<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/microblaze/include, branch v6.8</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'asm-generic-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic</title>
<updated>2024-01-11T02:13:44+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2024-01-11T02:13:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c29901006179c4c87f9335771e50814ec5707239'/>
<id>c29901006179c4c87f9335771e50814ec5707239</id>
<content type='text'>
Pull asm-generic cleanups from Arnd Bergmann:
 "A series from Baoquan He cleans up the asm-generic/io.h to remove the
  ioremap_uc() definition from everything except x86, which still needs
  it for pre-PAT systems. This series notably contains a patch from
  Jiaxun Yang that converts MIPS to use asm-generic/io.h like every
  other architecture does, enabling future cleanups.

  Some of my own patches fix -Wmissing-prototype warnings in
  architecture specific code across several architectures. This is now
  needed as the warning is enabled by default. There are still some
  remaining warnings in minor platforms, but the series should catch
  most of the widely used ones make them more consistent with one
  another.

  David McKay fixes a bug in __generic_cmpxchg_local() when this is used
  on 64-bit architectures. This could currently only affect parisc64 and
  sparc64.

  Additional cleanups address from Linus Walleij, Uwe Kleine-König,
  Thomas Huth, and Kefeng Wang help reduce unnecessary inconsistencies
  between architectures"

* tag 'asm-generic-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: Fix 32 bit __generic_cmpxchg_local
  Hexagon: Make pfn accessors statics inlines
  ARC: mm: Make virt_to_pfn() a static inline
  mips: remove extraneous asm-generic/iomap.h include
  sparc: Use $(kecho) to announce kernel images being ready
  arm64: vdso32: Define BUILD_VDSO32_64 to correct prototypes
  csky: fix arch_jump_label_transform_static override
  arch: add do_page_fault prototypes
  arch: add missing prepare_ftrace_return() prototypes
  arch: vdso: consolidate gettime prototypes
  arch: include linux/cpu.h for trap_init() prototype
  arch: fix asm-offsets.c building with -Wmissing-prototypes
  arch: consolidate arch_irq_work_raise prototypes
  hexagon: Remove CONFIG_HEXAGON_ARCH_VERSION from uapi header
  asm/io: remove unnecessary xlate_dev_mem_ptr() and unxlate_dev_mem_ptr()
  mips: io: remove duplicated codes
  arch/*/io.h: remove ioremap_uc in some architectures
  mips: add &lt;asm-generic/io.h&gt; including
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull asm-generic cleanups from Arnd Bergmann:
 "A series from Baoquan He cleans up the asm-generic/io.h to remove the
  ioremap_uc() definition from everything except x86, which still needs
  it for pre-PAT systems. This series notably contains a patch from
  Jiaxun Yang that converts MIPS to use asm-generic/io.h like every
  other architecture does, enabling future cleanups.

  Some of my own patches fix -Wmissing-prototype warnings in
  architecture specific code across several architectures. This is now
  needed as the warning is enabled by default. There are still some
  remaining warnings in minor platforms, but the series should catch
  most of the widely used ones make them more consistent with one
  another.

  David McKay fixes a bug in __generic_cmpxchg_local() when this is used
  on 64-bit architectures. This could currently only affect parisc64 and
  sparc64.

  Additional cleanups address from Linus Walleij, Uwe Kleine-König,
  Thomas Huth, and Kefeng Wang help reduce unnecessary inconsistencies
  between architectures"

