There's a runtime failure when running HW_TAGS-enabled kernel built with
GCC on hardware that doesn't support MTE.  GCC-built kernels always have
CONFIG_KASAN_STACK enabled, even though stack instrumentation isn't
supported by HW_TAGS.  Having that config enabled causes KASAN to issue
MTE-only instructions to unpoison kernel stacks, which causes the failure.

Fix the issue by disallowing CONFIG_KASAN_STACK when HW_TAGS is used.

(The commit that introduced CONFIG_KASAN_HW_TAGS specified proper
 dependency for CONFIG_KASAN_STACK_ENABLE but not for CONFIG_KASAN_STACK.)

Link: https://lkml.kernel.org/r/59e75426241dbb5611277758c8d4d6f5f9298dac.1615215441.git.andreyknvl@google.com
Fixes: 6a63a63f

 ("kasan: introduce CONFIG_KASAN_HW_TAGS")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently, kasan_free_nondeferred_pages()->kasan_free_pages() is called
after debug_pagealloc_unmap_pages(). This causes a crash when
debug_pagealloc is enabled, as HW_TAGS KASAN can't set tags on an
unmapped page.

This patch puts kasan_free_nondeferred_pages() before
debug_pagealloc_unmap_pages() and arch_free_page(), which can also make
the page unavailable.

Link: https://lkml.kernel.org/r/24cd7db274090f0e5bc3adcdc7399243668e3171.1614987311.git.andreyknvl@google.com
Fixes: 94ab5b61

 ("kasan, arm64: enable CONFIG_KASAN_HW_TAGS")
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

process_madvise currently requires ptrace attach capability.
PTRACE_MODE_ATTACH gives one process complete control over another
process.  It effectively removes the security boundary between the two
processes (in one direction).  Granting ptrace attach capability even to a
system process is considered dangerous since it creates an attack surface.
This severely limits the usage of this API.

The operations process_madvise can perform do not affect the correctness
of the operation of the target process; they only affect where the data is
physically located (and therefore, how fast it can be accessed).  What we
want is the ability for one process to influence another process in order
to optimize performance across the entire system while leaving the
security boundary intact.

Replace PTRACE_MODE_ATTACH with a combination of PTRACE_MODE_READ and
CAP_SYS_NICE.  PTRACE_MODE_READ to prevent leaking ASLR metadata and
CAP_SYS_NICE for influencing process performance.

Link: https://lkml.kernel.org/r/20210303185807.2160264-1-surenb@google.com


Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tim Murray <timmurray@google.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: <stable@vger.kernel.org>	[5.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix a sparse warning by using rcu_dereference().  Technically this is a
bug and a sufficiently aggressive compiler could reload the `real_parent'
pointer outside the protection of the rcu lock (and access freed memory),
but I think it's pretty unlikely to happen.

Link: https://lkml.kernel.org/r/20210221194207.1351703-1-willy@infradead.org
Fixes: b18dc5f2

 ("mm, oom: skip vforked tasks from being selected")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Some architectures prefix all functions with a constant string ('.' on
ppc64).  Add ARCH_FUNC_PREFIX, which may optionally be defined in
<asm/kfence.h>, so that get_stack_skipnr() can work properly.

Link: https://lkml.kernel.org/r/f036c53d-7e81-763c-47f4-6024c6c5f058@csgroup.eu
Link: https://lkml.kernel.org/r/20210304144000.1148590-1-elver@google.com


Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

cache_alloc_debugcheck_after() performs checks on an object, including
adjusting the returned pointer.  None of this should apply to KFENCE
objects.  While for non-bulk allocations, the checks are skipped when we
allocate via KFENCE, for bulk allocations cache_alloc_debugcheck_after()
is called via cache_alloc_debugcheck_after_bulk().

Fix it by skipping cache_alloc_debugcheck_after() for KFENCE objects.

Link: https://lkml.kernel.org/r/20210304205256.2162309-1-elver@google.com


Signed-off-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use %td for ptrdiff_t.

Link: https://lkml.kernel.org/r/3abbe4c9-16ad-c168-a90f-087978ccd8f7@csgroup.eu
Link: https://lkml.kernel.org/r/20210303121157.3430807-1-elver@google.com


Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Separating compiler-clang.h from compiler-gcc.h inadventently dropped the
definitions of the three HAVE_BUILTIN_BSWAP macros, which requires falling
back to the open-coded version and hoping that the compiler detects it.

Since all versions of clang support the __builtin_bswap interfaces, add
back the flags and have the headers pick these up automatically.

This results in a 4% improvement of compilation speed for arm defconfig.

