Re: [PATCH v2] x86/debug: Fix DR6 handling

2021-01-29 Thread Tom de Vries
On 1/29/21 3:48 PM, Borislav Petkov wrote: > On Thu, Jan 28, 2021 at 10:16:27PM +0100, Peter Zijlstra wrote: >> >> Tom reported that one of the GDB test-cases failed, and Boris bisected >> it to commit: >> >> d53d9bc0cf78 ("x86/debug: Change thread.debugreg6 to thread.virtual_dr6") >> >> The debu

Re: [PATCH v2] x86/debug: Fix DR6 handling

2021-01-29 Thread Borislav Petkov
On Fri, Jan 29, 2021 at 04:41:09PM +0100, Oleg Nesterov wrote: > This seems to fix the problem reported by Jan, see his test-case below. Should it be part of tools/testing/selftests/breakpoints/ ? tglx has one destined for there already, wouldn't hurt to have a second one: https://lkml.kernel.

[PATCH v2] x86/debug: Fix DR6 handling

2021-01-28 Thread Peter Zijlstra
Tom reported that one of the GDB test-cases failed, and Boris bisected it to commit: d53d9bc0cf78 ("x86/debug: Change thread.debugreg6 to thread.virtual_dr6") The debugging session led us to commit: 6c0aca288e72 ("x86: Ignore trap bits on single step exceptions") It turns out that TF and