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  1. 27 3月, 2017 1 次提交
  3. 30 1月, 2017 1 次提交
    • J
      x86/mm/cpa: Avoid wbinvd() for PREEMPT · 459fbe00
      由 John Ogness 提交于 
      Although wbinvd() is faster than flushing many individual pages, it blocks
the memory bus for "long" periods of time (>100us), thus directly causing
unusually large latencies on all CPUs, regardless of any CPU isolation
features that may be active. This is an unpriviledged operatation as it is
exposed to user space via the graphics subsystem.

For 1024 pages, flushing those pages individually can take up to 2200us,
but the task remains fully preemptible during that time.
Signed-off-by: NJohn Ogness <john.ogness@linutronix.de>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: linux-rt-users <linux-rt-users@vger.kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      459fbe00
  5. 25 12月, 2016 1 次提交
  7. 20 9月, 2016 1 次提交
    • M
      x86/mm/pat: Prevent hang during boot when mapping pages · e535ec08
      由 Matt Fleming 提交于 
      There's a mixture of signed 32-bit and unsigned 32-bit and 64-bit data
types used for keeping track of how many pages have been mapped.

This leads to hangs during boot when mapping large numbers of pages
(multiple terabytes, as reported by Waiman) because those values are
interpreted as being negative.

commit 74256377 ("x86/mm/pat: Avoid truncation when converting
cpa->numpages to address") fixed one of those bugs, but there is
another lurking in __change_page_attr_set_clr().

Additionally, the return value type for the populate_*() functions can
return negative values when a large number of pages have been mapped,
triggering the error paths even though no error occurred.

Consistently use 64-bit types on 64-bit platforms when counting pages.
Even in the signed case this gives us room for regions 8PiB
(pebibytes) in size whilst still allowing the usual negative value
error checking idiom.
Reported-by: NWaiman Long <waiman.long@hpe.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
CC: Theodore Ts'o <tytso@mit.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Scott J Norton <scott.norton@hpe.com>
Cc: Douglas Hatch <doug.hatch@hpe.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
      e535ec08
  9. 24 7月, 2016 2 次提交
    • A
      x86/mm/cpa: Add missing comment in populate_pdg() · 55920d31
      由 Andy Lutomirski 提交于 
      In commit:

  21cbc2822aa1 ("x86/mm/cpa: Unbreak populate_pgd(): stop trying to deallocate failed PUDs")

I intended to add this comment, but I failed at using git.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/242baf8612394f4e31216f96d13c4d2e9b90d1b7.1469293159.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      55920d31
    • A
      x86/mm/cpa: Fix populate_pgd(): Stop trying to deallocate failed PUDs · 530dd8d4
      由 Andy Lutomirski 提交于 
      Valdis Kletnieks bisected a boot failure back to this recent commit:

  360cb4d1 ("x86/mm/cpa: In populate_pgd(), don't set the PGD entry until it's populated")

I broke the case where a PUD table got allocated -- populate_pud()
would wander off a pgd_none entry and get lost.  I'm not sure how
this survived my testing.

Fix the original issue in a much simpler way.  The problem
was that, if we allocated a PUD table, failed to populate it, and
freed it, another CPU could potentially keep using the PGD entry we
installed (either by copying it via vmalloc_fault or by speculatively
caching it).  There's a straightforward fix: simply leave the
top-level entry in place if this happens.  This can't waste any
significant amount of memory -- there are at most 256 entries like
this systemwide and, as a practical matter, if we hit this failure
path repeatedly, we're likely to reuse the same page anyway.

For context, this is a reversion with this hunk added in:

	if (ret < 0) {
+		/*
+		 * Leave the PUD page in place in case some other CPU or thread
+		 * already found it, but remove any useless entries we just
+		 * added to it.
+		 */
-		unmap_pgd_range(cpa->pgd, addr,
+		unmap_pud_range(pgd_entry, addr,
			        addr + (cpa->numpages << PAGE_SHIFT));
		return ret;
	}

This effectively open-codes what the now-deleted unmap_pgd_range()
function used to do except that unmap_pgd_range() used to try to
free the page as well.
Reported-by: NValdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Mike Krinkin <krinkin.m.u@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Link: http://lkml.kernel.org/r/21cbc2822aa18aa812c0215f4231dbf5f65afa7f.1469249789.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      530dd8d4
  11. 15 7月, 2016 2 次提交
  13. 13 7月, 2016 1 次提交
    • D
      x86/mm: Use pte_none() to test for empty PTE · dcb32d99
      由 Dave Hansen 提交于 
      The page table manipulation code seems to have grown a couple of
sites that are looking for empty PTEs.  Just in case one of these
entries got a stray bit set, use pte_none() instead of checking
for a zero pte_val().

