<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/um/include, branch linux-5.0.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>x86/mpx, mm/core: Fix recursive munmap() corruption</title>
<updated>2019-05-25T16:22:14+00:00</updated>
<author>
<name>Dave Hansen</name>
<email>dave.hansen@linux.intel.com</email>
</author>
<published>2019-04-19T19:47:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a816dc52fe7701568578574670865d63f691506f'/>
<id>a816dc52fe7701568578574670865d63f691506f</id>
<content type='text'>
commit 5a28fc94c9143db766d1ba5480cae82d856ad080 upstream.

This is a bit of a mess, to put it mildly.  But, it's a bug
that only seems to have showed up in 4.20 but wasn't noticed
until now, because nobody uses MPX.

MPX has the arch_unmap() hook inside of munmap() because MPX
uses bounds tables that protect other areas of memory.  When
memory is unmapped, there is also a need to unmap the MPX
bounds tables.  Barring this, unused bounds tables can eat 80%
of the address space.

But, the recursive do_munmap() that gets called vi arch_unmap()
wreaks havoc with __do_munmap()'s state.  It can result in
freeing populated page tables, accessing bogus VMA state,
double-freed VMAs and more.

See the "long story" further below for the gory details.

To fix this, call arch_unmap() before __do_unmap() has a chance
to do anything meaningful.  Also, remove the 'vma' argument
and force the MPX code to do its own, independent VMA lookup.

== UML / unicore32 impact ==

Remove unused 'vma' argument to arch_unmap().  No functional
change.

I compile tested this on UML but not unicore32.

== powerpc impact ==

powerpc uses arch_unmap() well to watch for munmap() on the
VDSO and zeroes out 'current-&gt;mm-&gt;context.vdso_base'.  Moving
arch_unmap() makes this happen earlier in __do_munmap().  But,
'vdso_base' seems to only be used in perf and in the signal
delivery that happens near the return to userspace.  I can not
find any likely impact to powerpc, other than the zeroing
happening a little earlier.

powerpc does not use the 'vma' argument and is unaffected by
its removal.

I compile-tested a 64-bit powerpc defconfig.

== x86 impact ==

For the common success case this is functionally identical to
what was there before.  For the munmap() failure case, it's
possible that some MPX tables will be zapped for memory that
continues to be in use.  But, this is an extraordinarily
unlikely scenario and the harm would be that MPX provides no
protection since the bounds table got reset (zeroed).

I can't imagine anyone doing this:

	ptr = mmap();
	// use ptr
	ret = munmap(ptr);
	if (ret)
		// oh, there was an error, I'll
		// keep using ptr.

Because if you're doing munmap(), you are *done* with the
memory.  There's probably no good data in there _anyway_.

This passes the original reproducer from Richard Biener as
well as the existing mpx selftests/.

The long story:

munmap() has a couple of pieces:

 1. Find the affected VMA(s)
 2. Split the start/end one(s) if neceesary
 3. Pull the VMAs out of the rbtree
 4. Actually zap the memory via unmap_region(), including
    freeing page tables (or queueing them to be freed).
 5. Fix up some of the accounting (like fput()) and actually
    free the VMA itself.

This specific ordering was actually introduced by:

  dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap")

during the 4.20 merge window.  The previous __do_munmap() code
was actually safe because the only thing after arch_unmap() was
remove_vma_list().  arch_unmap() could not see 'vma' in the
rbtree because it was detached, so it is not even capable of
doing operations unsafe for remove_vma_list()'s use of 'vma'.

Richard Biener reported a test that shows this in dmesg:

  [1216548.787498] BUG: Bad rss-counter state mm:0000000017ce560b idx:1 val:551
  [1216548.787500] BUG: non-zero pgtables_bytes on freeing mm: 24576

What triggered this was the recursive do_munmap() called via
arch_unmap().  It was freeing page tables that has not been
properly zapped.

But, the problem was bigger than this.  For one, arch_unmap()
can free VMAs.  But, the calling __do_munmap() has variables
that *point* to VMAs and obviously can't handle them just
getting freed while the pointer is still in use.

