riscv: Fix set_direct_map_default_noflush() to reset _PAGE_EXEC

When resetting the linear mapping permissions, we must make sure that we
clear the X bit so that do not end up with WX mappings (since we set
PAGE_KERNEL).

Fixes: 395a21ff859c ("riscv: add ARCH_HAS_SET_DIRECT_MAP support")
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20231213134027.155327-3-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Fix wrong usage of lm_alias() when splitting a huge linear mapping

lm_alias() can only be used on kernel mappings since it explicitly uses
__pa_symbol(), so simply fix this by checking where the address belongs
to before.

Fixes: 311cd2f6e253 ("riscv: Fix set_memory_XX() and set_direct_map_XX() by splitting huge linear mappings")
Reported-by: syzbot+afb726d49f84c8d95ee1@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-riscv/000000000000620dd0060c02c5e1@google.com/
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231212195400.128457-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Use accessors to page table entries instead of direct dereference

As very well explained in commit 20a004e7b017 ("arm64: mm: Use
READ_ONCE/WRITE_ONCE when accessing page tables"), an architecture whose
page table walker can modify the PTE in parallel must use
READ_ONCE()/WRITE_ONCE() macro to avoid any compiler transformation.

So apply that to riscv which is such architecture.

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20231213203001.179237-5-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

riscv: Fix set_memory_XX() and set_direct_map_XX() by splitting huge linear mappings

When STRICT_KERNEL_RWX is set, any change of permissions on any kernel
mapping (vmalloc/modules/kernel text...etc) should be applied on its
linear mapping alias. The problem is that the riscv kernel uses huge
mappings for the linear mapping and walk_page_range_novma() does not
split those huge mappings.

So this patchset implements such split in order to apply fine-grained
permissions on the linear mapping.

Below is the difference before and after (the first PUD mapping is split
into PTE/PMD mappings):

Before:

---[ Linear mapping ]---
0xffffaf8000080000-0xffffaf8000200000 0x0000000080080000 1536K PTE D A G . . W R V
0xffffaf8000200000-0xffffaf8077c00000 0x0000000080200000 1914M PMD D A G . . W R V
0xffffaf8077c00000-0xffffaf8078800000 0x00000000f7c00000 12M PMD D A G . . . R V
0xffffaf8078800000-0xffffaf8078c00000 0x00000000f8800000 4M PMD D A G . . W R V
0xffffaf8078c00000-0xffffaf8079200000 0x00000000f8c00000 6M PMD D A G . . . R V
0xffffaf8079200000-0xffffaf807e600000 0x00000000f9200000 84M PMD D A G . . W R V
0xffffaf807e600000-0xffffaf807e716000 0x00000000fe600000 1112K PTE D A G . . W R V
0xffffaf807e717000-0xffffaf807e71a000 0x00000000fe717000 12K PTE D A G . . W R V
0xffffaf807e71d000-0xffffaf807e71e000 0x00000000fe71d000 4K PTE D A G . . W R V
0xffffaf807e722000-0xffffaf807e800000 0x00000000fe722000 888K PTE D A G . . W R V
0xffffaf807e800000-0xffffaf807fe00000 0x00000000fe800000 22M PMD D A G . . W R V
0xffffaf807fe00000-0xffffaf807ff54000 0x00000000ffe00000 1360K PTE D A G . . W R V
0xffffaf807ff55000-0xffffaf8080000000 0x00000000fff55000 684K PTE D A G . . W R V
0xffffaf8080000000-0xffffaf8400000000 0x0000000100000000 14G PUD D A G . . W R V

After:

