Messages in this thread | | | Subject | Re: [PATCH v2 0/3] x86/dumpstack: Print registers with the same log level as the backtrace | From | Dmitry Safonov <> | Date | Mon, 20 Jul 2020 19:51:51 +0100 |
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Hi Ingo, Thomas,
Could you take these to x86/tip tree? (in case they are good enough)
On 6/29/20 3:48 PM, Dmitry Safonov wrote: > Changes since v1 [3]: > - Use (enum show_regs_mode) instead of (int) [nit by Jann, thanks!] > - Add acks from Petr > > show_trace_log_lvl() provides x86 platform-specific way to unwind > backtrace with a given log level. Unfortunately, registers dump(s) are > not printed with the same log level - instead, KERN_DEFAULT is always > used. > > Arista's switches uses quite common setup with rsyslog, where only > urgent messages goes to console (console_log_level=KERN_ERR), everything > else goes into /var/log/ as the console baud-rate often is indecently > slow (9600 bps). > > Backtrace dumps without registers printed have proven to be as useful as > morning standups. Furthermore, in order to introduce KERN_UNSUPPRESSED > (which I believe is still the most elegant way to fix raciness of sysrq[1]) > the log level should be passed down the stack to register dumping > functions. Besides, I have a potential use-case for printing traces > with KERN_DEBUG level [2] (where registers dump shouldn't appear with > higher log level than the backtrace). > > Cc: Andy Lutomirski <luto@kernel.org> > Cc: Borislav Petkov <bp@alien8.de> > Cc: "H. Peter Anvin" <hpa@zytor.com> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Jann Horn <jannh@google.com> > Cc: Petr Mladek <pmladek@suse.com> > Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> > Cc: Steven Rostedt <rostedt@goodmis.org> > Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > Cc: Thomas Gleixner <tglx@linutronix.de> > Cc: x86@kernel.org > [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/ > [2]: https://lore.kernel.org/linux-doc/20190724170249.9644-1-dima@arista.com/ > [3]: https://lore.kernel.org/lkml/20200623162958.331051-1-dima@arista.com/ > Dmitry Safonov (3): > x86/dumpstack: Add log_lvl to show_iret_regs() > x86/dumpstack: Add log_lvl to __show_regs() > x86/dumpstack: Show registers dump with trace's log level > > arch/x86/include/asm/kdebug.h | 5 ++-- > arch/x86/kernel/dumpstack.c | 23 +++++++++------- > arch/x86/kernel/process_32.c | 29 ++++++++++---------- > arch/x86/kernel/process_64.c | 51 ++++++++++++++++++----------------- > 4 files changed, 57 insertions(+), 51 deletions(-) >
Thanks, Dmitry
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