<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/mips, branch v5.5</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge tag 'mips_fixes_5.5_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux</title>
<updated>2020-01-04T22:16:57+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2020-01-04T22:16:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c420ddda506b80ec2686e405698d37fafeea3b7a'/>
<id>c420ddda506b80ec2686e405698d37fafeea3b7a</id>
<content type='text'>
Pull MIPS fixes from Paul Burton:
 "A collection of MIPS fixes:

   - Fill the struct cacheinfo shared_cpu_map field with sensible
     values, notably avoiding issues with perf which was unhappy in the
     absence of these values.

   - A boot fix for Loongson 2E &amp; 2F machines which was fallout from
     some refactoring performed this cycle.

   - A Kconfig dependency fix for the Loongson CPU HWMon driver.

   - A couple of VDSO fixes, ensuring gettimeofday() behaves
     appropriately for kernel configurations that don't include support
     for a clocksource the VDSO can use &amp; fixing the calling convention
     for the n32 &amp; n64 VDSOs which would previously clobber the $gp/$28
     register.

   - A build fix for vmlinuz compressed images which were
     inappropriately building with -fsanitize-coverage despite not being
     part of the kernel proper, then failing to link due to the missing
     __sanitizer_cov_trace_pc() function.

   - A couple of eBPF JIT fixes, including disabling it for MIPS32 due
     to a large number of issues with the code generated there &amp;
     reflecting ISA dependencies in Kconfig to enforce that systems
     which don't support the JIT must include the interpreter"

* tag 'mips_fixes_5.5_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: Avoid VDSO ABI breakage due to global register variable
  MIPS: BPF: eBPF JIT: check for MIPS ISA compliance in Kconfig
  MIPS: BPF: Disable MIPS32 eBPF JIT
  MIPS: Prevent link failure with kcov instrumentation
  MIPS: Kconfig: Use correct form for 'depends on'
  mips: Fix gettimeofday() in the vdso library
  MIPS: Fix boot on Fuloong2 systems
  mips: cacheinfo: report shared CPU map
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull MIPS fixes from Paul Burton:
 "A collection of MIPS fixes:

   - Fill the struct cacheinfo shared_cpu_map field with sensible
     values, notably avoiding issues with perf which was unhappy in the
     absence of these values.

   - A boot fix for Loongson 2E &amp; 2F machines which was fallout from
     some refactoring performed this cycle.

   - A Kconfig dependency fix for the Loongson CPU HWMon driver.

   - A couple of VDSO fixes, ensuring gettimeofday() behaves
     appropriately for kernel configurations that don't include support
     for a clocksource the VDSO can use &amp; fixing the calling convention
     for the n32 &amp; n64 VDSOs which would previously clobber the $gp/$28
     register.

   - A build fix for vmlinuz compressed images which were
     inappropriately building with -fsanitize-coverage despite not being
     part of the kernel proper, then failing to link due to the missing
     __sanitizer_cov_trace_pc() function.

   - A couple of eBPF JIT fixes, including disabling it for MIPS32 due
     to a large number of issues with the code generated there &amp;
     reflecting ISA dependencies in Kconfig to enforce that systems
     which don't support the JIT must include the interpreter"

* tag 'mips_fixes_5.5_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: Avoid VDSO ABI breakage due to global register variable
  MIPS: BPF: eBPF JIT: check for MIPS ISA compliance in Kconfig
  MIPS: BPF: Disable MIPS32 eBPF JIT
  MIPS: Prevent link failure with kcov instrumentation
  MIPS: Kconfig: Use correct form for 'depends on'
  mips: Fix gettimeofday() in the vdso library
  MIPS: Fix boot on Fuloong2 systems
  mips: cacheinfo: report shared CPU map
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Avoid VDSO ABI breakage due to global register variable</title>
<updated>2020-01-03T00:41:16+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paulburton@kernel.org</email>
</author>
<published>2020-01-02T04:50:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bbcc5672b0063b0e9d65dc8787a4f09c3b5bb5cc'/>
<id>bbcc5672b0063b0e9d65dc8787a4f09c3b5bb5cc</id>
<content type='text'>
Declaring __current_thread_info as a global register variable has the
effect of preventing GCC from saving &amp; restoring its value in cases
where the ABI would typically do so.