The use pte_same() makes me a bit nervous.  If we were doing a
pte_same() check against two cleared entries and one of them had
a stray bit set, it might fail the pte_same() check.  But, I
don't think we ever _do_ pte_same() for cleared entries.  It is
almost entirely used for checking for races in fault-in paths.
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: dave.hansen@intel.com
Cc: linux-mm@kvack.org
Cc: mhocko@suse.com
Link: http://lkml.kernel.org/r/20160708001915.813703D9@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      dcb32d99
  15. 10 7月, 2016 1 次提交
    • T
      x86/mm: Do not reference phys addr beyond kernel · 4ff53087
      由 Thomas Garnier 提交于 
      The new physical address randomized KASLR implementation can cause the
kernel to be aligned close to the end of physical memory. In this case,
_brk_end aligned to PMD will go beyond what is expected safe and hit
the assert in __phys_addr_symbol():

	VIRTUAL_BUG_ON(y >= KERNEL_IMAGE_SIZE);

Instead, perform an inclusive range check to avoid incorrectly triggering
the assert:

	kernel BUG at arch/x86/mm/physaddr.c:38!
	invalid opcode: 0000 [#1] SMP
	...
	RIP: 0010:[<ffffffffbe055721>] __phys_addr_symbol+0x41/0x50
	...
	Call Trace:
	[<ffffffffbe052eb9>] cpa_process_alias+0xa9/0x210
	[<ffffffffbe109011>] ? do_raw_spin_unlock+0xc1/0x100
	[<ffffffffbe051eef>] __change_page_attr_set_clr+0x8cf/0xbd0
	[<ffffffffbe201a4d>] ? vm_unmap_aliases+0x7d/0x210
	[<ffffffffbe05237c>] change_page_attr_set_clr+0x18c/0x4e0
	[<ffffffffbe0534ec>] set_memory_4k+0x2c/0x40
	[<ffffffffbefb08b3>] check_bugs+0x28/0x2a
	[<ffffffffbefa4f52>] start_kernel+0x49d/0x4b9
	[<ffffffffbefa4120>] ? early_idt_handler_array+0x120/0x120
	[<ffffffffbefa4423>] x86_64_start_reservations+0x29/0x2b
	[<ffffffffbefa4568>] x86_64_start_kernel+0x143/0x152
Signed-off-by: NThomas Garnier <thgarnie@google.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Link: http://lkml.kernel.org/r/20160615190545.GA26071@www.outflux.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      4ff53087
  17. 28 4月, 2016 1 次提交
  19. 31 3月, 2016 2 次提交
  21. 16 3月, 2016 2 次提交
  23. 26 2月, 2016 1 次提交
  25. 25 2月, 2016 1 次提交
    • J
      x86/mm: Avoid premature success when changing page attributes · 405e1133
      由 Jan Beulich 提交于 
      set_memory_nx() (and set_memory_x()) currently differ in behavior from
all other set_memory_*() functions when encountering a virtual address
space hole within the kernel address range: They stop processing at the
hole, but nevertheless report success (making the caller believe the
operation was carried out on the entire range). While observed to be a
problem - triggering the CONFIG_DEBUG_WX warning - only with out of
tree code, I suspect (but didn't check) that on x86-64 the
CONFIG_DEBUG_PAGEALLOC logic in free_init_pages() would, when called
from free_initmem(), have the same effect on the set_memory_nx() called
from mark_rodata_ro().

