<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git, branch v4.19-rc7</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>Linux 4.19-rc7</title>
<updated>2018-10-07T15:26:02+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2018-10-07T15:26:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0238df646e6224016a45505d2c111a24669ebe21'/>
<id>0238df646e6224016a45505d2c111a24669ebe21</id>
<content type='text'>
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'char-misc-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc</title>
<updated>2018-10-07T06:15:57+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2018-10-07T06:15:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fb1c592cf4c9eeb84ec6bce13c13c11c7d05b6c7'/>
<id>fb1c592cf4c9eeb84ec6bce13c13c11c7d05b6c7</id>
<content type='text'>
I wrote:
  "Char/Misc fixes for 4.19-rc7

   Here are 8 small fixes for some char/misc driver issues

   Included here are:
	- fpga driver fixes
	- thunderbolt bugfixes
	- firmware core revert/fix
	- hv core fix
	- hv tool fix

   All of these have been in linux-next with no reported issues."

* tag 'char-misc-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  thunderbolt: Initialize after IOMMUs
  thunderbolt: Do not handle ICM events after domain is stopped
  firmware: Always initialize the fw_priv list object
  docs: fpga: document fpga manager flags
  fpga: bridge: fix obvious function documentation error
  tools: hv: fcopy: set 'error' in case an unknown operation was requested
  fpga: do not access region struct after fpga_region_unregister
  Drivers: hv: vmbus: Use get/put_cpu() in vmbus_connect()
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I wrote:
  "Char/Misc fixes for 4.19-rc7

   Here are 8 small fixes for some char/misc driver issues

   Included here are:
	- fpga driver fixes
	- thunderbolt bugfixes
	- firmware core revert/fix
	- hv core fix
	- hv tool fix

   All of these have been in linux-next with no reported issues."

* tag 'char-misc-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  thunderbolt: Initialize after IOMMUs
  thunderbolt: Do not handle ICM events after domain is stopped
  firmware: Always initialize the fw_priv list object
  docs: fpga: document fpga manager flags
  fpga: bridge: fix obvious function documentation error
  tools: hv: fcopy: set 'error' in case an unknown operation was requested
  fpga: do not access region struct after fpga_region_unregister
  Drivers: hv: vmbus: Use get/put_cpu() in vmbus_connect()
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'tty-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty</title>
<updated>2018-10-07T06:14:59+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2018-10-07T06:14:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4ebaf0754c7a1109e66693f488f02b78f5875fee'/>
<id>4ebaf0754c7a1109e66693f488f02b78f5875fee</id>
<content type='text'>
I wrote:
  "Serial driver fixes for 4.19-rc7

   Here are 3 small serial driver fixes for 4.19-rc7
    - 2 sh-sci bugfixes for reported issues
    - a revert of the PM handling for the 8250_dw code

   All of these have been in linux-next with no reported issues."

* tag 'tty-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "serial: sh-sci: Allow for compressed SCIF address"
  Revert "serial: sh-sci: Remove SCIx_RZ_SCIFA_REGTYPE"
  Revert "serial: 8250_dw: Fix runtime PM handling"
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I wrote:
  "Serial driver fixes for 4.19-rc7

   Here are 3 small serial driver fixes for 4.19-rc7
    - 2 sh-sci bugfixes for reported issues
    - a revert of the PM handling for the 8250_dw code

   All of these have been in linux-next with no reported issues."

* tag 'tty-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  Revert "serial: sh-sci: Allow for compressed SCIF address"
  Revert "serial: sh-sci: Remove SCIx_RZ_SCIFA_REGTYPE"
  Revert "serial: 8250_dw: Fix runtime PM handling"
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'usb-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb</title>
<updated>2018-10-07T06:14:06+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2018-10-07T06:14:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cc02f852872d2f9f3a15b3429b77998271814de0'/>
<id>cc02f852872d2f9f3a15b3429b77998271814de0</id>
<content type='text'>
I wrote:
  "USB fixes for 4.19-rc7

   Here are some small USB fixes for 4.19-rc7

   These include:
     - the usual xhci bugfixes for reported issues
     - some new serial driver device ids
     - bugfix for the option serial driver for some devices
     - bugfix for the cdc_acm driver that has been there for a long time.

   All of these have been in linux-next for a while with no reported
   issues."

