linux-kernel - Re: [PATCH mm-unstable v2 01/10] mm/kvm: add mmu_notifier_ops->test_clear

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <e948d02f-cd93-b6e2-72fd-123e483f66fe@redhat.com>
Date:   Fri, 9 Jun 2023 11:04:29 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Jason Gunthorpe <jgg@...pe.ca>, Yu Zhao <yuzhao@...gle.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Alistair Popple <apopple@...dia.com>,
        Anup Patel <anup@...infault.org>,
        Ben Gardon <bgardon@...gle.com>,
        Borislav Petkov <bp@...en8.de>,
        Catalin Marinas <catalin.marinas@....com>,
        Chao Peng <chao.p.peng@...ux.intel.com>,
        Christophe Leroy <christophe.leroy@...roup.eu>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Fabiano Rosas <farosas@...ux.ibm.com>,
        Gaosheng Cui <cuigaosheng1@...wei.com>,
        Gavin Shan <gshan@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
        James Morse <james.morse@....com>,
        "Jason A. Donenfeld" <Jason@...c4.com>,
        Jonathan Corbet <corbet@....net>,
        Marc Zyngier <maz@...nel.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Michael Larabel <michael@...haellarabel.com>,
        Mike Rapoport <rppt@...nel.org>,
        Nicholas Piggin <npiggin@...il.com>,
        Oliver Upton <oliver.upton@...ux.dev>,
        Paul Mackerras <paulus@...abs.org>,
        Peter Xu <peterx@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Thomas Huth <thuth@...hat.com>, Will Deacon <will@...nel.org>,
        Zenghui Yu <yuzenghui@...wei.com>, kvmarm@...ts.linux.dev,
        kvm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-mm@...ck.org, linuxppc-dev@...ts.ozlabs.org,
        linux-trace-kernel@...r.kernel.org, x86@...nel.org,
        linux-mm@...gle.com
Subject: Re: [PATCH mm-unstable v2 01/10] mm/kvm: add
 mmu_notifier_ops->test_clear_young()

On 5/31/23 21:17, Jason Gunthorpe wrote:
>> +	int (*test_clear_young)(struct mmu_notifier *mn, struct mm_struct *mm,
>> +				unsigned long start, unsigned long end,
>> +				bool clear, unsigned long *bitmap);
>> +
> Why leave clear_young behind? Just make a NULL bitmap mean
> clear_young?

It goes away in patch 2, together with:

@@ -437,7 +412,7 @@ static inline int mmu_notifier_clear_young(struct mm_struct *mm,
  					   unsigned long end)
  {
  	if (mm_has_notifiers(mm))
-		return __mmu_notifier_clear_young(mm, start, end);
+		return __mmu_notifier_test_clear_young(mm, start, end, true, NULL);
  	return 0;
  }
  
@@ -445,7 +420,7 @@ static inline int mmu_notifier_test_young(struct mm_struct *mm,
  					  unsigned long address)
  {
  	if (mm_has_notifiers(mm))
-		return __mmu_notifier_test_young(mm, address);
+		return __mmu_notifier_test_clear_young(mm, address, address + 1, false, NULL);
  	return 0;
  }
  

Paolo