To quote GCC documentation:

&gt; If the register is a call-saved register, call ABI is affected: the
&gt; register will not be restored in function epilogue sequences after the
&gt; variable has been assigned. Therefore, functions cannot safely return
&gt; to callers that assume standard ABI.

When our position independent VDSO is built for the n32 or n64 ABIs all
functions it exposes should be preserving the value of $gp/$28 for their
caller, but in the presence of the __current_thread_info global register
variable GCC stops doing so &amp; simply clobbers $gp/$28 when calculating
the address of the GOT.

In cases where the VDSO returns success this problem will typically be
masked by the caller in libc returning &amp; restoring $gp/$28 itself, but
that is by no means guaranteed. In cases where the VDSO returns an error
libc will typically contain a fallback path which will now fail
(typically with a bad memory access) if it attempts anything which
relies upon the value of $gp/$28 - eg. accessing anything via the GOT.

One fix for this would be to move the declaration of
__current_thread_info inside the current_thread_info() function,
demoting it from global register variable to local register variable &amp;
avoiding inadvertently creating a non-standard calling ABI for the VDSO.
Unfortunately this causes issues for clang, which doesn't support local
register variables as pointed out by commit fe92da0f355e ("MIPS: Changed
current_thread_info() to an equivalent supported by both clang and GCC")
which introduced the global register variable before we had a VDSO to
worry about.

Instead, fix this by continuing to use the global register variable for
the kernel proper but declare __current_thread_info as a simple extern
variable when building the VDSO. It should never be referenced, and will
cause a link error if it is. This resolves the calling convention issue
for the VDSO without having any impact upon the build of the kernel
itself for either clang or gcc.

Signed-off-by: Paul Burton &lt;paulburton@kernel.org&gt;
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Reported-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Reviewed-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Tested-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Christian Brauner &lt;christian.brauner@canonical.com&gt;
Cc: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v4.4+
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Declaring __current_thread_info as a global register variable has the
effect of preventing GCC from saving &amp; restoring its value in cases
where the ABI would typically do so.

To quote GCC documentation:

&gt; If the register is a call-saved register, call ABI is affected: the
&gt; register will not be restored in function epilogue sequences after the
&gt; variable has been assigned. Therefore, functions cannot safely return
&gt; to callers that assume standard ABI.

When our position independent VDSO is built for the n32 or n64 ABIs all
functions it exposes should be preserving the value of $gp/$28 for their
caller, but in the presence of the __current_thread_info global register
variable GCC stops doing so &amp; simply clobbers $gp/$28 when calculating
the address of the GOT.

In cases where the VDSO returns success this problem will typically be
masked by the caller in libc returning &amp; restoring $gp/$28 itself, but
that is by no means guaranteed. In cases where the VDSO returns an error
libc will typically contain a fallback path which will now fail
(typically with a bad memory access) if it attempts anything which
relies upon the value of $gp/$28 - eg. accessing anything via the GOT.

One fix for this would be to move the declaration of
__current_thread_info inside the current_thread_info() function,
demoting it from global register variable to local register variable &amp;
avoiding inadvertently creating a non-standard calling ABI for the VDSO.
Unfortunately this causes issues for clang, which doesn't support local
register variables as pointed out by commit fe92da0f355e ("MIPS: Changed
current_thread_info() to an equivalent supported by both clang and GCC")
which introduced the global register variable before we had a VDSO to
worry about.

Instead, fix this by continuing to use the global register variable for
the kernel proper but declare __current_thread_info as a simple extern
variable when building the VDSO. It should never be referenced, and will
cause a link error if it is. This resolves the calling convention issue
for the VDSO without having any impact upon the build of the kernel
itself for either clang or gcc.

Signed-off-by: Paul Burton &lt;paulburton@kernel.org&gt;
Fixes: ebb5e78cc634 ("MIPS: Initial implementation of a VDSO")
Reported-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Reviewed-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Tested-by: Jason A. Donenfeld &lt;Jason@zx2c4.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Christian Brauner &lt;christian.brauner@canonical.com&gt;
Cc: Vincenzo Frascino &lt;vincenzo.frascino@arm.com&gt;
Cc: &lt;stable@vger.kernel.org&gt; # v4.4+
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2019-12-22T17:54:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2019-12-22T17:54:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=78bac77b521b032f96077c21241cc5d5668482c5'/>
<id>78bac77b521b032f96077c21241cc5d5668482c5</id>
<content type='text'>
Pull networking fixes from David Miller:

 1) Several nf_flow_table_offload fixes from Pablo Neira Ayuso,
    including adding a missing ipv6 match description.

