Hi all, The Debian kernel recently enabled the PAGE_EXTENSION and PAGE_POISONING options. Unfortunately this causes a kernel crash very early during the boot on Loongson 3 machines: [ 0.941596] pci 0000:00:13.2: Device 1002:4396, irq 6 [ 0.946664] pci 0000:00:14.1: Device 1002:439c, irq 0 [ 0.951730] pci 0000:00:14.2: Device 1002:4383, irq 5 [ 0.956796] pci 0000:00:14.5: Device 1002:4399, irq 6 [ 0.961843] pci 0000:01:05.0: Device 1002:9615, irq 6 [ 0.966907] pci 0000:07:00.0: Device 10ec:8168, irq 5 [ 0.973196] clocksource: Switched to clocksource MIPS [ 0.997909] Unhandled kernel unaligned access[#1]: [ 1.002567] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-0.bpo.2-loongson-3 #1 Debian 4.9.18-1~bpo8+1 [ 1.012074] task: 980000027e1c2ba0 task.stack: 980000027e154000 [ 1.018005] $ 0 : 0000000000000000 ffffffff802082e4 0000000000000000 0000000000000000 [ 1.026032] $ 4 : 0000000000000002 ffffffff80431288 0000000000000000 8e75000000000016 [ 1.034061] $ 8 : ffffffffffffffff ffffffff809837fe 0000000000000001 78616d5f79746972 [ 1.042090] $12 : 980000027e157a28 000000001000001e 0000000000000000 0000000000000000 [ 1.050119] $16 : 980000027e157a30 ffffffff80431284 ffffffff80a20000 0000000000000000 [ 1.058148] $20 : ffffffff8e020018 8e75000000000016 ffffffff80431258 ffffffff80b56ee8 [ 1.066177] $24 : 0000000000000020 0000000000000000 [ 1.074206] $28 : 980000027e154000 980000027e1579d0 ffffffff80a80000 ffffffff802082e4 [ 1.082236] Hi : 0000000000000004 [ 1.085814] Lo : ccccccccccccccd1 [ 1.089406] epc : ffffffff80212300 do_ade+0x220/0x900 [ 1.094637] ra : ffffffff802082e4 resume_userspace_check+0x0/0x10 [ 1.100999] Status: 9400cce3 KX SX UX KERNEL EXL IE [ 1.105975] Cause : 00000010 (ExcCode 04) [ 1.109988] BadVA : 8e75000000000019 [ 1.113568] PrId : 00006305 (ICT Loongson-3) [ 1.117930] Modules linked in: [ 1.120988] Process swapper/0 (pid: 1, threadinfo=980000027e154000, task=980000027e1c2ba0, tls=0000000000000000) [ 1.131196] Stack : 0000000000000000 0000000000040912 00000000024040d0 8e74fffffffffffe [ 1.139224] ffffffffd6eb8e8c 980000027e157c18 980000027c0f9440 980000027c0f9440 [ 1.147253] 0000000000000000 ffffffff80a5ec30 ffffffff80b56ee8 ffffffff802082e4 [ 1.155282] 0000000000000000 ffffffff80431258 fffffffffffffffe 980000027e1c2ba0 [ 1.163311] 980000027c0f9440 980000027e157c18 0000000000000000 0000000000000000 [ 1.171340] ffffffffffffffff ffffffff809837fe 0000000000000001 78616d5f79746972 [ 1.179369] 0000000000000000 ffffffff80581584 0000000000000000 0000000000000000 [ 1.187398] 8e74fffffffffffe ffffffffd6eb8e8c 980000027e157c18 980000027c0f9440 [ 1.195427] 980000027c0f9440 0000000000000000 ffffffff80a5ec30 ffffffff80b56ee8 [ 1.203457] 0000000000000020 0000000000000000 000000000000001d 0000000000400000 [ 1.211486] ... [ 1.213931] Call Trace: [ 1.216378] [<ffffffff80212300>] do_ade+0x220/0x900 [ 1.221272] [<ffffffff802082e4>] resume_userspace_check+0x0/0x10 [ 1.227290] [<ffffffff80431284>] __d_lookup+0x8c/0x190 [ 1.232436] [<ffffffff804313d8>] d_lookup+0x50/0x88 [ 1.237326] [<ffffffff8041e418>] lookup_dcache+0x30/0xb8 [ 1.242649] [<ffffffff80421e38>] __lookup_hash+0x30/0xb8 [ 1.247971] [<ffffffff80422010>] lookup_one_len+0x150/0x1d0 [ 1.253559] [<ffffffff804b615c>] start_creating+0x84/0x110 [ 1.259055] [<ffffffff804b6760>] tracefs_create_file+0x48/0x130 [ 1.264998] [<ffffffff8032ae7c>] trace_create_file+0x1c/0x58 [ 1.270672] [<ffffffff8033a8b0>] event_create_dir+0x118/0x568 [ 1.276435] [<ffffffff80b2dc1c>] event_trace_init+0x298/0x348 [ 1.282182] [<ffffffff80200600>] do_one_initcall+0x60/0x190 [ 1.287770] [<ffffffff80b1cefc>] kernel_init_freeable+0x200/0x2d8 [ 1.293884] [<ffffffff808664a0>] kernel_init+0x20/0x130 [ 1.299114] [<ffffffff802083c4>] ret_from_kernel_thread+0x14/0x1c [ 1.305225] Code: 00431024 1440ffeb 00200825 <8ab70003> 9ab70000 24150000 16a00022 0200202d 8e020120 [ 1.314991] [ 1.316540] ---[ end trace c4de331138101c00 ]--- [ 1.321224] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 1.321224] [ 1.330294] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 1.330294] Adding page_poison=0 to the command line improves the things a bit, the kernel is able to boot, but crashes a bit later in different ways: [ 214.317350] Call Trace: [ 214.319810] [<ffffffff802122e8>] do_ade+0x718/0x900 [ 214.324721] [<ffffffff80207de4>] resume_userspace_check+0x0/0x10 [ 214.330777] [<ffffffff804317bc>] __d_lookup+0x8c/0x198 [ 214.335944] [<ffffffff80431918>] d_lookup+0x50/0x88 [ 214.340865] [<ffffffff8049b8e0>] proc_flush_task+0xb0/0x1d0 [ 214.346470] [<ffffffff802415b0>] release_task+0xb0/0x4d0 [ 214.351810] [<ffffffff80242054>] wait_consider_task+0x684/0xc80 [ 214.357761] [<ffffffff8024276c>] do_wait+0x11c/0x328 [ 214.362753] [<ffffffff80243cec>] SyS_wait4+0xac/0x130 [ 214.367849] [<ffffffff802ee110>] compat_SyS_wait4+0xf8/0x108 [ 214.373551] [<ffffffff8021e244>] syscall_common+0x18/0x3c [ 327.510496] Call Trace: [ 327.512969] [<ffffffff802122e8>] do_ade+0x718/0x900 [ 327.517887] [<ffffffff80207de4>] resume_userspace_check+0x0/0x10 [ 327.523945] [<ffffffff80430f84>] __d_lookup_rcu+0xac/0x230 [ 327.529462] [<ffffffff80421d10>] lookup_fast+0x78/0x380 [ 327.534715] [<ffffffff804223cc>] walk_component+0x54/0x3b0 [ 327.540230] [<ffffffff80422dd4>] path_lookupat+0x9c/0x1a0 [ 327.545663] [<ffffffff80424e1c>] filename_lookup+0x94/0x140 [ 327.551276] [<ffffffff80418238>] vfs_fstatat+0x88/0xf8 [ 327.556445] [<ffffffff804184bc>] SyS_newstat+0x44/0x80 [ 327.561625] [<ffffffff8021e244>] syscall_common+0x18/0x3c [ 136.167237] Call Trace: [ 136.167244] [<ffffffff802122e8>] do_ade+0x718/0x900 [ 136.167258] [<ffffffff80207de4>] resume_userspace_check+0x0/0x10 [ 136.167281] [<ffffffff804316cc>] __d_lookup+0x8c/0x198 [ 136.167289] [<ffffffff80421d80>] lookup_fast+0x1d8/0x380 [ 136.167296] [<ffffffff804237d4>] path_openat+0x1cc/0x1140 [ 136.167305] [<ffffffff80425c24>] do_filp_open+0xe4/0x130 [ 136.167328] [<ffffffff8040fb34>] do_sys_open+0x194/0x268 [ 136.167348] [<ffffffff8021e244>] syscall_common+0x18/0x3c Note that the malta and octeon flavours are not affected by this bug, so it looks like Loongson 3 specific. Any help to find the root cause would be appreciated. Thanks, Aurelien -- Aurelien Jarno GPG: 4096R/1DDD8C9B aurelien@xxxxxxxxxxx http://www.aurel32.net
