Testcase:
1. create a minix file system and mount it
2. open a file on the file system with O_RDWR|O_CREAT|O_TRUNC|O_DIRECT
3. open fails with -EINVAL but leaves an empty file behind. All other
   open() failures don't leave the failed open files behind.

It is hard to check the direct_IO op before creating the inode.  Just as
ext4 and btrfs do, this patch will resolve the issue by allowing to
create the file with O_DIRECT but returning error when writing the file.

Link: https://lkml.kernel.org/r/20220107133626.413379-1-qhjin.dev@gmail.com


Signed-off-by: Qinghua Jin <qhjin.dev@gmail.com>
Reported-by: Colin Ian King <colin.king@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

head, tail, ring_size are declared as unsigned int, so all local
variables that operate with these fields have to be unsigned to avoid
signed integer overflow.

Right now, it isn't an issue because the maximum pipe size is limited by
1U<<31.

Link: https://lkml.kernel.org/r/20220106171946.36128-1-avagin@gmail.com


Signed-off-by: Andrei Vagin <avagin@gmail.com>
Suggested-by: Dmitry Safonov <0x7f454c46@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Right now, kcalloc is used to allocate a pipe_buffer array.  The size of
the pipe_buffer struct is 40 bytes.  kcalloc allows allocating reliably
chunks with sizes less or equal to PAGE_ALLOC_COSTLY_ORDER (3).  It
means that the maximum pipe size is 3.2MB in this case.

In CRIU, we use pipes to dump processes memory.  CRIU freezes a target
process, injects a parasite code into it and then this code splices
memory into pipes.  If a maximum pipe size is small, we need to do many
iterations or create many pipes.

kvcalloc attempt to allocate physically contiguous memory, but upon
failure, fall back to non-contiguous (vmalloc) allocation and so it
isn't limited by PAGE_ALLOC_COSTLY_ORDER.

The maximum pipe size for non-root users is limited by the
/proc/sys/fs/pipe-max-size sysctl that is 1MB by default, so only the
root user will be able to trigger vmalloc allocations.

Link: https://lkml.kernel.org/r/20220104171058.22580-1-avagin@gmail.com


Signed-off-by: Andrei Vagin <avagin@gmail.com>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

initcall_blacklist() should return 1 to indicate that it handled its
cmdline arguments.

set_debug_rodata() should return 1 to indicate that it handled its
cmdline arguments.  Print a warning if the option string is invalid.

This prevents these strings from being added to the 'init' program's
environment as they are not init arguments/parameters.

Link: https://lkml.kernel.org/r/20220221050901.23985-1-rdunlap@infradead.org


Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Igor noted in [1] that there are quite a few __setup() handling
functions that return incorrect values.  Doing this can be harmless, but
it can also cause strings to be added to init's argument or environment
list, polluting them.

Since __setup() handling and return values are not documented, first add
documentation for that.  Also add more documentation for early_param()
handling and return values.

For __setup() functions, returning 0 (not handled) has questionable
value if it is just a malformed option value, as in

  rodata=junk

since returning 0 would just cause "rodata=junk" to be added to init's
environment unnecessarily:

  Run /sbin/init as init process
    with arguments:
      /sbin/init
    with environment:
      HOME=/
      TERM=linux
      splash=native
      rodata=junk

Also, there are no recommendations on whether to print a warning when an
unknown parameter value is seen.  I am not addressing that here.

[1] lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru

Link: https://lkml.kernel.org/r/20220221050852.1147-1-rdunlap@infradead.org


Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: Igor Zhbanov <i.zhbanov@omprussia.ru>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use ktime_us_delta() to make the initcall_debug log more precise than
right shifting the result of ktime_to_ns() by 10 bits.

Link: https://lkml.kernel.org/r/20220209053350.15771-1-mark-pk.tsai@mediatek.com


Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Tested-by: Andrew Halaney <ahalaney@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Kees Cook <keescook@chromium.org>
Cc: Valentin Schneider <valentin.schneider@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 0ee3e7b8 ("checkpatch: get default codespell dictionary path
from package location") introduced the ability to search for the
codespell dictionary rather than hardcoding its path.

codespell requires Python 3.6 or above, but on some systems, the python
executable is a Python 2.7 interpreter.  In this case, searching for the
dictionary fails, subsequently making codespell fail:

  No codespell typos will be found - file '/usr/share/codespell/dictionary.txt': No such file or directory

So, use python3 to remove ambiguity.