 2) Several heap overflow fixes in mwifiex from qize wang and Ganapathi
    Bhat.

 3) Fix uninit value in bond_neigh_init(), from Eric Dumazet.

 4) Fix non-ACPI probing of nxp-nci, from Stephan Gerhold.

 5) Fix use after free in tipc_disc_rcv(), from Tuong Lien.

 6) Enforce limit of 33 tail calls in mips and riscv JIT, from Paul
    Chaignon.

 7) Multicast MAC limit test is off by one in qede, from Manish Chopra.

 8) Fix established socket lookup race when socket goes from
    TCP_ESTABLISHED to TCP_LISTEN, because there lacks an intervening
    RCU grace period. From Eric Dumazet.

 9) Don't send empty SKBs from tcp_write_xmit(), also from Eric Dumazet.

10) Fix active backup transition after link failure in bonding, from
    Mahesh Bandewar.

11) Avoid zero sized hash table in gtp driver, from Taehee Yoo.

12) Fix wrong interface passed to -&gt;mac_link_up(), from Russell King.

13) Fix DSA egress flooding settings in b53, from Florian Fainelli.

14) Memory leak in gmac_setup_txqs(), from Navid Emamdoost.

15) Fix double free in dpaa2-ptp code, from Ioana Ciornei.

16) Reject invalid MTU values in stmmac, from Jose Abreu.

17) Fix refcount leak in error path of u32 classifier, from Davide
    Caratti.

18) Fix regression causing iwlwifi firmware crashes on boot, from Anders
    Kaseorg.

19) Fix inverted return value logic in llc2 code, from Chan Shu Tak.

20) Disable hardware GRO when XDP is attached to qede, frm Manish
    Chopra.

21) Since we encode state in the low pointer bits, dst metrics must be
    at least 4 byte aligned, which is not necessarily true on m68k. Add
    annotations to fix this, from Geert Uytterhoeven.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (160 commits)
  sfc: Include XDP packet headroom in buffer step size.
  sfc: fix channel allocation with brute force
  net: dst: Force 4-byte alignment of dst_metrics
  selftests: pmtu: fix init mtu value in description
  hv_netvsc: Fix unwanted rx_table reset
  net: phy: ensure that phy IDs are correctly typed
  mod_devicetable: fix PHY module format
  qede: Disable hardware gro when xdp prog is installed
  net: ena: fix issues in setting interrupt moderation params in ethtool
  net: ena: fix default tx interrupt moderation interval
  net/smc: unregister ib devices in reboot_event
  net: stmmac: platform: Fix MDIO init for platforms without PHY
  llc2: Fix return statement of llc_stat_ev_rx_null_dsap_xid_c (and _test_c)
  net: hisilicon: Fix a BUG trigered by wrong bytes_compl
  net: dsa: ksz: use common define for tag len
  s390/qeth: don't return -ENOTSUPP to userspace
  s390/qeth: fix promiscuous mode after reset
  s390/qeth: handle error due to unsupported transport mode
  cxgb4: fix refcount init for TC-MQPRIO offload
  tc-testing: initial tdc selftests for cls_u32
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from David Miller:

 1) Several nf_flow_table_offload fixes from Pablo Neira Ayuso,
    including adding a missing ipv6 match description.

 2) Several heap overflow fixes in mwifiex from qize wang and Ganapathi
    Bhat.

 3) Fix uninit value in bond_neigh_init(), from Eric Dumazet.

 4) Fix non-ACPI probing of nxp-nci, from Stephan Gerhold.

 5) Fix use after free in tipc_disc_rcv(), from Tuong Lien.

 6) Enforce limit of 33 tail calls in mips and riscv JIT, from Paul
    Chaignon.

 7) Multicast MAC limit test is off by one in qede, from Manish Chopra.

 8) Fix established socket lookup race when socket goes from
    TCP_ESTABLISHED to TCP_LISTEN, because there lacks an intervening
    RCU grace period. From Eric Dumazet.

