lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 21 Sep 2020 15:38:21 +0200 From: "Rafael J. Wysocki" <rafael@...nel.org> To: "Paul E. McKenney" <paulmck@...nel.org>, Borislav Petkov <bp@...en8.de> Cc: Sven Joachim <svenjoac@....de>, Peter Zijlstra <peterz@...radead.org>, "Rafael J. Wysocki" <rjw@...ysocki.net>, "the arch/x86 maintainers" <x86@...nel.org>, Tony Luck <tony.luck@...el.com>, Len Brown <lenb@...nel.org>, Daniel Lezcano <daniel.lezcano@...aro.org>, Linux Kernel Mailing List <linux-kernel@...r.kernel.org>, ACPI Devel Maling List <linux-acpi@...r.kernel.org>, Linux PM <linux-pm@...r.kernel.org>, Ulf Hansson <ulf.hansson@...aro.org>, Thomas Gleixner <tglx@...utronix.de>, Naresh Kamboju <naresh.kamboju@...aro.org>, Josh Triplett <josh@...htriplett.org>, Steven Rostedt <rostedt@...dmis.org>, Mathieu Desnoyers <mathieu.desnoyers@...icios.com>, Lai Jiangshan <jiangshanlai@...il.com>, Joel Fernandes <joel@...lfernandes.org>, rcu@...r.kernel.org Subject: Re: [PATCH] rcu/tree: Export rcu_idle_{enter,exit} to module On Mon, Sep 21, 2020 at 3:32 PM Paul E. McKenney <paulmck@...nel.org> wrote: > > On Mon, Sep 21, 2020 at 12:37:41PM +0200, Borislav Petkov wrote: > > Lemme add whatever get_maintainer spits, to Cc. > > > > On Mon, Sep 21, 2020 at 11:12:33AM +0200, Sven Joachim wrote: > > > On 2020-09-15 12:32 +0200, Peter Zijlstra wrote: > > > > > > > The C3 BusMaster idle code takes lock in a number of places, some deep > > > > inside the ACPI code. Instead of wrapping it all in RCU_NONIDLE, have > > > > the driver take over RCU-idle duty and avoid flipping RCU state back > > > > and forth a lot. > > > > > > > > ( by marking 'C3 && bm_check' as RCU_IDLE, we _must_ call enter_bm() for > > > > that combination, otherwise we'll loose RCU-idle, this requires > > > > shuffling some code around ) > > > > > > > > Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org> > > > > > > I got modpost errors in 5.9-rc6 after this patch: > > > > > > ERROR: modpost: "rcu_idle_enter" [drivers/acpi/processor.ko] undefined! > > > ERROR: modpost: "rcu_idle_exit" [drivers/acpi/processor.ko] undefined! > > > > > > Reverting commit 1fecfdbb7acc made them go away. Notably my > > > configuration had CONFIG_ACPI_PROCESSOR=m, changing that > > > to CONFIG_ACPI_PROCESSOR=y let the build succeed as well. > > > > I guess this. Running randconfigs on it for a while, to see what else > > breaks. > > > > --- > > From: Borislav Petkov <bp@...e.de> > > Date: Mon, 21 Sep 2020 12:31:36 +0200 > > > > Fix this link error: > > > > ERROR: modpost: "rcu_idle_enter" [drivers/acpi/processor.ko] undefined! > > ERROR: modpost: "rcu_idle_exit" [drivers/acpi/processor.ko] undefined! > > > > when CONFIG_ACPI_PROCESSOR is built as module. PeterZ says that in light > > of ARM needing those soon too, they should simply be exported. > > > > Fixes: 1fecfdbb7acc ("ACPI: processor: Take over RCU-idle for C3-BM idle") > > Reported-by: Sven Joachim <svenjoac@....de> > > Suggested-by: Peter Zijlstra <peterz@...radead.org> > > Signed-off-by: Borislav Petkov <bp@...e.de> > > Reviewed-by: Paul E. McKenney <paulmckrcu@...nel.org> OK Applied as 5.9-rc7 material, thanks! > > --- > > kernel/rcu/tree.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > index 8ce77d9ac716..f78ee759af9c 100644 > > --- a/kernel/rcu/tree.c > > +++ b/kernel/rcu/tree.c > > @@ -673,6 +673,7 @@ void rcu_idle_enter(void) > > lockdep_assert_irqs_disabled(); > > rcu_eqs_enter(false); > > } > > +EXPORT_SYMBOL_GPL(rcu_idle_enter); > > > > #ifdef CONFIG_NO_HZ_FULL > > /** > > @@ -886,6 +887,7 @@ void rcu_idle_exit(void) > > rcu_eqs_exit(false); > > local_irq_restore(flags); > > } > > +EXPORT_SYMBOL_GPL(rcu_idle_exit); > > > > #ifdef CONFIG_NO_HZ_FULL > > /** > > -- > > 2.21.0 > > > > -- > > Regards/Gruss, > > Boris. > > > > https://people.kernel.org/tglx/notes-about-netiquette
Powered by blists - more mailing lists