From: Nadav Amit <namit@vmware.com>
To: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@kernel.org>,
Will Deacon <will.deacon@arm.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
"naveen.n.rao@linux.vnet.ibm.com"
<naveen.n.rao@linux.vnet.ibm.com>,
"anil.s.keshavamurthy@intel.com" <anil.s.keshavamurthy@intel.com>,
"davem@davemloft.net" <davem@davemloft.net>,
"mhiramat@kernel.org" <mhiramat@kernel.org>,
"rostedt@goodmis.org" <rostedt@goodmis.org>,
"mingo@redhat.com" <mingo@redhat.com>,
"ast@kernel.org" <ast@kernel.org>,
"daniel@iogearbox.net" <daniel@iogearbox.net>,
"jeyu@kernel.org" <jeyu@kernel.org>,
"netdev@vger.kernel.org" <netdev@vger.kern
Subject: Re: [PATCH v2 4/4] x86/vmalloc: Add TLB efficient x86 arch_vunmap
Date: Wed, 12 Dec 2018 06:30:56 +0000 [thread overview]
Message-ID: <90B10050-0CF1-48B2-B671-508FB092C2FE@vmware.com> (raw)
In-Reply-To: <20181212000354.31955-5-rick.p.edgecombe@intel.com>
> On Dec 11, 2018, at 4:03 PM, Rick Edgecombe <rick.p.edgecombe@intel.com> wrote:
>
> This adds a more efficient x86 architecture specific implementation of
> arch_vunmap, that can free any type of special permission memory with only 1 TLB
> flush.
>
> In order to enable this, _set_pages_p and _set_pages_np are made non-static and
> renamed set_pages_p_noflush and set_pages_np_noflush to better communicate
> their different (non-flushing) behavior from the rest of the set_pages_*
> functions.
>
> The method for doing this with only 1 TLB flush was suggested by Andy
> Lutomirski.
>
[snip]
> + /*
> + * If the vm being freed has security sensitive capabilities such as
> + * executable we need to make sure there is no W window on the directmap
> + * before removing the X in the TLB. So we set not present first so we
> + * can flush without any other CPU picking up the mapping. Then we reset
> + * RW+P without a flush, since NP prevented it from being cached by
> + * other cpus.
> + */
> + set_area_direct_np(area);
> + vm_unmap_aliases();
Does vm_unmap_aliases() flush in the TLB the direct mapping range as well? I
can only find the flush of the vmalloc range.
next prev parent reply other threads:[~2018-12-12 6:30 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-12 0:03 [PATCH v2 0/4] Don’t leave executable TLB entries to freed pages Rick Edgecombe
2018-12-12 0:03 ` [PATCH v2 1/4] vmalloc: New flags for safe vfree on special perms Rick Edgecombe
2018-12-12 2:20 ` Andy Lutomirski
2018-12-12 19:50 ` Edgecombe, Rick P
2018-12-12 19:57 ` Andy Lutomirski
2018-12-12 22:01 ` Edgecombe, Rick P
2018-12-15 18:52 ` Andy Lutomirski
2018-12-18 0:23 ` Edgecombe, Rick P
2018-12-18 1:02 ` Andy Lutomirski
2018-12-21 16:39 ` Ard Biesheuvel
2018-12-21 17:12 ` Andy Lutomirski
2018-12-21 17:25 ` Ard Biesheuvel
2018-12-21 19:57 ` Edgecombe, Rick P
2018-12-22 11:12 ` Ard Biesheuvel
2018-12-12 0:03 ` [PATCH v2 2/4] modules: Add new special vfree flags Rick Edgecombe
2018-12-12 23:40 ` Nadav Amit
2018-12-13 19:02 ` Edgecombe, Rick P
2018-12-13 19:27 ` Nadav Amit
2018-12-13 21:48 ` Edgecombe, Rick P
2018-12-12 0:03 ` [PATCH v2 3/4] bpf: switch to new vmalloc " Rick Edgecombe
2018-12-12 0:03 ` [PATCH v2 4/4] x86/vmalloc: Add TLB efficient x86 arch_vunmap Rick Edgecombe
2018-12-12 2:24 ` Andy Lutomirski
2018-12-12 19:51 ` Edgecombe, Rick P
2018-12-12 6:30 ` Nadav Amit [this message]
2018-12-12 21:05 ` Edgecombe, Rick P
2018-12-12 21:16 ` Nadav Amit
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