Note: it might also be worth revisiting which architectures set
CONFIG_ARCH_USE_BUILTIN_BSWAP for one compiler or the other, today this is
set on six architectures (arm32, csky, mips, powerpc, s390, x86), while
another ten architectures define custom helpers (alpha, arc, ia64, m68k,
mips, nios2, parisc, sh, sparc, xtensa), and the rest (arm64, h8300,
hexagon, microblaze, nds32, openrisc, riscv) just get the unoptimized
version and rely on the compiler to detect it.

A long time ago, the compiler builtins were architecture specific, but
nowadays, all compilers that are able to build the kernel have correct
implementations of them, though some may not be as optimized as the inline
asm versions.

The patch that dropped the optimization landed in v4.19, so as discussed
it would be fairly safe to backport this revert to stable kernels to the
4.19/5.4/5.10 stable kernels, but there is a remaining risk for
regressions, and it has no known side-effects besides compile speed.

Link: https://lkml.kernel.org/r/20210226161151.2629097-1-arnd@kernel.org
Link: https://lore.kernel.org/lkml/20210225164513.3667778-1-arnd@kernel.org/
Fixes: 815f0ddb

 ("include/linux/compiler*.h: make compiler-*.h mutually exclusive")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Guo Ren <guoren@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 7b4693e6 ("MAINTAINERS: add uapi directories to API/ABI
section") added include/uapi/ and arch/*/include/uapi/ so that patches
modifying them CC linux-api.  However that was already done in the past
and resulted in too much noise and thus later removed, as explained in
b14fd334 ("MAINTAINERS: trim the file triggers for ABI/API")

To prevent another round of addition and removal in the future, change the
entries to X: (explicit exclusion) for documentation purposes, although
they are not subdirectories of broader included directories, as there is
apparently no defined way to add plain comments in subsystem sections.

Link: https://lkml.kernel.org/r/20210301100255.25229-1-vbabka@suse.cz


Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Acked-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There is a deadlock in bm_register_write:

First, in the begining of the function, a lock is taken on the binfmt_misc
root inode with inode_lock(d_inode(root)).

Then, if the user used the MISC_FMT_OPEN_FILE flag, the function will call
open_exec on the user-provided interpreter.

open_exec will call a path lookup, and if the path lookup process includes
the root of binfmt_misc, it will try to take a shared lock on its inode
again, but it is already locked, and the code will get stuck in a deadlock

To reproduce the bug:
$ echo ":iiiii:E::ii::/proc/sys/fs/binfmt_misc/bla:F" > /proc/sys/fs/binfmt_misc/register

backtrace of where the lock occurs (#5):
0  schedule () at ./arch/x86/include/asm/current.h:15
1  0xffffffff81b51237 in rwsem_down_read_slowpath (sem=0xffff888003b202e0, count=<optimized out>, state=state@entry=2) at kernel/locking/rwsem.c:992
2  0xffffffff81b5150a in __down_read_common (state=2, sem=<optimized out>) at kernel/locking/rwsem.c:1213
3  __down_read (sem=<optimized out>) at kernel/locking/rwsem.c:1222
4  down_read (sem=<optimized out>) at kernel/locking/rwsem.c:1355
5  0xffffffff811ee22a in inode_lock_shared (inode=<optimized out>) at ./include/linux/fs.h:783
6  open_last_lookups (op=0xffffc9000022fe34, file=0xffff888004098600, nd=0xffffc9000022fd10) at fs/namei.c:3177
7  path_openat (nd=nd@entry=0xffffc9000022fd10, op=op@entry=0xffffc9000022fe34, flags=flags@entry=65) at fs/namei.c:3366
8  0xffffffff811efe1c in do_filp_open (dfd=<optimized out>, pathname=pathname@entry=0xffff8880031b9000, op=op@entry=0xffffc9000022fe34) at fs/namei.c:3396
9  0xffffffff811e493f in do_open_execat (fd=fd@entry=-100, name=name@entry=0xffff8880031b9000, flags=<optimized out>, flags@entry=0) at fs/exec.c:913
10 0xffffffff811e4a92 in open_exec (name=<optimized out>) at fs/exec.c:948
11 0xffffffff8124aa84 in bm_register_write (file=<optimized out>, buffer=<optimized out>, count=19, ppos=<optimized out>) at fs/binfmt_misc.c:682
12 0xffffffff811decd2 in vfs_write (file=file@entry=0xffff888004098500, buf=buf@entry=0xa758d0 ":iiiii:E::ii::i:CF
", count=count@entry=19, pos=pos@entry=0xffffc9000022ff10) at fs/read_write.c:603
13 0xffffffff811defda in ksys_write (fd=<optimized out>, buf=0xa758d0 ":iiiii:E::ii::i:CF
", count=19) at fs/read_write.c:658
14 0xffffffff81b49813 in do_syscall_64 (nr=<optimized out>, regs=0xffffc9000022ff58) at arch/x86/entry/common.c:46
15 0xffffffff81c0007c in entry_SYSCALL_64 () at arch/x86/entry/entry_64.S:120