---[ Linear mapping ]---
0xffffaf8000080000-0xffffaf8000200000 0x0000000080080000 1536K PTE D A G . . W R V
0xffffaf8000200000-0xffffaf8077c00000 0x0000000080200000 1914M PMD D A G . . W R V
0xffffaf8077c00000-0xffffaf8078800000 0x00000000f7c00000 12M PMD D A G . . . R V
0xffffaf8078800000-0xffffaf8078a00000 0x00000000f8800000 2M PMD D A G . . W R V
0xffffaf8078a00000-0xffffaf8078c00000 0x00000000f8a00000 2M PTE D A G . . W R V
0xffffaf8078c00000-0xffffaf8079200000 0x00000000f8c00000 6M PMD D A G . . . R V
0xffffaf8079200000-0xffffaf807e600000 0x00000000f9200000 84M PMD D A G . . W R V
0xffffaf807e600000-0xffffaf807e716000 0x00000000fe600000 1112K PTE D A G . . W R V
0xffffaf807e717000-0xffffaf807e71a000 0x00000000fe717000 12K PTE D A G . . W R V
0xffffaf807e71d000-0xffffaf807e71e000 0x00000000fe71d000 4K PTE D A G . . W R V
0xffffaf807e722000-0xffffaf807e800000 0x00000000fe722000 888K PTE D A G . . W R V
0xffffaf807e800000-0xffffaf807fe00000 0x00000000fe800000 22M PMD D A G . . W R V
0xffffaf807fe00000-0xffffaf807ff54000 0x00000000ffe00000 1360K PTE D A G . . W R V
0xffffaf807ff55000-0xffffaf8080000000 0x00000000fff55000 684K PTE D A G . . W R V
0xffffaf8080000000-0xffffaf8080800000 0x0000000100000000 8M PMD D A G . . W R V
0xffffaf8080800000-0xffffaf8080af6000 0x0000000100800000 3032K PTE D A G . . W R V
0xffffaf8080af6000-0xffffaf8080af8000 0x0000000100af6000 8K PTE D A G . X . R V
0xffffaf8080af8000-0xffffaf8080c00000 0x0000000100af8000 1056K PTE D A G . . W R V
0xffffaf8080c00000-0xffffaf8081a00000 0x0000000100c00000 14M PMD D A G . . W R V
0xffffaf8081a00000-0xffffaf8081a40000 0x0000000101a00000 256K PTE D A G . . W R V
0xffffaf8081a40000-0xffffaf8081a44000 0x0000000101a40000 16K PTE D A G . X . R V
0xffffaf8081a44000-0xffffaf8081a52000 0x0000000101a44000 56K PTE D A G . . W R V
0xffffaf8081a52000-0xffffaf8081a54000 0x0000000101a52000 8K PTE D A G . X . R V
...
0xffffaf809e800000-0xffffaf80c0000000 0x000000011e800000 536M PMD D A G . . W R V
0xffffaf80c0000000-0xffffaf8400000000 0x0000000140000000 13G PUD D A G . . W R V

Note that this also fixes memfd_secret() syscall which uses
set_direct_map_invalid_noflush() and set_direct_map_default_noflush() to
remove the pages from the linear mapping. Below is the kernel page table
while a memfd_secret() syscall is running, you can see all the !valid
page table entries in the linear mapping:

...
0xffffaf8082240000-0xffffaf8082241000 0x0000000102240000 4K PTE D A G . . W R .
0xffffaf8082241000-0xffffaf8082250000 0x0000000102241000 60K PTE D A G . . W R V
0xffffaf8082250000-0xffffaf8082252000 0x0000000102250000 8K PTE D A G . . W R .
0xffffaf8082252000-0xffffaf8082256000 0x0000000102252000 16K PTE D A G . . W R V
0xffffaf8082256000-0xffffaf8082257000 0x0000000102256000 4K PTE D A G . . W R .
0xffffaf8082257000-0xffffaf8082258000 0x0000000102257000 4K PTE D A G . . W R V
0xffffaf8082258000-0xffffaf8082259000 0x0000000102258000 4K PTE D A G . . W R .
0xffffaf8082259000-0xffffaf808225a000 0x0000000102259000 4K PTE D A G . . W R V
0xffffaf808225a000-0xffffaf808225c000 0x000000010225a000 8K PTE D A G . . W R .
0xffffaf808225c000-0xffffaf8082266000 0x000000010225c000 40K PTE D A G . . W R V
0xffffaf8082266000-0xffffaf8082268000 0x0000000102266000 8K PTE D A G . . W R .
0xffffaf8082268000-0xffffaf8082284000 0x0000000102268000 112K PTE D A G . . W R V
0xffffaf8082284000-0xffffaf8082288000 0x0000000102284000 16K PTE D A G . . W R .
0xffffaf8082288000-0xffffaf808229c000 0x0000000102288000 80K PTE D A G . . W R V
0xffffaf808229c000-0xffffaf80822a0000 0x000000010229c000 16K PTE D A G . . W R .
0xffffaf80822a0000-0xffffaf80822a5000 0x00000001022a0000 20K PTE D A G . . W R V
0xffffaf80822a5000-0xffffaf80822a6000 0x00000001022a5000 4K PTE D A G . . . R V
0xffffaf80822a6000-0xffffaf80822ab000 0x00000001022a6000 20K PTE D A G . . W R V
...

And when the memfd_secret() fd is released, the linear mapping is
correctly reset:

...
0xffffaf8082240000-0xffffaf80822a5000 0x0000000102240000 404K PTE D A G . . W R V
0xffffaf80822a5000-0xffffaf80822a6000 0x00000001022a5000 4K PTE D A G . . . R V
0xffffaf80822a6000-0xffffaf80822af000 0x00000001022a6000 36K PTE D A G . . W R V
...

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20231108075930.7157-3-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

mm: enable page walking API to lock vmas during the walk

walk_page_range() and friends often operate under write-locked mmap_lock.
With introduction of vma locks, the vmas have to be locked as well during
such walks to prevent concurrent page faults in these areas. Add an
additional member to mm_walk_ops to indicate locking requirements for the
walk.

The change ensures that page walks which prevent concurrent page faults
by write-locking mmap_lock, operate correctly after introduction of
per-vma locks. With per-vma locks page faults can be handled under vma
lock without taking mmap_lock at all, so write locking mmap_lock would
not stop them. The change ensures vmas are properly locked during such
walks.

A sample issue this solves is do_mbind() performing queue_pages_range()
to queue pages for migration. Without this change a concurrent page
can be faulted into the area and be left out of migration.

Link: https://lkml.kernel.org/r/20230804152724.3090321-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Suggested-by: Jann Horn <jannh@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

RISC-V: mm: Enable huge page support to kernel_page_present() function

Currently kernel_page_present() function doesn't support huge page
detection causes the function to mistakenly return false to the
hibernation core.

Add huge page detection to the function to solve the problem.

Fixes: 9e953cda5cdf ("riscv: Introduce huge page support for 32/64bit kernel")
Signed-off-by: Sia Jee Heng <jeeheng.sia@starfivetech.com>
Reviewed-by: Ley Foon Tan <leyfoon.tan@starfivetech.com>
Reviewed-by: Mason Huo <mason.huo@starfivetech.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20230330064321.1008373-4-jeeheng.sia@starfivetech.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

mm: pagewalk: Fix race between unmap and page walker

The mmap lock protects the page walker from changes to the page tables
during the walk. However a read lock is insufficient to protect those
areas which don't have a VMA as munmap() detaches the VMAs before
downgrading to a read lock and actually tearing down PTEs/page tables.

For users of walk_page_range() the solution is to simply call pte_hole()
immediately without checking the actual page tables when a VMA is not
present. We now never call __walk_page_range() without a valid vma.

For walk_page_range_novma() the locking requirements are tightened to
require the mmap write lock to be taken, and then walking the pgd
directly with 'no_vma' set.

This in turn means that all page walkers either have a valid vma, or
it's that special 'novma' case for page table debugging. As a result,
all the odd '(!walk->vma && !walk->no_vma)' tests can be removed.