* tag 'asm-generic-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic:
  asm-generic: Fix 32 bit __generic_cmpxchg_local
  Hexagon: Make pfn accessors statics inlines
  ARC: mm: Make virt_to_pfn() a static inline
  mips: remove extraneous asm-generic/iomap.h include
  sparc: Use $(kecho) to announce kernel images being ready
  arm64: vdso32: Define BUILD_VDSO32_64 to correct prototypes
  csky: fix arch_jump_label_transform_static override
  arch: add do_page_fault prototypes
  arch: add missing prepare_ftrace_return() prototypes
  arch: vdso: consolidate gettime prototypes
  arch: include linux/cpu.h for trap_init() prototype
  arch: fix asm-offsets.c building with -Wmissing-prototypes
  arch: consolidate arch_irq_work_raise prototypes
  hexagon: Remove CONFIG_HEXAGON_ARCH_VERSION from uapi header
  asm/io: remove unnecessary xlate_dev_mem_ptr() and unxlate_dev_mem_ptr()
  mips: io: remove duplicated codes
  arch/*/io.h: remove ioremap_uc in some architectures
  mips: add &lt;asm-generic/io.h&gt; including
</pre>
</div>
</content>
</entry>
<entry>
<title>microblaze: add missing forward declaration</title>
<updated>2023-12-21T00:26:30+00:00</updated>
<author>
<name>Kent Overstreet</name>
<email>kent.overstreet@linux.dev</email>
</author>
<published>2023-12-21T00:25:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a484ba4e8b8f2b29377a09c3ffea74de7f877e37'/>
<id>a484ba4e8b8f2b29377a09c3ffea74de7f877e37</id>
<content type='text'>
Signed-off-by: Kent Overstreet &lt;kent.overstreet@linux.dev&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Kent Overstreet &lt;kent.overstreet@linux.dev&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch: add missing prepare_ftrace_return() prototypes</title>
<updated>2023-11-23T10:32:32+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2023-08-09T10:07:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=1d6571a8794ba276a078a8ca9d84ccc157f8b6c3'/>
<id>1d6571a8794ba276a078a8ca9d84ccc157f8b6c3</id>
<content type='text'>
The prototype for prepare_ftrace_return() is architecture specific and
can't be in a global header. Since it's normally called from assembly,
it doesn't really need a prototype, but we get a warning if it's missing:

arch/csky/kernel/ftrace.c:147:6: error: no previous prototype for 'prepare_ftrace_return' [-Werror=missing-prototypes]
arch/microblaze/kernel/ftrace.c:22:6: error: no previous prototype for 'prepare_ftrace_return' [-Werror=missing-prototypes]
arch/mips/kernel/ftrace.c:305:6: error: no previous prototype for 'prepare_ftrace_return' [-Werror=missing-prototypes]

Add the prototypes for the three architectures that don't already have
one in asm/ftrace.h.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The prototype for prepare_ftrace_return() is architecture specific and
can't be in a global header. Since it's normally called from assembly,
it doesn't really need a prototype, but we get a warning if it's missing:

arch/csky/kernel/ftrace.c:147:6: error: no previous prototype for 'prepare_ftrace_return' [-Werror=missing-prototypes]
arch/microblaze/kernel/ftrace.c:22:6: error: no previous prototype for 'prepare_ftrace_return' [-Werror=missing-prototypes]
arch/mips/kernel/ftrace.c:305:6: error: no previous prototype for 'prepare_ftrace_return' [-Werror=missing-prototypes]

Add the prototypes for the three architectures that don't already have
one in asm/ftrace.h.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'microblaze-v6.6' of git://git.monstr.eu/linux-2.6-microblaze</title>
<updated>2023-09-05T17:15:22+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-09-05T17:15:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=893a259caa6f08477bff2bccf1df0cdff38271ac'/>
<id>893a259caa6f08477bff2bccf1df0cdff38271ac</id>
<content type='text'>
Pull microblaze updates from Michal Simek:

 - Cleanup DT headers

 - Remove unused zalloc_maybe_bootmem()

 - Make virt_to_pfn() a static inline

* tag 'microblaze-v6.6' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Make virt_to_pfn() a static inline
  microblaze: Remove zalloc_maybe_bootmem()
  microblaze: Explicitly include correct DT includes
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull microblaze updates from Michal Simek:

 - Cleanup DT headers

 - Remove unused zalloc_maybe_bootmem()

 - Make virt_to_pfn() a static inline

* tag 'microblaze-v6.6' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Make virt_to_pfn() a static inline
  microblaze: Remove zalloc_maybe_bootmem()
  microblaze: Explicitly include correct DT includes
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2023-08-31T19:20:12+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-08-31T19:20:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=df57721f9a63e8a1fb9b9b2e70de4aa4c7e0cd2e'/>
<id>df57721f9a63e8a1fb9b9b2e70de4aa4c7e0cd2e</id>
<content type='text'>
Pull x86 shadow stack support from Dave Hansen:
 "This is the long awaited x86 shadow stack support, part of Intel's
  Control-flow Enforcement Technology (CET).