 9) Don't send empty SKBs from tcp_write_xmit(), also from Eric Dumazet.

10) Fix active backup transition after link failure in bonding, from
    Mahesh Bandewar.

11) Avoid zero sized hash table in gtp driver, from Taehee Yoo.

12) Fix wrong interface passed to -&gt;mac_link_up(), from Russell King.

13) Fix DSA egress flooding settings in b53, from Florian Fainelli.

14) Memory leak in gmac_setup_txqs(), from Navid Emamdoost.

15) Fix double free in dpaa2-ptp code, from Ioana Ciornei.

16) Reject invalid MTU values in stmmac, from Jose Abreu.

17) Fix refcount leak in error path of u32 classifier, from Davide
    Caratti.

18) Fix regression causing iwlwifi firmware crashes on boot, from Anders
    Kaseorg.

19) Fix inverted return value logic in llc2 code, from Chan Shu Tak.

20) Disable hardware GRO when XDP is attached to qede, frm Manish
    Chopra.

21) Since we encode state in the low pointer bits, dst metrics must be
    at least 4 byte aligned, which is not necessarily true on m68k. Add
    annotations to fix this, from Geert Uytterhoeven.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (160 commits)
  sfc: Include XDP packet headroom in buffer step size.
  sfc: fix channel allocation with brute force
  net: dst: Force 4-byte alignment of dst_metrics
  selftests: pmtu: fix init mtu value in description
  hv_netvsc: Fix unwanted rx_table reset
  net: phy: ensure that phy IDs are correctly typed
  mod_devicetable: fix PHY module format
  qede: Disable hardware gro when xdp prog is installed
  net: ena: fix issues in setting interrupt moderation params in ethtool
  net: ena: fix default tx interrupt moderation interval
  net/smc: unregister ib devices in reboot_event
  net: stmmac: platform: Fix MDIO init for platforms without PHY
  llc2: Fix return statement of llc_stat_ev_rx_null_dsap_xid_c (and _test_c)
  net: hisilicon: Fix a BUG trigered by wrong bytes_compl
  net: dsa: ksz: use common define for tag len
  s390/qeth: don't return -ENOTSUPP to userspace
  s390/qeth: fix promiscuous mode after reset
  s390/qeth: handle error due to unsupported transport mode
  cxgb4: fix refcount init for TC-MQPRIO offload
  tc-testing: initial tdc selftests for cls_u32
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: BPF: eBPF JIT: check for MIPS ISA compliance in Kconfig</title>
<updated>2019-12-18T23:15:04+00:00</updated>
<author>
<name>Alexander Lobakin</name>
<email>alobakin@dlink.ru</email>
</author>
<published>2019-12-06T08:07:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f596cf0d8062cb5d0a4513a8b3afca318c13be10'/>
<id>f596cf0d8062cb5d0a4513a8b3afca318c13be10</id>
<content type='text'>
It is completely wrong to check for compile-time MIPS ISA revision in
the body of bpf_int_jit_compile() as it may lead to get MIPS JIT fully
omitted by the CC while the rest system will think that the JIT is
actually present and works [1].
We can check if the selected CPU really supports MIPS eBPF JIT at
configure time and avoid such situations when kernel can be built
without both JIT and interpreter, but with CONFIG_BPF_SYSCALL=y.

[1] https://lore.kernel.org/linux-mips/09d713a59665d745e21d021deeaebe0a@dlink.ru/

Fixes: 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32 architecture.")
Cc: &lt;stable@vger.kernel.org&gt; # v5.2+
Signed-off-by: Alexander Lobakin &lt;alobakin@dlink.ru&gt;
Signed-off-by: Paul Burton &lt;paulburton@kernel.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Hassan Naveed &lt;hnaveed@wavecomp.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Martin KaFai Lau &lt;kafai@fb.com&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Cc: Andrii Nakryiko &lt;andriin@fb.com&gt;
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It is completely wrong to check for compile-time MIPS ISA revision in
the body of bpf_int_jit_compile() as it may lead to get MIPS JIT fully
omitted by the CC while the rest system will think that the JIT is
actually present and works [1].
We can check if the selected CPU really supports MIPS eBPF JIT at
configure time and avoid such situations when kernel can be built
without both JIT and interpreter, but with CONFIG_BPF_SYSCALL=y.