In addition, when searching for dictionary.txt, do not check if the
codespell executable exists since,

 - checkpatch.pl only uses dictionary.txt, not the codespell
   executable.

 - codespell can be installed via a Python package manager, in which
   case the codespell executable may not be present in a typical $PATH,
   but a dictionary does exist.

Link: https://lkml.kernel.org/r/20220309180048.147672-1-sagarmp@cs.unc.edu


Signed-off-by: Sagar Patel <sagarmp@cs.unc.edu>
Reviewed-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Add early_param as another exception to the blank line preferred after
function/struct/union declaration or definition test.

Link: https://lkml.kernel.org/r/3bd6ada59f411a7685d7e64eeb670540d4bfdcde.camel@perches.com


Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Single line code like:

	if (foo) bar;

should generally be written:

	if (foo)
		bar;

Add a --fix test to do so.

This fix is not done when an ASSIGN_IN_IF in the same line exists.

Link: https://lkml.kernel.org/r/20220128185924.80137-2-joe@perches.com


Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There is no effective difference.

Given the large number of uses of "GPL v2", emit this message only for
patches as a trivial treeside sed could be done one day.

Ref: commit bf7fbeea ("module: Cure the MODULE_LICENSE "GPL" vs. "GPL v2" bogosity")

Link: https://lkml.kernel.org/r/20220128185924.80137-1-joe@perches.com


Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix kernel-doc warings in lib/bitmap.c:

  lib/bitmap.c:498: warning: Function parameter or member 'buf' not described in 'bitmap_print_to_buf'
  lib/bitmap.c:498: warning: Function parameter or member 'maskp' not described in 'bitmap_print_to_buf'
  lib/bitmap.c:498: warning: Function parameter or member 'nmaskbits' not described in 'bitmap_print_to_buf'
  lib/bitmap.c:498: warning: Function parameter or member 'off' not described in 'bitmap_print_to_buf'
  lib/bitmap.c:498: warning: Function parameter or member 'count' not described in 'bitmap_print_to_buf'
  lib/bitmap.c:561: warning: contents before sections
  lib/bitmap.c:606: warning: Function parameter or member 'buf' not described in 'bitmap_print_list_to_buf'
  lib/bitmap.c:606: warning: Function parameter or member 'maskp' not described in 'bitmap_print_list_to_buf'
  lib/bitmap.c:606: warning: Function parameter or member 'nmaskbits' not described in 'bitmap_print_list_to_buf'
  lib/bitmap.c:606: warning: Function parameter or member 'off' not described in 'bitmap_print_list_to_buf'
  lib/bitmap.c:606: warning: Function parameter or member 'count' not described in 'bitmap_print_list_to_buf'
  lib/bitmap.c:819: warning: missing initial short description on line:
   * bitmap_parselist_user()

This still leaves 15 warnings for function return values not described,
similar to this one:

  bitmap.c:890: warning: No description found for return value of 'bitmap_parse'

Link: https://lkml.kernel.org/r/20220306065823.5153-1-rdunlap@infradead.org


Fixes: 1fae5629 ("cpumask: introduce cpumap_print_list/bitmask_to_buf to support large bitmask and list")
Fixes: 4b060420 ("bitmap, irq: add smp_affinity_list interface to /proc/irq")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Yury Norov <yury.norov@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Tian Tao <tiantao6@hisilicon.com>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

0Day robots reported there is compiling issue for 'csky' ARCH when
CONFIG_DEBUG_FORCE_DATA_SECTION_ALIGNED is enabled [1]:

All errors (new ones prefixed by >>):

   {standard input}: Assembler messages:
>> {standard input}:2277: Error: pcrel offset for branch to .LS000B too far (0x3c)

Which was discussed in [2].  And as there is no solution for csky yet, add
some dependency for this config to limit it to several ARCHs which have no
compiling issue so far.

