Re: [PATCH] wifi: ath11k: allocate dummy net_device dynamically

Kalle Valo
2024-03-20T14:32:53Z

Breno Leitao <leitao@debian.org> writes:

> Embedding net_device into structures prohibits the usage of flexible
> arrays in the net_device structure. For more details, see the discussion
> at [1].
>
> Un-embed the net_device from struct ath11k_ext_irq_grp by converting it
> into a pointer. Then use the leverage alloc_netdev() to allocate the
> net_device object at ath11k_ahb_config_ext_irq() for ahb, and
> ath11k_pcic_ext_irq_config() for pcic.
>
> The free of the device occurs at ath11k_ahb_free_ext_irq() for the ahb
> case, and ath11k_pcic_free_ext_irq() for the pcic case.
>
> [1] https://lore.kernel.org/all/20240229225910.79e224cf@kernel.org/
>
> Signed-off-by: Breno Leitao <leitao@debian.org>

This crashes on my nuc x86 test box with WCN6855 hw2.0 when running
rmmod, stacktrace below. I used tag ath-202403201010 from my ath.git
tree as the baseline. Sorry that I'm not able to debug this further
right now.

[ 116.584290] rmmod ath11k_pci
[ 117.274127] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC KASAN
[ 117.274175] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[ 117.274210] CPU: 1 PID: 1467 Comm: rmmod Not tainted 6.8.0-wt-ath+ #1338
[ 117.274259] Hardware name: Intel(R) Client Systems NUC8i7HVK/NUC8i7HVB, BIOS HNKBLi70.86A.0067.2021.0528.1339 05/28/2021
[ 117.274290] RIP: 0010:memcmp (lib/string.c:666)
[ 117.274335] Code: 24 0f 85 1a ff ff ff 49 83 ed 08 48 83 c3 08 49 83 c4 08 49 83 fd 07 0f 86 fb fe ff ff 48 89 d8 48 89 de 48 c1 e8 03 83 e6 07 <42> 0f b6 14 30 48 8d 43 07 48 89 c1 48 c1 e9 03 40 38 f2 40 0f 9e
All code
========
0: 24 0f and $0xf,%al
2: 85 1a test %ebx,(%rdx)
4: ff (bad)
5: ff (bad)
6: ff 49 83 decl -0x7d(%rcx)
9: ed in (%dx),%eax
a: 08 48 83 or %cl,-0x7d(%rax)
d: c3 ret
e: 08 49 83 or %cl,-0x7d(%rcx)
11: c4 (bad)
12: 08 49 83 or %cl,-0x7d(%rcx)
15: fd std
16: 07 (bad)
17: 0f 86 fb fe ff ff jbe 0xffffffffffffff18
1d: 48 89 d8 mov %rbx,%rax
20: 48 89 de mov %rbx,%rsi
23: 48 c1 e8 03 shr $0x3,%rax
27: 83 e6 07 and $0x7,%esi
2a:* 42 0f b6 14 30 movzbl (%rax,%r14,1),%edx <-- trapping instruction
2f: 48 8d 43 07 lea 0x7(%rbx),%rax
33: 48 89 c1 mov %rax,%rcx
36: 48 c1 e9 03 shr $0x3,%rcx
3a: 40 38 f2 cmp %sil,%dl
3d: 40 rex
3e: 0f .byte 0xf
3f: 9e sahf

