RE: Bug Report:bpf, sockmap: On cleanup we additionally need to remove cached skb

RE: Bug Report:bpf, sockmap: On cleanup we additionally need to remove cached skb

[John Fastabend]

Jun Miao wrote:
> Hi,
> 
>    From our netperf stress test with your patch, the Call trace still 
> can reproduce, as follow:

Hi Jun,

Is this testing with sockmap and BPF? If not I can't see how the above
patch is the correct bisection. That patch touches internals of skmsg
handling in a specific backlog case which would only be used in BPF
use case.

Thanks,
John


> 
> *Test Log:*
> 
> [ 6405.990626] Writes:  Total: 12095025292  Max/Min: 379145540/237527212   Fail: 0
> [ 6436.970251] ------------[ cut here ]------------
> [ 6436.975016] WARNING: CPU: 0 PID: 42336 at net/core/stream.c:207 sk_stream_kill_queues+0x11a/0x140
> [ 6436.984044] Modules linked in: i10nm_edac iTCO_wdt intel_pmc_bxt iTCO_vendor_support intel_rapl_msr watchdog intel_rapl_common intel_th_gth x86_pkg_temp_thermal intel_powerclamp coretemp crct10dif_pclmul crct10dif_common aesni_intel crypto_simd cryptd qat_c4xxx(O) intel_qat(O) dh_generic uio intel_spi_pci intel_spi intel_th_pci ice i2c_i801 spi_nor intel_th i2c_smbus i2c_ismt wmi acpi_cpufreq sch_fq_codel openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 fuse [last unloaded: i10nm_edac]
> [ 6437.029831] CPU: 0 PID: 42336 Comm: netperf Tainted: G        W  O      5.15.0-rc3 #1
> [ 6437.039374] Hardware name: Intel Corporation JACOBSVILLE/JACOBSVILLE, BIOS JBVLCRB2.86B.0014.P67.2103111848 03/11/2021
> [ 6437.050212] RIP: 0010:sk_stream_kill_queues+0x11a/0x140
> [ 6437.055581] Code: 93 90 02 00 00 85 d2 75 21 8b 83 48 02 00 00 85 c0 75 23 5b 41 5c 5d c3 48 89 df e8 10 d1 fe ff 8b 93 90 02 00 00 85 d2 74 df <0f> 0b 8b 83 48 02 00 00 85 c0 74 dd 0f 0b 5b 41 5c 5d c3 0f 0b eb
> [ 6437.074492] RSP: 0018:ffffac32425d7d90 EFLAGS: 00010282
> [ 6437.079861] RAX: ffffffff9931cfc0 RBX: ffff9cd4eda58d40 RCX: 0000000000000000
> [ 6437.087139] RDX: 00000000fffffb80 RSI: 0000000000000480 RDI: ffff9cd4eda58ea8
> [ 6437.094424] RBP: ffffac32425d7da0 R08: 0000000000000000 R09: 0000000000000000
> [ 6437.101705] R10: 0000000000000000 R11: 0000000000000000 R12: ffff9cd4eda58ea8
> [ 6437.108986] R13: ffff9cd4eda58dc8 R14: 0000000000000000 R15: ffff9cd57079d230
> [ 6437.116263] FS:  00007fe132d96740(0000) GS:ffff9ce3ba200000(0000) knlGS:0000000000000000
> [ 6437.124498] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 6437.130385] CR2: 0000556041d81128 CR3: 0000000165aa4000 CR4: 0000000000350ef0
> [ 6437.137668] Call Trace:
> [ 6437.140259]  inet_csk_destroy_sock+0x64/0x150
> [ 6437.144762]  __tcp_close+0x3b2/0x4e0
> [ 6437.148484]  tcp_close+0x25/0x80
> [ 6437.151858]  inet_release+0x4d/0x90
> [ 6437.155494]  __sock_release+0x3f/0xb0
> [ 6437.159305]  sock_close+0x18/0x20
> [ 6437.162765]  __fput+0xb0/0x280
> [ 6437.165967]  ____fput+0xe/0x10
> [ 6437.169167]  task_work_run+0x61/0xb0
> [ 6437.172889]  exit_to_user_mode_loop+0x114/0x120
> [ 6437.177568]  exit_to_user_mode_prepare+0xe9/0x150
> [ 6437.182421]  syscall_exit_to_user_mode+0x1e/0x60
> [ 6437.187183]  do_syscall_64+0x50/0x90
> [ 6437.190904]  entry_SYSCALL_64_after_hwframe+0x44/0xae
> [ 6437.196097] RIP: 0033:0x7fe132e950c7
> [ 6437.199820] Code: b8 ff ff ff ff e9 3e ff ff ff 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 33 b1 f8 ff
> [ 6437.218732] RSP: 002b:00007fffc46df2c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
> [ 6437.226449] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fe132e950c7
> [ 6437.233727] RDX: 0000000000000001 RSI: 00007fffc46df2e4 RDI: 0000000000000004
> [ 6437.241007] RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000
> [ 6437.248286] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
> [ 6437.255565] R13: 0000000000000001 R14: 0000000000000000 R15: 0000559ace3650c0
> [ 6437.262847] irq event stamp: 0
> [ 6437.266049] hardirqs last  enabled at (0): [<0000000000000000>] 0x0
> [ 6437.272463] hardirqs last disabled at (0): [<ffffffff96d134fd>] copy_process+0x74d/0x18a0
> [ 6437.280786] softirqs last  enabled at (0): [<ffffffff96d134fd>] copy_process+0x74d/0x18a0
> [ 6437.289109] softirqs last disabled at (0): [<0000000000000000>] 0x0
> [ 6437.295524] ---[ end trace 42c5ce4ee9dd57c1 ]---

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