LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
To: "rppt@kernel.org" <rppt@kernel.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"peterz@infradead.org" <peterz@infradead.org>,
	"keescook@chromium.org" <keescook@chromium.org>,
	"Weiny, Ira" <ira.weiny@intel.com>,
	"linux-hardening@vger.kernel.org"
	<linux-hardening@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"vbabka@suse.cz" <vbabka@suse.cz>,
	"x86@kernel.org" <x86@kernel.org>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"Williams, Dan J" <dan.j.williams@intel.com>,
	"Lutomirski, Andy" <luto@kernel.org>,
	"kernel-hardening@lists.openwall.com" 
	<kernel-hardening@lists.openwall.com>,
	"Hansen, Dave" <dave.hansen@intel.com>,
	"shakeelb@google.com" <shakeelb@google.com>
Subject: Re: [RFC PATCH v2 05/19] x86, mm: Use cache of page tables
Date: Tue, 31 Aug 2021 19:09:19 +0000	[thread overview]
Message-ID: <d7e9e00b2cdab115fa9d6bc83549d6f37b3bf043.camel@intel.com> (raw)
In-Reply-To: <YS3q4Q+ybxweHoLK@kernel.org>

On Tue, 2021-08-31 at 11:40 +0300, Mike Rapoport wrote:
> On Mon, Aug 30, 2021 at 04:59:13PM -0700, Rick Edgecombe wrote:
<trim>
> > 
> > diff --git a/arch/x86/include/asm/pgalloc.h
> > b/arch/x86/include/asm/pgalloc.h
> > index c7ec5bb88334..1ff308ea76cd 100644
> > --- a/arch/x86/include/asm/pgalloc.h
> > +++ b/arch/x86/include/asm/pgalloc.h
> > @@ -7,6 +7,10 @@
> >  #include <linux/pagemap.h>
> >  
> >  #define __HAVE_ARCH_PTE_ALLOC_ONE
> > +#ifdef CONFIG_PKS_PG_TABLES
> > +#define __HAVE_ARCH_FREE_TABLE
> > +#define __HAVE_ARCH_ALLOC_TABLE
> 
> I think one define would suffice. If we'd ever have an architecture
> that
> can implement only one of those, we update the ifdefery in
> asm-generic/pgalloc.h
> 
Good point, I'll change it.

> > +#endif
> >  #define __HAVE_ARCH_PGD_FREE
> >  #include <asm-generic/pgalloc.h>
> >  
> > @@ -162,7 +166,7 @@ static inline void p4d_free(struct mm_struct
> > *mm, p4d_t *p4d)
> >  		return;
> >  
> >  	BUG_ON((unsigned long)p4d & (PAGE_SIZE-1));
> > -	free_page((unsigned long)p4d);
> > +	free_table(virt_to_page(p4d));
> >  }
> >  
> >  extern void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d);
> 
> ...
> 
> > diff --git a/include/asm-generic/pgalloc.h b/include/asm-
> > generic/pgalloc.h
> > index 02932efad3ab..e576c19abc8c 100644
> > --- a/include/asm-generic/pgalloc.h
> > +++ b/include/asm-generic/pgalloc.h
> > @@ -2,11 +2,26 @@
> >  #ifndef __ASM_GENERIC_PGALLOC_H
> >  #define __ASM_GENERIC_PGALLOC_H
> >  
> > +#include <linux/mm.h>
> > +
> 
> Why is this required?
> 
> >  #ifdef CONFIG_MMU
> >  
> >  #define GFP_PGTABLE_KERNEL	(GFP_KERNEL | __GFP_ZERO)
> >  #define GFP_PGTABLE_USER	(GFP_PGTABLE_KERNEL | __GFP_ACCOUNT)
> >  
> > +#ifndef __HAVE_ARCH_ALLOC_TABLE
> > +static inline struct page *alloc_table(gfp_t gfp)
> > +{
> > +	return alloc_page(gfp);
> > +}
> > +#else /* __HAVE_ARCH_ALLOC_TABLE */
> > +extern struct page *alloc_table(gfp_t gfp);
> > +#endif /* __HAVE_ARCH_ALLOC_TABLE */
> > +
> > +#ifdef __HAVE_ARCH_FREE_TABLE
> > +extern void free_table(struct page *);
> > +#endif /* __HAVE_ARCH_FREE_TABLE */
> > +
> >  /**
> >   * __pte_alloc_one_kernel - allocate a page for PTE-level kernel
> > page table
> >   * @mm: the mm_struct of the current context
> 
> ...
> 
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index c13c7af7cad3..ab63d5a201cb 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -2327,6 +2327,13 @@ static inline bool ptlock_init(struct page
> > *page) { return true; }
> >  static inline void ptlock_free(struct page *page) {}
> >  #endif /* USE_SPLIT_PTE_PTLOCKS */
> >  
> > +#ifndef CONFIG_PKS_PG_TABLES
> > +static inline void free_table(struct page *table_page)
> > +{
> > +	__free_pages(table_page, 0);
> > +}
> > +#endif /* CONFIG_PKS_PG_TABLES */
> > +
> 
> Can't this live in asm-generic/pgalloc.h?
> Then you won't need to include linux/mm.h there.
Some architectures couldn't find it in asm-generic/pgalloc.h. There is
some other page table stuff in linux/mm.h so didn't seem too strange.

