From: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
To: "shakeelb@google.com" <shakeelb@google.com>
Cc: "kernel-hardening@lists.openwall.com"
<kernel-hardening@lists.openwall.com>,
"luto@kernel.org" <luto@kernel.org>,
"Hansen, Dave" <dave.hansen@intel.com>,
"x86@kernel.org" <x86@kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"peterz@infradead.org" <peterz@infradead.org>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"rppt@kernel.org" <rppt@kernel.org>,
"linux-hardening@vger.kernel.org"
<linux-hardening@vger.kernel.org>,
"Weiny, Ira" <ira.weiny@intel.com>,
"Williams, Dan J" <dan.j.williams@intel.com>
Subject: Re: [PATCH RFC 5/9] x86, mm: Use cache of page tables
Date: Fri, 7 May 2021 16:27:27 +0000 [thread overview]
Message-ID: <588d4b82a6cb47383e73e5d375b2b1766b4d3511.camel@intel.com> (raw)
In-Reply-To: <CALvZod7ieLEObX0y-7X+_zMwaVN5o0P-ZwZVLqCAK5ytQrNs9w@mail.gmail.com>
On Thu, 2021-05-06 at 11:24 -0700, Shakeel Butt wrote:
> On Tue, May 4, 2021 at 5:36 PM Rick Edgecombe
> <rick.p.edgecombe@intel.com> wrote:
> >
> [...]
> > +#ifdef CONFIG_PKS_PG_TABLES
> > +struct page *alloc_table(gfp_t gfp)
> > +{
> > + struct page *table;
> > +
> > + if (!pks_page_en)
> > + return alloc_page(gfp);
> > +
> > + table = get_grouped_page(numa_node_id(), &gpc_pks);
> > + if (!table)
> > + return NULL;
> > +
> > + if (gfp & __GFP_ZERO)
> > + memset(page_address(table), 0, PAGE_SIZE);
> > +
> > + if (memcg_kmem_enabled() &&
> > + gfp & __GFP_ACCOUNT &&
> > + !__memcg_kmem_charge_page(table, gfp, 0)) {
> > + free_table(table);
> > + table = NULL;
> > + }
> > +
> > + VM_BUG_ON_PAGE(*(unsigned long *)&table->ptl, table);
>
> table can be NULL due to charge failure.
Argh, yes. Thank you. I'll remove the VM_BUG_ON, it was left
accidentally.
next prev parent reply other threads:[~2021-05-07 16:27 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-05 0:30 [PATCH RFC 0/9] PKS write protected page tables Rick Edgecombe
2021-05-05 0:30 ` [PATCH RFC 1/9] list: Support getting most recent element in list_lru Rick Edgecombe
2021-05-05 0:30 ` [PATCH RFC 2/9] list: Support list head not in object for list_lru Rick Edgecombe
2021-05-05 0:30 ` [PATCH RFC 3/9] x86/mm/cpa: Add grouped page allocations Rick Edgecombe
2021-05-05 12:08 ` Mike Rapoport
2021-05-05 13:09 ` Peter Zijlstra
2021-05-05 18:45 ` Mike Rapoport
2021-05-05 21:57 ` Edgecombe, Rick P
2021-05-09 9:39 ` Mike Rapoport
2021-05-10 19:38 ` Edgecombe, Rick P
2021-05-05 0:30 ` [PATCH RFC 4/9] mm: Explicitly zero page table lock ptr Rick Edgecombe
2021-05-05 0:30 ` [PATCH RFC 5/9] x86, mm: Use cache of page tables Rick Edgecombe
2021-05-05 8:51 ` Peter Zijlstra
2021-05-05 12:09 ` Mike Rapoport
2021-05-05 13:19 ` Peter Zijlstra
2021-05-05 21:54 ` Edgecombe, Rick P
2021-05-06 17:59 ` Matthew Wilcox
2021-05-06 18:24 ` Shakeel Butt
2021-05-07 16:27 ` Edgecombe, Rick P [this message]
2021-05-05 0:30 ` [PATCH RFC 6/9] x86/mm/cpa: Add set_memory_pks() Rick Edgecombe
2021-05-05 0:30 ` [PATCH RFC 7/9] x86/mm/cpa: Add perm callbacks to grouped pages Rick Edgecombe
2021-05-05 0:30 ` [PATCH RFC 8/9] x86, mm: Protect page tables with PKS Rick Edgecombe
2021-05-05 0:30 ` [PATCH RFC 9/9] x86, cpa: PKS protect direct map page tables Rick Edgecombe
2021-05-05 2:03 ` [PATCH RFC 0/9] PKS write protected " Ira Weiny
2021-05-05 6:25 ` Kees Cook
2021-05-05 8:37 ` Peter Zijlstra
2021-05-05 18:38 ` Kees Cook
2021-05-05 19:51 ` Edgecombe, Rick P
2021-05-06 0:00 ` Ira Weiny
2021-05-05 11:08 ` Vlastimil Babka
2021-05-05 11:56 ` Peter Zijlstra
2021-05-05 19:46 ` Edgecombe, Rick P
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