From: Mark Rutland <mark.rutland@arm.com> To: Andy Lutomirski <luto@kernel.org> Cc: "Jürgen Groß" <jgross@suse.com>, "Peter Zijlstra" <peterz@infradead.org>, "Stefano Stabellini" <sstabellini@kernel.org>, "VMware, Inc." <pv-drivers@vmware.com>, "X86 ML" <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>, "Linux Virtualization" <virtualization@lists.linux-foundation.org>, "Ingo Molnar" <mingo@redhat.com>, "Borislav Petkov" <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>, xen-devel <xen-devel@lists.xenproject.org>, "Thomas Gleixner" <tglx@linutronix.de>, "Boris Ostrovsky" <boris.ostrovsky@oracle.com> Subject: Re: [PATCH v2 05/12] x86: rework arch_local_irq_restore() to not use popf Date: Wed, 9 Dec 2020 14:02:21 +0000 [thread overview] Message-ID: <20201209140221.GA9087@C02TD0UTHF1T.local> (raw) In-Reply-To: <20201209132710.GA8566@C02TD0UTHF1T.local> On Wed, Dec 09, 2020 at 01:27:10PM +0000, Mark Rutland wrote: > On Sun, Nov 22, 2020 at 01:44:53PM -0800, Andy Lutomirski wrote: > > On Sat, Nov 21, 2020 at 10:55 PM Jürgen Groß <jgross@suse.com> wrote: > > > On 20.11.20 12:59, Peter Zijlstra wrote: > > > > If someone were to write horrible code like: > > > > > > > > local_irq_disable(); > > > > local_irq_save(flags); > > > > local_irq_enable(); > > > > local_irq_restore(flags); > > > > > > > > we'd be up some creek without a paddle... now I don't _think_ we have > > > > genius code like that, but I'd feel saver if we can haz an assertion in > > > > there somewhere... > I was just talking to Peter on IRC about implementing the same thing for > arm64, so could we put this in the generic irqflags code? IIUC we can > use raw_irqs_disabled() to do the check. > > As this isn't really entry specific (and IIUC the cases this should > catch would break lockdep today), maybe we should add a new > DEBUG_IRQFLAGS for this, that DEBUG_LOCKDEP can also select? > > Something like: > > #define local_irq_restore(flags) \ > do { \ > if (!raw_irqs_disabled_flags(flags)) { \ > trace_hardirqs_on(); \ > } else if (IS_ENABLED(CONFIG_DEBUG_IRQFLAGS) { \ > if (unlikely(raw_irqs_disabled()) \ Whoops; that should be !raw_irqs_disabled(). > warn_bogus_irqrestore(); \ > } \ > raw_local_irq_restore(flags); \ > } while (0) > > ... perhaps? (ignoring however we deal with once-ness). If no-one shouts in the next day or two I'll spin this as its own patch. Mark.
WARNING: multiple messages have this Message-ID (diff)
From: Mark Rutland <mark.rutland@arm.com> To: Andy Lutomirski <luto@kernel.org> Cc: "Jürgen Groß" <jgross@suse.com>, "Stefano Stabellini" <sstabellini@kernel.org>, "Peter Zijlstra" <peterz@infradead.org>, "X86 ML" <x86@kernel.org>, LKML <linux-kernel@vger.kernel.org>, "Linux Virtualization" <virtualization@lists.linux-foundation.org>, "VMware, Inc." <pv-drivers@vmware.com>, "Ingo Molnar" <mingo@redhat.com>, "Borislav Petkov" <bp@alien8.de>, "H. Peter Anvin" <hpa@zytor.com>, xen-devel <xen-devel@lists.xenproject.org>, "Thomas Gleixner" <tglx@linutronix.de>, "Boris Ostrovsky" <boris.ostrovsky@oracle.com> Subject: Re: [PATCH v2 05/12] x86: rework arch_local_irq_restore() to not use popf Date: Wed, 9 Dec 2020 14:02:21 +0000 [thread overview] Message-ID: <20201209140221.GA9087@C02TD0UTHF1T.local> (raw) In-Reply-To: <20201209132710.GA8566@C02TD0UTHF1T.local> On Wed, Dec 09, 2020 at 01:27:10PM +0000, Mark Rutland wrote: > On Sun, Nov 22, 2020 