I tried a couple of things here.  First, I tried to fix the page
table freeing problem in isolation, but I then found the VMA
issue.  I also tried having the MPX code return a flag if it
modified the rbtree which would force __do_munmap() to re-walk
to restart.  That spiralled out of control in complexity pretty
fast.

Just moving arch_unmap() and accepting that the bonkers failure
case might eat some bounds tables seems like the simplest viable
fix.

This was also reported in the following kernel bugzilla entry:

  https://bugzilla.kernel.org/show_bug.cgi?id=203123

There are some reports that this commit triggered this bug:

  dd2283f2605 ("mm: mmap: zap pages with read mmap_sem in munmap")

While that commit certainly made the issues easier to hit, I believe
the fundamental issue has been with us as long as MPX itself, thus
the Fixes: tag below is for one of the original MPX commits.

[ mingo: Minor edits to the changelog and the patch. ]

Reported-by: Richard Biener &lt;rguenther@suse.de&gt;
Reported-by: H.J. Lu &lt;hjl.tools@gmail.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Yang Shi &lt;yang.shi@linux.alibaba.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Guan Xuetao &lt;gxt@pku.edu.cn&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-um@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: stable@vger.kernel.org
Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap")
Link: http://lkml.kernel.org/r/20190419194747.5E1AD6DC@viggo.jf.intel.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5a28fc94c9143db766d1ba5480cae82d856ad080 upstream.

This is a bit of a mess, to put it mildly.  But, it's a bug
that only seems to have showed up in 4.20 but wasn't noticed
until now, because nobody uses MPX.

MPX has the arch_unmap() hook inside of munmap() because MPX
uses bounds tables that protect other areas of memory.  When
memory is unmapped, there is also a need to unmap the MPX
bounds tables.  Barring this, unused bounds tables can eat 80%
of the address space.

But, the recursive do_munmap() that gets called vi arch_unmap()
wreaks havoc with __do_munmap()'s state.  It can result in
freeing populated page tables, accessing bogus VMA state,
double-freed VMAs and more.

See the "long story" further below for the gory details.

To fix this, call arch_unmap() before __do_unmap() has a chance
to do anything meaningful.  Also, remove the 'vma' argument
and force the MPX code to do its own, independent VMA lookup.

== UML / unicore32 impact ==

Remove unused 'vma' argument to arch_unmap().  No functional
change.

I compile tested this on UML but not unicore32.

== powerpc impact ==

powerpc uses arch_unmap() well to watch for munmap() on the
VDSO and zeroes out 'current-&gt;mm-&gt;context.vdso_base'.  Moving
arch_unmap() makes this happen earlier in __do_munmap().  But,
'vdso_base' seems to only be used in perf and in the signal
delivery that happens near the return to userspace.  I can not
find any likely impact to powerpc, other than the zeroing
happening a little earlier.

powerpc does not use the 'vma' argument and is unaffected by
its removal.

I compile-tested a 64-bit powerpc defconfig.

== x86 impact ==

For the common success case this is functionally identical to
what was there before.  For the munmap() failure case, it's
possible that some MPX tables will be zapped for memory that
continues to be in use.  But, this is an extraordinarily
unlikely scenario and the harm would be that MPX provides no
protection since the bounds table got reset (zeroed).

I can't imagine anyone doing this:

	ptr = mmap();
	// use ptr
	ret = munmap(ptr);
	if (ret)
		// oh, there was an error, I'll
		// keep using ptr.

Because if you're doing munmap(), you are *done* with the
memory.  There's probably no good data in there _anyway_.

This passes the original reproducer from Richard Biener as
well as the existing mpx selftests/.

The long story:

munmap() has a couple of pieces:

 1. Find the affected VMA(s)
 2. Split the start/end one(s) if neceesary
 3. Pull the VMAs out of the rbtree
 4. Actually zap the memory via unmap_region(), including
    freeing page tables (or queueing them to be freed).
 5. Fix up some of the accounting (like fput()) and actually
    free the VMA itself.

This specific ordering was actually introduced by:

  dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap")

during the 4.20 merge window.  The previous __do_munmap() code
was actually safe because the only thing after arch_unmap() was
remove_vma_list().  arch_unmap() could not see 'vma' in the
rbtree because it was detached, so it is not even capable of
doing operations unsafe for remove_vma_list()'s use of 'vma'.