[1]. https://lore.kernel.org/lkml/202202271612.W32UJAj2-lkp@intel.com/
[2]. https://www.spinics.net/lists/linux-kbuild/msg30298.html

Link: https://lkml.kernel.org/r/20220304021100.GN4548@shbuild999.sh.intel.com


Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Guo Ren <guoren@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

It's not obvious that bitfield.h doesn't guarantee the bits.h inclusion
and the example in the former is confusing.  Some developers think that
it's okay to just include bitfield.h to get it working.  Change example
to explicitly include necessary headers in order to avoid confusion.

Link: https://lkml.kernel.org/r/20220207123341.47533-1-andriy.shevchenko@linux.intel.com


Fixes: 3e9b3112 ("add basic register-field manipulation macros")
Depends-on: 8bd9cb51 ("locking/atomics, asm-generic: Move some macros from <linux/bitops.h> to a new <linux/bits.h> file")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reported-by: Jan Dąbroś <jsd@semihalf.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Building a kernel with CONFIG_CC_OPTIMISE_FOR_SIZE leads to
__ilog2_u32() being duplicated 50 times and __ilog2_u64() 3 times in
vmlinux on a tiny powerpc32 config.

__ilog2_u32() being 2 instructions it is not worth being kept out of
line, so force inlining.  Allthough the u64 version is a bit bigger,
there is still a small benefit in keeping it inlined.  On a 64 bits
config there's a real benefit.

With this change the size of vmlinux text is reduced by 1 kbytes, which
is approx 50% more than the size of the removed functions.

Before the patch there is for instance:

	c00d2a94 <__ilog2_u32>:
	c00d2a94:	7c 63 00 34 	cntlzw  r3,r3
	c00d2a98:	20 63 00 1f 	subfic  r3,r3,31
	c00d2a9c:	4e 80 00 20 	blr

	c00d36d8 <__order_base_2>:
	c00d36d8:	28 03 00 01 	cmplwi  r3,1
	c00d36dc:	40 81 00 2c 	ble     c00d3708 <__order_base_2+0x30>
	c00d36e0:	94 21 ff f0 	stwu    r1,-16(r1)
	c00d36e4:	7c 08 02 a6 	mflr    r0
	c00d36e8:	38 63 ff ff 	addi    r3,r3,-1
	c00d36ec:	90 01 00 14 	stw     r0,20(r1)
	c00d36f0:	4b ff f3 a5 	bl      c00d2a94 <__ilog2_u32>
	c00d36f4:	80 01 00 14 	lwz     r0,20(r1)
	c00d36f8:	38 63 00 01 	addi    r3,r3,1
	c00d36fc:	7c 08 03 a6 	mtlr    r0
	c00d3700:	38 21 00 10 	addi    r1,r1,16
	c00d3704:	4e 80 00 20 	blr
	c00d3708:	38 60 00 00 	li      r3,0
	c00d370c:	4e 80 00 20 	blr

With the patch it has become:

	c00d356c <__order_base_2>:
	c00d356c:	28 03 00 01 	cmplwi  r3,1
	c00d3570:	40 81 00 14 	ble     c00d3584 <__order_base_2+0x18>
	c00d3574:	38 63 ff ff 	addi    r3,r3,-1
	c00d3578:	7c 63 00 34 	cntlzw  r3,r3
	c00d357c:	20 63 00 20 	subfic  r3,r3,32
	c00d3580:	4e 80 00 20 	blr
	c00d3584:	38 60 00 00 	li      r3,0
	c00d3588:	4e 80 00 20 	blr

No more need for __order_base_2() to setup a stack frame and
save/restore caller address. And the following 'add 1' is
merged in the subtract.

Another typical use of it:

	c080ff28 <hugepagesz_setup>:
	...
	c080fff8:	7f c3 f3 78 	mr      r3,r30
	c080fffc:	4b 8f 81 f1 	bl      c01081ec <__ilog2_u32>
	c0810000:	38 63 ff f2 	addi    r3,r3,-14
	...

Becomes

	c080ff1c <hugepagesz_setup>:
	...
	c080ffec:	7f c3 00 34 	cntlzw  r3,r30
	c080fff0:	20 63 00 11 	subfic  r3,r3,17
	...

Here no need to move r30 argument to r3 then substract 14 to result.  Just
work on r30 and merge the 'sub 14' with the 'sub from 31'.

