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* [PATCH v3 00/22] tracing vs world
@ 2020-02-19 14:47 Peter Zijlstra
  2020-02-19 14:47 ` [PATCH v3 01/22] hardirq/nmi: Allow nested nmi_enter() Peter Zijlstra
                   ` (21 more replies)
  0 siblings, 22 replies; 99+ messages in thread
From: Peter Zijlstra @ 2020-02-19 14:47 UTC (permalink / raw)
  To: linux-kernel, linux-arch, rostedt
  Cc: peterz, mingo, joel, gregkh, gustavo, tglx, paulmck, josh,
	mathieu.desnoyers, jiangshanlai, luto, tony.luck, frederic,
	dan.carpenter, mhiramat

Hi all,


These here patches are the result of Mathieu and Steve trying to get commit
865e63b04e9b2 ("tracing: Add back in rcu_irq_enter/exit_irqson() for rcuidle
tracepoints") reverted again.

One of the things discovered is that tracing MUST NOT happen before nmi_enter()
or after nmi_exit(). Audit results of the previous version are still valid.

This then snowballed into auditing other exceptions, notably #MC, and #BP. Lots
of patches came out of that.

I would love for some tooling in this area. Dan, smatch has full callchains
right? Would it be possible to have an __assert_no_tracing__() marker of sorts
that validates that no possible callchain reaching that assertion has hit
tracing before that point?

It would mean you have to handle the various means of 'notrace' annotation
(both the function attribute as well as the Makefile rules), recognising
tracepoints and ideally handling NOKPROBE annotations.

Changes since -v2:

 - #MC / ist_enter() audit -- first 4 patches. After this in_nmi() should
   always be set 'correctly'.
 - RCU IRQ enter/exit function simplification
 - #BP / poke_int3_handler() audit -- last many patches.
 - pulled in some locking/kcsan patches

Changes since -v1:

 - Added tags
 - Changed #4; changed nmi_enter() to use __preempt_count_add() vs
   marking preempt_count_add() notrace.
 - Changed #5; confusion on which functions are notrace due to Makefile
 - Added #9; remove limitation on the perf-function-trace coupling


^ permalink raw reply	[flat|nested] 99+ messages in thread

end of thread, other threads:[~2020-02-20 16:22 UTC | newest]