Code starting with the faulting instruction
===========================================
0: 42 0f b6 14 30 movzbl (%rax,%r14,1),%edx
5: 48 8d 43 07 lea 0x7(%rbx),%rax
9: 48 89 c1 mov %rax,%rcx
c: 48 c1 e9 03 shr $0x3,%rcx
10: 40 38 f2 cmp %sil,%dl
13: 40 rex
14: 0f .byte 0xf
15: 9e sahf
[ 117.274385] RSP: 0018:ffffc90004177af0 EFLAGS: 00010246
[ 117.274423] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff57f2de9
[ 117.274461] RDX: 0000000000000020 RSI: 0000000000000000 RDI: 0000000000000000
[ 117.274493] RBP: ffffc90004177b20 R08: 0000000000000001 R09: fffffbfff57f3342
[ 117.274529] R10: ffffffffabf99a17 R11: ffffffffaa325926 R12: ffff888112c54bf8
[ 117.274568] R13: 0000000000000020 R14: dffffc0000000000 R15: ffff888112c54688
[ 117.274603] FS: 00007f1520d33740(0000) GS:ffff888231c00000(0000) knlGS:0000000000000000
[ 117.274637] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 117.274672] CR2: 00007f675c010d68 CR3: 000000010a9a0001 CR4: 00000000003706f0
[ 117.274707] Call Trace:
[ 117.274740] <TASK>
[ 117.274776] ? show_regs (arch/x86/kernel/dumpstack.c:479)
[ 117.274841] ? die_addr (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:460)
[ 117.274891] ? exc_general_protection (arch/x86/kernel/traps.c:701 arch/x86/kernel/traps.c:643)
[ 117.274935] ? asm_exc_general_protection (./arch/x86/include/asm/idtentry.h:564)
[ 117.274983] ? do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1))
[ 117.275019] ? memcmp (lib/string.c:666)
[ 117.275050] dev_addr_check (net/core/dev_addr_lists.c:513 (discriminator 1))
[ 117.275090] dev_addr_flush (net/core/dev_addr_lists.c:535)
[ 117.275127] free_netdev (net/core/dev.c:10976)
[ 117.275164] ath11k_pcic_free_irq (drivers/net/wireless/ath/ath11k/pcic.c:312 (discriminator 2) drivers/net/wireless/ath/ath11k/pcic.c:334 (discriminator 2)) ath11k
[ 117.275234] ath11k_pci_remove (drivers/net/wireless/ath/ath11k/pci.c:478 drivers/net/wireless/ath/ath11k/pci.c:987) ath11k_pci
[ 117.275273] pci_device_remove (./include/linux/pm_runtime.h:140 drivers/pci/pci-driver.c:477)
[ 117.275309] device_remove (drivers/base/dd.c:570)
[ 117.275338] device_release_driver_internal (drivers/base/dd.c:1274 drivers/base/dd.c:1295)
[ 117.275374] ? __kasan_check_read (mm/kasan/shadow.c:32)
[ 117.275412] driver_detach (drivers/base/dd.c:1359)
[ 117.275448] bus_remove_driver (drivers/base/bus.c:736)
[ 117.275481] driver_unregister (drivers/base/driver.c:275)
[ 117.275518] pci_unregister_driver (./include/linux/spinlock.h:351 drivers/pci/pci-driver.c:85 drivers/pci/pci-driver.c:1472)
[ 117.275553] ? find_module_all (kernel/module/main.c:357 (discriminator 1))
[ 117.275588] ath11k_pci_exit (drivers/net/wireless/ath/ath11k/pci.c:1069) ath11k_pci
[ 117.275625] __do_sys_delete_module (kernel/module/main.c:756)
[ 117.275663] ? module_flags (kernel/module/main.c:700)
[ 117.275697] ? kmem_cache_free (mm/slub.c:4299 (discriminator 3) mm/slub.c:4363 (discriminator 3))
[ 117.275726] ? __fput (fs/file_table.c:390)
[ 117.275763] ? debug_smp_processor_id (lib/smp_processor_id.c:61)
[ 117.275802] __x64_sys_delete_module (kernel/module/main.c:698)
[ 117.275890] do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1))
[ 117.275925] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:129)
[ 117.275954] RIP: 0033:0x7f1520e80c8b
[ 117.275994] Code: 73 01 c3 48 8b 0d 05 c2 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d d5 c1 0c 00 f7 d8 64 89 01 48
All code
========
0: 73 01 jae 0x3
2: c3 ret
3: 48 8b 0d 05 c2 0c 00 mov 0xcc205(%rip),%rcx # 0xcc20f
a: f7 d8 neg %eax
c: 64 89 01 mov %eax,%fs:(%rcx)
f: 48 83 c8 ff or $0xffffffffffffffff,%rax
13: c3 ret
14: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1)
1b: 00 00 00
1e: 90 nop
1f: f3 0f 1e fa endbr64
23: b8 b0 00 00 00 mov $0xb0,%eax
28: 0f 05 syscall
2a:* 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction
30: 73 01 jae 0x33
32: c3 ret
33: 48 8b 0d d5 c1 0c 00 mov 0xcc1d5(%rip),%rcx # 0xcc20f
3a: f7 d8 neg %eax
3c: 64 89 01 mov %eax,%fs:(%rcx)
3f: 48 rex.W

