Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-20 Thread Eiichi Tsukata
On 2019/07/20 21:49, Andy Lutomirski wrote: > On Fri, Jul 19, 2019 at 8:59 PM Eiichi Tsukata wrote: >> ... >> >> >> >> debug() // dr6: 0x4ff0, user_mode: 1 >> TRACE_IRQS_OFF >> arch_stack_user_walk() >> debug() // dr6: 0x4ff1 == 0x4ff0 | 0x0ff1 ... (*) >>

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-20 Thread Andy Lutomirski
On Fri, Jul 19, 2019 at 8:59 PM Eiichi Tsukata wrote: > > > On 2019/07/19 5:27, Andy Lutomirski wrote: > > Hi all- > > > > I suspect that a bunch of the bugs you're all finding boil down to: > > > > - Nested debug exceptions could corrupt the outer exception's DR6. > > - Nested debug exceptions

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-19 Thread Eiichi Tsukata
On 2019/07/19 5:27, Andy Lutomirski wrote: > Hi all- > > I suspect that a bunch of the bugs you're all finding boil down to: > > - Nested debug exceptions could corrupt the outer exception's DR6. > - Nested debug exceptions in which *both* exceptions came from the > kernel were probably all

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-18 Thread Andy Lutomirski
Hi all- I suspect that a bunch of the bugs you're all finding boil down to: - Nested debug exceptions could corrupt the outer exception's DR6. - Nested debug exceptions in which *both* exceptions came from the kernel were probably all kinds of buggy - Data breakpoints in bad places in the

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-17 Thread Eiichi Tsukata
On 2019/07/17 6:51, Vegard Nossum wrote: > ... > > Got a different one: > > WARNING: CPU: 0 PID: 2150 at arch/x86/kernel/traps.c:791 do_debug+0xfe/0x240 > CPU: 0 PID: 2150 Comm: init Not tainted 5.2.0+ #124 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS >

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-17 Thread Vegard Nossum
On 7/17/19 10:07 AM, Peter Zijlstra wrote: On Tue, Jul 16, 2019 at 09:33:50PM +0200, Vegard Nossum wrote: [ cut here ] General protection fault in user access. Non-canonical address? WARNING: CPU: 0 PID: 5039 at arch/x86/mm/extable.c:126 ex_handler_uaccess+0x5d/0x70

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-17 Thread Peter Zijlstra
On Tue, Jul 16, 2019 at 09:33:50PM +0200, Vegard Nossum wrote: > [ cut here ] > General protection fault in user access. Non-canonical address? > WARNING: CPU: 0 PID: 5039 at arch/x86/mm/extable.c:126 > ex_handler_uaccess+0x5d/0x70 > CPU: 0 PID: 5039 Comm: init Not tainted

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-17 Thread Vegard Nossum
On 7/17/19 3:02 AM, Andy Lutomirski wrote: On Tue, Jul 16, 2019 at 2:53 PM Vegard Nossum wrote: On 7/16/19 9:33 PM, Vegard Nossum wrote: On 7/11/19 1:40 PM, Peter Zijlstra wrote: Hi, Here's the latest (and hopefully final) set of tracing vs CR2 patches. They are basically the same as

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-17 Thread Peter Zijlstra
On Tue, Jul 16, 2019 at 06:02:33PM -0700, Andy Lutomirski wrote: > On a different thread, Peter and I decided that the last patch in this > series (the one that removes the _DEBUG stuff) is wrong. Can you see > if these are reproducible with that patch removed? Wrong is maybe the wrong word

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-16 Thread Andy Lutomirski
On Tue, Jul 16, 2019 at 2:53 PM Vegard Nossum wrote: > > > On 7/16/19 9:33 PM, Vegard Nossum wrote: > > > > On 7/11/19 1:40 PM, Peter Zijlstra wrote: > >> Hi, > >> > >> Here's the latest (and hopefully final) set of tracing vs CR2 patches. > >> > >> They are basically the same as v2, with only

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-16 Thread Vegard Nossum
On 7/16/19 9:33 PM, Vegard Nossum wrote: On 7/11/19 1:40 PM, Peter Zijlstra wrote: Hi, Here's the latest (and hopefully final) set of tracing vs CR2 patches. They are basically the same as v2, with only minor edits and tags collected from the last review. Please consider. Hi, I ran

Re: [PATCH v3 0/6] Tracing vs CR2

2019-07-16 Thread Vegard Nossum
On 7/11/19 1:40 PM, Peter Zijlstra wrote: Hi, Here's the latest (and hopefully final) set of tracing vs CR2 patches. They are basically the same as v2, with only minor edits and tags collected from the last review. Please consider. Hi, I ran my own battery of tests on your patch set on

[PATCH v3 0/6] Tracing vs CR2

2019-07-11 Thread Peter Zijlstra
Hi, Here's the latest (and hopefully final) set of tracing vs CR2 patches. They are basically the same as v2, with only minor edits and tags collected from the last review. Please consider.