request_module DoS
From: Herbert Xu
Date: Fri May 06 2022 - 23:09:12 EST
Hi:
There are some code paths in the kernel where you can reliably
trigger a request_module of a non-existant module. For example,
if you attempt to load a non-existent crypto algorithm, or create
a socket of a non-existent network family, it will result in a
request_module call that is guaranteed to fail.
As user-space can do this repeatedly, it can quickly overwhelm
the concurrency limit in kmod. This in itself is expected,
however, at least on some platforms this appears to result in
a live-lock. Here is an example triggered by stress-ng on ppc64:
[ 529.853264] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l, throttling...
[ 529.854329] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l, throttling...
[ 529.854341] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l, throttling...
[ 529.854419] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l, throttling...
[ 529.925327] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l, throttling...
[ 529.925328] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l, throttling...
[ 529.925328] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l, throttling...
[ 529.925356] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128, throttling...
[ 529.925373] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l, throttling...
[ 529.925397] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l, throttling...
[ 534.863623] __request_module: 572 callbacks suppressed
[ 534.863632] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 534.863642] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 534.864113] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 534.864989] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 534.865908] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 534.873626] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 534.873682] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l-all, throttling...
[ 534.874487] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 534.875200] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-rfc4106(gcm(aes))-all, throttling...
[ 534.883333] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 539.903506] __request_module: 604 callbacks suppressed
[ 539.903514] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 539.923693] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-anubis-all, throttling...
[ 539.985508] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-rsa-all, throttling...
[ 540.005381] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 540.033224] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 540.035282] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 540.044614] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 540.045344] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 540.063380] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 540.073839] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 545.013451] __request_module: 364 callbacks suppressed
[ 545.013463] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-morus640-all, throttling...
[ 545.055639] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128-all, throttling...
[ 545.073121] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aes, throttling...
[ 545.113218] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-morus640-all, throttling...
[ 545.143335] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-anubis, throttling...
[ 545.153122] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 545.213393] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128-all, throttling...
[ 545.423560] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-blowfish-all, throttling...
[ 545.485459] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aes, throttling...
[ 545.493302] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aes, throttling...
[ 546.373762] request_module: modprobe crypto-blowfish cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 550.114824] __request_module: 89 callbacks suppressed
[ 550.114836] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128-all, throttling...
[ 550.133698] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 550.134293] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-blowfish-all, throttling...
[ 550.134367] request_module: modprobe crypto-aegis128 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 550.134380] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128-all, throttling...
[ 550.143479] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128-all, throttling...
[ 550.184477] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 550.213325] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128-all, throttling...
[ 550.273658] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module cryptomgr, throttling...
[ 550.354497] request_module: modprobe crypto-aegis128 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 550.354531] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128-all, throttling...
[ 550.373253] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 551.553129] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 555.125406] __request_module: 463 callbacks suppressed
[ 555.125414] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l-all, throttling...
[ 555.144260] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l-all, throttling...
[ 555.353349] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l-all, throttling...
[ 555.363333] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-camellia-all, throttling...
[ 555.374176] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l-all, throttling...
[ 555.404280] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l-all, throttling...
[ 555.424795] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis128l-all, throttling...
[ 555.425009] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-camellia-all, throttling...
[ 555.433594] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-morus1280-all, throttling...
[ 555.434605] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-camellia-all, throttling...
[ 560.135515] __request_module: 528 callbacks suppressed
[ 560.135525] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 560.213142] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 560.213155] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 560.253160] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 560.273546] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 560.295392] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 560.295393] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 560.295447] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 560.295493] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 560.295539] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256, throttling...
[ 565.313118] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 565.313191] __request_module: 269 callbacks suppressed
[ 565.313193] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 565.313211] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 565.313224] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 565.313241] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 565.313253] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 565.934584] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-cast6-all, throttling...
[ 565.993559] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 566.163898] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module cryptomgr, throttling...
[ 566.324557] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 566.885018] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 567.123450] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 567.144416] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 568.224505] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 568.224517] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 568.263714] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 568.263737] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 569.123115] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 570.323756] __request_module: 27 callbacks suppressed
[ 570.323763] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 570.383775] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 570.393602] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 570.443781] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 570.473465] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 570.583827] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 570.833842] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 570.863734] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-cast6-all, throttling...
[ 570.915448] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aes, throttling...
[ 570.923497] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aes, throttling...
[ 573.374203] request_module: modprobe crypto-aegis256-all cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 573.485584] request_module: modprobe crypto-morus1280 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 573.745565] request_module: modprobe crypto-aegis256-all cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 573.853349] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 573.853453] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 574.053100] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 574.073611] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 574.073679] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 574.114243] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 574.204498] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 575.384942] __request_module: 37 callbacks suppressed
[ 575.384948] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 575.554612] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 575.614579] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 575.623600] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 575.635387] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 575.654233] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 575.764383] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 575.783091] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 575.783802] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 575.823309] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 578.783308] __request_module: 17 callbacks suppressed
[ 578.783319] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 578.943468] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 579.013776] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 579.074271] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 579.124351] request_module: modprobe crypto-cast5-all cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 579.473229] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 579.744561] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 579.744565] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 579.833100] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 579.845320] request_module: modprobe crypto-aegis256 cannot be processed, kmod busy with 50 threads for more than 5 seconds now
[ 580.414590] __request_module: 25 callbacks suppressed
[ 580.414597] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-aegis256-all, throttling...