This unexpected behavior is a result of change_page_attr_set_clr()
special casing changes to only the NX bit, in that it passes "false" as
the "checkalias" argument to __change_page_attr_set_clr(). Since this
flag becomes the "primary" argument of both __change_page_attr() and
__cpa_process_fault(), the latter would so far return success without
adjusting cpa->numpages. Success to the higher level callers, however,
means that whatever cpa->numpages currently holds is the count of
successfully processed pages. The cases when __change_page_attr() calls
__cpa_process_fault(), otoh, don't generally mean the entire range got
processed (as can be seen from one of the two success return paths in
__cpa_process_fault() already adjusting ->numpages).
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/56BB0AD402000078000D05BF@prv-mh.provo.novell.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      405e1133
  27. 22 2月, 2016 3 次提交
    • K
      x86/mm: Always enable CONFIG_DEBUG_RODATA and remove the Kconfig option · 9ccaf77c
      由 Kees Cook 提交于 
      This removes the CONFIG_DEBUG_RODATA option and makes it always enabled.

This simplifies the code and also makes it clearer that read-only mapped
memory is just as fundamental a security feature in kernel-space as it is
in user-space.
Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Brown <david.brown@linaro.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Cc: linux-arch <linux-arch@vger.kernel.org>
Link: http://lkml.kernel.org/r/1455748879-21872-4-git-send-email-keescook@chromium.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      9ccaf77c
    • S
      x86/mm/pat: Don't implicitly allow _PAGE_RW in kernel_map_pages_in_pgd() · 15f003d2
      由 Sai Praneeth 提交于 
      As part of the preparation for the EFI_MEMORY_RO flag added in the UEFI
2.5 specification, we need the ability to map pages in kernel page
tables without _PAGE_RW being set.

Modify kernel_map_pages_in_pgd() to require its callers to pass _PAGE_RW
if the pages need to be mapped read/write. Otherwise, we'll map the
pages as read-only.
Signed-off-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Lee, Chun-Yi <jlee@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1455712566-16727-12-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
      15f003d2
    • S
      x86/mm/pat: Use _PAGE_GLOBAL bit for EFI page table mappings · 39763015
      由 Sai Praneeth 提交于 
      Since EFI page tables can be treated as kernel page tables they should
be global. All the other page mapping functions in pageattr.c set the
_PAGE_GLOBAL bit and we want to avoid inconsistencies when we map a page
in the EFI code paths, for example when that page is split in
__split_large_page(), etc. It also makes it easier to validate that the
EFI region mappings have the correct attributes because there are fewer
differences compared with regular kernel mappings.
Signed-off-by: NSai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1455712566-16727-4-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
      39763015
  29. 29 1月, 2016 1 次提交
    • M
      x86/mm/pat: Avoid truncation when converting cpa->numpages to address · 74256377
      由 Matt Fleming 提交于 
      There are a couple of nasty truncation bugs lurking in the pageattr
code that can be triggered when mapping EFI regions, e.g. when we pass
a cpa->pgd pointer. Because cpa->numpages is a 32-bit value, shifting
left by PAGE_SHIFT will truncate the resultant address to 32-bits.

Viorel-Cătălin managed to trigger this bug on his Dell machine that
provides a ~5GB EFI region which requires 1236992 pages to be mapped.
When calling populate_pud() the end of the region gets calculated
incorrectly in the following buggy expression,

  end = start + (cpa->numpages << PAGE_SHIFT);

And only 188416 pages are mapped. Next, populate_pud() gets invoked
for a second time because of the loop in __change_page_attr_set_clr(),
only this time no pages get mapped because shifting the remaining
number of pages (1048576) by PAGE_SHIFT is zero. At which point the
loop in __change_page_attr_set_clr() spins forever because we fail to
map progress.

Hitting this bug depends very much on the virtual address we pick to
map the large region at and how many pages we map on the initial run
through the loop. This explains why this issue was only recently hit
with the introduction of commit

  a5caa209 ("x86/efi: Fix boot crash by mapping EFI memmap
   entries bottom-up at runtime, instead of top-down")

It's interesting to note that safe uses of cpa->numpages do exist in
the pageattr code. If instead of shifting ->numpages we multiply by
PAGE_SIZE, no truncation occurs because PAGE_SIZE is a UL value, and
so the result is unsigned long.

To avoid surprises when users try to convert very large cpa->numpages
values to addresses, change the data type from 'int' to 'unsigned
long', thereby making it suitable for shifting by PAGE_SHIFT without
any type casting.