Link: https://lkml.kernel.org/r/803a2ac3d923ebcfd0dd40f5886b05cae7bb0aba.1644243860.git.christophe.leroy@csgroup.eu


Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(1) compiler_types.h is unconditionally included via an -include flag
    (see scripts/Makefile.lib), and it defines __compiler_offsetof
    unconditionally.  So testing for definedness of __compiler_offsetof is
    mostly pointless.

(2) Every relevant compiler provides __builtin_offsetof (even sparse
    has had that for 14 years), and if for whatever reason one would end
    up picking up the poor man's fallback definition (C file compiler with
    completely custom CFLAGS?), newer clang versions won't treat the
    result as an Integer Constant Expression, so if used in place where
    such is required (static initializer or static_assert), one would get
    errors like

      t.c:11:16: error: static_assert expression is not an integral constant expression
      t.c:11:16: note: cast that performs the conversions of a reinterpret_cast is not allowed in a constant expression
      t.c:4:33: note: expanded from macro 'offsetof'
      #define offsetof(TYPE, MEMBER)  ((size_t)&((TYPE *)0)->MEMBER)

So just define offsetof unconditionally and directly in terms of
__builtin_offsetof.

Link: https://lkml.kernel.org/r/20220202102147.326672-1-linux@rasmusvillemoes.dk


Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Currently it's not possible to enable DEBUG_INFO for an all*config
build, since it is marked as "depends on !COMPILE_TEST".

This generally makes sense because a debug build of an all*config target
ends up taking much longer and the output is much larger.  Having this
be "default off" makes sense.

However, there are cases where enabling DEBUG_INFO for such builds is
useful for doing treewide A/B comparisons of build options, etc.

Make DEBUG_INFO selectable from any of the DWARF version choice options,
with DEBUG_INFO_NONE being the default for COMPILE_TEST.

The mutually exclusive relationship between DWARF5 and BTF must be
inverted, but the result remains the same.  Additionally moves
DEBUG_KERNEL and DEBUG_MISC up to the top of the menu because they were
enabling features _above_ it, making it weird to navigate menuconfig.

[keescook@chromium.org: make DEBUG_INFO always default=n]
  Link: https://lkml.kernel.org/r/20220128214131.580131-1-keescook@chromium.org
  Link: https://lore.kernel.org/lkml/YfRY6+CaQxX7O8vF@dev-arch.archlinux-ax161

Link: https://lkml.kernel.org/r/20220125075126.891825-1-keescook@chromium.org


Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Use helper macro __ATTR_RW to define kobj_attribute to make code more
clear.  Minor readability improvement.

Link: https://lkml.kernel.org/r/20220222112034.48298-1-linmiaohe@huawei.com


Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Several attributes depend on __CHECKER__, but previously there was no
clue in the tree about when __CHECKER__ might be defined.  Add hints at
the most common places (__kernel, __user, __iomem, __bitwise) and in the
sparse documentation.

Link: https://lkml.kernel.org/r/20220310220927.245704-3-helgaas@kernel.org


Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: "Michael S . Tsirkin" <mst@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There are no users of "__bitwise__" except the definition of
"__bitwise".  Remove __bitwise__ and define __bitwise directly.

This is a follow-up to 05de9700 ("linux/types.h: enable endian
checks for all sparse builds").

[akpm@linux-foundation.org: change the tools/include/linux/types.h definition also]

Link: https://lkml.kernel.org/r/20220310220927.245704-2-helgaas@kernel.org


Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix a spelling problem to remove warnings found by running
scripts/kernel-doc, which is caused by using 'make W=1'.

  fs/proc/vmcore.c:492: warning: Function parameter or member 'size' not described in 'vmcore_alloc_buf'
  fs/proc/vmcore.c:492: warning: Excess function parameter 'sizez' description in 'vmcore_alloc_buf'

Link: https://lkml.kernel.org/r/20220129011449.105278-1-yang.lee@linux.alibaba.com


Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Lockdep noticed that there is chance for a deadlock if we have concurrent
mmap, concurrent read, and the addition/removal of a callback.