at 01:44:53PM -0800, Andy Lutomirski wrote: > > On Sat, Nov 21, 2020 at 10:55 PM Jürgen Groß <jgross@suse.com> wrote: > > > On 20.11.20 12:59, Peter Zijlstra wrote: > > > > If someone were to write horrible code like: > > > > > > > > local_irq_disable(); > > > > local_irq_save(flags); > > > > local_irq_enable(); > > > > local_irq_restore(flags); > > > > > > > > we'd be up some creek without a paddle... now I don't _think_ we have > > > > genius code like that, but I'd feel saver if we can haz an assertion in > > > > there somewhere... > I was just talking to Peter on IRC about implementing the same thing for > arm64, so could we put this in the generic irqflags code? IIUC we can > use raw_irqs_disabled() to do the check. > > As this isn't really entry specific (and IIUC the cases this should > catch would break lockdep today), maybe we should add a new > DEBUG_IRQFLAGS for this, that DEBUG_LOCKDEP can also select? > > Something like: > > #define local_irq_restore(flags) \ > do { \ > if (!raw_irqs_disabled_flags(flags)) { \ > trace_hardirqs_on(); \ > } else if (IS_ENABLED(CONFIG_DEBUG_IRQFLAGS) { \ > if (unlikely(raw_irqs_disabled()) \ Whoops; that should be !raw_irqs_disabled(). > warn_bogus_irqrestore(); \ > } \ > raw_local_irq_restore(flags); \ > } while (0) > > ... perhaps? (ignoring however we deal with once-ness). If no-one shouts in the next day or two I'll spin this as its own patch. Mark. _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
next prev parent reply other threads:[~2020-12-09 14:03 UTC|newest] Thread overview: 107+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-11-20 11:46 [PATCH v2 00/12] x86: major paravirt cleanup Juergen Gross 2020-11-20 11:46 ` Juergen Gross via Virtualization 2020-11-20 11:46 ` [PATCH v2 01/12] x86/xen: use specific Xen pv interrupt entry for MCE Juergen Gross 2020-12-09 21:03 ` Thomas Gleixner 2020-11-20 11:46 ` [PATCH v2 02/12] x86/xen: use specific Xen pv interrupt entry for DF Juergen Gross 2020-12-09 21:03 ` Thomas Gleixner 2020-11-20 11:46 ` [PATCH v2 03/12] x86/pv: switch SWAPGS to ALTERNATIVE Juergen Gross 2020-11-20 11:46 ` Juergen Gross via Virtualization 2020-11-27 11:31 ` Borislav Petkov 2020-11-27 11:31 ` Borislav Petkov 2020-12-09 21:07 ` Thomas Gleixner 2020-12-09 21:07 ` Thomas Gleixner 2020-11-20 11:46 ` [PATCH v2 04/12] x86/xen: drop USERGS_SYSRET64 paravirt call Juergen Gross 2020-11-20 11:46 ` Juergen Gross via Virtualization 2020-12-02 12:32 ` Borislav Petkov 2020-12-02 12:32 ` Borislav Petkov 2020-12-02 14:48 ` Jürgen Groß 2020-12-02 14:48 ` Jürgen Groß via Virtualization 2020-12-02 17:08 ` Borislav Petkov 2020-12-02 17:08 ` Borislav Petkov 2020-11-20 11:46 ` [PATCH v2 05/12] x86: rework arch_local_irq_restore() to not use popf Juergen Gross 2020-11-20 11:46 ` Juergen Gross via Virtualization 2020-11-20 11:59 ` Peter Zijlstra 2020-11-20 11:59 ` Peter Zijlstra 2020-11-20 12:05 ` Jürgen Groß 2020-11-20 12:05 ` Jürgen Groß via Virtualization 2020-11-22 6:55 ` Jürgen Groß 2020-11-22 6:55 ` Jürgen Groß via Virtualization 2020-11-22 21:44 ` Andy Lutomirski 2020-11-22 21:44 ` Andy Lutomirski 2020-11-22 21:44 ` Andy Lutomirski 2020-11-23 5:21 ` Jürgen Groß 2020-11-23 5:21 ` Jürgen Groß via Virtualization 2020-11-23 15:15 ` Andy Lutomirski 2020-11-23 15:15 ` Andy Lutomirski 2020-12-09 13:27 ` Mark Rutland 2020-12-09 13:27 ` Mark Rutland 2020-12-09 14:02 ` Mark Rutland [this message] 2020-12-09 14:02 ` Mark Rutland 2020-12-09 14:05 ` Jürgen Groß 2020-12-09 14:05 ` Jürgen Groß via Virtualization 2020-12-09 18:15 ` Mark Rutland 2020-12-09 18:15 ` Mark Rutland 2020-12-09 18:54 ` Thomas Gleixner 2020-12-09 18:54 ` Thomas Gleixner 2020-12-10 11:10 ` Mark Rutland 2020-12-10 11:10 ` Mark Rutland 2020-12-10 20:15 ` x86/ioapic: Cleanup the timer_works() irqflags mess Thomas Gleixner 2020-12-10 20:15 ` Thomas Gleixner 2020-12-10 22:04 ` [tip: x86/apic] " tip-bot2 for Thomas Gleixner 2020-12-11 5:10 ` Jürgen Groß 2020-12-11 5:10 ` Jürgen Groß via Virtualization 2020-11-27 2:20 ` [x86] 97e8f0134a: fio.write_iops 8.6% improvement kernel test robot 2020-11-20 11:46 ` [PATCH v2 06/12] x86/paravirt: switch time pvops functions to use static_call() Juergen Gross 2020-11-20 11:46 ` Juergen Gross via Virtualization 2020-11-20 12:01 ` Peter Zijlstra 2020-11-20 12:01 ` Peter Zijlstra 2020-11-20 12:07 ` Jürgen Groß 2020-11-20 12:07 ` Jürgen Groß via Virtualization 2020-11-20 11:46 ` [PATCH v2 07/12] x86: add new features for paravirt patching Juergen Gross 2020-12-08 18:43 ` Borislav Petkov 2020-12-09 7:30 ` Jürgen Groß 2020-12-09 12:03 ` Borislav Petkov 2020-12-09 12:22 ` Jürgen Groß 2020-12-10 17:58 ` Borislav Petkov 2020-11-20 11:46 ` [PATCH v2 08/12] x86/paravirt: remove no longer needed 32-bit pvops cruft Juergen Gross 2020-11-20 11:46 ` Juergen Gross via Virtualization 2020-11-20 12:08 ` Peter Zijlstra 2020-11-20 12:08 ` Peter Zijlstra 2020-11-20 12:16 ` Jürgen Groß 2020-11-20 12:16 ` Jürgen Groß via Virtualization 2020-11-20 16:52 ` Arvind Sankar 2020-11-20 11:46 ` [PATCH v2 09/12] x86/paravirt: switch iret pvops to ALTERNATIVE Juergen Gross 2020-11-20 11:46 ` Juergen Gross via Virtualization 2020-11-20 11:46 ` [PATCH v2 10/12] x86/paravirt: add new macros PVOP_ALT* supporting pvops in ALTERNATIVEs Juergen Gross 2020-11-20 11:46 ` Juergen Gross via Virtualization 2020-11-20 11:46 ` [PATCH v2 11/12] x86/paravirt: switch functions with custom code to ALTERNATIVE Juergen Gross 2020-11-20 11:46 ` Juergen Gross via Virtualization 2020-11-20 15:46 ` kernel test robot 2020-11-20 15:46 ` kernel test robot 2020-11-20 15:46 ` kernel test robot 2020-11-25 15:46 ` [x86/paravirt] fd8d46a7a2: kernel-selftests.livepatch.test-callbacks.sh.fail kernel test robot 2020-11-20 11:46 ` [PATCH v2 12/12] x86/paravirt: have only one paravirt patch function Juergen Gross 2020-11-20 11:46 ` Juergen Gross via Virtualization 2020-11-20 14:18 ` kernel test robot 2020-11-20 14:18 ` kernel test robot 2020-11-20 14:18 ` kernel test robot 2020-11-20 12:53 ` [PATCH v2 00/12] x86: major paravirt cleanup Peter Zijlstra 2020-11-20 12:53 ` Peter Zijlstra 2020-11-23 13:43 ` Peter Zijlstra 2020-11-23 13:43 ` Peter Zijlstra 2020-12-15 11:42 ` Jürgen Groß 2020-12-15 11:42 ` Jürgen Groß via Virtualization 2020-12-15 14:18 ` Peter Zijlstra 2020-12-15 14:18 ` Peter Zijlstra 2020-12-15 14:54 ` Peter Zijlstra 2020-12-15 14:54 ` Peter Zijlstra 2020-12-15 15:07 ` Jürgen Groß 2020-12-15 15:07 ` Jürgen Groß via Virtualization 2020-12-16 0:38 ` Josh Poimboeuf 2020-12-16 0:38 ` Josh Poimboeuf 2020-12-16 8:40 ` Peter Zijlstra 2020-12-16 8:40 ` Peter Zijlstra 2020-12-16 16:56 ` Josh Poimboeuf 2020-12-16 16:56 ` Josh Poimboeuf 2020-12-16 17:58 ` Peter Zijlstra 2020-12-16 17:58 ` Peter Zijlstra
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