To solve the issue, the open_exec call is moved to before the write
lock is taken by bm_register_write

Link: https://lkml.kernel.org/r/20210228224414.95962-1-liorribak@gmail.com
Fixes: 948b701a

 ("binfmt_misc: add persistent opened binary handler for containers")
Signed-off-by: Lior Ribak <liorribak@gmail.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zero_user_segments() is used from __block_write_begin_int(), for example
like the following

	zero_user_segments(page, 4096, 1024, 512, 918)

But new the zero_user_segments() implementation for for HIGHMEM +
TRANSPARENT_HUGEPAGE doesn't handle "start > end" case correctly, and hits
BUG_ON().  (we can fix __block_write_begin_int() instead though, it is the
old and multiple usage)

Also it calls kmap_atomic() unnecessarily while start == end == 0.

Link: https://lkml.kernel.org/r/87v9ab60r4.fsf@mail.parknet.co.jp
Fixes: 0060ef3b

 ("mm: support THPs in zero_user_segments")
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is the last missing piece of the COW-during-fork effort when there're
pinned pages found.  One can reference 70e806e4 ("mm: Do early cow for
pinned pages during fork() for ptes", 2020-09-27) for more information,
since we do similar things here rather than pte this time, but just for
hugetlb.

Note that after Jason's recent work on 57efa1fe ("mm/gup: prevent
gup_fast from racing with COW during fork", 2020-12-15) which is safer and
easier to understand, we're safe now within the whole copy_page_range()
against gup-fast, we don't need the wr-protect trick that proposed in
70e806e4 anymore.

Link: https://lkml.kernel.org/r/20210217233547.93892-6-peterx@redhat.com


Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Gal Pressman <galpress@amazon.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Roland Scheidegger <sroland@vmware.com>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Wei Zhang <wzam@amazon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

After is_cow_mapping() is exported in mm.h, replace some manual checks
elsewhere throughout the tree but start to use the new helper.

Link: https://lkml.kernel.org/r/20210217233547.93892-5-peterx@redhat.com


Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@ziepe.ca>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Roland Scheidegger <sroland@vmware.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Gal Pressman <galpress@amazon.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Wei Zhang <wzam@amazon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We've got quite a few places (pte, pmd, pud) that explicitly checked
against whether we should break the cow right now during fork().  It's
easier to provide a helper, especially before we work the same thing on
hugetlbfs.

Since we'll reference is_cow_mapping() in mm.h, move it there too.
Actually it suites mm.h more since internal.h is mm/ only, but mm.h is
exported to the whole kernel.  With that we should expect another patch to
use is_cow_mapping() whenever we can across the kernel since we do use it
quite a lot but it's always done with raw code against VM_* flags.

Link: https://lkml.kernel.org/r/20210217233547.93892-4-peterx@redhat.com


Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Gal Pressman <galpress@amazon.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Roland Scheidegger <sroland@vmware.com>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Wei Zhang <wzam@amazon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

All the regions maintained in hugetlb reserved map is inclusive on "from"
but exclusive on "to".  We can break earlier even if rg->from==t because
it already means no possible intersection.

This does not need a Fixes in all cases because when it happens
(rg->from==t) we'll not break out of the loop while we should, however the
next thing we'd do is still add the last file_region we'd need and quit
the loop in the next round.  So this change is not a bugfix (since the old
code should still run okay iiuc), but we'd better still touch it up to
make it logically sane.

Link: https://lkml.kernel.org/r/20210217233547.93892-3-peterx@redhat.com


Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Gal Pressman <galpress@amazon.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Roland Scheidegger <sroland@vmware.com>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Cc: Wei Zhang <wzam@amazon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "mm/hugetlb: Early cow on fork, and a few cleanups", v5.

As reported by Gal [1], we still miss the code clip to handle early cow
for hugetlb case, which is true.  Again, it still feels odd to fork()
after using a few huge pages, especially if they're privately mapped to
me..  However I do agree with Gal and Jason in that we should still have
that since that'll complete the early cow on fork effort at least, and
it'll still fix issues where buffers are not well under control and not
easy to apply MADV_DONTFORK.

The first two patches (1-2) are some cleanups I noticed when reading into
the hugetlb reserve map code.  I think it's good to have but they're not
necessary for fixing the fork issue.

