This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-bugs] [Bug 252] system crash while creating DomU on a large memorys

To: xen-bugs@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-bugs] [Bug 252] system crash while creating DomU on a large memorysystem/PAEenabled
From: bugzilla-daemon@xxxxxxxxxxxxxxxxxxx
Date: Wed, 28 Sep 2005 15:54:39 +0000
Delivery-date: Wed, 28 Sep 2005 15:54:43 +0000
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
List-help: <mailto:xen-bugs-request@lists.xensource.com?subject=help>
List-id: Xen Bugzilla <xen-bugs.lists.xensource.com>
List-post: <mailto:xen-bugs@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-bugs>, <mailto:xen-bugs-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-bugs>, <mailto:xen-bugs-request@lists.xensource.com?subject=unsubscribe>
Reply-to: bugs@xxxxxxxxxxxxxxxxxx
Sender: xen-bugs-bounces@xxxxxxxxxxxxxxxxxxx

------- Additional Comments From aravindh.puthiyaparambil@xxxxxxxxxx  
2005-09-28 15:54 -------
The alignment check is happening on a "lock cmpxchg8b". Is it possible for ACs
to happen when going across page boundaries on cmpxchg8b? Is there any other
scenario when ACs with cmpxchg8b in CPL 0?


This is what I see on the serial console when the system dies. 

(XEN) (file=traps.c, line=960) Non-priv domain attempted
(XEN) CPU:    3
(XEN) RIP:    e010:[<ffff83000014a750>] get_page+0x108/0x14a
(XEN) RFLAGS: 0000000000010286   CONTEXT: hypervisor
(XEN) rax: 0000000080000002   rbx: 0000000080000003   rcx: 0000000000fcd080
(XEN) rdx: 0000000000fcd080   rsi: ffff830000fcd080   rdi: ffff8284021e713c
(XEN) rbp: ffff830000213bc8   rsp: ffff830000213b78   r8:  00000000deadbeef
(XEN) r9:  00000000deadbeef   r10: ffff8300001aefe0   r11: 0000000000000206
(XEN) r12: ffff8300001cb780   r13: 0000000000000180   r14: ffffffff802b0aa3
(XEN) r15: ffff880000000000   cr0: 000000008005003b   cr3: 00000000e7ea0000
(XEN) Xen stack trace from rsp=ffff830000213b78:
(XEN)    ffff8300001cb900 0000000000213f28 00fcd08000213ba8 ffff83000012a4dd 
(XEN)    00fcd08000fcd080 8000000200fcd080 8000000280000003 ffff830000fcd080 
(XEN)    ffff8284021e7128 0000000000000000 ffff830000213c18 ffff830000140f7e 
(XEN)    ffffffff802b0aa8 0000000000000000 0000000000000008 ffff830000000065 
(XEN)    ffff8284021e7128 00000000000d8fa1 ffff830000fcd080 00000000d8fa1065 
(XEN)    ffff830000213c98 ffff8300001422ac 0000000000000000 ffff830000fcd080 
(XEN)    0000000100000008 07fffc0200000065 07fffc0230000002 0000000000000000 
(XEN)    0000000000000008 ffff8300d8fa3600 ffff830000213c78 ffff830000fcd080 
(XEN)    00000000d8fa1067 07fffc0230000003 00000000d8fa1065 ffff8300d8fa3600 
(XEN)    ffff830000213f08 ffff830000145b3c ffff830000213cc8 000000000012a4dd 
(XEN)    ffff830000213cc8 000000000012a4ab ffff830000213ce8 ffff83000012a218 
(XEN)    ffff830000213d38 ffff830000213cf8 00007cffffdec2e7 ffff83000013ae51 
(XEN)    ffff800000000000 ffffffff80105000 00000000005c2000 ffffffff80105010 
(XEN)    ffff830000213dd8 ffff830000000008 00000004021b1f70 0000000080000002 
(XEN)    0000000080000002 00000004f0000001 0000000080000001 0000000080000002 
(XEN)    ffff8284021b1f64 80000002f0000001 8000000180000002 ffff8284021b1f50 
(XEN)    ffff830000213d98 ffff83000014a7b0 ffff830000fcd080 ffff8284021b1f50 
(XEN)    ffff830000213dd8 ffff8300001415e7 0000000000000000 ffff830000fcd080 
(XEN)    ffff8284021b1f50 00000000000d7a62 ffff830000fcd080 00000000d7a62027 
(XEN)    ffff830000213e58 ffff83000014230f 0000000020000000 00000000000d8fa3 
(XEN) Xen call trace:
(XEN)    [<ffff83000014a750>] get_page+0x108/0x14a
(XEN)    [<ffff830000140f7e>] get_page_from_l1e+0x27e/0x28c
(XEN)    [<ffff8300001422ac>] mod_l1_entry+0x21d/0x28c
(XEN)    [<ffff830000145b3c>] do_mmu_update+0x553/0x14bd
(XEN)    [<ffff83000016a940>] syscall_enter+0xa0/0xfa
(XEN) ****************************************
(XEN) Panic on CPU 3:
(XEN) CPU3 FATAL TRAP: vector = 17 (alignment check)
(XEN) [error_code=0000]
(XEN) ****************************************

Here is the code snippet which caused the AC to happen.
       __asm__ __volatile__(
ffff83000014a736:       48 8b 7d f0             mov 
ffff83000014a73a:       48 83 c7 14             add $0x14,%rdi
ffff83000014a73e:       8b 55 d8                mov 
ffff83000014a741:       8b 45 e4                mov 
ffff83000014a744:       8b 4d d8                mov 
ffff83000014a747:       89 4d c4                mov 
ffff83000014a74a:       8b 5d e0                mov 
ffff83000014a74d:       8b 4d c4                mov 
ffff83000014a750:       f0 0f c7 0f             lock cmpxchg8b (%rdi)
ffff83000014a754:       89 ce                   mov %ecx,%esi
ffff83000014a756:       89 45 c4                mov 
ffff83000014a759:       89 d0                   mov %edx,%eax
ffff83000014a75b:       89 45 d4                mov 
ffff83000014a75e:       8b 45 c4                mov 
ffff83000014a761:       89 45 dc                mov 
ffff83000014a764:       89 f0                   mov %esi,%eax
ffff83000014a766:       89 45 d8                mov 
            LOCK_PREFIX "cmpxchg8b %3"
            : "=d" (nd), "=a" (y), "=c" (d),
              "=m" (*(volatile u64 *)(&page->count_info))
            : "0" (d), "1" (x), "c" (d), "b" (nx) );

Configure bugmail: 
------- You are receiving this mail because: -------
You are the assignee for the bug, or are watching the assignee.

Xen-bugs mailing list

<Prev in Thread] Current Thread [Next in Thread>