* tag 'usb-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: xhci-mtk: resume USB3 roothub first
  xhci: Add missing CAS workaround for Intel Sunrise Point xHCI
  usb: cdc_acm: Do not leak URB buffers
  USB: serial: simple: add Motorola Tetra MTP6550 id
  USB: serial: option: add two-endpoints device-id flag
  USB: serial: option: improve Quectel EP06 detection
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I wrote:
  "USB fixes for 4.19-rc7

   Here are some small USB fixes for 4.19-rc7

   These include:
     - the usual xhci bugfixes for reported issues
     - some new serial driver device ids
     - bugfix for the option serial driver for some devices
     - bugfix for the cdc_acm driver that has been there for a long time.

   All of these have been in linux-next for a while with no reported
   issues."

* tag 'usb-4.19-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: xhci-mtk: resume USB3 roothub first
  xhci: Add missing CAS workaround for Intel Sunrise Point xHCI
  usb: cdc_acm: Do not leak URB buffers
  USB: serial: simple: add Motorola Tetra MTP6550 id
  USB: serial: option: add two-endpoints device-id flag
  USB: serial: option: improve Quectel EP06 detection
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux</title>
<updated>2018-10-07T05:07:33+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2018-10-07T05:07:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=055d8d9eae35ac1edb97fcf70f357cea227bf3b2'/>
<id>055d8d9eae35ac1edb97fcf70f357cea227bf3b2</id>
<content type='text'>
Wolfram writes:
  "i2c for 4.19

   I2C has three driver bugfixes and a fix for a typo for you."

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: designware: Call i2c_dw_clk_rate() only when calculating timings
  i2c: i2c-scmi: fix for i2c_smbus_write_block_data
  i2c: i2c-isch: fix spelling mistake "unitialized" -&gt; "uninitialized"
  i2c: i2c-qcom-geni: Properly handle DMA safe buffers
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Wolfram writes:
  "i2c for 4.19

   I2C has three driver bugfixes and a fix for a typo for you."

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: designware: Call i2c_dw_clk_rate() only when calculating timings
  i2c: i2c-scmi: fix for i2c_smbus_write_block_data
  i2c: i2c-isch: fix spelling mistake "unitialized" -&gt; "uninitialized"
  i2c: i2c-qcom-geni: Properly handle DMA safe buffers
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi</title>
<updated>2018-10-07T05:06:52+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2018-10-07T05:06:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=40fa9167d307de29be2740bc10c4093502a917ed'/>
<id>40fa9167d307de29be2740bc10c4093502a917ed</id>
<content type='text'>
James writes:
  "SCSI fixes on 20181006

   Small fix for an unititialized mutex in the qedi driver."

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: qedi: Initialize the stats mutex lock
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
James writes:
  "SCSI fixes on 20181006

   Small fix for an unititialized mutex in the qedi driver."

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: qedi: Initialize the stats mutex lock
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'powerpc-4.19-4' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux</title>
<updated>2018-10-07T05:05:43+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2018-10-07T05:05:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cd2093cb45a4d9332d4e5a2170602f74bca298a4'/>
<id>cd2093cb45a4d9332d4e5a2170602f74bca298a4</id>
<content type='text'>
Michael writes:
  "powerpc fixes for 4.19 #4

   Four regression fixes.

   A fix for a change to lib/xz which broke our zImage loader when
   building with XZ compression. OK'ed by Herbert who merged the
   original patch.

   The recent fix we did to avoid patching __init text broke some 32-bit
   machines, fix that.

   Our show_user_instructions() could be tricked into printing kernel
   memory, add a check to avoid that.

   And a fix for a change to our NUMA initialisation logic, which causes
   crashes in some kdump configurations.

   Thanks to:
     Christophe Leroy, Hari Bathini, Jann Horn, Joel Stanley, Meelis
     Roos, Murilo Opsfelder Araujo, Srikar Dronamraju."

* tag 'powerpc-4.19-4' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/numa: Skip onlining a offline node in kdump path
  powerpc: Don't print kernel instructions in show_user_instructions()
  powerpc/lib: fix book3s/32 boot failure due to code patching
  lib/xz: Put CRC32_POLY_LE in xz_private.h
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Michael writes:
  "powerpc fixes for 4.19 #4

   Four regression fixes.

   A fix for a change to lib/xz which broke our zImage loader when
   building with XZ compression. OK'ed by Herbert who merged the
   original patch.

   The recent fix we did to avoid patching __init text broke some 32-bit
   machines, fix that.

   Our show_user_instructions() could be tricked into printing kernel
   memory, add a check to avoid that.

