<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/mips, branch v5.14</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'tty-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty</title>
<updated>2021-08-08T17:23:13+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-08-08T17:23:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6463e54cc64ec87d550ae86c697b466fecf7ba7b'/>
<id>6463e54cc64ec87d550ae86c697b466fecf7ba7b</id>
<content type='text'>
Pull tty/serial fixes from Greg KH:
 "Here are some small tty/serial driver fixes for 5.14-rc5 to resolve a
  number of reported problems.

  They include:

   - mips serial driver fixes

   - 8250 driver fixes for reported problems

   - fsl_lpuart driver fixes

   - other tiny driver fixes

  All have been in linux-next for a while with no reported problems"

* tag 'tty-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250_pci: Avoid irq sharing for MSI(-X) interrupts.
  serial: 8250_mtk: fix uart corruption issue when rx power off
  tty: serial: fsl_lpuart: fix the wrong return value in lpuart32_get_mctrl
  serial: 8250_pci: Enumerate Elkhart Lake UARTs via dedicated driver
  serial: 8250: fix handle_irq locking
  serial: tegra: Only print FIFO error message when an error occurs
  MIPS: Malta: Do not byte-swap accesses to the CBUS UART
  serial: 8250: Mask out floating 16/32-bit bus bits
  serial: max310x: Unprepare and disable clock in error path
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull tty/serial fixes from Greg KH:
 "Here are some small tty/serial driver fixes for 5.14-rc5 to resolve a
  number of reported problems.

  They include:

   - mips serial driver fixes

   - 8250 driver fixes for reported problems

   - fsl_lpuart driver fixes

   - other tiny driver fixes

  All have been in linux-next for a while with no reported problems"

* tag 'tty-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250_pci: Avoid irq sharing for MSI(-X) interrupts.
  serial: 8250_mtk: fix uart corruption issue when rx power off
  tty: serial: fsl_lpuart: fix the wrong return value in lpuart32_get_mctrl
  serial: 8250_pci: Enumerate Elkhart Lake UARTs via dedicated driver
  serial: 8250: fix handle_irq locking
  serial: tegra: Only print FIFO error message when an error occurs
  MIPS: Malta: Do not byte-swap accesses to the CBUS UART
  serial: 8250: Mask out floating 16/32-bit bus bits
  serial: max310x: Unprepare and disable clock in error path
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'kbuild-fixes-v5.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild</title>
<updated>2021-08-07T17:03:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-08-07T17:03:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4972bb90c3956817c8e0eea15a348ab635d1acdd'/>
<id>4972bb90c3956817c8e0eea15a348ab635d1acdd</id>
<content type='text'>
Pull Kbuild fixes from Masahiro Yamada:

 - Correct the Extended Regular Expressions in tools

 - Adjust scripts/checkversion.pl for the current Kbuild

 - Unset sub_make_done for 'make install' to make DKMS work again

* tag 'kbuild-fixes-v5.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: cancel sub_make_done for the install target to fix DKMS
  scripts: checkversion: modernize linux/version.h search strings
  mips: Fix non-POSIX regexp
  x86/tools/relocs: Fix non-POSIX regexp
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull Kbuild fixes from Masahiro Yamada:

 - Correct the Extended Regular Expressions in tools

 - Adjust scripts/checkversion.pl for the current Kbuild

 - Unset sub_make_done for 'make install' to make DKMS work again

* tag 'kbuild-fixes-v5.14-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: cancel sub_make_done for the install target to fix DKMS
  scripts: checkversion: modernize linux/version.h search strings
  mips: Fix non-POSIX regexp
  x86/tools/relocs: Fix non-POSIX regexp
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'mips-fixes_5.14_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux</title>
<updated>2021-08-06T18:31:11+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-08-06T18:31:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cb407fc81d68f3a61e82eda4e7f9421e67f8aece'/>
<id>cb407fc81d68f3a61e82eda4e7f9421e67f8aece</id>
<content type='text'>
Pull MIPS fix from Thomas Bogendoerfer:
 "Fix PMD accounting change"

* tag 'mips-fixes_5.14_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: check return value of pgtable_pmd_page_ctor
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull MIPS fix from Thomas Bogendoerfer:
 "Fix PMD accounting change"

