d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Don't let the upper bits of %dr6/%dr7 get set.

Browse Source 
Submitted by:  Nate Eldredge <neldredge@math.ucsd.edu>
This commit is contained in:
Peter Wemm 2005-09-27 18:10:26 +00:00
parent 7e9e371f2d
commit 458d22f302
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=150635
1 changed files with 4 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
sys/amd64/amd64/machdep.c
View File

@ -1726,11 +1726,15 @@ set_dbregs(struct thread *td, struct dbreg *dbregs)
* check for undefined settings. Setting these bit patterns
* result in undefined behaviour and can lead to an unexpected
* TRCTRAP or a general protection fault right here.
* Upper bits of dr6 and dr7 must not be set
*/
for (i = 0, mask1 = 0x3<<16, mask2 = 0x2<<16; i < 8;
i++, mask1 <<= 2, mask2 <<= 2)
if ((dbregs->dr[7] & mask1) == mask2)
return (EINVAL);
if ((dbregs->dr[6] & 0xffffffff00000000ul) != 0 ||
(dbregs->dr[7] & 0xffffffff00000000ul) != 0)
return (EINVAL);
pcb = td->td_pcb;