Richard Biener reported a test that shows this in dmesg:

  [1216548.787498] BUG: Bad rss-counter state mm:0000000017ce560b idx:1 val:551
  [1216548.787500] BUG: non-zero pgtables_bytes on freeing mm: 24576

What triggered this was the recursive do_munmap() called via
arch_unmap().  It was freeing page tables that has not been
properly zapped.

But, the problem was bigger than this.  For one, arch_unmap()
can free VMAs.  But, the calling __do_munmap() has variables
that *point* to VMAs and obviously can't handle them just
getting freed while the pointer is still in use.

I tried a couple of things here.  First, I tried to fix the page
table freeing problem in isolation, but I then found the VMA
issue.  I also tried having the MPX code return a flag if it
modified the rbtree which would force __do_munmap() to re-walk
to restart.  That spiralled out of control in complexity pretty
fast.

Just moving arch_unmap() and accepting that the bonkers failure
case might eat some bounds tables seems like the simplest viable
fix.

This was also reported in the following kernel bugzilla entry:

  https://bugzilla.kernel.org/show_bug.cgi?id=203123

There are some reports that this commit triggered this bug:

  dd2283f2605 ("mm: mmap: zap pages with read mmap_sem in munmap")

While that commit certainly made the issues easier to hit, I believe
the fundamental issue has been with us as long as MPX itself, thus
the Fixes: tag below is for one of the original MPX commits.

[ mingo: Minor edits to the changelog and the patch. ]

Reported-by: Richard Biener &lt;rguenther@suse.de&gt;
Reported-by: H.J. Lu &lt;hjl.tools@gmail.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Yang Shi &lt;yang.shi@linux.alibaba.com&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Guan Xuetao &lt;gxt@pku.edu.cn&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Jeff Dike &lt;jdike@addtoit.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Michal Hocko &lt;mhocko@suse.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Richard Weinberger &lt;richard@nod.at&gt;
Cc: Rik van Riel &lt;riel@surriel.com&gt;
Cc: Vlastimil Babka &lt;vbabka@suse.cz&gt;
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-um@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: stable@vger.kernel.org
Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap")
Link: http://lkml.kernel.org/r/20190419194747.5E1AD6DC@viggo.jf.intel.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>mm: treewide: remove unused address argument from pte_alloc functions</title>
<updated>2019-01-04T21:13:47+00:00</updated>
<author>
<name>Joel Fernandes (Google)</name>
<email>joel@joelfernandes.org</email>
</author>
<published>2019-01-03T23:28:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4cf58924951ef80eec636b863e7a53973c44261a'/>
<id>4cf58924951ef80eec636b863e7a53973c44261a</id>
<content type='text'>
Patch series "Add support for fast mremap".

This series speeds up the mremap(2) syscall by copying page tables at
the PMD level even for non-THP systems.  There is concern that the extra
'address' argument that mremap passes to pte_alloc may do something
subtle architecture related in the future that may make the scheme not
work.  Also we find that there is no point in passing the 'address' to
pte_alloc since its unused.  This patch therefore removes this argument
tree-wide resulting in a nice negative diff as well.  Also ensuring
along the way that the enabled architectures do not do anything funky
with the 'address' argument that goes unnoticed by the optimization.

Build and boot tested on x86-64.  Build tested on arm64.  The config
enablement patch for arm64 will be posted in the future after more
testing.

The changes were obtained by applying the following Coccinelle script.
(thanks Julia for answering all Coccinelle questions!).
Following fix ups were done manually:
* Removal of address argument from  pte_fragment_alloc
* Removal of pte_alloc_one_fast definitions from m68k and microblaze.