* tag 'mips-fixes_5.14_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: check return value of pgtable_pmd_page_ctor
</pre>
</div>
</content>
</entry>
<entry>
<title>mips: Fix non-POSIX regexp</title>
<updated>2021-08-05T11:52:03+00:00</updated>
<author>
<name>H. Nikolaus Schaller</name>
<email>hns@goldelico.com</email>
</author>
<published>2021-07-08T08:57:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=28bbbb9875a35975904e46f9b06fa689d051b290'/>
<id>28bbbb9875a35975904e46f9b06fa689d051b290</id>
<content type='text'>
When cross compiling a MIPS kernel on a BSD based HOSTCC leads
to errors like

  SYNC    include/config/auto.conf.cmd - due to: .config
egrep: empty (sub)expression
  UPD     include/config/kernel.release
  HOSTCC  scripts/dtc/dtc.o - due to target missing

It turns out that egrep uses this egrep pattern:

		(|MINOR_|PATCHLEVEL_)

This is not valid syntax or gives undefined results according
to POSIX 9.5.3 ERE Grammar

	https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html

It seems to be silently accepted by the Linux egrep implementation
while a BSD host complains.

Such patterns can be replaced by a transformation like

	"(|p1|p2)" -&gt; "(p1|p2)?"

Fixes: 48c35b2d245f ("[MIPS] There is no __GNUC_MAJOR__")
Signed-off-by: H. Nikolaus Schaller &lt;hns@goldelico.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When cross compiling a MIPS kernel on a BSD based HOSTCC leads
to errors like

  SYNC    include/config/auto.conf.cmd - due to: .config
egrep: empty (sub)expression
  UPD     include/config/kernel.release
  HOSTCC  scripts/dtc/dtc.o - due to target missing

It turns out that egrep uses this egrep pattern:

		(|MINOR_|PATCHLEVEL_)

This is not valid syntax or gives undefined results according
to POSIX 9.5.3 ERE Grammar

	https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html

It seems to be silently accepted by the Linux egrep implementation
while a BSD host complains.

Such patterns can be replaced by a transformation like

	"(|p1|p2)" -&gt; "(p1|p2)?"

Fixes: 48c35b2d245f ("[MIPS] There is no __GNUC_MAJOR__")
Signed-off-by: H. Nikolaus Schaller &lt;hns@goldelico.com&gt;
Signed-off-by: Masahiro Yamada &lt;masahiroy@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: check return value of pgtable_pmd_page_ctor</title>
<updated>2021-08-05T09:45:42+00:00</updated>
<author>
<name>Huang Pei</name>
<email>huangpei@loongson.cn</email>
</author>
<published>2021-07-21T09:30:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6aa32467299e9e12280a6aec9dbc21bf2db830b0'/>
<id>6aa32467299e9e12280a6aec9dbc21bf2db830b0</id>
<content type='text'>
+. According to Documentation/vm/split_page_table_lock, handle failure
of pgtable_pmd_page_ctor

+. Use GFP_KERNEL_ACCOUNT instead of GFP_KERNEL|__GFP_ACCOUNT

+. Adjust coding style

Fixes: ed914d48b6a1 ("MIPS: add PMD table accounting into MIPS')
Reported-by: Joshua Kinard &lt;kumba@gentoo.org&gt;
Signed-off-by: Huang Pei &lt;huangpei@loongson.cn&gt;
Reviewed-by: Joshua Kinard &lt;kumba@gentoo.org&gt;
Signed-off-by: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
+. According to Documentation/vm/split_page_table_lock, handle failure
of pgtable_pmd_page_ctor

+. Use GFP_KERNEL_ACCOUNT instead of GFP_KERNEL|__GFP_ACCOUNT

+. Adjust coding style

Fixes: ed914d48b6a1 ("MIPS: add PMD table accounting into MIPS')
Reported-by: Joshua Kinard &lt;kumba@gentoo.org&gt;
Signed-off-by: Huang Pei &lt;huangpei@loongson.cn&gt;
Reviewed-by: Joshua Kinard &lt;kumba@gentoo.org&gt;
Signed-off-by: Thomas Bogendoerfer &lt;tsbogend@alpha.franken.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'net-5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2021-07-30T23:01:36+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-07-30T23:01:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c7d102232649226a69dddd58a4942cf13cff4f7c'/>
<id>c7d102232649226a69dddd58a4942cf13cff4f7c</id>
<content type='text'>
Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.14-rc4, including fixes from bpf, can, WiFi
  (mac80211) and netfilter trees.