The last two patches (3-4) are the real fix.

I tested this with a fork() after some vfio-pci assignment, so I'm pretty
sure the page copy path could trigger well (page will be accounted right
after the fork()), but I didn't do data check since the card I assigned is
some random nic.

  https://github.com/xzpeter/linux/tree/fork-cow-pin-huge

[1] https://lore.kernel.org/lkml/27564187-4a08-f187-5a84-3df50009f6ca@amazon.com/

Introduce hugetlb_resv_map_add() helper to add a new file_region rather
than duplication the similar code twice in add_reservation_in_range().

Link: https://lkml.kernel.org/r/20210217233547.93892-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20210217233547.93892-2-peterx@redhat.com


Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Gal Pressman <galpress@amazon.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Wei Zhang <wzam@amazon.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jann Horn <jannh@google.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Roland Scheidegger <sroland@vmware.com>
Cc: VMware Graphics <linux-graphics-maintainer@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

When a new mm is created, its PASID should be cleared, i.e.  the PASID is
initialized to its init state 0 on both ARM and X86.

This patch was part of the series introducing mm->pasid, but got lost
along the way [1].  It still makes sense to have it, because each address
space has a different PASID.  And the IOMMU code in
iommu_sva_alloc_pasid() expects the pasid field of a new mm struct to be
cleared.

[1] https://lore.kernel.org/linux-iommu/YDgh53AcQHT+T3L0@otcwcpicx3.sc.intel.com/

Link: https://lkml.kernel.org/r/20210302103837.2562625-1-jean-philippe@linaro.org


Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Cc: Jacob Pan <jacob.jun.pan@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There could be struct pages that are not backed by actual physical memory.
This can happen when the actual memory bank is not a multiple of
SECTION_SIZE or when an architecture does not register memory holes
reserved by the firmware as memblock.memory.

Such pages are currently initialized using init_unavailable_mem() function
that iterates through PFNs in holes in memblock.memory and if there is a
struct page corresponding to a PFN, the fields of this page are set to
default values and it is marked as Reserved.

init_unavailable_mem() does not take into account zone and node the page
belongs to and sets both zone and node links in struct page to zero.

Before commit 73a6e474 ("mm: memmap_init: iterate over memblock
regions rather that check each PFN") the holes inside a zone were
re-initialized during memmap_init() and got their zone/node links right.
However, after that commit nothing updates the struct pages representing
such holes.

On a system that has firmware reserved holes in a zone above ZONE_DMA, for
instance in a configuration below:

	# grep -A1 E820 /proc/iomem
	7a17b000-7a216fff : Unknown E820 type
	7a217000-7bffffff : System RAM

unset zone link in struct page will trigger

	VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);

in set_pfnblock_flags_mask() when called with a struct page from a range
other than E820_TYPE_RAM because there are pages in the range of
ZONE_DMA32 but the unset zone link in struct page makes them appear as a
part of ZONE_DMA.

Interleave initialization of the unavailable pages with the normal
initialization of memory map, so that zone and node information will be
properly set on struct pages that are not backed by the actual memory.

With this change the pages for holes inside a zone will get proper
zone/node links and the pages that are not spanned by any node will get
links to the adjacent zone/node.  The holes between nodes will be
prepended to the zone/node above the hole and the trailing pages in the
last section that will be appended to the zone/node below.

[akpm@linux-foundation.org: don't initialize static to zero, use %llu for u64]

Link: https://lkml.kernel.org/r/20210225224351.7356-2-rppt@kernel.org
Fixes: 73a6e474

 ("mm: memmap_init: iterate over memblock regions rather that check each PFN")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reported-by: Qian Cai <cai@lca.pw>
Reported-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Łukasz Majczak <lma@semihalf.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Sarvela, Tomi P" <tomi.p.sarvela@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I read the commit log of the following two:

- bc083a64 ("init/Kconfig: make COMPILE_TEST depend on !UML")
- 334ef6ed ("init/Kconfig: make COMPILE_TEST depend on !S390")

Both are talking about HAS_IOMEM dependency missing in many drivers.

So, 'depends on HAS_IOMEM' seems the direct, sensible solution to me.

This does not change the behavior of UML. UML still cannot enable
COMPILE_TEST because it does not provide HAS_IOMEM.

The current dependency for S390 is too strong. Under the condition of
CONFIG_PCI=y, S390 provides HAS_IOMEM, hence can enable COMPILE_TEST.

I also removed the meaningless 'default n'.

