menu "GCOV-based kernel profiling" config GCOV_KERNEL bool "Enable gcov-based kernel profiling" depends on DEBUG_FS select CONSTRUCTORS if !UML default n ---help--- This option enables gcov-based code profiling (e.g. for code coverage measurements). If unsure, say N. Additionally specify CONFIG_GCOV_PROFILE_ALL=y to get profiling data for the entire kernel. To enable profiling for specific files or directories, add a line similar to the following to the respective Makefile: For a single file (e.g. main.o): GCOV_PROFILE_main.o := y For all files in one directory: GCOV_PROFILE := y To exclude files from being profiled even when CONFIG_GCOV_PROFILE_ALL is specified, use: GCOV_PROFILE_main.o := n and: GCOV_PROFILE := n Note that the debugfs filesystem has to be mounted to access profiling data. config ARCH_HAS_GCOV_PROFILE_ALL def_bool n config GCOV_PROFILE_ALL bool "Profile entire Kernel" depends on !COMPILE_TEST depends on GCOV_KERNEL depends on ARCH_HAS_GCOV_PROFILE_ALL default n ---help--- This options activates profiling for the entire kernel. If unsure, say N. Note that a kernel compiled with profiling flags will be significantly larger and run slower. Also be sure to exclude files from profiling which are not linked to the kernel image to prevent linker errors. choice prompt "Specify GCOV format" depends on GCOV_KERNEL default GCOV_FORMAT_AUTODETECT ---help--- The gcov format is usually determined by the GCC version, but there are exceptions where format changes are integrated in lower-version GCCs. In such a case use this option to adjust the format used in the kernel accordingly. If unsure, choose "Autodetect". config GCOV_FORMAT_AUTODETECT bool "Autodetect" ---help--- Select this option to use the format that corresponds to your GCC version. config GCOV_FORMAT_3_4 bool "GCC 3.4 format" ---help--- Select this option to use the format defined by GCC 3.4. config GCOV_FORMAT_4_7 bool "GCC 4.7 format" ---help--- Select this option to use the format defined by GCC 4.7. endchoice endmenu input type='hidden' name='id' value='b2504a5dbef3305ef41988ad270b0e8ec289331c'/>
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authorEric Dumazet <edumazet@google.com>2017-01-31 10:20:32 -0800
committerDavid S. Miller <davem@davemloft.net>2017-02-01 12:02:48 -0500
commitb2504a5dbef3305ef41988ad270b0e8ec289331c (patch)
tree361fc2c2a0a52a5804a32058f981ff9862a4d3bc /net
parent160ca0142431c19386db976302fd4b07c587f651 (diff)
net: reduce skb_warn_bad_offload() noise
Dmitry reported warnings occurring in __skb_gso_segment() [1] All SKB_GSO_DODGY producers can allow user space to feed packets that trigger the current check. We could prevent them from doing so, rejecting packets, but this might add regressions to existing programs. It turns out our SKB_GSO_DODGY handlers properly set up checksum information that is needed anyway when packets needs to be segmented. By checking again skb_needs_check() after skb_mac_gso_segment(), we should remove these pesky warnings, at a very minor cost. With help from Willem de Bruijn [1] WARNING: CPU: 1 PID: 6768 at net/core/dev.c:2439 skb_warn_bad_offload+0x2af/0x390 net/core/dev.c:2434 lo: caps=(0x000000a2803b7c69, 0x0000000000000000) len=138 data_len=0 gso_size=15883 gso_type=4 ip_summed=0 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 6768 Comm: syz-executor1 Not tainted 4.9.0 #5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801c063ecd8 ffffffff82346bdf ffffffff00000001 1ffff100380c7d2e ffffed00380c7d26 0000000041b58ab3 ffffffff84b37e38 ffffffff823468f1 ffffffff84820740 ffffffff84f289c0 dffffc0000000000 ffff8801c063ee20 Call Trace: [<ffffffff82346bdf>] __dump_stack lib/dump_stack.c:15 [inline] [<ffffffff82346bdf>] dump_stack+0x2ee/0x3ef lib/dump_stack.c:51 [<ffffffff81827e34>] panic+0x1fb/0x412 kernel/panic.c:179 [<ffffffff8141f704>] __warn+0x1c4/0x1e0 kernel/panic.c:542 [<ffffffff8141f7e5>] warn_slowpath_fmt+0xc5/0x100 kernel/panic.c:565 [<ffffffff8356cbaf>] skb_warn_bad_offload+0x2af/0x390 net/core/dev.c:2434 [<ffffffff83585cd2>] __skb_gso_segment+0x482/0x780 net/core/dev.c:2706 [<ffffffff83586f19>] skb_gso_segment include/linux/netdevice.h:3985 [inline] [<ffffffff83586f19>] validate_xmit_skb+0x5c9/0xc20 net/core/dev.c:2969 [<ffffffff835892bb>] __dev_queue_xmit+0xe6b/0x1e70 net/core/dev.c:3383 [<ffffffff8358a2d7>] dev_queue_xmit+0x17/0x20 net/core/dev.c:3424 [<ffffffff83ad161d>] packet_snd net/packet/af_packet.c:2930 [inline] [<ffffffff83ad161d>] packet_sendmsg+0x32ed/0x4d30 net/packet/af_packet.c:2955 [<ffffffff834f0aaa>] sock_sendmsg_nosec net/socket.c:621 [inline] [<ffffffff834f0aaa>] sock_sendmsg+0xca/0x110 net/socket.c:631 [<ffffffff834f329a>] ___sys_sendmsg+0x8fa/0x9f0 net/socket.c:1954 [<ffffffff834f5e58>] __sys_sendmsg+0x138/0x300 net/socket.c:1988 [<ffffffff834f604d>] SYSC_sendmsg net/socket.c:1999 [inline] [<ffffffff834f604d>] SyS_sendmsg+0x2d/0x50 net/socket.c:1995 [<ffffffff84371941>] entry_SYSCALL_64_fastpath+0x1f/0xc2 Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/dev.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/net/core/dev.c b/net/core/dev.c