This resolves a crash if loaded under qemu + haxm under windows.
See https://www.spinics.net/lists/kernel/msg2689835.html for details.
Here is a boot log (the log is from chromeos-4.4, but Tao Wu says that
the same log is also seen with vanilla v4.4.110-rc1).
[ 0.712750] Freeing unused kernel memory: 552K
[ 0.721821] init: Corrupted page table at address
57b029b332e0
[ 0.722761] PGD
80000000bb238067 PUD
bc36a067 PMD
bc369067 PTE
45d2067
[ 0.722761] Bad pagetable: 000b [#1] PREEMPT SMP
[ 0.722761] Modules linked in:
[ 0.722761] CPU: 1 PID: 1 Comm: init Not tainted 4.4.96 #31
[ 0.722761] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[ 0.722761] task:
ffff8800bc290000 ti:
ffff8800bc28c000 task.ti:
ffff8800bc28c000
[ 0.722761] RIP: 0010:[<
ffffffff83f4129e>] [<
ffffffff83f4129e>] __clear_user+0x42/0x67
[ 0.722761] RSP: 0000:
ffff8800bc28fcf8 EFLAGS:
00010202
[ 0.722761] RAX:
0000000000000000 RBX:
00000000000001a4 RCX:
00000000000001a4
[ 0.722761] RDX:
0000000000000000 RSI:
0000000000000008 RDI:
000057b029b332e0
[ 0.722761] RBP:
ffff8800bc28fd08 R08:
ffff8800bc290000 R09:
ffff8800bb2f4000
[ 0.722761] R10:
ffff8800bc290000 R11:
ffff8800bb2f4000 R12:
000057b029b332e0
[ 0.722761] R13:
0000000000000000 R14:
000057b029b33340 R15:
ffff8800bb1e2a00
[ 0.722761] FS:
0000000000000000(0000) GS:
ffff8800bfb00000(0000) knlGS:
0000000000000000
[ 0.722761] CS: 0010 DS: 0000 ES: 0000 CR0:
000000008005003b
[ 0.722761] CR2:
000057b029b332e0 CR3:
00000000bb2f8000 CR4:
00000000000006e0
[ 0.722761] Stack:
[ 0.722761]
000057b029b332e0 ffff8800bb95fa80 ffff8800bc28fd18 ffffffff83f4120c
[ 0.722761]
ffff8800bc28fe18 ffffffff83e9e7a1 ffff8800bc28fd68 0000000000000000
[ 0.722761]
ffff8800bc290000 ffff8800bc290000 ffff8800bc290000 ffff8800bc290000
[ 0.722761] Call Trace:
[ 0.722761] [<
ffffffff83f4120c>] clear_user+0x2e/0x30
[ 0.722761] [<
ffffffff83e9e7a1>] load_elf_binary+0xa7f/0x18f7
[ 0.722761] [<
ffffffff83de2088>] search_binary_handler+0x86/0x19c
[ 0.722761] [<
ffffffff83de389e>] do_execveat_common.isra.26+0x909/0xf98
[ 0.722761] [<
ffffffff844febe0>] ? rest_init+0x87/0x87
[ 0.722761] [<
ffffffff83de40be>] do_execve+0x23/0x25
[ 0.722761] [<
ffffffff83c002e3>] run_init_process+0x2b/0x2d
[ 0.722761] [<
ffffffff844fec4d>] kernel_init+0x6d/0xda
[ 0.722761] [<
ffffffff84505b2f>] ret_from_fork+0x3f/0x70
[ 0.722761] [<
ffffffff844febe0>] ? rest_init+0x87/0x87
[ 0.722761] Code: 86 84 be 12 00 00 00 e8 87 0d e8 ff 66 66 90 48 89 d8 48 c1
eb 03 4c 89 e7 83 e0 07 48 89 d9 be 08 00 00 00 31 d2 48 85 c9 74 0a <48> 89 17
48 01 f7 ff c9 75 f6 48 89 c1 85 c9 74 09 88 17 48 ff
[ 0.722761] RIP [<
ffffffff83f4129e>] __clear_user+0x42/0x67
[ 0.722761] RSP <
ffff8800bc28fcf8>
[ 0.722761] ---[ end trace
def703879b4ff090 ]---
[ 0.722761] BUG: sleeping function called from invalid context at /mnt/host/source/src/third_party/kernel/v4.4/kernel/locking/rwsem.c:21