[1] https://lore.kernel.org/linux-mips/09d713a59665d745e21d021deeaebe0a@dlink.ru/

Fixes: 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32 architecture.")
Cc: &lt;stable@vger.kernel.org&gt; # v5.2+
Signed-off-by: Alexander Lobakin &lt;alobakin@dlink.ru&gt;
Signed-off-by: Paul Burton &lt;paulburton@kernel.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Hassan Naveed &lt;hnaveed@wavecomp.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Martin KaFai Lau &lt;kafai@fb.com&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Yonghong Song &lt;yhs@fb.com&gt;
Cc: Andrii Nakryiko &lt;andriin@fb.com&gt;
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: bpf@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: BPF: Disable MIPS32 eBPF JIT</title>
<updated>2019-12-18T23:15:03+00:00</updated>
<author>
<name>Paul Burton</name>
<email>paulburton@kernel.org</email>
</author>
<published>2019-12-05T18:23:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f8fffebdea752a25757b906f3dffecf1a59a6194'/>
<id>f8fffebdea752a25757b906f3dffecf1a59a6194</id>
<content type='text'>
Commit 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32
architecture.") enabled our eBPF JIT for MIPS32 kernels, whereas it has
previously only been availailable for MIPS64. It was my understanding at
the time that the BPF test suite was passing &amp; JITing a comparable
number of tests to our cBPF JIT [1], but it turns out that was not the
case.

The eBPF JIT has a number of problems on MIPS32:

- Most notably various code paths still result in emission of MIPS64
  instructions which will cause reserved instruction exceptions &amp; kernel
  panics when run on MIPS32 CPUs.

- The eBPF JIT doesn't account for differences between the O32 ABI used
  by MIPS32 kernels versus the N64 ABI used by MIPS64 kernels. Notably
  arguments beyond the first 4 are passed on the stack in O32, and this
  is entirely unhandled when JITing a BPF_CALL instruction. Stack space
  must be reserved for arguments even if they all fit in registers, and
  the callee is free to assume that stack space has been reserved for
  its use - with the eBPF JIT this is not the case, so calling any
  function can result in clobbering values on the stack &amp; unpredictable
  behaviour. Function arguments in eBPF are always 64-bit values which
  is also entirely unhandled - the JIT still uses a single (32-bit)
  register per argument. As a result all function arguments are always
  passed incorrectly when JITing a BPF_CALL instruction, leading to
  kernel crashes or strange behavior.

- The JIT attempts to bail our on use of ALU64 instructions or 64-bit
  memory access instructions. The code doing this at the start of
  build_one_insn() incorrectly checks whether BPF_OP() equals BPF_DW,
  when it should really be checking BPF_SIZE() &amp; only doing so when
  BPF_CLASS() is one of BPF_{LD,LDX,ST,STX}. This results in false
  positives that cause more bailouts than intended, and that in turns
  hides some of the problems described above.

- The kernel's cBPF-&gt;eBPF translation makes heavy use of 64-bit eBPF
  instructions that the MIPS32 eBPF JIT bails out on, leading to most
  cBPF programs not being JITed at all.

Until these problems are resolved, revert the enabling of the eBPF JIT
on MIPS32 done by commit 716850ab104d ("MIPS: eBPF: Initial eBPF support
for MIPS32 architecture.").

Note that this does not undo the changes made to the eBPF JIT by that
commit, since they are a useful starting point to providing MIPS32
support - they're just not nearly complete.

[1] https://lore.kernel.org/linux-mips/MWHPR2201MB13583388481F01A422CE7D66D4410@MWHPR2201MB1358.namprd22.prod.outlook.com/

Signed-off-by: Paul Burton &lt;paulburton@kernel.org&gt;
Fixes: 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32 architecture.")
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Hassan Naveed &lt;hnaveed@wavecomp.com&gt;
Cc: Tony Ambardar &lt;itugrok@yahoo.com&gt;
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: &lt;stable@vger.kernel.org&gt; # v5.2+
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32
architecture.") enabled our eBPF JIT for MIPS32 kernels, whereas it has
previously only been availailable for MIPS64. It was my understanding at
the time that the BPF test suite was passing &amp; JITing a comparable
number of tests to our cBPF JIT [1], but it turns out that was not the
case.

