Messages in this thread | | | Date | Thu, 26 Oct 2023 12:29:50 -0700 | From | Pawan Gupta <> | Subject | Re: [PATCH v3 2/6] x86/entry_64: Add VERW just before userspace transition |
| |
On Thu, Oct 26, 2023 at 07:25:27PM +0300, Nikolay Borisov wrote: > > > On 25.10.23 г. 23:52 ч., Pawan Gupta wrote: > > <snip> > > > @@ -1520,6 +1530,7 @@ SYM_CODE_START(ignore_sysret) > > UNWIND_HINT_END_OF_STACK > > ENDBR > > mov $-ENOSYS, %eax > > + CLEAR_CPU_BUFFERS > > nit: Just out of curiosity is it really needed in this case or it's doesn > for the sake of uniformity so that all ring3 transitions are indeed > covered??
Interrupts returning to kernel don't clear the CPU buffers. I believe interrupts will be enabled here, and getting an interrupt here could leak the data that interrupt touched.
| |