   And a fix for a change to our NUMA initialisation logic, which causes
   crashes in some kdump configurations.

   Thanks to:
     Christophe Leroy, Hari Bathini, Jann Horn, Joel Stanley, Meelis
     Roos, Murilo Opsfelder Araujo, Srikar Dronamraju."

* tag 'powerpc-4.19-4' of https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/numa: Skip onlining a offline node in kdump path
  powerpc: Don't print kernel instructions in show_user_instructions()
  powerpc/lib: fix book3s/32 boot failure due to code patching
  lib/xz: Put CRC32_POLY_LE in xz_private.h
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2018-10-06T09:11:30+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2018-10-06T09:11:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=c1d84a1b42ef70d8ae601df9cadedc7ed4f1beb1'/>
<id>c1d84a1b42ef70d8ae601df9cadedc7ed4f1beb1</id>
<content type='text'>
Dave writes:
  "Networking fixes:

  1) Fix truncation of 32-bit right shift in bpf, from Jann Horn.

  2) Fix memory leak in wireless wext compat, from Stefan Seyfried.

  3) Use after free in cfg80211's reg_process_hint(), from Yu Zhao.

  4) Need to cancel pending work when unbinding in smsc75xx otherwise
     we oops, also from Yu Zhao.

  5) Don't allow enslaving a team device to itself, from Ido Schimmel.

  6) Fix backwards compat with older userspace for rtnetlink FDB dumps.
     From Mauricio Faria.

  7) Add validation of tc policy netlink attributes, from David Ahern.

  8) Fix RCU locking in rawv6_send_hdrinc(), from Wei Wang."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  net: mvpp2: Extract the correct ethtype from the skb for tx csum offload
  ipv6: take rcu lock in rawv6_send_hdrinc()
  net: sched: Add policy validation for tc attributes
  rtnetlink: fix rtnl_fdb_dump() for ndmsg header
  yam: fix a missing-check bug
  net: bpfilter: Fix type cast and pointer warnings
  net: cxgb3_main: fix a missing-check bug
  bpf: 32-bit RSH verification must truncate input before the ALU op
  net: phy: phylink: fix SFP interface autodetection
  be2net: don't flip hw_features when VXLANs are added/deleted
  net/packet: fix packet drop as of virtio gso
  net: dsa: b53: Keep CPU port as tagged in all VLANs
  openvswitch: load NAT helper
  bnxt_en: get the reduced max_irqs by the ones used by RDMA
  bnxt_en: free hwrm resources, if driver probe fails.
  bnxt_en: Fix enables field in HWRM_QUEUE_COS2BW_CFG request
  bnxt_en: Fix VNIC reservations on the PF.
  team: Forbid enslaving team device to itself
  net/usb: cancel pending work when unbinding smsc75xx
  mlxsw: spectrum: Delete RIF when VLAN device is removed
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Dave writes:
  "Networking fixes:

  1) Fix truncation of 32-bit right shift in bpf, from Jann Horn.

  2) Fix memory leak in wireless wext compat, from Stefan Seyfried.

  3) Use after free in cfg80211's reg_process_hint(), from Yu Zhao.

  4) Need to cancel pending work when unbinding in smsc75xx otherwise
     we oops, also from Yu Zhao.

  5) Don't allow enslaving a team device to itself, from Ido Schimmel.

  6) Fix backwards compat with older userspace for rtnetlink FDB dumps.
     From Mauricio Faria.

  7) Add validation of tc policy netlink attributes, from David Ahern.