The alternative would be to make liberal use of casting, but that is
far more likely to cause problems in the future when someone adds more
code and fails to cast properly; this bug was difficult enough to
track down in the first place.
Reported-and-tested-by: NViorel-Cătălin Răpițeanu <rapiteanu.catalin@gmail.com>
Acked-by: NBorislav Petkov <bp@alien8.de>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=110131
Link: http://lkml.kernel.org/r/1454067370-10374-1-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      74256377
  31. 12 1月, 2016 1 次提交
    • D
      x86/mm/pat: Make split_page_count() check for empty levels to fix /proc/meminfo output · c9e0d391
      由 Dave Jones 提交于 
      In CONFIG_PAGEALLOC_DEBUG=y builds, we disable 2M pages.

Unfortunatly when we split up mappings during boot,
split_page_count() doesn't take this into account, and
starts decrementing an empty direct_pages_count[] level.

This results in /proc/meminfo showing crazy things like:

  DirectMap2M:    18446744073709543424 kB
Signed-off-by: NDave Jones <davej@codemonkey.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      c9e0d391
  33. 09 1月, 2016 1 次提交
  35. 29 11月, 2015 1 次提交
    • M
      x86/mm/pat: Ensure cpa->pfn only contains page frame numbers · edc3b912
      由 Matt Fleming 提交于 
      The x86 pageattr code is confused about the data that is stored
in cpa->pfn, sometimes it's treated as a page frame number,
sometimes it's treated as an unshifted physical address, and in
one place it's treated as a pte.

The result of this is that the mapping functions do not map the
intended physical address.

This isn't a problem in practice because most of the addresses
we're mapping in the EFI code paths are already mapped in
'trampoline_pgd' and so the pageattr mapping functions don't
actually do anything in this case. But when we move to using a
separate page table for the EFI runtime this will be an issue.
Signed-off-by: NMatt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: NBorislav Petkov <bp@suse.de>
Acked-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1448658575-17029-3-git-send-email-matt@codeblueprint.co.ukSigned-off-by: NIngo Molnar <mingo@kernel.org>
      edc3b912
  37. 25 10月, 2015 1 次提交
  39. 23 9月, 2015 4 次提交
  41. 25 8月, 2015 1 次提交
  43. 07 6月, 2015 2 次提交
    • T
      x86/mm/pat: Add set_memory_wt() for Write-Through type · 623dffb2
      由 Toshi Kani 提交于 
      Now that reserve_ram_pages_type() accepts the WT type, add
set_memory_wt(), set_memory_array_wt() and set_pages_array_wt()
in order to be able to set memory to Write-Through page cache
mode.

Also, extend ioremap_change_attr() to accept the WT type.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: hch@lst.de
Cc: hmh@hmh.eng.br
Cc: jgross@suse.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: linux-nvdimm@lists.01.org
Cc: stefan.bader@canonical.com
Cc: yigal@plexistor.com
Link: http://lkml.kernel.org/r/1433436928-31903-13-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      623dffb2
    • B
      x86/mm/pat: Remove pat_enabled() checks · 7202fdb1
      由 Borislav Petkov 提交于 
      Now that we emulate a PAT table when PAT is disabled, there's no
need for those checks anymore as the PAT abstraction will handle
those cases too.

Based on a conglomerate patch from Toshi Kani.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reviewed-by: NToshi Kani <toshi.kani@hp.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: hch@lst.de
Cc: hmh@hmh.eng.br
Cc: jgross@suse.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: linux-nvdimm@lists.01.org
Cc: stefan.bader@canonical.com
Cc: yigal@plexistor.com
Link: http://lkml.kernel.org/r/1433436928-31903-4-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      7202fdb1
  45. 03 6月, 2015 1 次提交
    • S
      x86/mm: Decouple <linux/vmalloc.h> from <asm/io.h> · d6472302
      由 Stephen Rothwell 提交于 
      Nothing in <asm/io.h> uses anything from <linux/vmalloc.h>, so
remove it from there and fix up the resulting build problems
triggered on x86 {64|32}-bit {def|allmod|allno}configs.

The breakages were triggering in places where x86 builds relied
on vmalloc() facilities but did not include <linux/vmalloc.h>
explicitly and relied on the implicit inclusion via <asm/io.h>.