// Options: --include-headers --no-includes
// Note: I split the 'identifier fn' line, so if you are manually
// running it, please unsplit it so it runs for you.

virtual patch

@pte_alloc_func_def depends on patch exists@
identifier E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
type T2;
@@

 fn(...
- , T2 E2
 )
 { ... }

@pte_alloc_func_proto_noarg depends on patch exists@
type T1, T2, T3, T4;
identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

(
- T3 fn(T1, T2);
+ T3 fn(T1);
|
- T3 fn(T1, T2, T4);
+ T3 fn(T1, T2);
)

@pte_alloc_func_proto depends on patch exists@
identifier E1, E2, E4;
type T1, T2, T3, T4;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

(
- T3 fn(T1 E1, T2 E2);
+ T3 fn(T1 E1);
|
- T3 fn(T1 E1, T2 E2, T4 E4);
+ T3 fn(T1 E1, T2 E2);
)

@pte_alloc_func_call depends on patch exists@
expression E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

 fn(...
-,  E2
 )

@pte_alloc_macro depends on patch exists@
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
identifier a, b, c;
expression e;
position p;
@@

(
- #define fn(a, b, c) e
+ #define fn(a, b) e
|
- #define fn(a, b) e
+ #define fn(a) e
)

Link: http://lkml.kernel.org/r/20181108181201.88826-2-joelaf@google.com
Signed-off-by: Joel Fernandes (Google) &lt;joel@joelfernandes.org&gt;
Suggested-by: Kirill A. Shutemov &lt;kirill@shutemov.name&gt;
Acked-by: Kirill A. Shutemov &lt;kirill@shutemov.name&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Julia Lawall &lt;Julia.Lawall@lip6.fr&gt;
Cc: Kirill A. Shutemov &lt;kirill@shutemov.name&gt;
Cc: William Kucharski &lt;william.kucharski@oracle.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Patch series "Add support for fast mremap".

This series speeds up the mremap(2) syscall by copying page tables at
the PMD level even for non-THP systems.  There is concern that the extra
'address' argument that mremap passes to pte_alloc may do something
subtle architecture related in the future that may make the scheme not
work.  Also we find that there is no point in passing the 'address' to
pte_alloc since its unused.  This patch therefore removes this argument
tree-wide resulting in a nice negative diff as well.  Also ensuring
along the way that the enabled architectures do not do anything funky
with the 'address' argument that goes unnoticed by the optimization.

Build and boot tested on x86-64.  Build tested on arm64.  The config
enablement patch for arm64 will be posted in the future after more
testing.

The changes were obtained by applying the following Coccinelle script.
(thanks Julia for answering all Coccinelle questions!).
Following fix ups were done manually:
* Removal of address argument from  pte_fragment_alloc
* Removal of pte_alloc_one_fast definitions from m68k and microblaze.

// Options: --include-headers --no-includes
// Note: I split the 'identifier fn' line, so if you are manually
// running it, please unsplit it so it runs for you.

virtual patch

@pte_alloc_func_def depends on patch exists@
identifier E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
type T2;
@@

 fn(...
- , T2 E2
 )
 { ... }

@pte_alloc_func_proto_noarg depends on patch exists@
type T1, T2, T3, T4;
identifier fn =~ "^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

(
- T3 fn(T1, T2);
+ T3 fn(T1);
|
- T3 fn(T1, T2, T4);
+ T3 fn(T1, T2);
)

@pte_alloc_func_proto depends on patch exists@
identifier E1, E2, E4;
type T1, T2, T3, T4;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

(
- T3 fn(T1 E1, T2 E2);
+ T3 fn(T1 E1);
|
- T3 fn(T1 E1, T2 E2, T4 E4);
+ T3 fn(T1 E1, T2 E2);
)

@pte_alloc_func_call depends on patch exists@
expression E2;
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
@@

 fn(...
-,  E2
 )

@pte_alloc_macro depends on patch exists@
identifier fn =~
"^(__pte_alloc|pte_alloc_one|pte_alloc|__pte_alloc_kernel|pte_alloc_one_kernel)$";
identifier a, b, c;
expression e;
position p;
@@

(
- #define fn(a, b, c) e
+ #define fn(a, b) e
|
- #define fn(a, b) e
+ #define fn(a) e
)