  8) Fix RCU locking in rawv6_send_hdrinc(), from Wei Wang."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  net: mvpp2: Extract the correct ethtype from the skb for tx csum offload
  ipv6: take rcu lock in rawv6_send_hdrinc()
  net: sched: Add policy validation for tc attributes
  rtnetlink: fix rtnl_fdb_dump() for ndmsg header
  yam: fix a missing-check bug
  net: bpfilter: Fix type cast and pointer warnings
  net: cxgb3_main: fix a missing-check bug
  bpf: 32-bit RSH verification must truncate input before the ALU op
  net: phy: phylink: fix SFP interface autodetection
  be2net: don't flip hw_features when VXLANs are added/deleted
  net/packet: fix packet drop as of virtio gso
  net: dsa: b53: Keep CPU port as tagged in all VLANs
  openvswitch: load NAT helper
  bnxt_en: get the reduced max_irqs by the ones used by RDMA
  bnxt_en: free hwrm resources, if driver probe fails.
  bnxt_en: Fix enables field in HWRM_QUEUE_COS2BW_CFG request
  bnxt_en: Fix VNIC reservations on the PF.
  team: Forbid enslaving team device to itself
  net/usb: cancel pending work when unbinding smsc75xx
  mlxsw: spectrum: Delete RIF when VLAN device is removed
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'akpm'</title>
<updated>2018-10-05T23:33:03+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2018-10-05T23:33:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=091a1eaa0e309b0e8dcbf3f2da12c7f3d03ed182'/>
<id>091a1eaa0e309b0e8dcbf3f2da12c7f3d03ed182</id>
<content type='text'>
* akpm:
  mm: madvise(MADV_DODUMP): allow hugetlbfs pages
  ocfs2: fix locking for res-&gt;tracking and dlm-&gt;tracking_list
  mm/vmscan.c: fix int overflow in callers of do_shrink_slab()
  mm/vmstat.c: skip NR_TLB_REMOTE_FLUSH* properly
  mm/vmstat.c: fix outdated vmstat_text
  proc: restrict kernel stack dumps to root
  mm/hugetlb: add mmap() encodings for 32MB and 512MB page sizes
  mm/migrate.c: split only transparent huge pages when allocation fails
  ipc/shm.c: use ERR_CAST() for shm_lock() error return
  mm/gup_benchmark: fix unsigned comparison to zero in __gup_benchmark_ioctl
  mm, thp: fix mlocking THP page with migration enabled
  ocfs2: fix crash in ocfs2_duplicate_clusters_by_page()
  hugetlb: take PMD sharing into account when flushing tlb/caches
  mm: migration: fix migration of huge PMD shared pages
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* akpm:
  mm: madvise(MADV_DODUMP): allow hugetlbfs pages
  ocfs2: fix locking for res-&gt;tracking and dlm-&gt;tracking_list
  mm/vmscan.c: fix int overflow in callers of do_shrink_slab()
  mm/vmstat.c: skip NR_TLB_REMOTE_FLUSH* properly
  mm/vmstat.c: fix outdated vmstat_text
  proc: restrict kernel stack dumps to root
  mm/hugetlb: add mmap() encodings for 32MB and 512MB page sizes
  mm/migrate.c: split only transparent huge pages when allocation fails
  ipc/shm.c: use ERR_CAST() for shm_lock() error return
  mm/gup_benchmark: fix unsigned comparison to zero in __gup_benchmark_ioctl
  mm, thp: fix mlocking THP page with migration enabled
  ocfs2: fix crash in ocfs2_duplicate_clusters_by_page()
  hugetlb: take PMD sharing into account when flushing tlb/caches
  mm: migration: fix migration of huge PMD shared pages
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: madvise(MADV_DODUMP): allow hugetlbfs pages</title>
<updated>2018-10-05T23:32:05+00:00</updated>
<author>
<name>Daniel Black</name>
<email>daniel@linux.ibm.com</email>
</author>
<published>2018-10-05T22:52:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d41aa5252394c065d1f04d1ceea885b70d00c9c6'/>
<id>d41aa5252394c065d1f04d1ceea885b70d00c9c6</id>
<content type='text'>
Reproducer, assuming 2M of hugetlbfs available:

Hugetlbfs mounted, size=2M and option user=testuser

  # mount | grep ^hugetlbfs
  hugetlbfs on /dev/hugepages type hugetlbfs (rw,pagesize=2M,user=dan)
  # sysctl vm.nr_hugepages=1
  vm.nr_hugepages = 1
  # grep Huge /proc/meminfo
  AnonHugePages:         0 kB
  ShmemHugePages:        0 kB
  HugePages_Total:       1
  HugePages_Free:        1
  HugePages_Rsvd:        0
  HugePages_Surp:        0
  Hugepagesize:       2048 kB
  Hugetlb:            2048 kB

Code:

  #include &lt;sys/mman.h&gt;
  #include &lt;stddef.h&gt;
  #define SIZE 2*1024*1024
  int main()
  {
    void *ptr;
    ptr = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_HUGETLB | MAP_ANONYMOUS, -1, 0);
    madvise(ptr, SIZE, MADV_DONTDUMP);
    madvise(ptr, SIZE, MADV_DODUMP);
  }

Compile and strace:

  mmap(NULL, 2097152, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, -1, 0) = 0x7ff7c9200000
  madvise(0x7ff7c9200000, 2097152, MADV_DONTDUMP) = 0
  madvise(0x7ff7c9200000, 2097152, MADV_DODUMP) = -1 EINVAL (Invalid argument)

hugetlbfs pages have VM_DONTEXPAND in the VmFlags driver pages based on
author testing with analysis from Florian Weimer[1].

