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Groups > linux.kernel > #1718528
| From | Mark Rutland <mark.rutland@arm.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [kernel-hardening] [PATCH v5 04/10] arm64: Add __flush_tlb_one() |
| Date | 2017-08-23 19:10 +0200 |
| Message-ID | <uhHkd-3jd-5@gated-at.bofh.it> (permalink) |
| References | (1 earlier) <ucFCp-3KK-17@gated-at.bofh.it> <udCMa-8ux-9@gated-at.bofh.it> <ueqzh-6tX-31@gated-at.bofh.it> <ueqSC-6B0-31@gated-at.bofh.it> <uhHay-30H-19@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, Aug 23, 2017 at 10:58:42AM -0600, Tycho Andersen wrote: > Hi Mark, > > On Mon, Aug 14, 2017 at 05:50:47PM +0100, Mark Rutland wrote: > > That said, is there any reason not to use flush_tlb_kernel_range() > > directly? > > So it turns out that there is a difference between __flush_tlb_one() and > flush_tlb_kernel_range() on x86: flush_tlb_kernel_range() flushes all the TLBs > via on_each_cpu(), where as __flush_tlb_one() only flushes the local TLB (which > I think is enough here). That sounds suspicious; I don't think that __flush_tlb_one() is sufficient. If you only do local TLB maintenance, then the page is left accessible to other CPUs via the (stale) kernel mappings. i.e. the page isn't exclusively mapped by userspace. Thanks, Mark.
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Re: [kernel-hardening] [PATCH v5 04/10] arm64: Add __flush_tlb_one() Mark Rutland <mark.rutland@arm.com> - 2017-08-12 13:30 +0200
Re: [kernel-hardening] [PATCH v5 04/10] arm64: Add __flush_tlb_one() Tycho Andersen <tycho@docker.com> - 2017-08-14 18:40 +0200
Re: [kernel-hardening] [PATCH v5 04/10] arm64: Add __flush_tlb_one() Mark Rutland <mark.rutland@arm.com> - 2017-08-14 19:00 +0200
Re: [kernel-hardening] [PATCH v5 04/10] arm64: Add __flush_tlb_one() Tycho Andersen <tycho@docker.com> - 2017-08-14 19:10 +0200
Re: [kernel-hardening] [PATCH v5 04/10] arm64: Add __flush_tlb_one() Tycho Andersen <tycho@docker.com> - 2017-08-23 19:00 +0200
Re: [kernel-hardening] [PATCH v5 04/10] arm64: Add __flush_tlb_one() Mark Rutland <mark.rutland@arm.com> - 2017-08-23 19:10 +0200
Re: [kernel-hardening] [PATCH v5 04/10] arm64: Add __flush_tlb_one() Tycho Andersen <tycho@docker.com> - 2017-08-23 19:20 +0200
Re: [kernel-hardening] [PATCH v5 04/10] arm64: Add __flush_tlb_one() Mark Rutland <mark.rutland@arm.com> - 2017-08-24 17:50 +0200
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