The eBPF JIT has a number of problems on MIPS32:

- Most notably various code paths still result in emission of MIPS64
  instructions which will cause reserved instruction exceptions &amp; kernel
  panics when run on MIPS32 CPUs.

- The eBPF JIT doesn't account for differences between the O32 ABI used
  by MIPS32 kernels versus the N64 ABI used by MIPS64 kernels. Notably
  arguments beyond the first 4 are passed on the stack in O32, and this
  is entirely unhandled when JITing a BPF_CALL instruction. Stack space
  must be reserved for arguments even if they all fit in registers, and
  the callee is free to assume that stack space has been reserved for
  its use - with the eBPF JIT this is not the case, so calling any
  function can result in clobbering values on the stack &amp; unpredictable
  behaviour. Function arguments in eBPF are always 64-bit values which
  is also entirely unhandled - the JIT still uses a single (32-bit)
  register per argument. As a result all function arguments are always
  passed incorrectly when JITing a BPF_CALL instruction, leading to
  kernel crashes or strange behavior.

- The JIT attempts to bail our on use of ALU64 instructions or 64-bit
  memory access instructions. The code doing this at the start of
  build_one_insn() incorrectly checks whether BPF_OP() equals BPF_DW,
  when it should really be checking BPF_SIZE() &amp; only doing so when
  BPF_CLASS() is one of BPF_{LD,LDX,ST,STX}. This results in false
  positives that cause more bailouts than intended, and that in turns
  hides some of the problems described above.

- The kernel's cBPF-&gt;eBPF translation makes heavy use of 64-bit eBPF
  instructions that the MIPS32 eBPF JIT bails out on, leading to most
  cBPF programs not being JITed at all.

Until these problems are resolved, revert the enabling of the eBPF JIT
on MIPS32 done by commit 716850ab104d ("MIPS: eBPF: Initial eBPF support
for MIPS32 architecture.").

Note that this does not undo the changes made to the eBPF JIT by that
commit, since they are a useful starting point to providing MIPS32
support - they're just not nearly complete.

[1] https://lore.kernel.org/linux-mips/MWHPR2201MB13583388481F01A422CE7D66D4410@MWHPR2201MB1358.namprd22.prod.outlook.com/

Signed-off-by: Paul Burton &lt;paulburton@kernel.org&gt;
Fixes: 716850ab104d ("MIPS: eBPF: Initial eBPF support for MIPS32 architecture.")
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Hassan Naveed &lt;hnaveed@wavecomp.com&gt;
Cc: Tony Ambardar &lt;itugrok@yahoo.com&gt;
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: &lt;stable@vger.kernel.org&gt; # v5.2+
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Prevent link failure with kcov instrumentation</title>
<updated>2019-12-18T23:15:03+00:00</updated>
<author>
<name>Jouni Hogander</name>
<email>jouni.hogander@unikie.com</email>
</author>
<published>2019-12-09T12:37:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a4a3893114a41e365274d5fab5d9ff5acc235ff0'/>
<id>a4a3893114a41e365274d5fab5d9ff5acc235ff0</id>
<content type='text'>
__sanitizer_cov_trace_pc() is not linked in and causing link
failure if KCOV_INSTRUMENT is enabled. Fix this by disabling
instrumentation for compressed image.

Signed-off-by: Jouni Hogander &lt;jouni.hogander@unikie.com&gt;
Signed-off-by: Paul Burton &lt;paulburton@kernel.org&gt;
Cc: Lukas Bulwahn &lt;lukas.bulwahn@gmail.com&gt;
Cc: linux-mips@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
__sanitizer_cov_trace_pc() is not linked in and causing link
failure if KCOV_INSTRUMENT is enabled. Fix this by disabling
instrumentation for compressed image.

Signed-off-by: Jouni Hogander &lt;jouni.hogander@unikie.com&gt;
Signed-off-by: Paul Burton &lt;paulburton@kernel.org&gt;
Cc: Lukas Bulwahn &lt;lukas.bulwahn@gmail.com&gt;
Cc: linux-mips@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>bpf, mips: Limit to 33 tail calls</title>
<updated>2019-12-11T12:57:22+00:00</updated>
<author>
<name>Paul Chaignon</name>
<email>paul.chaignon@orange.com</email>
</author>
<published>2019-12-09T18:52:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e49e6f6db04e915dccb494ae10fa14888fea6f89'/>
<id>e49e6f6db04e915dccb494ae10fa14888fea6f89</id>
<content type='text'>
All BPF JIT compilers except RISC-V's and MIPS' enforce a 33-tail calls
limit at runtime.  In addition, a test was recently added, in tailcalls2,
to check this limit.

