> On 2017年01月11日 20:01, Johannes Berg wrote: > > Sure, ssh won't - I was thinking of netconsole: > > https://www.kernel.org/doc/Documentation/networking/netconsole.txt > > Oh, I see. Thanks, I will try. > > Masashi Honma. Hi, I made a quick test with dongle using ath9k_htc driver and I indeed reproduce the issue. Here is the stack trace I get: I added a trace before calling skb_copy_expand to get the headroom of the buffer before the copy and the headroom asked by the driver. [ 83.200261] MESH fwd: skb_headroom=154, needed headroom=24 [ 83.200346] skbuff: skb_under_panic: text:ffffffffa034c028 len:154 put:8 head:ffff880213422e00 data:ffff880213422dfa tail:0x94 end:0xc0 dev:<NULL> [ 83.200359] ------------[ cut here ]------------ [ 83.200362] kernel BUG at ../net/core/skbuff.c:105! [ 83.200364] invalid opcode: 0000 [#1] SMP [ 83.200366] Modules linked in: ath9k_htc ath9k_common ath9k_hw ath10k_pci ath10k_core mac80211 ath cfg80211 x86_pkg_temp_thermal [ 83.200377] CPU: 4 PID: 29 Comm: ksoftirqd/4 Not tainted 4.9.0+ #3 [ 83.200379] Hardware name: Dell Inc. OptiPlex 990/06D7TR, BIOS A19 08/26/2015 [ 83.200381] task: ffff880223e55cc0 task.stack: ffffc90000db8000 [ 83.200383] RIP: 0010:[<ffffffff8170094c>] [<ffffffff8170094c>] skb_panic+0x5c/0x60 [ 83.200391] RSP: 0018:ffffc90000dbbba0 EFLAGS: 00010286 [ 83.200393] RAX: 0000000000000086 RBX: 0000000000000006 RCX: 0000000000000000 [ 83.200398] RDX: ffff8802253126d8 RSI: ffff88022530cb28 RDI: ffff88022530cb28 [ 83.200400] RBP: ffffc90000dbbbc0 R08: 0000000000030e9a R09: 0000000000000005 [ 83.200401] R10: 0000000000000000 R11: 00000000000002c8 R12: ffff880222d0a000 [ 83.200403] R13: 0000000000009200 R14: ffff880221ba7f00 R15: 0000000000000010 [ 83.200406] FS: 0000000000000000(0000) GS:ffff880225300000(0000) knlGS:0000000000000000 [ 83.200408] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 83.200410] CR2: 00007fd414010c98 CR3: 000000022247d000 CR4: 00000000000406e0 [ 83.200411] Stack: [ 83.200413] ffff880213422dfa 0000000000000094 00000000000000c0 ffffffff81c308d9 [ 83.200417] ffffc90000dbbbd0 ffffffff817019b7 ffffc90000dbbc00 ffffffffa034c028 [ 83.200420] ffff880221ba7f00 ffff8802226d15a0 0000000000000000 ffffc90000dbbcb8 [ 83.200423] Call Trace: [ 83.200429] [<ffffffff817019b7>] skb_push+0x37/0x40 [ 83.200435] [<ffffffffa034c028>] htc_issue_send.constprop.2+0x28/0x60 [ath9k_htc] [ 83.200441] [<ffffffffa034c3d1>] htc_send+0x11/0x20 [ath9k_htc] [ 83.200445] [<ffffffffa034fbd7>] ath9k_htc_tx_start+0xd7/0x2a0 [ath9k_htc] [ 83.200450] [<ffffffffa0351328>] ath9k_htc_tx+0xa8/0xd0 [ath9k_htc] [ 83.200471] [<ffffffffa00d7027>] ieee80211_tx_frags+0x137/0x1f0 [mac80211] [ 83.200489] [<ffffffffa00d71fc>] __ieee80211_tx+0x7c/0x180 [mac80211] [ 83.200506] [<ffffffffa00dc575>] ieee80211_tx+0xe5/0x110 [mac80211] [ 83.200518] [<ffffffffa00dddef>] ieee80211_tx_pending+0x8f/0x1f0 [mac80211] [ 83.200522] [<ffffffff81090386>] ? pick_next_task_fair+0x406/0x470 [ 83.200528] [<ffffffff8105f11a>] tasklet_action+0xda/0xf0 [ 83.200532] [<ffffffff8105f6c2>] __do_softirq+0xe2/0x270 [ 83.200536] [<ffffffff8105f867>] run_ksoftirqd+0x17/0x30 [ 83.200540] [<ffffffff8107a565>] smpboot_thread_fn+0x105/0x160 [ 83.200543] [<ffffffff8107a460>] ? sort_range+0x20/0x20 [ 83.200547] [<ffffffff81076de5>] kthread+0xc5/0xe0 [ 83.200550] [<ffffffff81076d20>] ? kthread_park+0x60/0x60 [ 83.200554] [<ffffffff81858bd2>] ret_from_fork+0x22/0x30 [ 83.200556] Code: c4 00 00 00 48 89 44 24 10 8b 87 c0 00 00 00 48 89 44 24 08 48 8b 87 d0 00 00 00 48 c7 c7 28 57 c3 81 48 89 04 24 e8 15 78 a2 ff <0f> 0b 66 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 65 4c 8b 34 [ 83.200596] RIP [<ffffffff8170094c>] skb_panic+0x5c/0x60 [ 83.200602] RSP <ffffc90000dbbba0> cedric