Code starting with the faulting instruction
===========================================
0: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax
6: 73 01 jae 0x9
8: c3 ret
9: 48 8b 0d d5 c1 0c 00 mov 0xcc1d5(%rip),%rcx # 0xcc1e5
10: f7 d8 neg %eax
12: 64 89 01 mov %eax,%fs:(%rcx)
15: 48 rex.W
[ 117.276031] RSP: 002b:00007ffe05526498 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[ 117.276069] RAX: ffffffffffffffda RBX: 00005582d521c7e0 RCX: 00007f1520e80c8b
[ 117.276098] RDX: 000000000000000a RSI: 0000000000000800 RDI: 00005582d521c848
[ 117.276134] RBP: 00007ffe055264f8 R08: 0000000000000000 R09: 0000000000000000
[ 117.276174] R10: 00007f1520efcac0 R11: 0000000000000206 R12: 00007ffe055266d0
[ 117.276208] R13: 00007ffe05527eb7 R14: 00005582d521b2a0 R15: 00005582d521c7e0
[ 117.276245] </TASK>
[ 117.276280] Modules linked in: ath11k_pci(-) ath11k mac80211 libarc4 cfg80211 qmi_helpers qrtr_mhi mhi qrtr nvme nvme_core
[ 117.276380] ---[ end trace 0000000000000000 ]---
[ 117.298338] RIP: 0010:memcmp (lib/string.c:666)
[ 117.298394] Code: 24 0f 85 1a ff ff ff 49 83 ed 08 48 83 c3 08 49 83 c4 08 49 83 fd 07 0f 86 fb fe ff ff 48 89 d8 48 89 de 48 c1 e8 03 83 e6 07 <42> 0f b6 14 30 48 8d 43 07 48 89 c1 48 c1 e9 03 40 38 f2 40 0f 9e
All code
========
0: 24 0f and $0xf,%al
2: 85 1a test %ebx,(%rdx)
4: ff (bad)
5: ff (bad)
6: ff 49 83 decl -0x7d(%rcx)
9: ed in (%dx),%eax
a: 08 48 83 or %cl,-0x7d(%rax)
d: c3 ret
e: 08 49 83 or %cl,-0x7d(%rcx)
11: c4 (bad)
12: 08 49 83 or %cl,-0x7d(%rcx)
15: fd std
16: 07 (bad)
17: 0f 86 fb fe ff ff jbe 0xffffffffffffff18
1d: 48 89 d8 mov %rbx,%rax
20: 48 89 de mov %rbx,%rsi
23: 48 c1 e8 03 shr $0x3,%rax
27: 83 e6 07 and $0x7,%esi
2a:* 42 0f b6 14 30 movzbl (%rax,%r14,1),%edx <-- trapping instruction
2f: 48 8d 43 07 lea 0x7(%rbx),%rax
33: 48 89 c1 mov %rax,%rcx
36: 48 c1 e9 03 shr $0x3,%rcx
3a: 40 38 f2 cmp %sil,%dl
3d: 40 rex
3e: 0f .byte 0xf
3f: 9e sahf

Code starting with the faulting instruction
===========================================
0: 42 0f b6 14 30 movzbl (%rax,%r14,1),%edx
5: 48 8d 43 07 lea 0x7(%rbx),%rax
9: 48 89 c1 mov %rax,%rcx
c: 48 c1 e9 03 shr $0x3,%rcx
10: 40 38 f2 cmp %sil,%dl
13: 40 rex
14: 0f .byte 0xf
15: 9e sahf
[ 117.298448] RSP: 0018:ffffc90004177af0 EFLAGS: 00010246
[ 117.298504] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff57f2de9
[ 117.298554] RDX: 0000000000000020 RSI: 0000000000000000 RDI: 0000000000000000
[ 117.298600] RBP: ffffc90004177b20 R08: 0000000000000001 R09: fffffbfff57f3342
[ 117.298651] R10: ffffffffabf99a17 R11: ffffffffaa325926 R12: ffff888112c54bf8
[ 117.298700] R13: 0000000000000020 R14: dffffc0000000000 R15: ffff888112c54688
[ 117.298749] FS: 00007f1520d33740(0000) GS:ffff888231c00000(0000) knlGS:0000000000000000
[ 117.298810] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 117.298871] CR2: 00007f675c010d68 CR3: 000000010a9a0001 CR4: 00000000003706f0
[ 117.298924] Kernel panic - not syncing: Fatal exception
[ 117.299488] Kernel Offset: 0x26600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 117.328105] Rebooting in 10 seconds..

--