  CET consists of two related security features: shadow stacks and
  indirect branch tracking. This series implements just the shadow stack
  part of this feature, and just for userspace.

  The main use case for shadow stack is providing protection against
  return oriented programming attacks. It works by maintaining a
  secondary (shadow) stack using a special memory type that has
  protections against modification. When executing a CALL instruction,
  the processor pushes the return address to both the normal stack and
  to the special permission shadow stack. Upon RET, the processor pops
  the shadow stack copy and compares it to the normal stack copy.

  For more information, refer to the links below for the earlier
  versions of this patch set"

Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/
Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/

* tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/shstk: Change order of __user in type
  x86/ibt: Convert IBT selftest to asm
  x86/shstk: Don't retry vm_munmap() on -EINTR
  x86/kbuild: Fix Documentation/ reference
  x86/shstk: Move arch detail comment out of core mm
  x86/shstk: Add ARCH_SHSTK_STATUS
  x86/shstk: Add ARCH_SHSTK_UNLOCK
  x86: Add PTRACE interface for shadow stack
  selftests/x86: Add shadow stack test
  x86/cpufeatures: Enable CET CR4 bit for shadow stack
  x86/shstk: Wire in shadow stack interface
  x86: Expose thread features in /proc/$PID/status
  x86/shstk: Support WRSS for userspace
  x86/shstk: Introduce map_shadow_stack syscall
  x86/shstk: Check that signal frame is shadow stack mem
  x86/shstk: Check that SSP is aligned on sigreturn
  x86/shstk: Handle signals for shadow stack
  x86/shstk: Introduce routines modifying shstk
  x86/shstk: Handle thread shadow stack
  x86/shstk: Add user-mode shadow stack support
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 shadow stack support from Dave Hansen:
 "This is the long awaited x86 shadow stack support, part of Intel's
  Control-flow Enforcement Technology (CET).

  CET consists of two related security features: shadow stacks and
  indirect branch tracking. This series implements just the shadow stack
  part of this feature, and just for userspace.

  The main use case for shadow stack is providing protection against
  return oriented programming attacks. It works by maintaining a
  secondary (shadow) stack using a special memory type that has
  protections against modification. When executing a CALL instruction,
  the processor pushes the return address to both the normal stack and
  to the special permission shadow stack. Upon RET, the processor pops
  the shadow stack copy and compares it to the normal stack copy.

  For more information, refer to the links below for the earlier
  versions of this patch set"

Link: https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@intel.com/
Link: https://lore.kernel.org/lkml/20230613001108.3040476-1-rick.p.edgecombe@intel.com/

* tag 'x86_shstk_for_6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (47 commits)
  x86/shstk: Change order of __user in type
  x86/ibt: Convert IBT selftest to asm
  x86/shstk: Don't retry vm_munmap() on -EINTR
  x86/kbuild: Fix Documentation/ reference
  x86/shstk: Move arch detail comment out of core mm
  x86/shstk: Add ARCH_SHSTK_STATUS
  x86/shstk: Add ARCH_SHSTK_UNLOCK
  x86: Add PTRACE interface for shadow stack
  selftests/x86: Add shadow stack test
  x86/cpufeatures: Enable CET CR4 bit for shadow stack
  x86/shstk: Wire in shadow stack interface
  x86: Expose thread features in /proc/$PID/status
  x86/shstk: Support WRSS for userspace
  x86/shstk: Introduce map_shadow_stack syscall
  x86/shstk: Check that signal frame is shadow stack mem
  x86/shstk: Check that SSP is aligned on sigreturn
  x86/shstk: Handle signals for shadow stack
  x86/shstk: Introduce routines modifying shstk
  x86/shstk: Handle thread shadow stack
  x86/shstk: Add user-mode shadow stack support
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>microblaze: implement the new page table range API</title>
<updated>2023-08-24T23:20:21+00:00</updated>
<author>
<name>Matthew Wilcox (Oracle)</name>
<email>willy@infradead.org</email>
</author>
<published>2023-08-02T15:13:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=27a8b944fe91503ba15241d9a8504a34af0009fa'/>
<id>27a8b944fe91503ba15241d9a8504a34af0009fa</id>
<content type='text'>
Rename PFN_SHIFT_OFFSET to PTE_PFN_SHIFT.  Change the calling convention
for set_pte() to be the same as other architectures.  Add
update_mmu_cache_range(), flush_icache_pages() and flush_dcache_folio().