This patch updates the tail call limit in MIPS' JIT compiler to allow
33 tail calls.

Fixes: b6bd53f9c4e8 ("MIPS: Add missing file for eBPF JIT.")
Reported-by: Mahshid Khezri &lt;khezri.mahshid@gmail.com&gt;
Signed-off-by: Paul Chaignon &lt;paul.chaignon@orange.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Martin KaFai Lau &lt;kafai@fb.com&gt;
Link: https://lore.kernel.org/bpf/b8eb2caac1c25453c539248e56ca22f74b5316af.1575916815.git.paul.chaignon@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
All BPF JIT compilers except RISC-V's and MIPS' enforce a 33-tail calls
limit at runtime.  In addition, a test was recently added, in tailcalls2,
to check this limit.

This patch updates the tail call limit in MIPS' JIT compiler to allow
33 tail calls.

Fixes: b6bd53f9c4e8 ("MIPS: Add missing file for eBPF JIT.")
Reported-by: Mahshid Khezri &lt;khezri.mahshid@gmail.com&gt;
Signed-off-by: Paul Chaignon &lt;paul.chaignon@orange.com&gt;
Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Acked-by: Martin KaFai Lau &lt;kafai@fb.com&gt;
Link: https://lore.kernel.org/bpf/b8eb2caac1c25453c539248e56ca22f74b5316af.1575916815.git.paul.chaignon@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: OCTEON: Replace SIZEOF_FIELD() macro</title>
<updated>2019-12-09T18:33:50+00:00</updated>
<author>
<name>Pankaj Bharadiya</name>
<email>pankaj.laxminarayan.bharadiya@intel.com</email>
</author>
<published>2019-09-24T10:58:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e43723292d6d7f217b572aab07f1f165189a1b56'/>
<id>e43723292d6d7f217b572aab07f1f165189a1b56</id>
<content type='text'>
Switch to the standard sizeof_field() macro to find the size of a member
of a struct and remove the custom SIZEOF_FIELD() macro.

Signed-off-by: Pankaj Bharadiya &lt;pankaj.laxminarayan.bharadiya@intel.com&gt;
Link: https://lore.kernel.org/r/20190924105839.110713-4-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Switch to the standard sizeof_field() macro to find the size of a member
of a struct and remove the custom SIZEOF_FIELD() macro.

Signed-off-by: Pankaj Bharadiya &lt;pankaj.laxminarayan.bharadiya@intel.com&gt;
Link: https://lore.kernel.org/r/20190924105839.110713-4-pankaj.laxminarayan.bharadiya@intel.com
Co-developed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch: sembuf.h: make uapi asm/sembuf.h self-contained</title>
<updated>2019-12-05T03:44:14+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2019-12-05T00:53:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0fb9dc28679a627f84974165c8011e0630529ece'/>
<id>0fb9dc28679a627f84974165c8011e0630529ece</id>
<content type='text'>
Userspace cannot compile &lt;asm/sembuf.h&gt; due to some missing type
definitions.  For example, building it for x86 fails as follows:

    CC      usr/include/asm/sembuf.h.s
  In file included from &lt;command-line&gt;:32:0:
  usr/include/asm/sembuf.h:17:20: error: field `sem_perm' has incomplete type
    struct ipc64_perm sem_perm; /* permissions .. see ipc.h */
                      ^~~~~~~~
  usr/include/asm/sembuf.h:24:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t sem_otime; /* last semop time */
    ^~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:25:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused1;
    ^~~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:26:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t sem_ctime; /* last change time */
    ^~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:27:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused2;
    ^~~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:29:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t sem_nsems; /* no. of semaphores in array */
    ^~~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:30:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused3;
    ^~~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:31:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused4;
    ^~~~~~~~~~~~~~~~

It is just a matter of missing include directive.

Include &lt;asm/ipcbuf.h&gt; to make it self-contained, and add it to
the compile-test coverage.