Thread overview: 99+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-19 14:47 [PATCH v3 00/22] tracing vs world Peter Zijlstra
2020-02-19 14:47 ` [PATCH v3 01/22] hardirq/nmi: Allow nested nmi_enter() Peter Zijlstra
2020-02-19 15:31   ` Steven Rostedt
2020-02-19 16:56     ` Borislav Petkov
2020-02-19 17:07       ` Peter Zijlstra
2020-02-20  8:41   ` Will Deacon
2020-02-20  9:19   ` Marc Zyngier
2020-02-20 13:18   ` Petr Mladek
2020-02-19 14:47 ` [PATCH v3 02/22] x86,mce: Delete ist_begin_non_atomic() Peter Zijlstra
2020-02-19 17:13   ` Borislav Petkov
2020-02-19 17:21     ` Andy Lutomirski
2020-02-19 17:33       ` Peter Zijlstra
2020-02-19 22:12         ` Andy Lutomirski
2020-02-19 22:33           ` Luck, Tony
2020-02-19 22:48             ` Andy Lutomirski
2020-02-20  7:39           ` Peter Zijlstra
2020-02-19 17:42       ` Borislav Petkov
2020-02-19 17:46         ` Peter Zijlstra
2020-02-19 14:47 ` [PATCH v3 03/22] x86: Replace ist_enter() with nmi_enter() Peter Zijlstra
2020-02-20 10:54   ` Borislav Petkov
2020-02-20 12:11     ` Peter Zijlstra
2020-02-19 14:47 ` [PATCH v3 04/22] x86/doublefault: Make memmove() notrace/NOKPROBE Peter Zijlstra
2020-02-19 15:36   ` Steven Rostedt
2020-02-19 15:40     ` Peter Zijlstra
2020-02-19 15:55       ` Steven Rostedt
2020-02-19 15:57       ` Peter Zijlstra
2020-02-19 16:04         ` Peter Zijlstra
2020-02-19 16:12           ` Steven Rostedt
2020-02-19 16:27             ` Paul E. McKenney
2020-02-19 16:34               ` Peter Zijlstra
2020-02-19 16:46                 ` Paul E. McKenney
2020-02-19 17:05               ` Steven Rostedt
2020-02-20 12:17         ` Borislav Petkov
2020-02-20 12:37           ` Peter Zijlstra
2020-02-19 15:47   ` Steven Rostedt
2020-02-19 14:47 ` [PATCH v3 05/22] rcu: Make RCU IRQ enter/exit functions rely on in_nmi() Peter Zijlstra
2020-02-19 16:31   ` Paul E. McKenney
2020-02-19 16:37     ` Peter Zijlstra
2020-02-19 16:45       ` Paul E. McKenney
2020-02-19 17:03       ` Peter Zijlstra
2020-02-19 17:42         ` Paul E. McKenney
2020-02-19 17:16     ` [PATCH] rcu/kprobes: Comment why rcu_nmi_enter() is marked NOKPROBE Steven Rostedt
2020-02-19 17:18       ` Joel Fernandes
2020-02-19 17:41       ` Paul E. McKenney
2020-02-20  5:54       ` Masami Hiramatsu
2020-02-19 14:47 ` [PATCH v3 06/22] rcu: Rename rcu_irq_{enter,exit}_irqson() Peter Zijlstra
2020-02-19 16:38   ` Paul E. McKenney
2020-02-19 14:47 ` [PATCH v3 07/22] rcu: Mark rcu_dynticks_curr_cpu_in_eqs() inline Peter Zijlstra
2020-02-19 16:39   ` Paul E. McKenney
2020-02-19 17:19     ` Steven Rostedt
2020-02-19 14:47 ` [PATCH v3 08/22] rcu,tracing: Create trace_rcu_{enter,exit}() Peter Zijlstra
2020-02-19 15:49   ` Steven Rostedt
2020-02-19 15:58     ` Peter Zijlstra
2020-02-19 16:15       ` Steven Rostedt
2020-02-19 16:35         ` Peter Zijlstra
2020-02-19 16:44           ` Paul E. McKenney
2020-02-20 10:34             ` Peter Zijlstra
2020-02-20 13:58               ` Paul E. McKenney
2020-02-19 14:47 ` [PATCH v3 09/22] sched,rcu,tracing: Avoid tracing before in_nmi() is correct Peter Zijlstra
2020-02-19 15:50   ` Steven Rostedt
2020-02-19 15:50   ` Steven Rostedt
2020-02-19 14:47 ` [PATCH v3 10/22] x86,tracing: Add comments to do_nmi() Peter Zijlstra
2020-02-19 15:51   ` Steven Rostedt
2020-02-19 14:47 ` [PATCH v3 11/22] perf,tracing: Prepare the perf-trace interface for RCU changes Peter Zijlstra
2020-02-19 14:47 ` [PATCH v3 12/22] tracing: Employ trace_rcu_{enter,exit}() Peter Zijlstra
2020-02-19 15:52   ` Steven Rostedt
2020-02-19 14:47 ` [PATCH v3 13/22] tracing: Remove regular RCU context for _rcuidle tracepoints (again) Peter Zijlstra
2020-02-19 15:53   ` Steven Rostedt
2020-02-19 16:43   ` Paul E. McKenney
2020-02-19 16:47     ` Peter Zijlstra
2020-02-19 17:05       ` Peter Zijlstra
2020-02-19 17:21         ` Steven Rostedt
2020-02-19 17:40           ` Paul E. McKenney
2020-02-19 18:00             ` Steven Rostedt
2020-02-19 19:05               ` Paul E. McKenney
2020-02-19 14:47 ` [PATCH v3 14/22] perf,tracing: Allow function tracing when !RCU Peter Zijlstra
2020-02-19 14:47 ` [PATCH v3 15/22] x86/int3: Ensure that poke_int3_handler() is not traced Peter Zijlstra
2020-02-19 14:47 ` [PATCH v3 16/22] locking/atomics, kcsan: Add KCSAN instrumentation Peter Zijlstra
2020-02-19 15:46   ` Steven Rostedt
2020-02-19 16:03     ` Peter Zijlstra
2020-02-19 16:50       ` Paul E. McKenney
2020-02-19 16:54         ` Peter Zijlstra
2020-02-19 17:36           ` Paul E. McKenney
2020-02-19 14:47 ` [PATCH v3 17/22] asm-generic/atomic: Use __always_inline for pure wrappers Peter Zijlstra
2020-02-19 14:47 ` [PATCH v3 18/22] asm-generic/atomic: Use __always_inline for fallback wrappers Peter Zijlstra
2020-02-19 16:55   ` Paul E. McKenney
2020-02-19 17:06     ` Peter Zijlstra
2020-02-19 17:35       ` Paul E. McKenney
2020-02-19 14:47 ` [PATCH v3 19/22] compiler: Simple READ/WRITE_ONCE() implementations Peter Zijlstra
2020-02-19 14:47 ` [PATCH v3 20/22] locking/atomics: Flip fallbacks and instrumentation Peter Zijlstra
2020-02-19 14:47 ` [PATCH v3 21/22] x86/int3: Avoid atomic instrumentation Peter Zijlstra
2020-02-19 14:47 ` [PATCH v3 22/22] x86/int3: Ensure that poke_int3_handler() is not sanitized Peter Zijlstra
2020-02-19 16:06   ` Dmitry Vyukov
2020-02-19 16:30     ` Peter Zijlstra
2020-02-19 16:51       ` Peter Zijlstra
2020-02-19 17:20       ` Peter Zijlstra
2020-02-20 10:37         ` Dmitry Vyukov
2020-02-20 12:06           ` Peter Zijlstra
2020-02-20 16:22             ` Dmitry Vyukov

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