Also add:

  - <linux/init.h> to <linux/io.h>
  - <asm/pgtable_types> to <asm/io.h>

... which were two other implicit header file dependencies.
Suggested-by: NDavid Miller <davem@davemloft.net>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
[ Tidied up the changelog. ]
Acked-by: NDavid Miller <davem@davemloft.net>
Acked-by: NTakashi Iwai <tiwai@suse.de>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NVinod Koul <vinod.koul@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Colin Cross <ccross@android.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: James E.J. Bottomley <JBottomley@odin.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Kristen Carlson Accardi <kristen@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Suma Ramars <sramars@cisco.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      d6472302
  47. 27 5月, 2015 1 次提交
    • L
      x86/mm/pat: Wrap pat_enabled into a function API · cb32edf6
      由 Luis R. Rodriguez 提交于 
      We use pat_enabled in x86-specific code to see if PAT is enabled
or not but we're granting full access to it even though readers
do not need to set it. If, for instance, we granted access to it
to modules later they then could override the variable
setting... no bueno.

This renames pat_enabled to a new static variable __pat_enabled.
Folks are redirected to use pat_enabled() now.

Code that sets this can only be internal to pat.c. Apart from
the early kernel parameter "nopat" to disable PAT, we also have
a few cases that disable it later and make use of a helper
pat_disable(). It is wrapped under an ifdef but since that code
cannot run unless PAT was enabled its not required to wrap it
with ifdefs, unwrap that. Likewise, since "nopat" doesn't really
change non-PAT systems just remove that ifdef as well.

Although we could add and use an early_param_off(), these
helpers don't use __read_mostly but we want to keep
__read_mostly for __pat_enabled as this is a hot path -- upon
boot, for instance, a simple guest may see ~4k accesses to
pat_enabled(). Since __read_mostly early boot params are not
that common we don't add a helper for them just yet.
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Walls <awalls@md.metrocast.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kyle McMartin <kyle@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1430425520-22275-3-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1432628901-18044-13-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      cb32edf6
  49. 11 5月, 2015 3 次提交
    • D
      x86/mm/pageattr: Remove an unused variable in slow_virt_to_phys() · 1fcb61c5
      由 Dexuan Cui 提交于 
      The patch doesn't change any logic.
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1429776428-4475-1-git-send-email-decui@microsoft.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1fcb61c5
    • L
      x86/mm: Add ioremap_uc() helper to map memory uncacheable (not UC-) · e4b6be33
      由 Luis R. Rodriguez 提交于 
      ioremap_nocache() currently uses UC- by default. Our goal is to
eventually make UC the default. Linux maps UC- to PCD=1, PWT=0
page attributes on non-PAT systems. Linux maps UC to PCD=1,
PWT=1 page attributes on non-PAT systems. On non-PAT and PAT
systems a WC MTRR has different effects on pages with either of
these attributes. In order to help with a smooth transition its
best to enable use of UC (PCD,1, PWT=1) on a region as that
ensures a WC MTRR will have no effect on a region, this however
requires us to have an way to declare a region as UC and we
currently do not have a way to do this.

  WC MTRR on non-PAT system with PCD=1, PWT=0 (UC-) yields WC.
  WC MTRR on non-PAT system with PCD=1, PWT=1 (UC)  yields UC.

  WC MTRR on PAT system with PCD=1, PWT=0 (UC-) yields WC.
  WC MTRR on PAT system with PCD=1, PWT=1 (UC)  yields UC.

A flip of the default ioremap_nocache() behaviour from UC- to UC
can therefore regress a memory region from effective memory type
WC to UC if MTRRs are used. Use of MTRRs should be phased out
and in the best case only arch_phys_wc_add() use will remain,
even if this happens arch_phys_wc_add() will have an effect on
non-PAT systems and changes to default ioremap_nocache()
behaviour could regress drivers.

Now, ideally we'd use ioremap_nocache() on the regions in which
we'd need uncachable memory types and avoid any MTRRs on those
regions. There are however some restrictions on MTRRs use, such
as the requirement of having the base and size of variable sized
MTRRs to be powers of two, which could mean having to use a WC
MTRR over a large area which includes a region in which
write-combining effects are undesirable.