  Current release - regressions:

   - mac80211: fix starting aggregation sessions on mesh interfaces

  Current release - new code bugs:

   - sctp: send pmtu probe only if packet loss in Search Complete state

   - bnxt_en: add missing periodic PHC overflow check

   - devlink: fix phys_port_name of virtual port and merge error

   - hns3: change the method of obtaining default ptp cycle

   - can: mcba_usb_start(): add missing urb-&gt;transfer_dma initialization

  Previous releases - regressions:

   - set true network header for ECN decapsulation

   - mlx5e: RX, avoid possible data corruption w/ relaxed ordering and
     LRO

   - phy: re-add check for PHY_BRCM_DIS_TXCRXC_NOENRGY on the BCM54811
     PHY

   - sctp: fix return value check in __sctp_rcv_asconf_lookup

  Previous releases - always broken:

   - bpf:
       - more spectre corner case fixes, introduce a BPF nospec
         instruction for mitigating Spectre v4
       - fix OOB read when printing XDP link fdinfo
       - sockmap: fix cleanup related races

   - mac80211: fix enabling 4-address mode on a sta vif after assoc

   - can:
       - raw: raw_setsockopt(): fix raw_rcv panic for sock UAF
       - j1939: j1939_session_deactivate(): clarify lifetime of session
         object, avoid UAF
       - fix number of identical memory leaks in USB drivers

   - tipc:
       - do not blindly write skb_shinfo frags when doing decryption
       - fix sleeping in tipc accept routine"

* tag 'net-5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (91 commits)
  gve: Update MAINTAINERS list
  can: esd_usb2: fix memory leak
  can: ems_usb: fix memory leak
  can: usb_8dev: fix memory leak
  can: mcba_usb_start(): add missing urb-&gt;transfer_dma initialization
  can: hi311x: fix a signedness bug in hi3110_cmd()
  MAINTAINERS: add Yasushi SHOJI as reviewer for the Microchip CAN BUS Analyzer Tool driver
  bpf: Fix leakage due to insufficient speculative store bypass mitigation
  bpf: Introduce BPF nospec instruction for mitigating Spectre v4
  sis900: Fix missing pci_disable_device() in probe and remove
  net: let flow have same hash in two directions
  nfc: nfcsim: fix use after free during module unload
  tulip: windbond-840: Fix missing pci_disable_device() in probe and remove
  sctp: fix return value check in __sctp_rcv_asconf_lookup
  nfc: s3fwrn5: fix undefined parameter values in dev_err()
  net/mlx5: Fix mlx5_vport_tbl_attr chain from u16 to u32
  net/mlx5e: Fix nullptr in mlx5e_hairpin_get_mdev()
  net/mlx5: Unload device upon firmware fatal error
  net/mlx5e: Fix page allocation failure for ptp-RQ over SF
  net/mlx5e: Fix page allocation failure for trap-RQ over SF
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.14-rc4, including fixes from bpf, can, WiFi
  (mac80211) and netfilter trees.

  Current release - regressions:

   - mac80211: fix starting aggregation sessions on mesh interfaces

  Current release - new code bugs:

   - sctp: send pmtu probe only if packet loss in Search Complete state

   - bnxt_en: add missing periodic PHC overflow check

   - devlink: fix phys_port_name of virtual port and merge error

   - hns3: change the method of obtaining default ptp cycle

   - can: mcba_usb_start(): add missing urb-&gt;transfer_dma initialization

  Previous releases - regressions:

   - set true network header for ECN decapsulation

   - mlx5e: RX, avoid possible data corruption w/ relaxed ordering and
     LRO

   - phy: re-add check for PHY_BRCM_DIS_TXCRXC_NOENRGY on the BCM54811
     PHY

   - sctp: fix return value check in __sctp_rcv_asconf_lookup

  Previous releases - always broken:

   - bpf:
       - more spectre corner case fixes, introduce a BPF nospec
         instruction for mitigating Spectre v4
       - fix OOB read when printing XDP link fdinfo
       - sockmap: fix cleanup related races

   - mac80211: fix enabling 4-address mode on a sta vif after assoc

   - can:
       - raw: raw_setsockopt(): fix raw_rcv panic for sock UAF
       - j1939: j1939_session_deactivate(): clarify lifetime of session
         object, avoid UAF
       - fix number of identical memory leaks in USB drivers

   - tipc:
       - do not blindly write skb_shinfo frags when doing decryption
       - fix sleeping in tipc accept routine"