Link: http://lkml.kernel.org/r/20181108181201.88826-2-joelaf@google.com
Signed-off-by: Joel Fernandes (Google) &lt;joel@joelfernandes.org&gt;
Suggested-by: Kirill A. Shutemov &lt;kirill@shutemov.name&gt;
Acked-by: Kirill A. Shutemov &lt;kirill@shutemov.name&gt;
Cc: Michal Hocko &lt;mhocko@kernel.org&gt;
Cc: Julia Lawall &lt;Julia.Lawall@lip6.fr&gt;
Cc: Kirill A. Shutemov &lt;kirill@shutemov.name&gt;
Cc: William Kucharski &lt;william.kucharski@oracle.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>um: Remove obsolete reenable_XX calls</title>
<updated>2018-12-27T21:48:35+00:00</updated>
<author>
<name>Anton Ivanov</name>
<email>anton.ivanov@cambridgegreys.com</email>
</author>
<published>2018-11-13T15:08:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=940b241d9050fc354f68c182e99fc3da1ff36bc0'/>
<id>940b241d9050fc354f68c182e99fc3da1ff36bc0</id>
<content type='text'>
reenable_fd has been a NOP since the introduction of the EPOLL
based interrupt controller.
reenable_channel() is no longer needed as the flow control is
now handled via the write IRQs on the channel.

Signed-off-by: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
reenable_fd has been a NOP since the introduction of the EPOLL
based interrupt controller.
reenable_channel() is no longer needed as the flow control is
now handled via the write IRQs on the channel.

Signed-off-by: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>um: remove redundant generic-y</title>
<updated>2018-12-27T21:48:34+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2018-12-16T14:37:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=efe5f5be1e40be76d25da69f76f0b68dc6bafb8e'/>
<id>efe5f5be1e40be76d25da69f76f0b68dc6bafb8e</id>
<content type='text'>
This commit removes redundant generic-y defines in
arch/um/include/asm/Kbuild.

It is redundant to define generic-y when arch-specific implementation
exists in arch/$(ARCH)/include/asm/*.h

Remove the following generic-y:

    hardirq.h
    io.h

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This commit removes redundant generic-y defines in
arch/um/include/asm/Kbuild.

It is redundant to define generic-y when arch-specific implementation
exists in arch/$(ARCH)/include/asm/*.h

Remove the following generic-y:

    hardirq.h
    io.h

Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>um: Avoid marking pages with "changed protection"</title>
<updated>2018-12-27T21:48:34+00:00</updated>
<author>
<name>Anton Ivanov</name>
<email>anton.ivanov@cambridgegreys.com</email>
</author>
<published>2018-12-05T12:37:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8892d8545f2d0342b9c550defbfb165db237044b'/>
<id>8892d8545f2d0342b9c550defbfb165db237044b</id>
<content type='text'>
Changing protection is a very high cost operation in UML
because in addition to an extra syscall it also interrupts
mmap merge sequences generated by the tlb.

While the condition is not particularly common it is worth
avoiding.

Signed-off-by: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Changing protection is a very high cost operation in UML
because in addition to an extra syscall it also interrupts
mmap merge sequences generated by the tlb.

While the condition is not particularly common it is worth
avoiding.

Signed-off-by: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>um: Add support for DISCARD in the UBD Driver</title>
<updated>2018-12-27T21:48:20+00:00</updated>
<author>
<name>Anton Ivanov</name>
<email>anton.ivanov@cambridgegreys.com</email>
</author>
<published>2018-11-14T18:41:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=50109b5a03b4024eb6b8df3ab8f427625f54fe92'/>
<id>50109b5a03b4024eb6b8df3ab8f427625f54fe92</id>
<content type='text'>
Support for DISCARD and WRITE_ZEROES in the ubd driver using
fallocate.

DISCARD is enabled by default and can be disabled using a new
UBD command line flag.

If the underlying fs on which the UBD image is stored does not
support DISCARD the support for both DISCARD and WRITE_ZEROES
is turned off.

Signed-off-by: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Support for DISCARD and WRITE_ZEROES in the ubd driver using
fallocate.

DISCARD is enabled by default and can be disabled using a new
UBD command line flag.

If the underlying fs on which the UBD image is stored does not
support DISCARD the support for both DISCARD and WRITE_ZEROES
is turned off.