[arnd@arndb.de: mark flush_dcache_folio() inline]
  Link: https://lkml.kernel.org/r/20230810141947.1236730-9-arnd@kernel.org
Link: https://lkml.kernel.org/r/20230802151406.3735276-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rename PFN_SHIFT_OFFSET to PTE_PFN_SHIFT.  Change the calling convention
for set_pte() to be the same as other architectures.  Add
update_mmu_cache_range(), flush_icache_pages() and flush_dcache_folio().

[arnd@arndb.de: mark flush_dcache_folio() inline]
  Link: https://lkml.kernel.org/r/20230810141947.1236730-9-arnd@kernel.org
Link: https://lkml.kernel.org/r/20230802151406.3735276-17-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Acked-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>microblaze: Make virt_to_pfn() a static inline</title>
<updated>2023-08-23T07:35:22+00:00</updated>
<author>
<name>Linus Walleij</name>
<email>linus.walleij@linaro.org</email>
</author>
<published>2023-08-08T08:40:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0d2b49479bf91c857d83608da7b64328e556dff7'/>
<id>0d2b49479bf91c857d83608da7b64328e556dff7</id>
<content type='text'>
Making virt_to_pfn() a static inline taking a strongly typed
(const void *) makes the contract of a passing a pointer of that
type to the function explicit and exposes any misuse of the
macro virt_to_pfn() acting polymorphic and accepting many types
such as (void *), (unitptr_t) or (unsigned long) as arguments
without warnings.

Move the function down in the file so __pa() exists in our
scope, and it compiles. This in turn requires moving __pa()
as it depends on __virt_to_phys() that was below. (Lazy macro
evaluation conflicts with strict function ordering.)

Make a symmetric change to pfn_to_virt() so we have type
checking both ways.

Due to this the &lt;asm/page.h&gt; file being included into some
assembly files, some further inclusion guards are needed
to make sure assembly keeps compiling.

Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Link: https://lore.kernel.org/r/20230808-virt-to-phys-microblaze-v1-1-e6df710fe0a1@linaro.org
Signed-off-by: Michal Simek &lt;michal.simek@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Making virt_to_pfn() a static inline taking a strongly typed
(const void *) makes the contract of a passing a pointer of that
type to the function explicit and exposes any misuse of the
macro virt_to_pfn() acting polymorphic and accepting many types
such as (void *), (unitptr_t) or (unsigned long) as arguments
without warnings.

Move the function down in the file so __pa() exists in our
scope, and it compiles. This in turn requires moving __pa()
as it depends on __virt_to_phys() that was below. (Lazy macro
evaluation conflicts with strict function ordering.)

Make a symmetric change to pfn_to_virt() so we have type
checking both ways.

Due to this the &lt;asm/page.h&gt; file being included into some
assembly files, some further inclusion guards are needed
to make sure assembly keeps compiling.

Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Link: https://lore.kernel.org/r/20230808-virt-to-phys-microblaze-v1-1-e6df710fe0a1@linaro.org
Signed-off-by: Michal Simek &lt;michal.simek@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>microblaze: Remove zalloc_maybe_bootmem()</title>
<updated>2023-08-23T07:35:22+00:00</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@csgroup.eu</email>
</author>
<published>2023-08-15T18:36:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b48edb8665fe7b90ff11b23bcc949fee95c035f0'/>
<id>b48edb8665fe7b90ff11b23bcc949fee95c035f0</id>
<content type='text'>
Last user of zalloc_maybe_bootmem() was removed by
commit 4308e3c9e1ea ("microblaze/PCI: Remove unused allocation &amp; free
of PCI host bridge structure")

Remove it.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Link: https://lore.kernel.org/r/bfb1601cac24d7ef8e741c83f9301e4a5a87a0b5.1692124505.git.christophe.leroy@csgroup.eu
Signed-off-by: Michal Simek &lt;michal.simek@amd.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Last user of zalloc_maybe_bootmem() was removed by
commit 4308e3c9e1ea ("microblaze/PCI: Remove unused allocation &amp; free
of PCI host bridge structure")

Remove it.

Signed-off-by: Christophe Leroy &lt;christophe.leroy@csgroup.eu&gt;
Link: https://lore.kernel.org/r/bfb1601cac24d7ef8e741c83f9301e4a5a87a0b5.1692124505.git.christophe.leroy@csgroup.eu
Signed-off-by: Michal Simek &lt;michal.simek@amd.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: Rename arch pte_mkwrite()'s to pte_mkwrite_novma()</title>
<updated>2023-07-11T21:10:56+00:00</updated>
<author>
<name>Rick Edgecombe</name>
<email>rick.p.edgecombe@intel.com</email>
</author>
<published>2023-06-13T00:10:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2f0584f3f4bd60bcc8735172981fb0bff86e74e0'/>
<id>2f0584f3f4bd60bcc8735172981fb0bff86e74e0</id>
<content type='text'>
The x86 Shadow stack feature includes a new type of memory called shadow
stack. This shadow stack memory has some unusual properties, which requires
some core mm changes to function properly.

One of these unusual properties is that shadow stack memory is writable,
but only in limited ways. These limits are applied via a specific PTE
bit combination. Nevertheless, the memory is writable, and core mm code
will need to apply the writable permissions in the typical paths that
call pte_mkwrite(). The goal is to make pte_mkwrite() take a VMA, so
that the x86 implementation of it can know whether to create regular
writable or shadow stack mappings.

But there are a couple of challenges to this. Modifying the signatures of
each arch pte_mkwrite() implementation would be error prone because some
are generated with macros and would need to be re-implemented. Also, some
pte_mkwrite() callers operate on kernel memory without a VMA.

So this can be done in a three step process. First pte_mkwrite() can be
renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite()
added that just calls pte_mkwrite_novma(). Next callers without a VMA can
be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers
can be changed to take/pass a VMA.

Start the process by renaming pte_mkwrite() to pte_mkwrite_novma() and
adding the pte_mkwrite() wrapper in linux/pgtable.h. Apply the same
pattern for pmd_mkwrite(). Since not all archs have a pmd_mkwrite_novma(),
create a new arch config HAS_HUGE_PAGE that can be used to tell if
pmd_mkwrite() should be defined. Otherwise in the !HAS_HUGE_PAGE cases the
compiler would not be able to find pmd_mkwrite_novma().

No functional change.

Suggested-by: Linus Torvalds &lt;torvalds@linuxfoundation.org&gt;
Signed-off-by: Rick Edgecombe &lt;rick.p.edgecombe@intel.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Acked-by: David Hildenbrand &lt;david@redhat.com&gt;
Link: https://lore.kernel.org/lkml/CAHk-=wiZjSu7c9sFYZb3q04108stgHff2wfbokGCCgW7riz+8Q@mail.gmail.com/
Link: https://lore.kernel.org/all/20230613001108.3040476-2-rick.p.edgecombe%40intel.com
</content>
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<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The x86 Shadow stack feature includes a new type of memory called shadow
stack. This shadow stack memory has some unusual properties, which requires
some core mm changes to function properly.

One of these unusual properties is that shadow stack memory is writable,
but only in limited ways. These limits are applied via a specific PTE
bit combination. Nevertheless, the memory is writable, and core mm code
will need to apply the writable permissions in the typical paths that
call pte_mkwrite(). The goal is to make pte_mkwrite() take a VMA, so
that the x86 implementation of it can know whether to create regular
writable or shadow stack mappings.