Link: https://lkml.kernel.org/r/20210224140809.1067582-1-masahiroy@kernel.org


Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KP Singh <kpsingh@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Quentin Perret <qperret@google.com>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: "Enrico Weigelt, metux IT consult" <lkml@metux.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With clang-13, some functions only get partially inlined, with a
specialized version referring to a global variable.  This triggers a
harmless build-time check for the intel-rng driver:

WARNING: modpost: drivers/char/hw_random/intel-rng.o(.text+0xe): Section mismatch in reference from the function stop_machine() to the function .init.text:intel_rng_hw_init()
The function stop_machine() references
the function __init intel_rng_hw_init().
This is often because stop_machine lacks a __init
annotation or the annotation of intel_rng_hw_init is wrong.

In this instance, an easy workaround is to force the stop_machine()
function to be inline, along with related interfaces that did not show the
same behavior at the moment, but theoretically could.

The combination of the two patches listed below triggers the behavior in
clang-13, but individually these commits are correct.

Link: https://lkml.kernel.org/r/20210225130153.1956990-1-arnd@kernel.org
Fixes: fe5595c0 ("stop_machine: Provide stop_machine_cpuslocked()")
Fixes: ee527cd3

 ("Use stop_machine_run in the Intel RNG driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The inlining logic in clang-13 is rewritten to often not inline some
functions that were inlined by all earlier compilers.

In case of the memblock interfaces, this exposed a harmless bug of a
missing __init annotation:

WARNING: modpost: vmlinux.o(.text+0x507c0a): Section mismatch in reference from the function memblock_bottom_up() to the variable .meminit.data:memblock
The function memblock_bottom_up() references
the variable __meminitdata memblock.
This is often because memblock_bottom_up lacks a __meminitdata
annotation or the annotation of memblock is wrong.

Interestingly, these annotations were present originally, but got removed
with the explanation that the __init annotation prevents the function from
getting inlined.  I checked this again and found that while this is the
case with clang, gcc (version 7 through 10, did not test others) does
inline the functions regardless.

As the previous change was apparently intended to help the clang builds,
reverting it to help the newer clang versions seems appropriate as well.
gcc builds don't seem to care either way.

Link: https://lkml.kernel.org/r/20210225133808.2188581-1-arnd@kernel.org
Fixes: 5bdba520 ("mm: memblock: drop __init from memblock functions to make it inline")
Reference: 2cfb3665

 ("include/linux/memblock.h: add __init to memblock_set_bottom_up()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Faiyaz Mohammed <faiyazm@codeaurora.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Aslan Bakirov <aslan@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull drm fixes from Dave Airlie:
 "Regular fixes for rc3. The i915 pull was based on the rc1 tag so I
  just cherry-picked the single fix from there to avoid it. The misc and
  amd trees seem to be on okay bases.

  It's a bunch of fixes across the tree, amdgpu has most of them a few
  ttm fixes around qxl, and nouveau.

  core:
   - Clear holes when converting compat ioctl's between 32-bits and
     64-bits.

  docs:
   - Use gitlab for drm bugzilla now.

  ttm:
   - Fix ttm page pool accounting.

  fbdev:
   - Fix oops in drm_fbdev_cleanup()

  shmem:
   - Assorted fixes for shmem helpers.

  qxl:
   - unpin qxl bos created as pinned when freeing them, and make ttm
     only warn once on this behavior.
   - Zero head.surface_id correctly in qxl.

  atyfb:
   - Use LCD management for atyfb on PPC_MAC.

  meson:
   - Shutdown kms poll helper in meson correctly.

  nouveau:
   - fix regression in bo syncing

  i915:
   - Wedge the GPU if command parser setup fails

  amdgpu:
   - Fix aux backlight control
   - Add a backlight override parameter
   - Various display fixes
   - PCIe DPM fix for vega
   - Polaris watermark fixes
   - Additional S0ix fix

  radeon:
   - Fix GEM regression
   - Fix AGP dependency handling"

* tag 'drm-fixes-2021-03-12-1' of git://anongit.freedesktop.org/drm/drm: (33 commits)
  drm/nouveau: fix dma syncing for loops (v2)
  drm/i915: Wedge the GPU if command parser setup fails
  drm/compat: Clear bounce structures
  drm/shmem-helpers: vunmap: Don't put pages for dma-buf
  drm: meson_drv add shutdown function
  drm/shmem-helper: Don't remove the offset in vm_area_struct pgoff
  drm/shmem-helper: Check for purged buffers in fault handler
  qxl: Fix uninitialised struct field head.surface_id
  drm/ttm: Fix TTM page pool accounting
  drm/ttm: soften TTM warnings
  drm: Use USB controller's DMA mask when importing dmabufs
  MAINTAINERS: update drm bug reporting URL
  fbdev: atyfb: use LCD management functions for PPC_PMAC also
  fbdev: atyfb: always declare aty_{ld,st}_lcd()
  drm/qxl: fix lockdep issue in qxl_alloc_release_reserved
  drm/qxl: unpin release objects
  drm/fb-helper: only unmap if buffer not null
  drm/amdgpu: fix S0ix handling when the CONFIG_AMD_PMC=m
  drm/radeon: fix AGP dependency
  drm/radeon: also init GEM funcs in radeon_gem_prime_import_sg_table
  ...