[ 0.722761] in_atomic(): 0, irqs_disabled(): 1, pid: 1, name: init
[ 0.722761] CPU: 1 PID: 1 Comm: init Tainted: G D 4.4.96 #31
[ 0.722761] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.7.5.1-0-g8936dbb-20141113_115728-nilsson.home.kraxel.org 04/01/2014
[ 0.722761]
0000000000000086 dcb5d76098c89836 ffff8800bc28fa30 ffffffff83f34004
[ 0.722761]
ffffffff84839dc2 0000000000000015 ffff8800bc28fa40 ffffffff83d57dc9
[ 0.722761]
ffff8800bc28fa68 ffffffff83d57e6a ffffffff84a53640 0000000000000000
[ 0.722761] Call Trace:
[ 0.722761] [<
ffffffff83f34004>] dump_stack+0x4d/0x63
[ 0.722761] [<
ffffffff83d57dc9>] ___might_sleep+0x13a/0x13c
[ 0.722761] [<
ffffffff83d57e6a>] __might_sleep+0x9f/0xa6
[ 0.722761] [<
ffffffff84502788>] down_read+0x20/0x31
[ 0.722761] [<
ffffffff83cc5d9b>] __blocking_notifier_call_chain+0x35/0x63
[ 0.722761] [<
ffffffff83cc5ddd>] blocking_notifier_call_chain+0x14/0x16
[ 0.800374] usb 1-1: new full-speed USB device number 2 using uhci_hcd
[ 0.722761] [<
ffffffff83cefe97>] profile_task_exit+0x1a/0x1c
[ 0.802309] [<
ffffffff83cac84e>] do_exit+0x39/0xe7f
[ 0.802309] [<
ffffffff83ce5938>] ? vprintk_default+0x1d/0x1f
[ 0.802309] [<
ffffffff83d7bb95>] ? printk+0x57/0x73
[ 0.802309] [<
ffffffff83c46e25>] oops_end+0x80/0x85
[ 0.802309] [<
ffffffff83c7b747>] pgtable_bad+0x8a/0x95
[ 0.802309] [<
ffffffff83ca7f4a>] __do_page_fault+0x8c/0x352
[ 0.802309] [<
ffffffff83eefba5>] ? file_has_perm+0xc4/0xe5
[ 0.802309] [<
ffffffff83ca821c>] do_page_fault+0xc/0xe
[ 0.802309] [<
ffffffff84507682>] page_fault+0x22/0x30
[ 0.802309] [<
ffffffff83f4129e>] ? __clear_user+0x42/0x67
[ 0.802309] [<
ffffffff83f4127f>] ? __clear_user+0x23/0x67
[ 0.802309] [<
ffffffff83f4120c>] clear_user+0x2e/0x30
[ 0.802309] [<
ffffffff83e9e7a1>] load_elf_binary+0xa7f/0x18f7
[ 0.802309] [<
ffffffff83de2088>] search_binary_handler+0x86/0x19c
[ 0.802309] [<
ffffffff83de389e>] do_execveat_common.isra.26+0x909/0xf98
[ 0.802309] [<
ffffffff844febe0>] ? rest_init+0x87/0x87
[ 0.802309] [<
ffffffff83de40be>] do_execve+0x23/0x25
[ 0.802309] [<
ffffffff83c002e3>] run_init_process+0x2b/0x2d
[ 0.802309] [<
ffffffff844fec4d>] kernel_init+0x6d/0xda
[ 0.802309] [<
ffffffff84505b2f>] ret_from_fork+0x3f/0x70
[ 0.802309] [<
ffffffff844febe0>] ? rest_init+0x87/0x87
[ 0.830559] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009
[ 0.830559]
[ 0.831305] Kernel Offset: 0x2c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 0.831305] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009
The crash part of this problem may be solved with the following patch
(thanks to Hugh for the hint). There is still another problem, though -
with this patch applied, the qemu session aborts with "VCPU Shutdown
request", whatever that means.
Cc: lepton <ytht.net@gmail.com>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>