As nicely explained by Boqun:
 "Lockdep warned about the above sequences because rw_semaphore is a
  fair read-write lock, and the following can cause a deadlock:

	TASK 1			TASK 2		TASK 3
	======			======		======
	down_write(mmap_lock);
				down_read(vmcore_cb_rwsem)
						down_write(vmcore_cb_rwsem); // blocked
	down_read(vmcore_cb_rwsem); // cannot get the lock because of the fairness
				down_read(mmap_lock); // blocked

  IOW, a reader can block another read if there is a writer queued by
  the second reader and the lock is fair"

To fix this, convert to srcu to make this deadlock impossible.  We need
srcu as our callbacks can sleep.  With this change, I cannot trigger any
lockdep warnings.

    ======================================================
    WARNING: possible circular locking dependency detected
    5.17.0-0.rc0.20220117git0c947b893d69.68.test.fc36.x86_64 #1 Not tainted
    ------------------------------------------------------
    makedumpfile/542 is trying to acquire lock:
    ffffffff832d2eb8 (vmcore_cb_rwsem){.+.+}-{3:3}, at: mmap_vmcore+0x340/0x580

    but task is already holding lock:
    ffff8880af226438 (&mm->mmap_lock#2){++++}-{3:3}, at: vm_mmap_pgoff+0x84/0x150

    which lock already depends on the new lock.

    the existing dependency chain (in reverse order) is:

    -> #1 (&mm->mmap_lock#2){++++}-{3:3}:
           lock_acquire+0xc3/0x1a0
           __might_fault+0x4e/0x70
           _copy_to_user+0x1f/0x90
           __copy_oldmem_page+0x72/0xc0
           read_from_oldmem+0x77/0x1e0
           read_vmcore+0x2c2/0x310
           proc_reg_read+0x47/0xa0
           vfs_read+0x101/0x340
           __x64_sys_pread64+0x5d/0xa0
           do_syscall_64+0x43/0x90
           entry_SYSCALL_64_after_hwframe+0x44/0xae

    -> #0 (vmcore_cb_rwsem){.+.+}-{3:3}:
           validate_chain+0x9f4/0x2670
           __lock_acquire+0x8f7/0xbc0
           lock_acquire+0xc3/0x1a0
           down_read+0x4a/0x140
           mmap_vmcore+0x340/0x580
           proc_reg_mmap+0x3e/0x90
           mmap_region+0x504/0x880
           do_mmap+0x38a/0x520
           vm_mmap_pgoff+0xc1/0x150
           ksys_mmap_pgoff+0x178/0x200
           do_syscall_64+0x43/0x90
           entry_SYSCALL_64_after_hwframe+0x44/0xae

    other info that might help us debug this:

     Possible unsafe locking scenario:

           CPU0                    CPU1
           ----                    ----
      lock(&mm->mmap_lock#2);
                                   lock(vmcore_cb_rwsem);
                                   lock(&mm->mmap_lock#2);
      lock(vmcore_cb_rwsem);

     *** DEADLOCK ***

    1 lock held by makedumpfile/542:
     #0: ffff8880af226438 (&mm->mmap_lock#2){++++}-{3:3}, at: vm_mmap_pgoff+0x84/0x150

    stack backtrace:
    CPU: 0 PID: 542 Comm: makedumpfile Not tainted 5.17.0-0.rc0.20220117git0c947b893d69.68.test.fc36.x86_64 #1
    Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
    Call Trace:
     __lock_acquire+0x8f7/0xbc0
     lock_acquire+0xc3/0x1a0
     down_read+0x4a/0x140
     mmap_vmcore+0x340/0x580
     proc_reg_mmap+0x3e/0x90
     mmap_region+0x504/0x880
     do_mmap+0x38a/0x520
     vm_mmap_pgoff+0xc1/0x150
     ksys_mmap_pgoff+0x178/0x200
     do_syscall_64+0x43/0x90

Link: https://lkml.kernel.org/r/20220119193417.100385-1-david@redhat.com


Fixes: cc5f2704 ("proc/vmcore: convert oldmem_pfn_is_ram callback to more generic vmcore callbacks")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Baoquan He <bhe@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

It's not a standard approach that use __get_free_page() to alloc path
buffer directly.  We'd better use kmalloc and PATH_MAX.

	PAGE_SIZE is different on different archs. An unlinked file
	with very long canonical pathname will readlink differently
	because "(deleted)" eats into a buffer.	--adobriyan

[akpm@linux-foundation.org: remove now-unneeded cast]

Link: https://lkml.kernel.org/r/Ye1fCxyZZ0I5lgOL@localhost.localdomain


Signed-off-by: Hao Lee <haolee.swjtu@gmail.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull kvm fix from Paolo Bonzini:
 "Fix for the SLS mitigation, which makes a 'SETcc/RET' pair grow
  to 'SETcc/RET/INT3'.