* tag 'net-5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (91 commits)
  gve: Update MAINTAINERS list
  can: esd_usb2: fix memory leak
  can: ems_usb: fix memory leak
  can: usb_8dev: fix memory leak
  can: mcba_usb_start(): add missing urb-&gt;transfer_dma initialization
  can: hi311x: fix a signedness bug in hi3110_cmd()
  MAINTAINERS: add Yasushi SHOJI as reviewer for the Microchip CAN BUS Analyzer Tool driver
  bpf: Fix leakage due to insufficient speculative store bypass mitigation
  bpf: Introduce BPF nospec instruction for mitigating Spectre v4
  sis900: Fix missing pci_disable_device() in probe and remove
  net: let flow have same hash in two directions
  nfc: nfcsim: fix use after free during module unload
  tulip: windbond-840: Fix missing pci_disable_device() in probe and remove
  sctp: fix return value check in __sctp_rcv_asconf_lookup
  nfc: s3fwrn5: fix undefined parameter values in dev_err()
  net/mlx5: Fix mlx5_vport_tbl_attr chain from u16 to u32
  net/mlx5e: Fix nullptr in mlx5e_hairpin_get_mdev()
  net/mlx5: Unload device upon firmware fatal error
  net/mlx5e: Fix page allocation failure for ptp-RQ over SF
  net/mlx5e: Fix page allocation failure for trap-RQ over SF
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'libata-5.14-2021-07-30' of git://git.kernel.dk/linux-block</title>
<updated>2021-07-30T17:56:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-07-30T17:56:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f6c5971bb78ee5c4b9659f2764e58c175b75638c'/>
<id>f6c5971bb78ee5c4b9659f2764e58c175b75638c</id>
<content type='text'>
Pull libata fixlets from Jens Axboe:

 - A fix for PIO highmem (Christoph)

 - Kill HAVE_IDE as it's now unused (Lukas)

* tag 'libata-5.14-2021-07-30' of git://git.kernel.dk/linux-block:
  arch: Kconfig: clean up obsolete use of HAVE_IDE
  libata: fix ata_pio_sector for CONFIG_HIGHMEM
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull libata fixlets from Jens Axboe:

 - A fix for PIO highmem (Christoph)

 - Kill HAVE_IDE as it's now unused (Lukas)

* tag 'libata-5.14-2021-07-30' of git://git.kernel.dk/linux-block:
  arch: Kconfig: clean up obsolete use of HAVE_IDE
  libata: fix ata_pio_sector for CONFIG_HIGHMEM
</pre>
</div>
</content>
</entry>
<entry>
<title>arch: Kconfig: clean up obsolete use of HAVE_IDE</title>
<updated>2021-07-30T14:19:09+00:00</updated>
<author>
<name>Lukas Bulwahn</name>
<email>lukas.bulwahn@gmail.com</email>
</author>
<published>2021-07-28T18:21:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=094121ef815f29d9e6a01fafca365831454ce293'/>
<id>094121ef815f29d9e6a01fafca365831454ce293</id>
<content type='text'>
The arch-specific Kconfig files use HAVE_IDE to indicate if IDE is
supported.

As IDE support and the HAVE_IDE config vanishes with commit b7fb14d3ac63
("ide: remove the legacy ide driver"), there is no need to mention
HAVE_IDE in all those arch-specific Kconfig files.

The issue was identified with ./scripts/checkkconfigsymbols.py.

Fixes: b7fb14d3ac63 ("ide: remove the legacy ide driver")
Suggested-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Lukas Bulwahn &lt;lukas.bulwahn@gmail.com&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Link: https://lore.kernel.org/r/20210728182115.4401-1-lukas.bulwahn@gmail.com
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The arch-specific Kconfig files use HAVE_IDE to indicate if IDE is
supported.

As IDE support and the HAVE_IDE config vanishes with commit b7fb14d3ac63
("ide: remove the legacy ide driver"), there is no need to mention
HAVE_IDE in all those arch-specific Kconfig files.

The issue was identified with ./scripts/checkkconfigsymbols.py.

