Messages in this thread | | | Date | Thu, 23 Apr 2015 07:11:52 -0400 | Subject | Re: [tip:x86/vdso] x86/vdso32/syscall.S: Do not load __USER32_DS to %ss | From | Brian Gerst <> |
| |
On Thu, Apr 23, 2015 at 5:56 AM, Borislav Petkov <bp@alien8.de> wrote: > On Thu, Apr 23, 2015 at 11:20:56AM +0200, Denys Vlasenko wrote: >> * what if %ss before syscall was NOT the usual value of 0x2b, but some >> other segment, not the typical 0-base, 0xffffffff limit 32-bit expand-up one? >> Not restoring proper %ss would not go well. >> [but then, Intel CPUs work, and old code worked....] > > Have we run the exact same reproducer on Intel already? > > Brian, can you run the same thing on an Intel box, if you haven't done > so already? > > Thanks.
Tested it on a Intel(R) Core(TM)2 Duo CPU T6400 @ 2.00GHz and cannot reproduce it there. Note that on Intel CPUs, we use the sysenter VDSO but return with sysret.
-- Brian Gerst
| |