From: "Nicholas Piggin" <npiggin@gmail.com>
To: "Nathan Lynch" <nathanl@linux.ibm.com>, <linuxppc-dev@lists.ozlabs.org>
Cc: tyreld@linux.ibm.com, nnac123@linux.ibm.com,
ldufour@linux.ibm.com, ajd@linux.ibm.com
Subject: Re: [PATCH 13/13] powerpc/rtas: place tracepoints in do_enter_rtas()
Date: Mon, 28 Nov 2022 13:07:41 +1000 [thread overview]
Message-ID: <CONLJ0VXR77H.JM4D75GQAF62@bobo> (raw)
In-Reply-To: <20221118150751.469393-14-nathanl@linux.ibm.com>
On Sat Nov 19, 2022 at 1:07 AM AEST, Nathan Lynch wrote:
> Call the just-added rtas tracepoints in do_enter_rtas(), taking care
> to avoid function name lookups in the CPU offline path.
>
> Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
> ---
> arch/powerpc/kernel/rtas.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
> index 198366d641d0..3487b42cfbf7 100644
> --- a/arch/powerpc/kernel/rtas.c
> +++ b/arch/powerpc/kernel/rtas.c
> @@ -38,6 +38,7 @@
> #include <asm/page.h>
> #include <asm/rtas.h>
> #include <asm/time.h>
> +#include <asm/trace.h>
> #include <asm/udbg.h>
>
> enum rtas_function_flags {
> @@ -525,6 +526,7 @@ void enter_rtas(unsigned long);
> static void do_enter_rtas(struct rtas_args *args)
> {
> unsigned long msr;
> + const char *name = NULL;
>
> /*
> * Make sure MSR[RI] is currently enabled as it will be forced later
> @@ -537,9 +539,30 @@ static void do_enter_rtas(struct rtas_args *args)
>
> hard_irq_disable(); /* Ensure MSR[EE] is disabled on PPC64 */
>
> + if ((trace_rtas_input_enabled() || trace_rtas_output_enabled())) {
> + /*
> + * rtas_token_to_function() uses xarray which uses RCU,
> + * but this code can run in the CPU offline path
> + * (e.g. stop-self), after it's become invalid to call
> + * RCU APIs.
> + */
We can call this in real-mode via pseries_machine_check_realmode
-> fwnmi_release_errinfo, so tracing should be disabled for that
case too... Does this_cpu_set_ftrace_enabled(0) in the early
machine check handler cover that sufficiently?
Thanks,
Nick
next prev parent reply other threads:[~2022-11-28 3:08 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-18 15:07 [PATCH 00/13] RTAS maintenance Nathan Lynch
2022-11-18 15:07 ` [PATCH 01/13] powerpc/rtas: document rtas_call() Nathan Lynch
2022-11-22 2:46 ` Andrew Donnellan
2022-11-18 15:07 ` [PATCH 02/13] powerpc/rtasd: use correct OF API for event scan rate Nathan Lynch
2022-11-22 2:39 ` Andrew Donnellan
2022-11-18 15:07 ` [PATCH 03/13] powerpc/rtas: avoid device tree lookups in rtas_os_term() Nathan Lynch
2022-11-22 3:03 ` Andrew Donnellan
2022-11-28 18:08 ` Nathan Lynch
2022-11-28 2:29 ` Nicholas Piggin
2022-11-28 18:26 ` Nathan Lynch
2022-11-29 6:45 ` Nicholas Piggin
2022-11-29 15:37 ` Nathan Lynch
2022-11-18 15:07 ` [PATCH 04/13] powerpc/rtas: avoid scheduling " Nathan Lynch
2022-11-22 3:17 ` Andrew Donnellan
2022-11-28 2:34 ` Nicholas Piggin
2022-11-18 15:07 ` [PATCH 05/13] powerpc/pseries/eeh: use correct API for error log size Nathan Lynch
2022-11-22 3:21 ` Andrew Donnellan
2022-11-28 20:22 ` Nathan Lynch
2022-11-18 15:07 ` [PATCH 06/13] powerpc/rtas: clean up rtas_error_log_max initialization Nathan Lynch
2022-11-22 3:40 ` Andrew Donnellan
2022-11-18 15:07 ` [PATCH 07/13] powerpc/rtas: clean up includes Nathan Lynch
2022-11-22 4:45 ` Andrew Donnellan
2022-11-18 15:07 ` [PATCH 08/13] powerpc/rtas: define pr_fmt and convert printk call sites Nathan Lynch
2022-11-22 4:07 ` Andrew Donnellan
2022-11-18 15:07 ` [PATCH 09/13] powerpc/rtas: mandate RTAS syscall filtering Nathan Lynch
2022-11-22 4:20 ` Andrew Donnellan
2022-11-18 15:07 ` [PATCH 10/13] powerpc/rtas: improve function information lookups Nathan Lynch
2022-11-23 2:51 ` Andrew Donnellan
2022-11-23 19:32 ` Nick Child
2022-11-24 3:28 ` Andrew Donnellan
2022-11-28 21:19 ` Nathan Lynch
2022-11-29 0:08 ` Nathan Lynch
2022-11-29 7:23 ` Andrew Donnellan
2022-11-29 15:33 ` Nathan Lynch
2022-11-23 20:06 ` Nick Child
2022-11-28 21:57 ` Nathan Lynch
2022-11-18 15:07 ` [PATCH 11/13] powerpc/rtas: strengthen do_enter_rtas() type safety, drop inline Nathan Lynch
2022-11-23 3:23 ` Andrew Donnellan
2022-11-28 2:37 ` Nicholas Piggin
2022-11-18 15:07 ` [PATCH 12/13] powerpc/tracing: tracepoints for RTAS entry and exit Nathan Lynch
2022-11-28 2:54 ` Nicholas Piggin
2022-11-18 15:07 ` [PATCH 13/13] powerpc/rtas: place tracepoints in do_enter_rtas() Nathan Lynch
2022-11-28 3:07 ` Nicholas Piggin [this message]
2022-11-28 23:44 ` Nathan Lynch
2022-11-29 0:49 ` Michael Ellerman
2022-11-29 20:24 ` Nathan Lynch
2022-11-30 7:43 ` Michael Ellerman
2022-11-29 6:47 ` Nicholas Piggin
2022-12-08 12:40 ` [PATCH 00/13] RTAS maintenance Michael Ellerman
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