Fixes: b7fb14d3ac63 ("ide: remove the legacy ide driver")
Suggested-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Signed-off-by: Lukas Bulwahn &lt;lukas.bulwahn@gmail.com&gt;
Acked-by: Randy Dunlap &lt;rdunlap@infradead.org&gt;
Link: https://lore.kernel.org/r/20210728182115.4401-1-lukas.bulwahn@gmail.com
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Acked-by: Geert Uytterhoeven &lt;geert@linux-m68k.org&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf</title>
<updated>2021-07-28T23:53:32+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2021-07-28T23:53:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=fc16a5322ee6c30ea848818722eee5d352f8d127'/>
<id>fc16a5322ee6c30ea848818722eee5d352f8d127</id>
<content type='text'>
Daniel Borkmann says:

====================
pull-request: bpf 2021-07-29

The following pull-request contains BPF updates for your *net* tree.

We've added 9 non-merge commits during the last 14 day(s) which contain
a total of 20 files changed, 446 insertions(+), 138 deletions(-).

The main changes are:

1) Fix UBSAN out-of-bounds splat for showing XDP link fdinfo, from Lorenz Bauer.

2) Fix insufficient Spectre v4 mitigation in BPF runtime, from Daniel Borkmann,
   Piotr Krysiuk and Benedict Schlueter.

3) Batch of fixes for BPF sockmap found under stress testing, from John Fastabend.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Daniel Borkmann says:

====================
pull-request: bpf 2021-07-29

The following pull-request contains BPF updates for your *net* tree.

We've added 9 non-merge commits during the last 14 day(s) which contain
a total of 20 files changed, 446 insertions(+), 138 deletions(-).

The main changes are:

1) Fix UBSAN out-of-bounds splat for showing XDP link fdinfo, from Lorenz Bauer.

2) Fix insufficient Spectre v4 mitigation in BPF runtime, from Daniel Borkmann,
   Piotr Krysiuk and Benedict Schlueter.

3) Batch of fixes for BPF sockmap found under stress testing, from John Fastabend.
====================

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf: Introduce BPF nospec instruction for mitigating Spectre v4</title>
<updated>2021-07-28T22:20:56+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2021-07-13T08:18:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f5e81d1117501546b7be050c5fbafa6efd2c722c'/>
<id>f5e81d1117501546b7be050c5fbafa6efd2c722c</id>
<content type='text'>
In case of JITs, each of the JIT backends compiles the BPF nospec instruction
/either/ to a machine instruction which emits a speculation barrier /or/ to
/no/ machine instruction in case the underlying architecture is not affected
by Speculative Store Bypass or has different mitigations in place already.

This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence'
instruction for mitigation. In case of arm64, we rely on the firmware mitigation
as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled,
it works for all of the kernel code with no need to provide any additional
instructions here (hence only comment in arm64 JIT). Other archs can follow
as needed. The BPF nospec instruction is specifically targeting Spectre v4
since i) we don't use a serialization barrier for the Spectre v1 case, and
ii) mitigation instructions for v1 and v4 might be different on some archs.

The BPF nospec is required for a future commit, where the BPF verifier does
annotate intermediate BPF programs with speculation barriers.

Co-developed-by: Piotr Krysiuk &lt;piotras@gmail.com&gt;
Co-developed-by: Benedict Schlueter &lt;benedict.schlueter@rub.de&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Piotr Krysiuk &lt;piotras@gmail.com&gt;
Signed-off-by: Benedict Schlueter &lt;benedict.schlueter@rub.de&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
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In case of JITs, each of the JIT backends compiles the BPF nospec instruction
/either/ to a machine instruction which emits a speculation barrier /or/ to
/no/ machine instruction in case the underlying architecture is not affected
by Speculative Store Bypass or has different mitigations in place already.

This covers both x86 and (implicitly) arm64: In case of x86, we use 'lfence'
instruction for mitigation. In case of arm64, we rely on the firmware mitigation
as controlled via the ssbd kernel parameter. Whenever the mitigation is enabled,
it works for all of the kernel code with no need to provide any additional
instructions here (hence only comment in arm64 JIT). Other archs can follow
as needed. The BPF nospec instruction is specifically targeting Spectre v4
since i) we don't use a serialization barrier for the Spectre v1 case, and
ii) mitigation instructions for v1 and v4 might be different on some archs.

The BPF nospec is required for a future commit, where the BPF verifier does
annotate intermediate BPF programs with speculation barriers.

Co-developed-by: Piotr Krysiuk &lt;piotras@gmail.com&gt;
Co-developed-by: Benedict Schlueter &lt;benedict.schlueter@rub.de&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Signed-off-by: Piotr Krysiuk &lt;piotras@gmail.com&gt;
Signed-off-by: Benedict Schlueter &lt;benedict.schlueter@rub.de&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
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