The inclusion of VM_DONTEXPAND into the VM_SPECIAL defination was a
consequence of the large useage of VM_DONTEXPAND in device drivers.

A consequence of [2] is that VM_DONTEXPAND marked pages are unable to be
marked DODUMP.

A user could quite legitimately madvise(MADV_DONTDUMP) their hugetlbfs
memory for a while and later request that madvise(MADV_DODUMP) on the same
memory.  We correct this omission by allowing madvice(MADV_DODUMP) on
hugetlbfs pages.

[1] https://stackoverflow.com/questions/52548260/madvisedodump-on-the-same-ptr-size-as-a-successful-madvisedontdump-fails-wit
[2] commit 0103bd16fb90 ("mm: prepare VM_DONTDUMP for using in drivers")

Link: http://lkml.kernel.org/r/20180930054629.29150-1-daniel@linux.ibm.com
Link: https://lists.launchpad.net/maria-discuss/msg05245.html
Fixes: 0103bd16fb90 ("mm: prepare VM_DONTDUMP for using in drivers")
Reported-by: Kenneth Penza &lt;kpenza@gmail.com&gt;
Signed-off-by: Daniel Black &lt;daniel@linux.ibm.com&gt;
Reviewed-by: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Cc: Konstantin Khlebnikov &lt;khlebnikov@openvz.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
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<pre>
Reproducer, assuming 2M of hugetlbfs available:

Hugetlbfs mounted, size=2M and option user=testuser

  # mount | grep ^hugetlbfs
  hugetlbfs on /dev/hugepages type hugetlbfs (rw,pagesize=2M,user=dan)
  # sysctl vm.nr_hugepages=1
  vm.nr_hugepages = 1
  # grep Huge /proc/meminfo
  AnonHugePages:         0 kB
  ShmemHugePages:        0 kB
  HugePages_Total:       1
  HugePages_Free:        1
  HugePages_Rsvd:        0
  HugePages_Surp:        0
  Hugepagesize:       2048 kB
  Hugetlb:            2048 kB

Code:

  #include &lt;sys/mman.h&gt;
  #include &lt;stddef.h&gt;
  #define SIZE 2*1024*1024
  int main()
  {
    void *ptr;
    ptr = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_HUGETLB | MAP_ANONYMOUS, -1, 0);
    madvise(ptr, SIZE, MADV_DONTDUMP);
    madvise(ptr, SIZE, MADV_DODUMP);
  }

Compile and strace:

  mmap(NULL, 2097152, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, -1, 0) = 0x7ff7c9200000
  madvise(0x7ff7c9200000, 2097152, MADV_DONTDUMP) = 0
  madvise(0x7ff7c9200000, 2097152, MADV_DODUMP) = -1 EINVAL (Invalid argument)

hugetlbfs pages have VM_DONTEXPAND in the VmFlags driver pages based on
author testing with analysis from Florian Weimer[1].

The inclusion of VM_DONTEXPAND into the VM_SPECIAL defination was a
consequence of the large useage of VM_DONTEXPAND in device drivers.

A consequence of [2] is that VM_DONTEXPAND marked pages are unable to be
marked DODUMP.

A user could quite legitimately madvise(MADV_DONTDUMP) their hugetlbfs
memory for a while and later request that madvise(MADV_DODUMP) on the same
memory.  We correct this omission by allowing madvice(MADV_DODUMP) on
hugetlbfs pages.

[1] https://stackoverflow.com/questions/52548260/madvisedodump-on-the-same-ptr-size-as-a-successful-madvisedontdump-fails-wit
[2] commit 0103bd16fb90 ("mm: prepare VM_DONTDUMP for using in drivers")

Link: http://lkml.kernel.org/r/20180930054629.29150-1-daniel@linux.ibm.com
Link: https://lists.launchpad.net/maria-discuss/msg05245.html
Fixes: 0103bd16fb90 ("mm: prepare VM_DONTDUMP for using in drivers")
Reported-by: Kenneth Penza &lt;kpenza@gmail.com&gt;
Signed-off-by: Daniel Black &lt;daniel@linux.ibm.com&gt;
Reviewed-by: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Cc: Konstantin Khlebnikov &lt;khlebnikov@openvz.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
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