Pull arch/csky updates from Guo Ren:
 "Here are three main features (cpu_hotplug, basic ftrace, basic perf)
  and some bugfixes:

  Features:
   - Add CPU-hotplug support for SMP
   - Add ftrace with function trace and function graph trace
   - Add Perf support
   - Add EM_CSKY_OLD 39
   - optimize kernel panic print.
   - remove syscall_exit_work

  Bugfixes:
   - fix abiv2 mmap(... O_SYNC) failure
   - fix gdb coredump error
   - remove vdsp implement for kernel
   - fix qemu failure to bootup sometimes
   - fix ftrace call-graph panic
   - fix device tree node reference leak
   - remove meaningless header-y
   - fix save hi,lo,dspcr regs in switch_stack
   - remove unused members in processor.h"

* tag 'csky-for-linus-4.21' of git://github.com/c-sky/csky-linux:
  csky: Add perf support for C-SKY
  csky: Add EM_CSKY_OLD 39
  clocksource/drivers/c-sky: fixup ftrace call-graph panic
  csky: ftrace call graph supported.
  csky: basic ftrace supported
  csky: remove unused members in processor.h
  csky: optimize kernel panic print.
  csky: stacktrace supported.
  csky: CPU-hotplug supported for SMP
  clocksource/drivers/c-sky: fixup qemu fail to bootup sometimes.
  csky: fixup save hi,lo,dspcr regs in switch_stack.
  csky: remove syscall_exit_work
  csky: fixup remove vdsp implement for kernel.
  csky: bugfix gdb coredump error.
  csky: fixup abiv2 mmap(... O_SYNC) failed.
  csky: define syscall_get_arch()
  elf-em.h: add EM_CSKY
  csky: remove meaningless header-y
  csky: Don't leak device tree node reference

Merge more updates from Andrew Morton:

 - procfs updates

 - various misc bits

 - lib/ updates

 - epoll updates

 - autofs

 - fatfs

 - a few more MM bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits)
  mm/page_io.c: fix polled swap page in
  checkpatch: add Co-developed-by to signature tags
  docs: fix Co-Developed-by docs
  drivers/base/platform.c: kmemleak ignore a known leak
  fs: don't open code lru_to_page()
  fs/: remove caller signal_pending branch predictions
  mm/: remove caller signal_pending branch predictions
  arch/arc/mm/fault.c: remove caller signal_pending_branch predictions
  kernel/sched/: remove caller signal_pending branch predictions
  kernel/locking/mutex.c: remove caller signal_pending branch predictions
  mm: select HAVE_MOVE_PMD on x86 for faster mremap
  mm: speed up mremap by 20x on large regions
  mm: treewide: remove unused address argument from pte_alloc functions
  initramfs: cleanup incomplete rootfs
  scripts/gdb: fix lx-version string output
  kernel/kcov.c: mark write_comp_data() as notrace
  kernel/sysctl: add panic_print into sysctl
  panic: add options to print system info when panic happens
  bfs: extra sanity checking and static inode bitmap
  exec: separate MM_ANONPAGES and RLIMIT_STACK accounting
  ...

Some non-generic ia64 configs don't build swiotlb, and thus should not
pull in the generic non-coherent DMA infrastructure.

Fixes: 68c60834

 ("swiotlb: remove dma_mark_clean")
Reported-by: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This has been broken forever, and nobody ever really noticed because
it's purely a performance issue.

Long long ago, in commit 6175ddf0 ("x86: Clean up mem*io functions")
Brian Gerst simplified the memory copies to and from iomem, since on
x86, the instructions to access iomem are exactly the same as the
regular instructions.

That is technically true, and things worked, and nobody said anything.
Besides, back then the regular memcpy was pretty simple and worked fine.

Nobody noticed except for David Laight, that is.  David has a testing a
TLP monitor he was writing for an FPGA, and has been occasionally
complaining about how memcpy_toio() writes things one byte at a time.

Which is completely unacceptable from a performance standpoint, even if
it happens to technically work.

The reason it's writing one byte at a time is because while it's
technically true that accesses to iomem are the same as accesses to
regular memory on x86, the _granularity_ (and ordering) of accesses
matter to iomem in ways that they don't matter to regular cached memory.

In particular, when ERMS is set, we default to using "rep movsb" for
larger memory copies.  That is indeed perfectly fine for real memory,
since the whole point is that the CPU is going to do cacheline
optimizations and executes the memory copy efficiently for cached
memory.

With iomem? Not so much.  With iomem, "rep movsb" will indeed work, but
it will copy things one byte at a time. Slowly and ponderously.

Now, originally, back in 2010 when commit 6175ddf0

 was done, we
didn't use ERMS, and this was much less noticeable.

Our normal memcpy() was simpler in other ways too.

Because in fact, it's not just about using the string instructions.  Our
memcpy() these days does things like "read and write overlapping values"
to handle the last bytes of the copy.  Again, for normal memory,
overlapping accesses isn't an issue.  For iomem? It can be.

So this re-introduces the specialized memcpy_toio(), memcpy_fromio() and
memset_io() functions.  It doesn't particularly optimize them, but it
tries to at least not be horrid, or do overlapping accesses.  In fact,
this uses the existing __inline_memcpy() function that we still had
lying around that uses our very traditional "rep movsl" loop followed by
movsw/movsb for the final bytes.

Somebody may decide to try to improve on it, but if we've gone almost a
decade with only one person really ever noticing and complaining, maybe
it's not worth worrying about further, once it's not _completely_ broken?

Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This actually enables the __put_user_goto() functionality in
unsafe_put_user().

For an example of the effect of this, this is the code generated for the

        unsafe_put_user(signo, &infop->si_signo, Efault);

in the waitid() system call:

	movl %ecx,(%rbx)        # signo, MEM[(struct __large_struct *)_2]

It's just one single store instruction, along with generating an
exception table entry pointing to the Efault label case in case that
instruction faults.

Before, we would generate this:

	xorl    %edx, %edx
	movl %ecx,(%rbx)        # signo, MEM[(struct __large_struct *)_3]
        testl   %edx, %edx
        jne     .L309

with the exception table generated for that 'mov' instruction causing us
to jump to a stub that set %edx to -EFAULT and then jumped back to the
'testl' instruction.

So not only do we now get rid of the extra code in the normal sequence,
we also avoid unnecessarily keeping that extra error register live
across it all.

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

This is finally the actual reason for the odd error handling in the
"unsafe_get/put_user()" functions, introduced over three years ago.

Using a "jump to error label" interface is somewhat odd, but very
convenient as a programming interface, and more importantly, it fits
very well with simply making the target be the exception handler address
directly from the inline asm.

The reason it took over three years to actually do this? We need "asm
goto" support for it, which only became the default on x86 last year.
It's now been a year that we've forced asm goto support (see commit
e501ce95

 "x86: Force asm-goto"), and so let's just do it here too.

[ Side note: this commit was originally done back in 2016. The above
  commentary about timing is obviously about it only now getting merged
  into my real upstream tree     - Linus ]

Sadly, gcc still only supports "asm goto" with asms that do not have any
outputs, so we are limited to only the put_user case for this.  Maybe in
several more years we can do the get_user case too.

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

swap_readpage() wants to do polling to bring in pages if asked to, but
it doesn't mark the bio as being polled.  Additionally, the looping
around the blk_poll() check isn't correct - if we get a zero return, we
should call io_schedule(), we can't just assume that the bio has
completed.  The regular bio->bi_private check should be used for that.

Link: http://lkml.kernel.org/r/e15243a8-2cdf-c32c-ecee-f289377c8ef9@kernel.dk


Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

As per Documentation/process/submitting-patches, Co-developed-by is a
valid signature.

This commit removes the warning.

Link: http://lkml.kernel.org/r/1544808928-20002-3-git-send-email-jorge.ramirez-ortiz@linaro.org


Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Himanshu Jha <himanshujha199640@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The accepted terminology will be Co-developed-by therefore lose the
capital letter from now on.

Link: http://lkml.kernel.org/r/1544808928-20002-2-git-send-email-jorge.ramirez-ortiz@linaro.org


Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
Acked-by: Himanshu Jha <himanshujha199640@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Niklas Cassel <niklas.cassel@linaro.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

unreferenced object 0xffff808ec6dc5a80 (size 128):
  comm "swapper/0", pid 1, jiffies 4294938063 (age 2560.530s)
  hex dump (first 32 bytes):
    ff ff ff ff 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b  ........kkkkkkkk
    6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
  backtrace:
    [<00000000476dcf8c>] kmem_cache_alloc_trace+0x430/0x500
    [<000000004f708d37>] platform_device_register_full+0xbc/0x1e8
    [<000000006c2a7ec7>] acpi_create_platform_device+0x370/0x450
    [<00000000ef135642>] acpi_default_enumeration+0x34/0x78
    [<000000003bd9a052>] acpi_bus_attach+0x2dc/0x3e0
    [<000000003cf4f7f2>] acpi_bus_attach+0x108/0x3e0
    [<000000003cf4f7f2>] acpi_bus_attach+0x108/0x3e0
    [<000000002968643e>] acpi_bus_scan+0xb0/0x110
    [<0000000010dd0bd7>] acpi_scan_init+0x1a8/0x410
    [<00000000965b3c5a>] acpi_init+0x408/0x49c
    [<00000000ed4b9fe2>] do_one_initcall+0x178/0x7f4
    [<00000000a5ac5a74>] kernel_init_freeable+0x9d4/0xa9c
    [<0000000070ea6c15>] kernel_init+0x18/0x138
    [<00000000fb8fff06>] ret_from_fork+0x10/0x1c
    [<0000000041273a0d>] 0xffffffffffffffff

Then, faddr2line pointed out this line,

/*
 * This memory isn't freed when the device is put,
 * I don't have a nice idea for that though.  Conceptually
 * dma_mask in struct device should not be a pointer.
 * See http://thread.gmane.org/gmane.linux.kernel.pci/9081
 */
pdev->dev.dma_mask =
	kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);

Since this leak has existed for more than 8 years and it does not
reference other parts of the memory, let kmemleak ignore it, so users
don't need to waste time reporting this in the future.

Link: http://lkml.kernel.org/r/20181206160751.36211-1-cai@gmx.us


Signed-off-by: Qian Cai <cai@gmx.us>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Multiple filesystems open code lru_to_page().  Rectify this by moving
the macro from mm_inline (which is specific to lru stuff) to the more
generic mm.h header and start using the macro where appropriate.

No functional changes.

Link: http://lkml.kernel.org/r/20181129104810.23361-1-nborisov@suse.com
Link: https://lkml.kernel.org/r/20181129075301.29087-1-nborisov@suse.com


Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Pankaj gupta <pagupta@redhat.com>
Acked-by: "Yan, Zheng" <zyan@redhat.com>		[ceph]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is already done for us internally by the signal machinery.

[akpm@linux-foundation.org: fix fs/buffer.c]
Link: http://lkml.kernel.org/r/20181116002713.8474-7-dave@stgolabs.net


Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is already done for us internally by the signal machinery.

Link: http://lkml.kernel.org/r/20181116002713.8474-5-dave@stgolabs.net


Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is already done for us internally by the signal machinery.

Link: http://lkml.kernel.org/r/20181116002713.8474-4-dave@stgolabs.net


Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is already done for us internally by the signal machinery.

Link: http://lkml.kernel.org/r/20181116002713.8474-3-dave@stgolabs.net


Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is already done for us internally by the signal machinery.

Link: http://lkml.kernel.org/r/20181116002713.8474-2-dave@stgolabs.net


Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Moving page-tables at the PMD-level on x86 is known to be safe.  Enable
this option so that we can do fast mremap when possible.

Link: http://lkml.kernel.org/r/20181108181201.88826-4-joelaf@google.com


Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Suggested-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Android needs to mremap large regions of memory during memory management
related operations.  The mremap system call can be really slow if THP is
not enabled.  The bottleneck is move_page_tables, which is copying each
pte at a time, and can be really slow across a large map.  Turning on
THP may not be a viable option, and is not for us.  This patch speeds up
the performance for non-THP system by copying at the PMD level when
possible.

The speedup is an order of magnitude on x86 (~20x).  On a 1GB mremap,
the mremap completion times drops from 3.4-3.6 milliseconds to 144-160
microseconds.

Before:
Total mremap time for 1GB data: 3521942 nanoseconds.
Total mremap time for 1GB data: 3449229 nanoseconds.
Total mremap time for 1GB data: 3488230 nanoseconds.

After:
Total mremap time for 1GB data: 150279 nanoseconds.
Total mremap time for 1GB data: 144665 nanoseconds.
Total mremap time for 1GB data: 158708 nanoseconds.

If THP is enabled the optimization is mostly skipped except in certain
situations.

[joel@joelfernandes.org: fix 'move_normal_pmd' unused function warning]
  Link: http://lkml.kernel.org/r/20181108224457.GB209347@google.com
Link: http://lkml.kernel.org/r/20181108181201.88826-3-joelaf@google.com


Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "Add support for fast mremap".

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

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

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

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

virtual patch

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

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

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

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

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

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

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

 fn(...
-,  E2
 )

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

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

Link: http://lkml.kernel.org/r/20181108181201.88826-2-joelaf@google.com


Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Suggested-by: Kirill A. Shutemov <kirill@shutemov.name>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Unpacking an external initrd may fail e.g.  not enough memory.  This
leads to an incomplete rootfs because some files might be extracted
already.  Fixed by cleaning the rootfs so the kernel is not using an
incomplete rootfs.

Link: http://lkml.kernel.org/r/20181030151805.5519-1-david.engraf@sysgo.com


Signed-off-by: David Engraf <david.engraf@sysgo.com>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A bug is present in GDB which causes early string termination when
parsing variables.  This has been reported [0], but we should ensure
that we can support at least basic printing of the core kernel strings.

For current gdb version (has been tested with 7.3 and 8.1), 'lx-version'
only prints one character.

  (gdb) lx-version
  L(gdb)

This can be fixed by casting 'linux_banner' as (char *).

  (gdb) lx-version
  Linux version 4.19.0-rc1+ (changbin@acer) (gcc version 7.3.0 (Ubuntu 7.3.0-16ubuntu3)) #21 SMP Sat Sep 1 21:43:30 CST 2018

[0] https://sourceware.org/bugzilla/show_bug.cgi?id=20077

[kbingham@kernel.org: add detail to commit message]
Link: http://lkml.kernel.org/r/20181111162035.8356-1-kieran.bingham@ideasonboard.com
Fixes: 2d061d99

 ("scripts/gdb: add version command")
Signed-off-by: Du Changbin <changbin.du@gmail.com>
Signed-off-by: Kieran Bingham <kbingham@kernel.org>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Since __sanitizer_cov_trace_const_cmp4 is marked as notrace, the
function called from __sanitizer_cov_trace_const_cmp4 shouldn't be
traceable either.  ftrace_graph_caller() gets called every time func
write_comp_data() gets called if it isn't marked 'notrace'.  This is the
backtrace from gdb:

 #0  ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:179
 #1  0xffffff8010201920 in ftrace_caller () at ../arch/arm64/kernel/entry-ftrace.S:151
 #2  0xffffff8010439714 in write_comp_data (type=5, arg1=0, arg2=0, ip=18446743524224276596) at ../kernel/kcov.c:116
 #3  0xffffff8010439894 in __sanitizer_cov_trace_const_cmp4 (arg1=<optimized out>, arg2=<optimized out>) at ../kernel/kcov.c:188
 #4  0xffffff8010201874 in prepare_ftrace_return (self_addr=18446743524226602768, parent=0xffffff801014b918, frame_pointer=18446743524223531344) at ./include/generated/atomic-instrumented.h:27
 #5  0xffffff801020194c in ftrace_graph_caller () at ../arch/arm64/kernel/entry-ftrace.S:182

Rework so that write_comp_data() that are called from
__sanitizer_cov_trace_*_cmp*() are marked as 'notrace'.

Commit 903e8ff8 ("kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notrace")
missed to mark write_comp_data() as 'notrace'. When that patch was
created gcc-7 was used. In lib/Kconfig.debug
config KCOV_ENABLE_COMPARISONS
	depends on $(cc-option,-fsanitize-coverage=trace-cmp)

That code path isn't hit with gcc-7. However, it were that with gcc-8.

Link: http://lkml.kernel.org/r/20181206143011.23719-1-anders.roxell@linaro.org


Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Co-developed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

So that we can also runtime chose to print out the needed system info
for panic, other than setting the kernel cmdline.

Link: http://lkml.kernel.org/r/1543398842-19295-3-git-send-email-feng.tang@intel.com


Signed-off-by: Feng Tang <feng.tang@intel.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Kernel panic issues are always painful to debug, partially because it's
not easy to get enough information of the context when panic happens.

And we have ramoops and kdump for that, while this commit tries to
provide a easier way to show the system info by adding a cmdline
parameter, referring some idea from sysrq handler.

Link: http://lkml.kernel.org/r/1543398842-19295-2-git-send-email-feng.tang@intel.com


Signed-off-by: Feng Tang <feng.tang@intel.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Strengthen validation of BFS superblock against corruption.  Make
in-core inode bitmap static part of superblock info structure.  Print a
warning when mounting a BFS filesystem created with "-N 512" option as
only 510 files can be created in the root directory.  Make the kernel
messages more uniform.  Update the 'prefix' passed to bfs_dump_imap() to
match the current naming of operations.  White space and comments
cleanup.

Link: http://lkml.kernel.org/r/CAK+_RLkFZMduoQF36wZFd3zLi-6ZutWKsydjeHFNdtRvZZEb4w@mail.gmail.com


Signed-off-by: Tigran Aivazian <aivazian.tigran@gmail.com>
Reported-by: 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>

get_arg_page() checks bprm->rlim_stack.rlim_cur and re-calculates the
"extra" size for argv/envp pointers every time, this is a bit ugly and
even not strictly correct: acct_arg_size() must not account this size.

Remove all the rlimit code in get_arg_page().  Instead, add bprm->argmin
calculated once at the start of __do_execve_file() and change
copy_strings to check bprm->p >= bprm->argmin.

The patch adds the new helper, prepare_arg_pages() which initializes
bprm->argc/envc and bprm->argmin.

[oleg@redhat.com: fix !CONFIG_MMU version of get_arg_page()]
  Link: http://lkml.kernel.org/r/20181126122307.GA1660@redhat.com
[akpm@linux-foundation.org: use max_t]
Link: http://lkml.kernel.org/r/20181112160910.GA28440@redhat.com


Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

load_script() simply truncates bprm->buf and this is very wrong if the
length of shebang string exceeds BINPRM_BUF_SIZE-2.  This can silently
truncate i_arg or (worse) we can execute the wrong binary if buf[2:126]
happens to be the valid executable path.

Change load_script() to return ENOEXEC if it can't find '\n' or zero in
bprm->buf.  Note that '\0' can come from either
prepare_binprm()->memset() or from kernel_read(), we do not care.

Link: http://lkml.kernel.org/r/20181112160931.GA28463@redhat.com


Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Ben Woodard <woodard@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We get a warning when building kernel with W=1:

  kernel/fork.c:167:13: warning: no previous prototype for `arch_release_thread_stack' [-Wmissing-prototypes]
  kernel/fork.c:779:13: warning: no previous prototype for `fork_init' [-Wmissing-prototypes]

Add the missing declaration in head file to fix this.

Also, remove arch_release_thread_stack() completely because no arch
seems to implement it since bb9d8126 (arch: remove tile port).

Link: http://lkml.kernel.org/r/1542170087-23645-1-git-send-email-wang.yi59@zte.com.cn


Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch introduces 3 new inline functions - is_fat12, is_fat16 and
is_fat32, and replaces every occurrence in the code in which the FS
variant (whether this is FAT12, FAT16 or FAT32) was previously checked
using msdos_sb_info->fat_bits.

Link: http://lkml.kernel.org/r/1544990640-11604-4-git-send-email-carmeli.tamir@gmail.com


Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAX_FAT is useless in msdos_fs.h, since it uses the MSDOS_SB function
that is defined in fat.h.  So really, this macro can be only called from
code that already includes fat.h.

Hence, this patch moves it to fat.h, right after MSDOS_SB is defined.  I
also changed it to an inline function in order to save the double call
to MSDOS_SB.  This was suggested by joe@perches.com in the previous
version.

This patch is required for the next in the series, in which the variant
(whether this is FAT12, FAT16 or FAT32) checks are replaced with new
macros.

Link: http://lkml.kernel.org/r/1544990640-11604-3-git-send-email-carmeli.tamir@gmail.com


Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The comment edited in this patch was the only reference to the
FAT_FIRST_ENT macro, which is not used anymore.  Moreover, the commented
line of code does not compile with the current code.

Since the FAT_FIRST_ENT macro checks the FAT variant in a way that the
patch series changes, I removed it, and instead wrote a clear
explanation of what was checked.

I verified that the changed comment is correct according to Microsoft
FAT spec, search for "BPB_Media" in the following references:

1. Microsoft FAT specification 2005
(http://read.pudn.com/downloads77/ebook/294884/FAT32%20Spec%20%28SDA%20Contribution%29.pdf).
Search for 'volume label'.
2. Microsoft Extensible Firmware Initiative, FAT32 File System Specification
(https://staff.washington.edu/dittrich/misc/fatgen103.pdf).
Search for 'volume label'.

Link: http://lkml.kernel.org/r/1544990640-11604-2-git-send-email-carmeli.tamir@gmail.com


Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The FAT file system volume label file stored in the root directory
should match the volume label field in the FAT boot sector.  As
consequence, the max length of these fields ought to be the same.  This
patch replaces the magic '11' usef in the struct fat_boot_sector with
MSDOS_NAME, which is used in struct msdos_dir_entry.

Please check the following references:
1. Microsoft FAT specification 2005
(http://read.pudn.com/downloads77/ebook/294884/FAT32%20Spec%20%28SDA%20Contribution%29.pdf).
Search for 'volume label'.
2. Microsoft Extensible Firmware Initiative, FAT32 File System Specification
(https://staff.washington.edu/dittrich/misc/fatgen103.pdf).
Search for 'volume label'.
3. User space code that creates FAT filesystem
sometimes uses MSDOS_NAME for the label, sometimes not.
Search for 'if (memcmp(label, NO_NAME, MSDOS_NAME))'.
I consider to make the same patch there as well.
https://github.com/dosfstools/dosfstools/blob/master/src/mkfs.fat.c

Link: http://lkml.kernel.org/r/1543096879-82837-1-git-send-email-carmeli.tamir@gmail.com


Signed-off-by: Carmeli Tamir <carmeli.tamir@gmail.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The immutable, append-only and no-dump attributes can only be retrieved
with an ioctl; implement the ->getattr() method to return them on statx.
Do not return the inode birthtime yet, because the issue of how best to
handle the post-2038 timestamps is still under discussion.

This patch is needed to pass xfstests generic/424.

Link: http://lkml.kernel.org/r/20181014163558.sxorxlzjqccq2lpw@eaf


Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 092a5345 ("autofs: take more care to not update last_used on
path walk") helped to (partially) resolve a problem where automounts
were not expiring due to aggressive accesses from user space.

This patch was later reverted because, for very large environments, it
meant more mount requests from clients and when there are a lot of
clients this caused a fairly significant increase in server load.

But there is a need for both types of expire check, depending on use
case, so add a mount option to allow for strict update of last use of
autofs dentrys (which just means not updating the last use on path walk
access).

Link: http://lkml.kernel.org/r/154296973880.9889.14085372741514507967.stgit@pluto-themaw-net


Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Change the superblock info.  catatonic setting to be part of a flags bit
field.

Link: http://lkml.kernel.org/r/154296973142.9889.17275721668508589639.stgit@pluto-themaw-net


Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The parse_options() function uses a long list of parameters, most of
which are present in the super block info structure already.

The mount parameters set in parse_options() options don't require
cleanup so using the super block info struct directly is simpler.

Link: http://lkml.kernel.org/r/154296972423.9889.9368859245676473329.stgit@pluto-themaw-net


Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Al Viro made some suggestions to improve the implementation of commit
0633da48 ("fix autofs_sbi() does not check super block type").

The check is unnecessary in all cases except for ioctl usage so placing
the check in the super block accessor function adds a small overhead to
the common case where it isn't needed.

So it's sufficient to do this in the ioctl code only.

Also the check in the ioctl code is needlessly complex.

[akpm@linux-foundation.org: declare autofs_fs_type in .h, not .c]
Link: http://lkml.kernel.org/r/154296970987.9889.1597442413573683096.stgit@pluto-themaw-net


Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Al 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 names should not be changed.

Link: http://lkml.kernel.org/r/20181124091829.GD10969@avx2


Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

There is no reason why we rearm the waitiqueue upon every fetch_events
retry (for when events are found yet send_events() fails).  If nothing
else, this saves four lock operations per retry, and furthermore reduces
the scope of the lock even further.

[akpm@linux-foundation.org: restore code to original position, fix and reflow comment]
Link: http://lkml.kernel.org/r/20181114182532.27981-2-dave@stgolabs.net


Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

It is currently called check_events because it, well, did exactly that.
However, since the lockless ep_events_available() call, the label no
longer checks, but just sends the events.  Rename as such.

Link: http://lkml.kernel.org/r/20181114182532.27981-1-dave@stgolabs.net


Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>