  This doesn't fit in 4 bytes any more, so the alignment has to
  change to 8 for this case"

* tag 'for-linus-5.17' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  kvm/emulate: Fix SETcc emulation function offsets with SLS

Pull input fixes from Dmitry Torokhov:
 "Two driver fixes:

   - a fix for zinitix touchscreen to properly report contacts

   - a fix for aiptek tablet driver to be more resilient to devices with
     incorrect descriptors"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: aiptek - properly check endpoint type
  Input: zinitix - do not report shadow fingers

The commit in Fixes started adding INT3 after RETs as a mitigation
against straight-line speculation.

The fastop SETcc implementation in kvm's insn emulator uses macro magic
to generate all possible SETcc functions and to jump to them when
emulating the respective instruction.

However, it hardcodes the size and alignment of those functions to 4: a
three-byte SETcc insn and a single-byte RET. BUT, with SLS, there's an
INT3 that gets slapped after the RET, which brings the whole scheme out
of alignment:

  15:   0f 90 c0                seto   %al
  18:   c3                      ret
  19:   cc                      int3
  1a:   0f 1f 00                nopl   (%rax)
  1d:   0f 91 c0                setno  %al
  20:   c3                      ret
  21:   cc                      int3
  22:   0f 1f 00                nopl   (%rax)
  25:   0f 92 c0                setb   %al
  28:   c3                      ret
  29:   cc                      int3

and this explodes like this:

  int3: 0000 [#1] PREEMPT SMP PTI
  CPU: 0 PID: 2435 Comm: qemu-system-x86 Not tainted 5.17.0-rc8-sls #1
  Hardware name: Dell Inc. Precision WorkStation T3400  /0TP412, BIOS A14 04/30/2012
  RIP: 0010:setc+0x5/0x8 [kvm]
  Code: 00 00 0f 1f 00 0f b6 05 43 24 06 00 c3 cc 0f 1f 80 00 00 00 00 0f 90 c0 c3 cc 0f \
	  1f 00 0f 91 c0 c3 cc 0f 1f 00 0f 92 c0 c3 cc <0f> 1f 00 0f 93 c0 c3 cc 0f 1f 00 \
	  0f 94 c0 c3 cc 0f 1f 00 0f 95 c0
  Call Trace:
   <TASK>
   ? x86_emulate_insn [kvm]
   ? x86_emulate_instruction [kvm]
   ? vmx_handle_exit [kvm_intel]
   ? kvm_arch_vcpu_ioctl_run [kvm]
   ? kvm_vcpu_ioctl [kvm]
   ? __x64_sys_ioctl
   ? do_syscall_64
   ? entry_SYSCALL_64_after_hwframe
   </TASK>

Raise the alignment value when SLS is enabled and use a macro for that
instead of hard-coding naked numbers.

Fixes: e463a09a ("x86: Add straight-line-speculation mitigation")
Reported-by: Jamie Heilman <jamie@audible.transient.net>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Jamie Heilman <jamie@audible.transient.net>
Link: https://lore.kernel.org/r/YjGzJwjrvxg5YZ0Z@audible.transient.net


[Add a comment and a bit of safety checking, since this is going to be changed
 again for IBT support. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Pull ARM SoC fix from Arnd Bergmann:
 "Here is one last regression fix for 5.17, reverting a patch that went
  into 5.16 as a cleanup that ended up breaking external interrupts on
  Layerscape chips.

  The revert makes it work again, but also reintroduces a build time
  warning about the nonstandard DT binding that will have to be dealt
  with in the future"

* tag 'soc-fixes-5.17-4' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  Revert "arm64: dts: freescale: Fix 'interrupt-map' parent address cells"

Pull SCSI fixes from James Bottomley:
 "Two small(ish) fixes, both in drivers"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: fnic: Finish scsi_cmnd before dropping the spinlock
  scsi: mpt3sas: Page fault in reply q processing

Merge tag 'perf-tools-fixes-for-v5.17-2022-03-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Avoid iterating empty evlist, fixing a segfault with 'perf stat --null'

 - Ignore case in topdown.slots check, fixing issue with Intel Icelake
   JSON metrics.

