Note: This is a beta release of Red Hat Bugzilla 5.0. The data contained within is a snapshot of the live data so any changes you make will not be reflected in the production Bugzilla. Also email is disabled so feel free to test any aspect of the site that you want. File any problems you find or give feedback here.
Bug 451622 - incorrect user_CS will cause GP loop
Summary: incorrect user_CS will cause GP loop
Alias: None
Product: Red Hat Enterprise Linux 5
Classification: Red Hat
Component: kernel-xen
Version: 5.1
Hardware: i686
OS: Linux
Target Milestone: rc
: ---
Assignee: Xen Maintainance List
QA Contact: Martin Jenner
Depends On:
TreeView+ depends on / blocked
Reported: 2008-06-16 09:13 UTC by Wei Kong
Modified: 2008-12-09 22:09 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2008-12-09 22:09:47 UTC
Target Upstream Version:

Attachments (Terms of Use)
Patch for this bug (deleted)
2008-06-16 09:24 UTC, Wei Kong
no flags Details | Diff

Description Wei Kong 2008-06-16 09:13:59 UTC
From Bugzilla Helper:
User-Agent: Mozilla/5.0 (compatible; Konqueror/3.5; Linux) KHTML/3.5.5 (like Gecko)

Description of problem:
The follow code will cause GP loop, due to set_user_cs() doesn't
set the right segment limit when do execshield on xen.
Test code, Call Trace, dmesg as below.

int main()
        void *addr;
        int test=0;
        addr = 0xF67FFFFD; //0xF67FFFFC 0xF67FFFFD

        test = ((*(long *)addr) == 0)?1:2;  //GP loop
        return 0;

Call Trace:
 [<c0406017>] show_stack+0x20/0x25
 [<c052d7a9>] showacpu+0x27/0x32
 [<c040e83e>] smp_call_function_interrupt+0x2f/0x4d
 [<c04413fb>] handle_IRQ_event+0x27/0x51
 [<c04414b8>] __do_IRQ+0x93/0xe8
 [<c0406d9b>] do_IRQ+0x93/0xae
 [<c05410ad>] evtchn_do_upcall+0x64/0x9b
 [<c0405515>] hypervisor_callback+0x3d/0x48
 [<c0405a51>] check_lazy_exec_limit+0x219/0x22a
 [<c05fce0e>] do_general_protection+0x47/0x13b
 [<c0405515>] hypervisor_callback+0x3d/0x48
 [<c05fcdc7>] do_general_protection+0x0/0x13b
 [<c04054d3>] error_code+0x2b/0x30

kernel: #GPF fixup (0[seg:0]) at 080483c9, CPU#1.
kernel:  exec_limit: ffffffff, user_cs: 0000ffff/00cffb00, CPU_cs: 000067ff/00cffb00.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. run the test code in desciption

Actual Results:

Expected Results:

Additional info:

Comment 1 Wei Kong 2008-06-16 09:24:52 UTC
Created attachment 309473 [details]
Patch for this bug

Comment 2 Chris Lalancette 2008-12-09 22:09:47 UTC
This is a dup of private BZ 457093, so it will be in 5.3.  I'll close this as a dup.

Chris Lalancette

*** This bug has been marked as a duplicate of bug 457093 ***

Note You need to log in before you can comment on or make changes to this bug.