>
> Cc: David Ahern <dsahern@kernel.org>
> ---
> include/net/ip.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/include/net/ip.h b/include/net/ip.h
> index b09c48d862cc..1262011d00b8 100644
> --- a/include/net/ip.h
> +++ b/include/net/ip.h
> @@ -442,6 +442,10 @@ static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
> !forwarding)
> return dst_mtu(dst);
>
> + /* 'forwarding = true' case should always honour route mtu */
> + unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
> + if (mtu) return mtu;
> +
> return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
> }
>
> --
> 2.28.0.681.g6f77f65b4e-goog
Eh, what I get for last minute removal of 'if (forwarding) {}' wrapper.
^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH] net/ipv4: always honour route mtu during forwarding
2020-09-23 4:40 [PATCH] net/ipv4: always honour route mtu during forwarding Maciej Żenczykowski
2020-09-23 4:46 ` Maciej Żenczykowski
@ 2020-09-23 21:33 ` kernel test robot
2020-09-24 1:06 ` Maciej Żenczykowski
2020-09-24 4:21 ` kernel test robot
2 siblings, 1 reply; 14+ messages in thread
From: kernel test robot @ 2020-09-23 21:33 UTC (permalink / raw)
To: kbuild-all
[-- Attachment #1: Type: text/plain, Size: 25693 bytes --]
Hi "Maciej,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on net-next/master]
[also build test WARNING on net/master linus/master v5.9-rc6 next-20200923]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Maciej-enczykowski/net-ipv4-always-honour-route-mtu-during-forwarding/20200923-124249
base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 748d1c8a425ec529d541f082ee7a81f6a51fa120
config: s390-randconfig-r034-20200923 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project d6ac649ccda289ecc2d2c0cb51892d57e8ec328c)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install s390 cross compiling tool for clang build
# apt-get install binutils-s390x-linux-gnu
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
(((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \
^
In file included from net/socket.c:62:
In file included from include/linux/netdevice.h:37:
In file included from include/linux/ethtool.h:18:
In file included from include/uapi/linux/ethtool.h:19:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
^
In file included from net/socket.c:62:
In file included from include/linux/netdevice.h:37:
In file included from include/linux/ethtool.h:18:
In file included from include/uapi/linux/ethtool.h:19:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0xff000000UL) >> 24)))
^
In file included from net/socket.c:62:
In file included from include/linux/netdevice.h:37:
In file included from include/linux/ethtool.h:18:
In file included from include/uapi/linux/ethtool.h:19:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32'
__fswab32(x))
^
In file included from net/socket.c:62:
In file included from include/linux/netdevice.h:37:
In file included from include/linux/ethtool.h:18:
In file included from include/uapi/linux/ethtool.h:19:
In file included from include/linux/if_ether.h:19:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
In file included from net/socket.c:105:
In file included from include/net/busy_poll.h:18:
>> include/net/ip.h:446:15: warning: ISO C90 forbids mixing declarations and code [-Wdeclaration-after-statement]
unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
^
21 warnings generated.
--
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:20:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \
^
In file included from net/core/sock.c:91:
In file included from include/linux/errqueue.h:6:
In file included from include/net/ip.h:22:
In file included from include/linux/ip.h:16:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
^
In file included from net/core/sock.c:91:
In file included from include/linux/errqueue.h:6:
In file included from include/net/ip.h:22:
In file included from include/linux/ip.h:16:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0xff000000UL) >> 24)))
^
In file included from net/core/sock.c:91:
In file included from include/linux/errqueue.h:6:
In file included from include/net/ip.h:22:
In file included from include/linux/ip.h:16:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32'
__fswab32(x))
^
In file included from net/core/sock.c:91:
In file included from include/linux/errqueue.h:6:
In file included from include/net/ip.h:22:
In file included from include/linux/ip.h:16:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
In file included from net/core/sock.c:91:
In file included from include/linux/errqueue.h:6:
>> include/net/ip.h:446:15: warning: ISO C90 forbids mixing declarations and code [-Wdeclaration-after-statement]
unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
^
In file included from net/core/sock.c:88:
In file included from ./arch/s390/include/generated/asm/unaligned.h:1:
In file included from include/asm-generic/unaligned.h:13:
In file included from include/linux/unaligned/access_ok.h:5:
In file included from include/linux/kernel.h:12:
In file included from include/linux/bitops.h:29:
arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
"oi %0,%b1\n"
^
arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
arch/s390/include/asm/bitops.h:90:4: error: invalid operand in inline asm: 'ni $0,${1:b}'
"ni %0,%b1\n"
^
arch/s390/include/asm/bitops.h:90:4: error: invalid operand in inline asm: 'ni $0,${1:b}'
arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
"oi %0,%b1\n"
^
arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
arch/s390/include/asm/bitops.h:90:4: error: invalid operand in inline asm: 'ni $0,${1:b}'
"ni %0,%b1\n"
^
arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
"oi %0,%b1\n"
^
arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
arch/s390/include/asm/bitops.h:90:4: error: invalid operand in inline asm: 'ni $0,${1:b}'
"ni %0,%b1\n"
^
21 warnings and 10 errors generated.