[ 580.423082] watchdog: CPU 784 self-detected hard LOCKUP @ plpar_hcall_norets_notrace+0x18/0x2c
[ 580.423097] watchdog: CPU 784 TB:1297691958559475, last heartbeat TB:1297686321743840 (11009ms ago)
[ 580.423099] Modules linked in: cast6_generic cast5_generic cast_common camellia_generic blowfish_generic blowfish_common tun nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 rfkill bonding tls ip_set nf_tables nfnetlink pseries_rng binfmt_misc drm drm_panel_orientation_quirks xfs libcrc32c sd_mod t10_pi sg ibmvscsi ibmveth scsi_transport_srp vmx_crypto dm_mirror dm_region_hash dm_log dm_mod fuse
[ 580.423136] CPU: 784 PID: 77071 Comm: stress-ng Kdump: loaded Not tainted 5.14.0-55.el9.ppc64le #1
[ 580.423139] NIP: c0000000000f8ff4 LR: c0000000001f7c38 CTR: 0000000000000000
[ 580.423140] REGS: c0000043fdd7bd60 TRAP: 0900 Not tainted (5.14.0-55.el9.ppc64le)
[ 580.423142] MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 28008202 XER: 20040000
[ 580.423148] CFAR: 0000000000000c00 IRQMASK: 1
GPR00: 0000000028008202 c0000044c46b3850 c000000002a46f00 0000000000000000
GPR04: ffffffffffffffff 0000000000000000 0000000000000010 c000000002a83060
GPR08: 0000000000000000 0000000000000001 0000000000000001 0000000000000000
GPR12: c0000000001b9530 c0000043ffe16700 0000000200000117 0000000010185ea8
GPR16: 0000000010212150 0000000010186198 00000000101863a0 000000001021b3c0
GPR20: 0000000000000001 0000000000000000 0000000000000001 00000000000000ff
GPR24: c0000043f4a00e14 c0000043fafe0e00 000000000c440000 0000000000000000
GPR28: c0000043f4a00e00 c0000043f4a00e00 c0000000021e0e00 c000000002561aa0
[ 580.423166] NIP [c0000000000f8ff4] plpar_hcall_norets_notrace+0x18/0x2c
[ 580.423168] LR [c0000000001f7c38] __pv_queued_spin_lock_slowpath+0x528/0x530
[ 580.423173] Call Trace:
[ 580.423174] [c0000044c46b3850] [0000000100006b60] 0x100006b60 (unreliable)
[ 580.423177] [c0000044c46b3910] [c000000000ea6948] _raw_spin_lock_irqsave+0xa8/0xc0
[ 580.423182] [c0000044c46b3940] [c0000000001dd7c0] prepare_to_wait_event+0x40/0x200
[ 580.423185] [c0000044c46b39a0] [c00000000019e9e0] __request_module+0x320/0x510
[ 580.423188] [c0000044c46b3ac0] [c0000000006f1a14] crypto_alg_mod_lookup+0x1e4/0x2e0
[ 580.423192] [c0000044c46b3b60] [c0000000006f2178] crypto_alloc_tfm_node+0xa8/0x1a0
[ 580.423194] [c0000044c46b3be0] [c0000000006f84f8] crypto_alloc_aead+0x38/0x50
[ 580.423196] [c0000044c46b3c00] [c00000000072cba0] aead_bind+0x70/0x140
[ 580.423199] [c0000044c46b3c40] [c000000000727824] alg_bind+0xb4/0x210
[ 580.423201] [c0000044c46b3cc0] [c000000000bc2ad4] __sys_bind+0x114/0x160
[ 580.423205] [c0000044c46b3d90] [c000000000bc2b48] sys_bind+0x28/0x40
[ 580.423207] [c0000044c46b3db0] [c000000000030880] system_call_exception+0x160/0x300
[ 580.423209] [c0000044c46b3e10] [c00000000000c168] system_call_vectored_common+0xe8/0x278
[ 580.423213] --- interrupt: 3000 at 0x7fff9b824464
[ 580.423214] NIP: 00007fff9b824464 LR: 0000000000000000 CTR: 0000000000000000
[ 580.423215] REGS: c0000044c46b3e80 TRAP: 3000 Not tainted (5.14.0-55.el9.ppc64le)
[ 580.423216] MSR: 800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: 42004802 XER: 00000000
[ 580.423221] IRQMASK: 0
GPR00: 0000000000000147 00007fffdcff2780 00007fff9b917100 0000000000000004
GPR04: 00007fffdcff27e0 0000000000000058 0000000000000000 0000000000000000
GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR12: 0000000000000000 00007fff9bc9efe0 0000000200000117 0000000010185ea8
GPR16: 0000000010212150 0000000010186198 00000000101863a0 000000001021b3c0
GPR20: 0000000000000004 00007fffdcff2a00 0000000300000117 00000000101862b8
GPR24: 0000000000000004 0000000046401570 0000000046401120 0000000046404650
GPR28: 0000000000000020 0000000000000020 0000000000000060 0000000046404bf0
[ 580.423236] NIP [00007fff9b824464] 0x7fff9b824464
[ 580.423237] LR [0000000000000000] 0x0
[ 580.423238] --- interrupt: 3000
[ 580.423239] Instruction dump:
[ 580.423241] e8690000 7c0803a6 3884fff8 78630100 78840020 4bfffeb8 3c4c0295 3842df24
[ 580.423244] 7c421378 7c000026 90010008 44000022 <38800000> 988d0931 80010008 7c0ff120
Would it be possible to modify kmod so that in such cases that
request_module calls fail more quickly rather than repeatedly
obtaining a spinlock that appears to be under high contention?
Thanks,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt