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Pavel Tatashin 99dac8af6e sparc64/mm: set fields in deferred pages
[ Upstream commit 2a20aa1710 ]

Without deferred struct page feature (CONFIG_DEFERRED_STRUCT_PAGE_INIT),
flags and other fields in "struct page"es are never changed prior to
first initializing struct pages by going through __init_single_page().

With deferred struct page feature enabled there is a case where we set
some fields prior to initializing:

mem_init() {
     register_page_bootmem_info();
     free_all_bootmem();
     ...
}

When register_page_bootmem_info() is called only non-deferred struct
pages are initialized.  But, this function goes through some reserved
pages which might be part of the deferred, and thus are not yet
initialized.

mem_init
register_page_bootmem_info
register_page_bootmem_info_node
 get_page_bootmem
  .. setting fields here ..
  such as: page->freelist = (void *)type;

free_all_bootmem()
free_low_memory_core_early()
 for_each_reserved_mem_region()
  reserve_bootmem_region()
   init_reserved_page() <- Only if this is deferred reserved page
    __init_single_pfn()
     __init_single_page()
      memset(0) <-- Loose the set fields here

We end up with similar issue as in the previous patch, where currently
we do not observe problem as memory is zeroed.  But, if flag asserts are
changed we can start hitting issues.

Also, because in this patch series we will stop zeroing struct page
memory during allocation, we must make sure that struct pages are
properly initialized prior to using them.

The deferred-reserved pages are initialized in free_all_bootmem().
Therefore, the fix is to switch the above calls.

Link: http://lkml.kernel.org/r/20171013173214.27300-4-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
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>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14 09:53:10 +01:00
arch sparc64/mm: set fields in deferred pages 2017-12-14 09:53:10 +01:00
block block: wake up all tasks blocked in get_request() 2017-12-14 09:53:10 +01:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto X.509: fix comparisons of ->pkey_algo 2017-12-14 09:52:53 +01:00
Documentation dt-bindings: usb: fix reg-property port-number range 2017-12-14 09:53:09 +01:00
drivers nfp: fix flower offload metadata flag usage 2017-12-14 09:53:09 +01:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs xfs: fix forgotten rcu read unlock when skipping inode reclaim 2017-12-14 09:53:09 +01:00
include lib/genalloc.c: make the avail variable an atomic_long_t 2017-12-14 09:53:08 +01:00
init License cleanup: add SPDX license identifiers to some files 2017-11-02 10:04:46 -07:00
ipc License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kernel pipe: match pipe_max_size data type with procfs 2017-12-14 09:53:08 +01:00
lib dynamic-debug-howto: fix optional/omitted ending line number to be LARGE instead of 0 2017-12-14 09:53:08 +01:00
mm mm, x86/mm: Fix performance regression in get_user_pages_fast() 2017-12-10 13:40:43 +01:00
net sunrpc: Fix rpc_task_begin trace point 2017-12-14 09:53:09 +01:00
samples License cleanup: add SPDX license identifiers to some files 2017-11-02 10:04:46 -07:00
scripts coccinelle: fix parallel build with CHECK=scripts/coccicheck 2017-12-14 09:53:06 +01:00
security apparmor: fix leak of null profile name if profile allocation fails 2017-12-14 09:53:06 +01:00
sound ALSA: usb-audio: Add check return value for usb_string() 2017-12-14 09:52:55 +01:00
tools x86/mpx/selftests: Fix up weird arrays 2017-12-14 09:53:06 +01:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt KVM: arm/arm64: vgic-its: Check result of allocation before use 2017-12-14 09:53:01 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support to generate LLVM assembly files 2017-04-25 08:13:52 +09:00
.mailmap .mailmap: Add Maciej W. Rozycki's Imagination e-mail address 2017-11-10 12:16:15 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge branch 'akpm' (patches from Andrew) 2017-11-09 18:26:51 -08:00
Makefile Linux 4.14.5 2017-12-10 13:40:45 +01:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.