The index variable should only be increased in one place.

Noticed this while trying to track down another oops.

v2: use while loop.

Fixes: f295c8cf

 ("drm/nouveau: fix dma syncing warning with debugging on.")
Signed-off-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210311043527.5376-1-airlied@gmail.com

Commit 311a50e7

 ("drm/i915: Add support for mandatory cmdparsing")
introduced mandatory command parsing but setup failures were not
translated into wedging the GPU which was probably the intent.

Possible errors come in two categories. Either the sanity check on
internal tables has failed, which should be caught in CI unless an
affected platform would be missed in testing; or memory allocation failure
happened during driver load, which should be extremely unlikely but for
correctness should still be handled.

v2:
 * Tidy coding style. (Chris)

[airlied: cherry-picked to avoid rc1 base]
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: 311a50e7

 ("drm/i915: Add support for mandatory cmdparsing")
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris.p.wilson@intel.com>
Reviewed-by: Chris Wilson <chris.p.wilson@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210302114213.1102223-1-tvrtko.ursulin@linux.intel.com


(cherry picked from commit 5a1a659762d35a6dc51047c9127c011303c77b7f)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

Merge tag 'amd-drm-fixes-5.12-2021-03-10' of https://gitlab.freedesktop.org/agd5f/linux

 into drm-fixes

amd-drm-fixes-5.12-2021-03-10:

amdgpu:
- Fix aux backlight control
- Add a backlight override parameter
- Various display fixes
- PCIe DPM fix for vega
- Polaris watermark fixes
- Additional S0ix fix

radeon:
- Fix GEM regression
- Fix AGP dependency handling

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210310221141.3974-1-alexander.deucher@amd.com

drm-misc-fixes for rc3, rebased on rc2:
- Fix oops in drm_fbdev_cleanup()
- unpin qxl bos created as pinned when freeing them,
  and make ttm only warn once on this behavior.
- Use LCD management for atyfb on PPC_MAC.
- Use gitlab for drm bugzilla now.
- Fix ttm page pool accounting.
- Zero head.surface_id correctly in qxl.
- Assorted fixes for shmem helpers.
- Shutdown kms poll helper in meson correctly.
- Clear holes when converting compat ioctl's between 32-bits and 64-bits.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/4606f08e-d0e8-c543-5e96-cee2fd728a41@linux.intel.com

Pull media fixes from Mauro Carvalho Chehab:
 "A couple of fixes:

   - fix a build issue with CEC

   - fix a deadlock at usbtv driver

   - fix some null pointer address issues at vsp1 driver

   - fix a wrong bitmap setting at rkisp1 driver"

* tag 'media/v5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  media: rkisp1: params: fix wrong bits settings
  media: v4l: vsp1: Fix uif null pointer access
  media: v4l: vsp1: Fix bru null pointer access
  media: usbtv: Fix deadlock on suspend
  media: rc: compile rc-cec.c into rc-core

The histogram mode is set using 'rkisp1_params_set_bits'.
Only the bits of the mode should be the value argument for
that function. Otherwise bits outside the mode mask are
turned on which is not what was intended.

Fixes: bae1155c

 ("media: staging: rkisp1: add output device for parameters")
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

RZ/G2L SoC has no UIF. This patch fixes null pointer access, when UIF
module is not used.

Fixes: 5e824f98

("media: v4l: vsp1: Integrate DISCOM in display pipeline")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

RZ/G2L SoC has only BRS. This patch fixes null pointer access,when only
BRS is enabled.

Fixes: cbb7fa49

("media: v4l: vsp1: Rename BRU to BRx")
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

usbtv doesn't support power management, so on system suspend the
.disconnect callback of the driver is called. The teardown sequence
includes a call to snd_card_free. Its implementation waits until the
refcount of the sound card device drops to zero, however, if its file is
open, snd_card_file_add takes a reference, which can't be dropped during
the suspend, because the userspace processes are already frozen at this
point. snd_card_free waits for completion forever, leading to a hang on
suspend.

This commit fixes this deadlock condition by replacing snd_card_free
with snd_card_free_when_closed, that doesn't wait until all references
are released, allowing suspend to progress.