--
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:20:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \
^
In file included from net/core/datagram.c:45:
In file included from include/linux/inet.h:42:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
^
In file included from net/core/datagram.c:45:
In file included from include/linux/inet.h:42:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0xff000000UL) >> 24)))
^
In file included from net/core/datagram.c:45:
In file included from include/linux/inet.h:42:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32'
__fswab32(x))
^
In file included from net/core/datagram.c:45:
In file included from include/linux/inet.h:42:
In file included from include/net/net_namespace.h:39:
In file included from include/linux/skbuff.h:31:
In file included from include/linux/dma-mapping.h:11:
In file included from include/linux/scatterlist.h:9:
In file included from arch/s390/include/asm/io.h:72:
include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
In file included from net/core/datagram.c:63:
In file included from include/net/busy_poll.h:18:
>> include/net/ip.h:446:15: warning: ISO C90 forbids mixing declarations and code [-Wdeclaration-after-statement]
unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
^
In file included from net/core/datagram.c:37:
In file included from include/linux/module.h:12:
In file included from include/linux/list.h:9:
In file included from include/linux/kernel.h:12:
In file included from include/linux/bitops.h:29:
arch/s390/include/asm/bitops.h:69:4: error: invalid operand in inline asm: 'oi $0,${1:b}'
"oi %0,%b1\n"
^
21 warnings and 1 error generated.
..
# https://github.com/0day-ci/linux/commit/d9552d77468fe90224e07225cfc8c3f838b28b1b
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Maciej-enczykowski/net-ipv4-always-honour-route-mtu-during-forwarding/20200923-124249
git checkout d9552d77468fe90224e07225cfc8c3f838b28b1b
vim +446 include/net/ip.h
434
435 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
436 bool forwarding)
437 {
438 struct net *net = dev_net(dst->dev);
439
440 if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
441 ip_mtu_locked(dst) ||
442 !forwarding)
443 return dst_mtu(dst);
444
445 /* 'forwarding = true' case should always honour route mtu */
> 446 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
447 if (mtu) return mtu;
448
449 return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
450 }
451
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org
[-- Attachment #2: config.gz --]
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^ permalink raw reply [flat|nested] 14+ messages in thread
* Re: [PATCH] net/ipv4: always honour route mtu during forwarding
2020-09-23 4:40 [PATCH] net/ipv4: always honour route mtu during forwarding Maciej Żenczykowski
@ 2020-09-24 4:21 ` kernel test robot
2020-09-23 21:33 ` [PATCH] " kernel test robot
2020-09-24 4:21 ` kernel test robot
2 siblings, 0 replies; 14+ messages in thread
From: kernel test robot @ 2020-09-24 4:21 UTC (permalink / raw)
To: Maciej Żenczykowski, Maciej Żenczykowski, David S . Miller
Cc: kbuild-all, Linux Network Development Mailing List,
Willem de Bruijn, Lorenzo Colitti, Sunmeet Gill, Vinay Paradkar,
Tyler Wear, David Ahern
[-- Attachment #1: Type: text/plain, Size: 2589 bytes --]
Hi "Maciej,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on net-next/master]
[also build test WARNING on net/master linus/master sparc-next/master next-20200923]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url: https://github.com/0day-ci/linux/commits/Maciej-enczykowski/net-ipv4-always-honour-route-mtu-during-forwarding/20200923-124249
base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 748d1c8a425ec529d541f082ee7a81f6a51fa120
config: parisc-randconfig-c003-20200923 (attached as .config)
compiler: hppa64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=parisc
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
All warnings (new ones prefixed by >>):
In file included from include/net/busy_poll.h:18,
from fs/select.c:32:
include/net/ip.h: In function 'ip_dst_mtu_maybe_forward':
>> include/net/ip.h:446:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]
446 | unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
| ^~~~~~~~
# https://github.com/0day-ci/linux/commit/d9552d77468fe90224e07225cfc8c3f838b28b1b
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Maciej-enczykowski/net-ipv4-always-honour-route-mtu-during-forwarding/20200923-124249
git checkout d9552d77468fe90224e07225cfc8c3f838b28b1b
vim +446 include/net/ip.h
434
435 static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
436 bool forwarding)
437 {
438 struct net *net = dev_net(dst->dev);
439
440 if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
441 ip_mtu_locked(dst) ||
442 !forwarding)
443 return dst_mtu(dst);
444
445 /* 'forwarding = true' case should always honour route mtu */
> 446 unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
447 if (mtu) return mtu;
448
449 return min(READ_ONCE(dst->dev->mtu), IP_MAX_MTU);
450 }
451
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
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^ permalink raw reply [flat|nested] 14+ messages in thread