But there are a couple of challenges to this. Modifying the signatures of
each arch pte_mkwrite() implementation would be error prone because some
are generated with macros and would need to be re-implemented. Also, some
pte_mkwrite() callers operate on kernel memory without a VMA.

So this can be done in a three step process. First pte_mkwrite() can be
renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite()
added that just calls pte_mkwrite_novma(). Next callers without a VMA can
be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers
can be changed to take/pass a VMA.

Start the process by renaming pte_mkwrite() to pte_mkwrite_novma() and
adding the pte_mkwrite() wrapper in linux/pgtable.h. Apply the same
pattern for pmd_mkwrite(). Since not all archs have a pmd_mkwrite_novma(),
create a new arch config HAS_HUGE_PAGE that can be used to tell if
pmd_mkwrite() should be defined. Otherwise in the !HAS_HUGE_PAGE cases the
compiler would not be able to find pmd_mkwrite_novma().

No functional change.

Suggested-by: Linus Torvalds &lt;torvalds@linuxfoundation.org&gt;
Signed-off-by: Rick Edgecombe &lt;rick.p.edgecombe@intel.com&gt;
Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Reviewed-by: Mike Rapoport (IBM) &lt;rppt@kernel.org&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Acked-by: David Hildenbrand &lt;david@redhat.com&gt;
Link: https://lore.kernel.org/lkml/CAHk-=wiZjSu7c9sFYZb3q04108stgHff2wfbokGCCgW7riz+8Q@mail.gmail.com/
Link: https://lore.kernel.org/all/20230613001108.3040476-2-rick.p.edgecombe%40intel.com
</pre>
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</entry>
<entry>
<title>Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm</title>
<updated>2023-06-28T17:59:38+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-06-28T17:59:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=77b1a7f7a05c673c187894b4ae898a8c0cdc776c'/>
<id>77b1a7f7a05c673c187894b4ae898a8c0cdc776c</id>
<content type='text'>
Pull non-mm updates from Andrew Morton:

 - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
   directories

 - Douglas Anderson has added a new "buddy" mode to the hardlockup
   detector. It permits the detector to work on architectures which
   cannot provide the required interrupts, by having CPUs periodically
   perform checks on other CPUs

 - Zhen Lei has enhanced kexec's ability to support two crash regions

 - Petr Mladek has done a lot of cleanup on the hard lockup detector's
   Kconfig entries

 - And the usual bunch of singleton patches in various places

* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  kernel/time/posix-stubs.c: remove duplicated include
  ocfs2: remove redundant assignment to variable bit_off
  watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
  powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
  devres: show which resource was invalid in __devm_ioremap_resource()
  watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
  watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
  watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
  watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
  watchdog/hardlockup: make the config checks more straightforward
  watchdog/hardlockup: sort hardlockup detector related config values a logical way
  watchdog/hardlockup: move SMP barriers from common code to buddy code
  watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
  watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
  watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
  watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
  watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
  watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
  watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
  watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull non-mm updates from Andrew Morton:

 - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
   directories

 - Douglas Anderson has added a new "buddy" mode to the hardlockup
   detector. It permits the detector to work on architectures which
   cannot provide the required interrupts, by having CPUs periodically
   perform checks on other CPUs

 - Zhen Lei has enhanced kexec's ability to support two crash regions

 - Petr Mladek has done a lot of cleanup on the hard lockup detector's
   Kconfig entries

 - And the usual bunch of singleton patches in various places

* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  kernel/time/posix-stubs.c: remove duplicated include
  ocfs2: remove redundant assignment to variable bit_off
  watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
  powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
  devres: show which resource was invalid in __devm_ioremap_resource()
  watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
  watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
  watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
  watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
  watchdog/hardlockup: make the config checks more straightforward
  watchdog/hardlockup: sort hardlockup detector related config values a logical way
  watchdog/hardlockup: move SMP barriers from common code to buddy code
  watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
  watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
  watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
  watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
  watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
  watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
  watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
  watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
  ...
</pre>
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</entry>
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