 - Fix symbol size calculation condition for fixing up corner case
   symbol end address obtained from Kallsyms.

* tag 'perf-tools-fixes-for-v5.17-2022-03-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  perf parse-events: Ignore case in topdown.slots check
  perf evlist: Avoid iteration for empty evlist.
  perf symbols: Fix symbol size calculation condition

Pull char/misc driver fix from Greg KH:
 "Here is a single driver fix for 5.17-final that has been submitted
  many times but I somehow missed it in my patch queue:

   - fix for counter sysfs code for reported problem

  This has been in linux-next all week with no reported issues"

* tag 'char-misc-5.17-final' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  counter: Stop using dev_get_drvdata() to get the counter device

Pull USB fixes from Greg KH:
 "Here are some small remaining USB fixes for 5.17-final.

  They include:

   - two USB gadget driver fixes for reported problems

   - usbtmc driver fix for syzbot found issues

   - musb patch partial revert to resolve a reported regression.

  All of these have been in linux-next this week with no reported
  problems"

* tag 'usb-5.17-final' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: gadget: Fix use-after-free bug by not setting udc->dev.driver
  usb: usbtmc: Fix bug in pipe direction for control transfers
  partially Revert "usb: musb: Set the DT node on the child device"
  usb: gadget: rndis: prevent integer overflow in rndis_set_response()

An issue with icelakex metrics:

  https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/perf/pmu-events/arch/x86/icelakex/icx-metrics.json?h=perf/core&id=65eab2bc7dab326ee892ec5a4c749470b368b51a#n48



That causes the slots not to be first.

Fixes: 94dbfd67 ("perf parse-events: Architecture specific leader override")
Reported-by: Caleb Biggers <caleb.biggers@intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Zhengjun Xing <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20220317224309.543736-1-irogers@google.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

As seen with 'perf stat --null ..' and reported in:
https://lore.kernel.org/lkml/YjCLcpcX2peeQVCH@kernel.org/



v2. Avoids setting evsel in the empty list case as suggested by Jiri Olsa.

    Committer testing:

Before:

  $  perf stat --null sleep 1
  Segmentation fault (core dumped)
  $

After:

  $  perf stat --null sleep 1

   Performance counter stats for 'sleep 1':

         1.010340646 seconds time elapsed

         0.001420000 seconds user
         0.000000000 seconds sys
  $

Fixes: 472832d2 ("perf evlist: Refactor evlist__for_each_cpu()")
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20220317231643.550902-1-irogers@google.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Before this patch, the symbol end address fixup to be called, needed two
conditions being met:

  if (prev->end == prev->start && prev->end != curr->start)

Where
  "prev->end == prev->start" means that prev is zero-long
                             (and thus needs a fixup)
and
  "prev->end != curr->start" means that fixup hasn't been applied yet

However, this logic is incorrect in the following situation:

*curr  = {rb_node = {__rb_parent_color = 278218928,
  rb_right = 0x0, rb_left = 0x0},
  start = 0xc000000000062354,
  end = 0xc000000000062354, namelen = 40, type = 2 '\002',
  binding = 0 '\000', idle = 0 '\000', ignore = 0 '\000',
  inlined = 0 '\000', arch_sym = 0 '\000', annotate2 = false,
  name = 0x1159739e "kprobe_optinsn_page\t[__builtin__kprobes]"}

*prev = {rb_node = {__rb_parent_color = 278219041,
  rb_right = 0x109548b0, rb_left = 0x109547c0},
  start = 0xc000000000062354,
  end = 0xc000000000062354, namelen = 12, type = 2 '\002',
  binding = 1 '\001', idle = 0 '\000', ignore = 0 '\000',
  inlined = 0 '\000', arch_sym = 0 '\000', annotate2 = false,
  name = 0x1095486e "optinsn_slot"}

In this case, prev->start == prev->end == curr->start == curr->end,
thus the condition above thinks that "we need a fixup due to zero
length of prev symbol, but it has been probably done, since the
prev->end == curr->start", which is wrong.

After the patch, the execution path proceeds to arch__symbols__fixup_end
function which fixes up the size of prev symbol by adding page_size to
its end offset.

Fixes: 3b01a413 ("perf symbols: Improve kallsyms symbol end addr calculation")
Signed-off-by: Michael Petlan <mpetlan@redhat.com>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20220317135536.805-1-mpetlan@redhat.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Pull arm64 fixes from Catalin Marinas:
 "Fix two compiler warnings introduced by recent commits: pointer
  arithmetic and double initialisation of struct field"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: errata: avoid duplicate field initializer
  arm64: fix clang warning about TRAMP_VALIAS

Pull cifs fix from Steve French:
 "Small fix for regression in multiuser mounts.

  The additional improvements suggested by Ronnie to make the server and
  session status handling code easier to read can wait for the 5.18
  merge window."

* tag '5.17-rc8-smb3-fix' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: fix incorrect session setup check for multiuser mounts

Pull block fixes from Jens Axboe:

 - Revert of a nvme target feature (Hannes)

 - Fix a memory leak with rq-qos (Ming)

* tag 'block-5.17-2022-03-18' of git://git.kernel.dk/linux-block:
  nvmet: revert "nvmet: make discovery NQN configurable"
  block: release rq qos structures for queue without disk

Pull drm fixes from Dave Airlie:
 "A few minor changes to finish things off, one mgag200 regression, imx
  fix and couple of panel changes.

  imx:
   - Don't test bus flags in atomic check

  mgag200:
   - Fix PLL setup on some models

  panel:
   - Fix bpp settings on Innolux G070Y2-L01
   - Fix DRM_PANEL_EDP Kconfig dependencies"

* tag 'drm-fixes-2022-03-18' of git://anongit.freedesktop.org/drm/drm:
  drm: Don't make DRM_PANEL_BRIDGE dependent on DRM_KMS_HELPERS
  drm/panel: simple: Fix Innolux G070Y2-L01 BPP settings
  drm/imx: parallel-display: Remove bus flags check in imx_pd_bridge_atomic_check()
  drm/mgag200: Fix PLL setup for g200wb and g200ew

The '.type' field is initialized both in place and in the macro
as reported by this W=1 warning:

arch/arm64/include/asm/cpufeature.h:281:9: error: initialized field overwritten [-Werror=override-init]
  281 |         (ARM64_CPUCAP_SCOPE_LOCAL_CPU | ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU)
      |         ^
arch/arm64/kernel/cpu_errata.c:136:17: note: in expansion of macro 'ARM64_CPUCAP_LOCAL_CPU_ERRATUM'
  136 |         .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,                         \
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/arm64/kernel/cpu_errata.c:145:9: note: in expansion of macro 'ERRATA_MIDR_RANGE'
  145 |         ERRATA_MIDR_RANGE(m, var, r_min, var, r_max)
      |         ^~~~~~~~~~~~~~~~~
arch/arm64/kernel/cpu_errata.c:613:17: note: in expansion of macro 'ERRATA_MIDR_REV_RANGE'
  613 |                 ERRATA_MIDR_REV_RANGE(MIDR_CORTEX_A510, 0, 0, 2),
      |                 ^~~~~~~~~~~~~~~~~~~~~
arch/arm64/include/asm/cpufeature.h:281:9: note: (near initialization for 'arm64_errata[18].type')
  281 |         (ARM64_CPUCAP_SCOPE_LOCAL_CPU | ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU)
      |         ^

Remove the extranous initializer.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 1dd498e5 ("KVM: arm64: Workaround Cortex-A510's single-step and PAC trap errata")
Link: https://lore.kernel.org/r/20220316183800.1546731-1-arnd@kernel.org


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The newly introduced TRAMP_VALIAS definition causes a build warning
with clang-14:

arch/arm64/include/asm/vectors.h:66:31: error: arithmetic on a null pointer treated as a cast from integer to pointer is a GNU extension [-Werror,-Wnull-pointer-arithmetic]
                return (char *)TRAMP_VALIAS + SZ_2K * slot;

Change the addition to something clang does not complain about.

Fixes: bd09128d ("arm64: Add percpu vectors for EL1")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: James Morse <james.morse@arm.com>
Link: https://lore.kernel.org/r/20220316183833.1563139-1-arnd@kernel.org


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>