Fixes: dd2283f2605e ("mm: mmap: zap pages with read mmap_sem in munmap")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch, mm: make kernel_page_present() always available

For architectures that enable ARCH_HAS_SET_MEMORY having the ability to
verify that a page is mapped in the kernel direct map can be useful
regardless of hibernation.

Add RISC-V implementation of kernel_page_present(), update its forward
declarations and stubs to be a part of set_memory API and remove ugly
ifdefery in inlcude/linux/mm.h around current declarations of
kernel_page_present().

Link: https://lkml.kernel.org/r/20201109192128.960-5-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch, mm: restore dependency of __kernel_map_pages() on DEBUG_PAGEALLOC

The design of DEBUG_PAGEALLOC presumes that __kernel_map_pages() must
never fail. With this assumption is wouldn't be safe to allow general
usage of this function.

Moreover, some architectures that implement __kernel_map_pages() have this
function guarded by #ifdef DEBUG_PAGEALLOC and some refuse to map/unmap
pages when page allocation debugging is disabled at runtime.

As all the users of __kernel_map_pages() were converted to use
debug_pagealloc_map_pages() it is safe to make it available only when
DEBUG_PAGEALLOC is set.

Link: https://lkml.kernel.org/r/20201109192128.960-4-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

RISC-V: Protect all kernel sections including init early

Currently, .init.text & .init.data are intermixed which makes it impossible
apply different permissions to them. .init.data shouldn't need exec
permissions while .init.text shouldn't have write permission. Moreover,
the strict permission are only enforced /init starts. This leaves the
kernel vulnerable from possible buggy built-in modules.

Keep .init.text & .data in separate sections so that different permissions
are applied to each section. Apply permissions to individual sections as
early as possible. This improves the kernel protection under
CONFIG_STRICT_KERNEL_RWX. We also need to restore the permissions for the
entire _init section after it is freed so that those pages can be used
for other purpose.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Tested-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: fix build warning of mm/pageattr

Add hearder for missing prototype. Also, static keyword should be at
beginning of declaration.

Signed-off-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

RISC-V: Acquire mmap lock before invoking walk_page_range

As per walk_page_range documentation, mmap lock should be acquired by the
caller before invoking walk_page_range. mmap_assert_locked gets triggered
without that. The details can be found here.

http://lists.infradead.org/pipermail/linux-riscv/2020-June/010335.html

Fixes: 395a21ff859c(riscv: add ARCH_HAS_SET_DIRECT_MAP support)
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

mmap locking API: convert mmap_sem call sites missed by coccinelle

Convert the last few remaining mmap_sem rwsem calls to use the new mmap
locking API. These were missed by coccinelle for some reason (I think
coccinelle does not support some of the preprocessor constructs in these
files ?)

[akpm@linux-foundation.org: convert linux-next leftovers]
[akpm@linux-foundation.org: more linux-next leftovers]
[akpm@linux-foundation.org: more linux-next leftovers]

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-6-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: introduce include/linux/pgtable.h

The include/linux/pgtable.h is going to be the home of generic page table
manipulation functions.

Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and
make the latter include asm/pgtable.h.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

riscv: add ARCH_SUPPORTS_DEBUG_PAGEALLOC support

ARCH_SUPPORTS_DEBUG_PAGEALLOC provides a hook to map and unmap
pages for debugging purposes. Implement the __kernel_map_pages
functions to fill the poison pattern.

Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: add ARCH_HAS_SET_DIRECT_MAP support

Add set_direct_map_*() functions for setting the direct map alias for
the page to its default permissions and to an invalid state that cannot
be cached in a TLB. (See d253ca0c ("x86/mm/cpa: Add set_direct_map_*()
functions")) Add a similar implementation for RISC-V.

Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

riscv: add ARCH_HAS_SET_MEMORY support

Add set_memory_ro/rw/x/nx architecture hooks to change the page
attribution.

Use own set_memory.h rather than generic set_memory.h
(i.e. include/asm-generic/set_memory.h), because we want to add other
function prototypes here.

Signed-off-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>