Signed-off-by: Anton Ivanov &lt;anton.ivanov@cambridgegreys.com&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-linus-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml</title>
<updated>2018-10-31T22:46:16+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-10-31T22:46:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9bb9d4fdce9e6b351b7b905f150745a0fccccc06'/>
<id>9bb9d4fdce9e6b351b7b905f150745a0fccccc06</id>
<content type='text'>
Pull UML updates from Richard Weinberger:

 - removal of old and dead code

 - a bug fix for our tty driver

 - other minor cleanups across the code base

* 'for-linus-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Make line/tty semantics use true write IRQ
  um: trap: fix spelling mistake, EACCESS -&gt; EACCES
  um: Don't hardcode path as it is architecture dependent
  um: NULL check before kfree is not needed
  um: remove unused AIO code
  um: Give start_idle_thread() a return code
  um: Remove update_debugregs()
  um: Drop own definition of PTRACE_SYSEMU/_SINGLESTEP
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull UML updates from Richard Weinberger:

 - removal of old and dead code

 - a bug fix for our tty driver

 - other minor cleanups across the code base

* 'for-linus-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Make line/tty semantics use true write IRQ
  um: trap: fix spelling mistake, EACCESS -&gt; EACCES
  um: Don't hardcode path as it is architecture dependent
  um: NULL check before kfree is not needed
  um: remove unused AIO code
  um: Give start_idle_thread() a return code
  um: Remove update_debugregs()
  um: Drop own definition of PTRACE_SYSEMU/_SINGLESTEP
</pre>
</div>
</content>
</entry>
<entry>
<title>um: remove unused AIO code</title>
<updated>2018-10-29T21:23:12+00:00</updated>
<author>
<name>Christoph Hellwig</name>
<email>hch@lst.de</email>
</author>
<published>2018-07-11T07:32:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=369cca266860db8222c991fced8caa42c3e5b05f'/>
<id>369cca266860db8222c991fced8caa42c3e5b05f</id>
<content type='text'>
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Richard Weinberger &lt;richard@nod.at&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vmlinux.lds.h: Move LSM_TABLE into INIT_DATA</title>
<updated>2018-10-11T03:40:21+00:00</updated>
<author>
<name>Kees Cook</name>
<email>keescook@chromium.org</email>
</author>
<published>2018-10-11T00:18:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3ac946d12e344a48c1192ef8910c6095a0d6a8ac'/>
<id>3ac946d12e344a48c1192ef8910c6095a0d6a8ac</id>
<content type='text'>
Since the struct lsm_info table is not an initcall, we can just move it
into INIT_DATA like all the other tables.

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Reviewed-by: John Johansen &lt;john.johansen@canonical.com&gt;
Reviewed-by: James Morris &lt;james.morris@microsoft.com&gt;
Signed-off-by: James Morris &lt;james.morris@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since the struct lsm_info table is not an initcall, we can just move it
into INIT_DATA like all the other tables.

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-by: Casey Schaufler &lt;casey@schaufler-ca.com&gt;
Reviewed-by: John Johansen &lt;john.johansen@canonical.com&gt;
Reviewed-by: James Morris &lt;james.morris@microsoft.com&gt;
Signed-off-by: James Morris &lt;james.morris@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-linus-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml</title>
<updated>2018-06-15T21:50:51+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-06-15T21:50:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8d1e5133bf260aabdf2cc6facd4a8e696414d16a'/>
<id>8d1e5133bf260aabdf2cc6facd4a8e696414d16a</id>
<content type='text'>
Pull uml updates from Richard Weinberger:
 "Minor updates for UML:

   - fixes for our new vector network driver by Anton

   - initcall cleanup by Alexander

   - We have a new mailinglist, sourceforge.net sucks"

* 'for-linus-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Fix raw interface options
  um: Fix initialization of vector queues
  um: remove uml initcalls
  um: Update mailing list address
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull uml updates from Richard Weinberger:
 "Minor updates for UML:

   - fixes for our new vector network driver by Anton

   - initcall cleanup by Alexander

   - We have a new mailinglist, sourceforge.net sucks"

* 'for-linus-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Fix raw interface options
  um: Fix initialization of vector queues
  um: remove uml initcalls
  um: Update mailing list address
</pre>
</div>
</content>
</entry>
</feed>
