On Thu, Dec 03 2020 at 18:38, Corentin Labbe wrote: > On Wed, Dec 02, 2020 at 09:59:36PM +0100, Thomas Gleixner wrote: >> On Wed, Dec 02 2020 at 20:55, Corentin Labbe wrote: >> > On Tue, Dec 01, 2020 at 04:15:08PM +0100, Thomas Gleixner wrote: >> > >> > The result could be seen at http://kernel.montjoie.ovh/129768.log >> > The log is 9Mb, but the ftrace dump seems not terminated, tell me if you need more. >> >> Correct, the interesting entries right before the crash are missing. Can >> you try to make the trace buffers smaller or wait longer before >> terminating the thing? >> >> 16k buffer size per CPU should be completely sufficient. That should >> give us roughly the last 100 entries per CPU. >> >> 'trace_buf_size=16k' >> >> is the command line option for that. > > I have set a longer timeout and now the job end with the crash: > http://kernel.montjoie.ovh/130094.log Ok. So here is the problem: [ 996.933980] cryptset-316 0d..3 73943313us : __kmap_local_pfn_prot: kmap_local_pfn: 0 ffefe000 [ 996.943030] cryptset-316 0d..4 73943317us : __kmap_local_pfn_prot: kmap_local_pfn: 1 ffefd000 [ 996.952080] cryptset-316 0d..4 73943419us : kunmap_local_indexed: kunmap_local: 1 ffefe000 There are two maps: 1) index 0 vaddr 0xffefe000 2) index 1 vaddr 0xffefd000 Now comes the unmap and unmaps 0xffefe000 which is the first map and not the second one. -> Fail [ 74.017103] [<c0251824>] (kunmap_local_indexed) from [<c046ca58>] (sg_miter_stop+0xb4/0x164) [ 74.025535] [<c046ca58>] (sg_miter_stop) from [<c046cef4>] (sg_miter_next+0xc/0xe4) [ 74.033191] [<c046cef4>] (sg_miter_next) from [<c075f5dc>] (sun4i_ss_opti_poll+0x278/0x40c) [ 74.041539] [<c075f5dc>] (sun4i_ss_opti_poll) from [<c075fc64>] (sun4i_ss_cipher_poll+0x4f4/0x5e4) [ 74.050497] [<c075fc64>] (sun4i_ss_cipher_poll) from [<c0421394>] (crypto_skcipher_encrypt+0x38/0x5c) [ 74.059713] [<c0421394>] (crypto_skcipher_encrypt) from [<c0432ba0>] (xts_encrypt+0x8c/0xd4) [ 74.068146] [<c0432ba0>] (xts_encrypt) from [<c0421394>] (crypto_skcipher_encrypt+0x38/0x5c) [ 74.076581] [<c0421394>] (crypto_skcipher_encrypt) from [<c043bfd4>] (skcipher_recvmsg+0x364/0x43c) [ 74.085625] [<c043bfd4>] (skcipher_recvmsg) from [<c07c8da0>] (sock_read_iter+0xa8/0xf8) [ 74.093713] [<c07c8da0>] (sock_read_iter) from [<c028ce94>] (vfs_read+0x2b8/0x2d8) [ 74.101279] [<c028ce94>] (vfs_read) from [<c028d394>] (ksys_read+0xb0/0xe4) [ 74.108237] [<c028d394>] (ksys_read) from [<c0100060>] (ret_fast_syscall+0x0/0x58) The unmap comes from sg_miter_stop() and looking at the previous map/unmap cycles there are never nested maps. [ 996.943030] cryptset-316 0d..4 73943317us : __kmap_local_pfn_prot: kmap_local_pfn: 1 ffefd000 is the first event which allocates a nested map. So something goes south either in sg_miter or in the crypto maze. Enabling CONFIG_DEBUG_KMAP_LOCAL and function tracing might give us more clue. Thanks, tglx