Fixes: 63ddf68d

 ("[media] usbtv: add audio support")
Signed-off-by: Maxim Mikityanskiy <maxtram95@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

The rc-cec keymap is unusual in that it can't be built as a module,
instead it is registered directly in rc-main.c if CONFIG_MEDIA_CEC_RC
is set. This is because it can be called from drm_dp_cec_set_edid() via
cec_register_adapter() in an asynchronous context, and it is not
allowed to use request_module() to load rc-cec.ko in that case. Trying to
do so results in a 'WARN_ON_ONCE(wait && current_is_async())'.

Since this keymap is only used if CONFIG_MEDIA_CEC_RC is set, we
just compile this keymap into the rc-core module and never as a
separate module.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Fixes: 2c6d1fff

 (drm: add support for DisplayPort CEC-Tunneling-over-AUX)
Reported-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Some of them have gaps, or fields we don't clear. Native ioctl code
does full copies plus zero-extends on size mismatch, so nothing can
leak. But compat is more hand-rolled so need to be careful.

None of these matter for performance, so just memset.

Also I didn't fix up the CONFIG_DRM_LEGACY or CONFIG_DRM_AGP ioctl, those
are security holes anyway.

Acked-by: Maxime Ripard <mripard@kernel.org>
Reported-by: syzbot+620cf21140fc7e772a5d@syzkaller.appspotmail.com # vblank ioctl
Cc: syzbot+620cf21140fc7e772a5d@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210222100643.400935-1-daniel.vetter@ffwll.ch
(cherry picked from commit e926c474

)
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

dma-buf importing was reworked in commit 7d2cd72a


("drm/shmem-helpers: Simplify dma-buf importing"). Before that commit
drm_gem_shmem_prime_import_sg_table() did set ->pages_use_count=1 and
drm_gem_shmem_vunmap_locked() could call drm_gem_shmem_put_pages()
unconditionally. Now without the use count set, put pages is called also
on dma-bufs. Fix this by only putting pages if it's not imported.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Fixes: 7d2cd72a

 ("drm/shmem-helpers: Simplify dma-buf importing")
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20210219122203.51130-1-noralf@tronnes.org
(cherry picked from commit cdea7251

)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

Problem: random stucks on reboot stage about 1/20 stuck/reboots
// debug kernel log
[    4.496660] reboot: kernel restart prepare CMD:(null)
[    4.498114] meson_ee_pwrc c883c000.system-controller:power-controller: shutdown begin
[    4.503949] meson_ee_pwrc c883c000.system-controller:power-controller: shutdown domain 0:VPU...
...STUCK...

Solution: add shutdown function to meson_drm driver
// debug kernel log
[    5.231896] reboot: kernel restart prepare CMD:(null)
[    5.246135] [drm:meson_drv_shutdown]
...
[    5.259271] meson_ee_pwrc c883c000.system-controller:power-controller: shutdown begin
[    5.274688] meson_ee_pwrc c883c000.system-controller:power-controller: shutdown domain 0:VPU...
[    5.338331] reboot: Restarting system
[    5.358293] psci: PSCI_0_2_FN_SYSTEM_RESET reboot_mode:0 cmd:(null)
bl31 reboot reason: 0xd
bl31 reboot reason: 0x0
system cmd  1.
...REBOOT...

Tested: on VIM1 VIM2 VIM3 VIM3L khadas sbcs - 1000+ successful reboots
and Odroid boards, WeTek Play2 (GXBB)

Fixes: bbbe775e

 ("drm: Add support for Amlogic Meson Graphic Controller")
Signed-off-by: Artem Lapkin <art@khadas.com>
Tested-by: Christian Hewitt <christianshewitt@gmail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210302042202.3728113-1-art@khadas.com


Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

When mmapping the shmem, it would previously adjust the pgoff in the
vm_area_struct to remove the fake offset that is added to be able to
identify the buffer. This patch removes the adjustment and makes the
fault handler use the vm_fault address to calculate the page offset
instead. Although using this address is apparently discouraged, several
DRM drivers seem to be doing it anyway.

The problem with removing the pgoff is that it prevents
drm_vma_node_unmap from working because that searches the mapping tree
by address. That doesn't work because all of the mappings are at offset
0. drm_vma_node_unmap is being used by the shmem helpers when purging
the buffer.

This fixes a bug in Panfrost which is using drm_gem_shmem_purge. Without
this the mapping for the purged buffer can still be accessed which might
mean it would access random pages from other buffers

v2: Don't check whether the unsigned page_offset is less than 0.