Add ioremap_uc() to help with the both phasing out of MTRR use
and also provide a way to blacklist small WC undesirable regions
in devices with mixed regions which are size-implicated to use
large WC MTRRs. Use of ioremap_uc() helps phase out MTRR use by
avoiding regressions with an eventual flip of default behaviour
or ioremap_nocache() from UC- to UC.

Drivers working with WC MTRRs can use the below table to review
and consider the use of ioremap*() and similar helpers to ensure
appropriate behaviour long term even if default
ioremap_nocache() behaviour changes from UC- to UC.

Although ioremap_uc() is being added we leave set_memory_uc() to
use UC- as only initial memory type setup is required to be able
to accommodate existing device drivers and phase out MTRR use.
It should also be clarified that set_memory_uc() cannot be used
with IO memory, even though its use will not return any errors,
it really has no effect.

  ----------------------------------------------------------------------
  MTRR Non-PAT   PAT    Linux ioremap value        Effective memory type
  ----------------------------------------------------------------------
                                                    Non-PAT |  PAT
       PAT
       |PCD
       ||PWT
       |||
  WC   000      WB      _PAGE_CACHE_MODE_WB            WC   |   WC
  WC   001      WC      _PAGE_CACHE_MODE_WC            WC*  |   WC
  WC   010      UC-     _PAGE_CACHE_MODE_UC_MINUS      WC*  |   WC
  WC   011      UC      _PAGE_CACHE_MODE_UC            UC   |   UC
  ----------------------------------------------------------------------
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Mike Travis <travis@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-fbdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1430343851-967-2-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1431332153-18566-9-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      e4b6be33
    • R
      x86/mm: Do not flush last cacheline twice in clflush_cache_range() · 6c434d61
      由 Ross Zwisler 提交于 
      The current algorithm used in clflush_cache_range() can cause
the last cache line of the buffer to be flushed twice. Fix that
algorithm so that each cache line will only be flushed once.
Reported-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Link: http://lkml.kernel.org/r/1430259192-18802-1-git-send-email-ross.zwisler@linux.intel.com
Link: http://lkml.kernel.org/r/1431332153-18566-5-git-send-email-bp@alien8.de
[ Changed it to 'void *' to simplify the type conversions. ]
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      6c434d61
  51. 05 3月, 2015 1 次提交
    • L
      x86/mm: Simplify enabling direct_gbpages · e5008abe
      由 Luis R. Rodriguez 提交于 
      direct_gbpages can be force enabled as an early parameter
but not really have taken effect when DEBUG_PAGEALLOC
or KMEMCHECK is enabled. You can also enable direct_gbpages
right now if you have an x86_64 architecture but your CPU
doesn't really have support for this feature. In both cases
PG_LEVEL_1G won't actually be enabled but direct_gbpages is used
in other areas under the assumptions that PG_LEVEL_1G
was set. Fix this by putting together all requirements
which make this feature sensible to enable under, and only
enable both finally flipping on PG_LEVEL_1G and leaving
PG_LEVEL_1G set when this is true.

We only enable this feature then to be possible on sensible
builds defined by the new ENABLE_DIRECT_GBPAGES. If the
CPU has support for it you can either enable this by using
the DIRECT_GBPAGES option or using the early kernel parameter.
If a platform had support for this you can always force disable
it as well.
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: JBeulich@suse.com
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: julia.lawall@lip6.fr
Link: http://lkml.kernel.org/r/1425518654-3403-3-git-send-email-mcgrof@do-not-panic.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      e5008abe
  53. 28 2月, 2015 1 次提交
  55. 14 12月, 2014 1 次提交
    • J
      mm/debug-pagealloc: make debug-pagealloc boottime configurable · 031bc574
      由 Joonsoo Kim 提交于 
      Now, we have prepared to avoid using debug-pagealloc in boottime.  So
introduce new kernel-parameter to disable debug-pagealloc in boottime, and
makes related functions to be disabled in this case.

Only non-intuitive part is change of guard page functions.  Because guard
page is effective only if debug-pagealloc is enabled, turning off
according to debug-pagealloc is reasonable thing to do.
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dave Hansen <dave@sr71.net>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Jungsoo Son <jungsoo.son@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      031bc574