> 
> >  static inline void pgtable_init(void)
> >  {
> >  	ptlock_cache_init();
> > @@ -2337,7 +2344,6 @@ static inline bool
> > pgtable_pte_page_ctor(struct page *page)
> >  {
> >  	if (!ptlock_init(page))
> >  		return false;
> > -	__SetPageTable(page);
> 
> This change is only valid when __HAVE_ARCH_ALLOC_TABLE is set.
Argh, thanks. Overall solution should still work I think. I'll rework
it to support both.

> 
> >  	inc_lruvec_page_state(page, NR_PAGETABLE);
> >  	return true;
> >  }
> > @@ -2345,7 +2351,6 @@ static inline bool
> > pgtable_pte_page_ctor(struct page *page)
> >  static inline void pgtable_pte_page_dtor(struct page *page)
> >  {
> >  	ptlock_free(page);
> > -	__ClearPageTable(page);
> >  	dec_lruvec_page_state(page, NR_PAGETABLE);
> >  }
> >  
> 
> 

  reply	other threads:[~2021-08-31 19:09 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-30 23:59 [RFC PATCH v2 00/19] PKS write protected " Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 01/19] list: Support getting most recent element in list_lru Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 02/19] list: Support list head not in object for list_lru Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 03/19] x86/mm/cpa: Add grouped page allocations Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 04/19] mm: Explicitly zero page table lock ptr Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 05/19] x86, mm: Use cache of page tables Rick Edgecombe
2021-08-31  8:40   ` Mike Rapoport
2021-08-31 19:09     ` Edgecombe, Rick P [this message]
2021-08-30 23:59 ` [RFC PATCH v2 06/19] x86/mm/cpa: Add perm callbacks to grouped pages Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 07/19] x86/cpufeatures: Add feature for pks tables Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 08/19] x86/mm/cpa: Add get_grouped_page_atomic() Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 09/19] x86/mm: Support GFP_ATOMIC in alloc_table_node() Rick Edgecombe
2021-08-31  8:32   ` Mike Rapoport
2021-08-30 23:59 ` [RFC PATCH v2 10/19] x86/mm: Use alloc_table() for fill_pte(), etc Rick Edgecombe
2021-08-31  8:47   ` Mike Rapoport
2021-08-31 18:48     ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 11/19] mm/sparsemem: Use alloc_table() for table allocations Rick Edgecombe
2021-08-31  8:55   ` Mike Rapoport
2021-08-31 18:25     ` Edgecombe, Rick P
2021-09-01  7:22       ` Mike Rapoport
2021-09-02 13:56         ` Vlastimil Babka
2021-08-30 23:59 ` [RFC PATCH v2 12/19] x86/mm: Use free_table in unmap path Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 13/19] mm/debug_vm_page_table: Use setters instead of WRITE_ONCE Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 14/19] x86/efi: Toggle table protections when copying Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 15/19] x86/mm/cpa: Add set_memory_pks() Rick Edgecombe
2021-08-30 23:59 ` [RFC PATCH v2 16/19] x86/mm: Protect page tables with PKS Rick Edgecombe
2021-08-31  8:56   ` Mike Rapoport
2021-08-31 17:55     ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 17/19] x86/mm/cpa: PKS protect direct map page tables Rick Edgecombe
2021-08-31 10:14   ` Mike Rapoport
2021-08-31 17:58     ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 18/19] x86/mm: Add PKS table soft mode Rick Edgecombe
2021-08-31  3:49   ` Randy Dunlap
2021-08-31 17:55     ` Edgecombe, Rick P
2021-08-30 23:59 ` [RFC PATCH v2 19/19] x86/mm: Add PKS table debug checking Rick Edgecombe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=d7e9e00b2cdab115fa9d6bc83549d6f37b3bf043.camel@intel.com \
    --to=rick.p.edgecombe@intel.com \
    --cc=akpm@linux-foundation.org \
    --cc=dan.j.williams@intel.com \
    --cc=dave.hansen@intel.com \
    --cc=ira.weiny@intel.com \
    --cc=keescook@chromium.org \
    --cc=kernel-hardening@lists.openwall.com \
    --cc=linux-hardening@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=luto@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rppt@kernel.org \
    --cc=shakeelb@google.com \
    --cc=vbabka@suse.cz \
    --cc=x86@kernel.org \
    --subject='Re: [RFC PATCH v2 05/19] x86, mm: Use cache of page tables' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).