Cc: stable@vger.kernel.org
Fixes: 17acb9f3

 ("drm/shmem: Add madvise state and purge helpers")
Signed-off-by: Neil Roberts <nroberts@igalia.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210223155125.199577-3-nroberts@igalia.com


Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

When a buffer is madvised as not needed and then purged, any attempts to
access the buffer from user-space should cause a bus fault. This patch
adds a check for that.

Cc: stable@vger.kernel.org
Fixes: 17acb9f3

 ("drm/shmem: Add madvise state and purge helpers")
Signed-off-by: Neil Roberts <nroberts@igalia.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210223155125.199577-2-nroberts@igalia.com


Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

The surface_id struct field in head is not being initialized and
static analysis warns that this is being passed through to
dev->monitors_config->heads[i] on an assignment. Clear up this
warning by initializing it to zero.

Addresses-Coverity: ("Uninitialized scalar variable")
Fixes: a6d3c4d7

 ("qxl: hook monitors_config updates into crtc, not encoder.")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20210304094928.2280722-1-colin.king@canonical.com


Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

Freed pages are not subtracted from the allocated_pages counter in
ttm_pool_type_fini(), causing a leak in the count on device removal.
The next shrinker invocation loops forever trying to free pages that are
no longer in the pool:

  rcu: INFO: rcu_sched self-detected stall on CPU
  rcu:  3-....: (9998 ticks this GP) idle=54e/1/0x4000000000000000 softirq=434857/434857 fqs=2237
    (t=10001 jiffies g=2194533 q=49211)
  NMI backtrace for cpu 3
  CPU: 3 PID: 1034 Comm: kswapd0 Tainted: P           O      5.11.0-com #1
  Hardware name: System manufacturer System Product Name/PRIME X570-PRO, BIOS 1405 11/19/2019
  Call Trace:
   <IRQ>
   ...
   </IRQ>
   sysvec_apic_timer_interrupt+0x77/0x80
   asm_sysvec_apic_timer_interrupt+0x12/0x20
  RIP: 0010:mutex_unlock+0x16/0x20
  Code: e7 48 8b 70 10 e8 7a 53 77 ff eb aa e8 43 6c ff ff 0f 1f 00 65 48 8b 14 25 00 6d 01 00 31 c9 48 89 d0 f0 48 0f b1 0f 48 39 c2 <74> 05 e9 e3 fe ff ff c3 66 90 48 8b 47 20 48 85 c0 74 0f 8b 50 10
  RSP: 0018:ffffbdb840797be8 EFLAGS: 00000246
  RAX: ffff9ff445a41c00 RBX: ffffffffc02a9ef8 RCX: 0000000000000000
  RDX: ffff9ff445a41c00 RSI: ffffbdb840797c78 RDI: ffffffffc02a9ac0
  RBP: 0000000000000080 R08: 0000000000000000 R09: ffffbdb840797c80
  R10: 0000000000000000 R11: fffffffffffffff5 R12: 0000000000000000
  R13: 0000000000000000 R14: 0000000000000084 R15: ffffffffc02a9a60
   ttm_pool_shrink+0x7d/0x90 [ttm]
   ttm_pool_shrinker_scan+0x5/0x20 [ttm]
   do_shrink_slab+0x13a/0x1a0
...

debugfs shows the incorrect total:

  $ cat /sys/kernel/debug/dri/0/ttm_page_pool
            --- 0--- --- 1--- --- 2--- --- 3--- --- 4--- --- 5--- --- 6--- --- 7--- --- 8--- --- 9--- ---10---
  wc      :        0        0        0        0        0        0        0        0        0        0        0
  uc      :        0        0        0        0        0        0        0        0        0        0        0
  wc 32   :        0        0        0        0        0        0        0        0        0        0        0
  uc 32   :        0        0        0        0        0        0        0        0        0        0        0
  DMA uc  :        0        0        0        0        0        0        0        0        0        0        0
  DMA wc  :        0        0        0        0        0        0        0        0        0        0        0
  DMA     :        0        0        0        0        0        0        0        0        0        0        0

  total   :     3029 of  8244261

Using ttm_pool_type_take() to remove pages from the pool before freeing
them correctly accounts for the freed pages.

Fixes: d099fc8f

 ("drm/ttm: new TT backend allocation pool v3")
Signed-off-by: Anthony DeRossi <ajderossi@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210303011723.22512-1-ajderossi@gmail.com


Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

QXL indeed unrefs pinned BOs and the warnings are spamming peoples log files.

Make sure we warn only once until the QXL driver is fixed.

Signed-off-by: Christian König <christian.koenig@amd.com>
References: https://lore.kernel.org/lkml/YD+eYcMMcdlXB8PY@alley/
Link: https://patchwork.freedesktop.org/patch/422834/


Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>