Messages in this thread | | | Date | Thu, 23 Oct 2014 18:00:35 +0100 | From | Andre Przywara <> | Subject | BPF crash with 3.18-rc1 on arm64 Juno hardware |
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Hi,
I see a crash with 3.18-rc1 on a Juno board related to bpf_jit (see dump below). Userland tries to carry on afterwards, but eventually hangs in RCU stalls. The kernel has just CONFIG_BPF_JIT enabled, I guess Ubuntu enables this automatically if detected.
The backtrace doesn't make too much sense to me:
void bpf_jit_free(struct bpf_prog *prog) { if (prog->jited) module_free(NULL, prog->bpf_func);
kfree(prog); } It crashes in kfree, but has survived the dereference before.
I have no clue about BPF, so if anyone could help me debug this, I'd be grateful.
Cheers, Andre.
* Starting Signal sysvinit that local filesystems are mounted [ OK ] * Starting configure network device security [ OK ] Unable to handle kernel paging request at virtual address 37fffbd21c02290 pgd = ffffffc976538000 [37fffbd21c02290] *pgd=0000000000000000, *pud=0000000000000000 Internal error: Oops: 96000004 [#1] PREEMPT SMP Modules linked in: CPU: 3 PID: 737 Comm: kworker/3:1 Not tainted 3.18.0-rc1+ #1666 Workqueue: events bpf_prog_free_deferred task: ffffffc977a89580 ti: ffffffc976494000 task.ti: ffffffc976494000 PC is at kfree+0x70/0x260 LR is at bpf_jit_free+0x34/0x40 pc : [<ffffffc0001b0634>] lr : [<ffffffc000099290>] pstate: a0000145 sp : ffffffc976497ca0 x29: ffffffc976497ca0 x28: 0000000000000000 x27: ffffffc97feff400 x26: ffffffc0009b0000 x25: 0000000000000000 x24: 0000000000000000 x23: ffffffc97ff03900 x22: ffffffc97feff400 x21: ffffffc000099290 x20: ffffff800009e000 x19: ffffff800009e000 x18: 0000007feb492820 x17: 0000007fb71c6980 x16: ffffffc0001fcc14 x15: 003b9aca00000000 x14: 0027947614000000 x13: ffffffffabb6d0e3 x12: 0000000000000018 x11: 0000000033c2a168 x10: 0000000000000006 x9 : ffffffc976497bd0 x8 : ffffffc977a89a90 x7 : ffffffc97736c4d0 x6 : 00000000000009be x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffffffc97feff7c0 x2 : 03ffffff02002780 x1 : 037fffff21c02290 x0 : ffffffbe00000000
Process kworker/3:1 (pid: 737, stack limit = 0xffffffc976494058) Stack: (0xffffffc976497ca0 to 0xffffffc976498000) ....
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