Re: [PATCH 24/30] panic: Refactor the panic path

2022-05-24 Thread Baoquan He
On 05/20/22 at 08:23am, Guilherme G. Piccoli wrote: > On 19/05/2022 20:45, Baoquan He wrote: > > [...] > >> I really appreciate the summary skill you have, to convert complex > >> problems in very clear and concise ideas. Thanks for that, very useful! > >> I agree with what was summarized above. >

Re: [PATCH 24/30] panic: Refactor the panic path

2022-05-24 Thread Baoquan He
On 05/24/22 at 10:01am, Petr Mladek wrote: > On Fri 2022-05-20 08:23:33, Guilherme G. Piccoli wrote: > > On 19/05/2022 20:45, Baoquan He wrote: > > > [...] > > >> I really appreciate the summary skill you have, to convert complex > > >> problems in very clear and concise ideas. Thanks for that, ver

Re: [PATCH] UML: add support for KASAN under x86_64

2022-05-24 Thread Vincent Whitchurch
On Wed, Mar 11, 2020 at 11:44:37PM +0100, Johannes Berg wrote: > On Wed, 2020-03-11 at 15:32 -0700, Patricia Alfonso wrote: > > I'll need some time to investigate these all myself. Having just > > gotten my first module to run about an hour ago, any more information > > about how you got these erro

Re: [PATCH] UML: add support for KASAN under x86_64

2022-05-24 Thread Johannes Berg
Hi Vincent, > Old thread, but I had a look at this the other day and I think I got it > working. Since the entire shadow area is mapped at init, we don't need > to do any mappings later. Nice!! I've always wanted to get back to this too. > It works both with and without KASAN_VMALLOC. KASAN_ST

Re: [PATCH 05/16] ptrace: Remove dead code from __ptrace_detach

2022-05-24 Thread Oleg Nesterov
Sorry for delay. On 05/18, Eric W. Biederman wrote: > > Ever since commit 28d838cc4dfe ("Fix ptrace self-attach rule") it has > been impossible to attach another thread in the same thread group. > > Remove the code from __ptrace_detach that was trying to support > detaching from a thread in the sa

Re: [PATCH 06/16] ptrace: Remove unnecessary locking in ptrace_(get|set)siginfo

2022-05-24 Thread Oleg Nesterov
On 05/18, Eric W. Biederman wrote: > > Since commit 9899d11f6544 ("ptrace: ensure arch_ptrace/ptrace_request > can never race with SIGKILL") it has been unnecessary for > ptrace_getsiginfo and ptrace_setsiginfo to use lock_task_sighand. ACK ___ linux-u

Re: [PATCH 07/16] signal: Wake up the designated parent

2022-05-24 Thread Oleg Nesterov
I fail to understand this patch... On 05/18, Eric W. Biederman wrote: > > Today if a process is ptraced only the ptracer will ever be woken up in > wait and why is this wrong? > Fixes: 75b95953a569 ("job control: Add @for_ptrace to > do_notify_parent_cldstop()") how does this change fix 75b959

Re: [PATCH 24/30] panic: Refactor the panic path

2022-05-24 Thread Eric W. Biederman
"Guilherme G. Piccoli" writes: > The panic() function is somewhat convoluted - a lot of changes were > made over the years, adding comments that might be misleading/outdated > now, it has a code structure that is a bit complex to follow, with > lots of conditionals, for example. The panic notifie

Re: [PATCH v7 21/25] Kbuild: add Rust support

2022-05-24 Thread Miguel Ojeda
On Mon, May 23, 2022 at 8:45 PM Nick Desaulniers wrote: > > I'm super not into having the rust optimization level differ from the > C optimization level. This is just someone having too much fun > wrapping every compiler flag in a kbuild option. Either folks wan't I mean, `Makefile`s are not my

Re: [PATCH 08/16] ptrace: Only populate last_siginfo from ptrace

2022-05-24 Thread Oleg Nesterov
On 05/18, Eric W. Biederman wrote: > > The code in ptrace_signal to populate siginfo if the signal number > changed is buggy. If the tracer contined the tracee using > ptrace_detach it is guaranteed to use the real_parent (or possibly a > new tracer) but definitely not the origional tracer to popu

Re: [PATCH 07/16] signal: Wake up the designated parent

2022-05-24 Thread Oleg Nesterov
On 05/24, Oleg Nesterov wrote: > > I fail to understand this patch... > > On 05/18, Eric W. Biederman wrote: > > > > Today if a process is ptraced only the ptracer will ever be woken up in > > wait > > and why is this wrong? > > > Fixes: 75b95953a569 ("job control: Add @for_ptrace to > > do_notify

[PATCH v3] mm: Avoid unnecessary page fault retires on shared memory types

2022-05-24 Thread Peter Xu
I observed that for each of the shared file-backed page faults, we're very likely to retry one more time for the 1st write fault upon no page. It's because we'll need to release the mmap lock for dirty rate limit purpose with balance_dirty_pages_ratelimited() (in fault_dirty_shared_page()). Then