Link: http://lkml.kernel.org/r/20191030063855.9989-3-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Userspace cannot compile &lt;asm/sembuf.h&gt; due to some missing type
definitions.  For example, building it for x86 fails as follows:

    CC      usr/include/asm/sembuf.h.s
  In file included from &lt;command-line&gt;:32:0:
  usr/include/asm/sembuf.h:17:20: error: field `sem_perm' has incomplete type
    struct ipc64_perm sem_perm; /* permissions .. see ipc.h */
                      ^~~~~~~~
  usr/include/asm/sembuf.h:24:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t sem_otime; /* last semop time */
    ^~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:25:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused1;
    ^~~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:26:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t sem_ctime; /* last change time */
    ^~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:27:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused2;
    ^~~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:29:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t sem_nsems; /* no. of semaphores in array */
    ^~~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:30:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused3;
    ^~~~~~~~~~~~~~~~
  usr/include/asm/sembuf.h:31:2: error: unknown type name `__kernel_ulong_t'
    __kernel_ulong_t __unused4;
    ^~~~~~~~~~~~~~~~

It is just a matter of missing include directive.

Include &lt;asm/ipcbuf.h&gt; to make it self-contained, and add it to
the compile-test coverage.

Link: http://lkml.kernel.org/r/20191030063855.9989-3-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arch: msgbuf.h: make uapi asm/msgbuf.h self-contained</title>
<updated>2019-12-05T03:44:14+00:00</updated>
<author>
<name>Masahiro Yamada</name>
<email>yamada.masahiro@socionext.com</email>
</author>
<published>2019-12-05T00:53:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9ef0e004181956e158fb7ceb9b43810a193f80cd'/>
<id>9ef0e004181956e158fb7ceb9b43810a193f80cd</id>
<content type='text'>
Userspace cannot compile &lt;asm/msgbuf.h&gt; due to some missing type
definitions.  For example, building it for x86 fails as follows:

    CC      usr/include/asm/msgbuf.h.s
  In file included from usr/include/asm/msgbuf.h:6:0,
                   from &lt;command-line&gt;:32:
  usr/include/asm-generic/msgbuf.h:25:20: error: field `msg_perm' has incomplete type
    struct ipc64_perm msg_perm;
                      ^~~~~~~~
  usr/include/asm-generic/msgbuf.h:27:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t msg_stime; /* last msgsnd time */
    ^~~~~~~~~~~~~~~
  usr/include/asm-generic/msgbuf.h:28:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t msg_rtime; /* last msgrcv time */
    ^~~~~~~~~~~~~~~
  usr/include/asm-generic/msgbuf.h:29:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t msg_ctime; /* last change time */
    ^~~~~~~~~~~~~~~
  usr/include/asm-generic/msgbuf.h:41:2: error: unknown type name `__kernel_pid_t'
    __kernel_pid_t msg_lspid; /* pid of last msgsnd */
    ^~~~~~~~~~~~~~
  usr/include/asm-generic/msgbuf.h:42:2: error: unknown type name `__kernel_pid_t'
    __kernel_pid_t msg_lrpid; /* last receive pid */
    ^~~~~~~~~~~~~~

It is just a matter of missing include directive.

Include &lt;asm/ipcbuf.h&gt; to make it self-contained, and add it to
the compile-test coverage.

Link: http://lkml.kernel.org/r/20191030063855.9989-2-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Userspace cannot compile &lt;asm/msgbuf.h&gt; due to some missing type
definitions.  For example, building it for x86 fails as follows:

    CC      usr/include/asm/msgbuf.h.s
  In file included from usr/include/asm/msgbuf.h:6:0,
                   from &lt;command-line&gt;:32:
  usr/include/asm-generic/msgbuf.h:25:20: error: field `msg_perm' has incomplete type
    struct ipc64_perm msg_perm;
                      ^~~~~~~~
  usr/include/asm-generic/msgbuf.h:27:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t msg_stime; /* last msgsnd time */
    ^~~~~~~~~~~~~~~
  usr/include/asm-generic/msgbuf.h:28:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t msg_rtime; /* last msgrcv time */
    ^~~~~~~~~~~~~~~
  usr/include/asm-generic/msgbuf.h:29:2: error: unknown type name `__kernel_time_t'
    __kernel_time_t msg_ctime; /* last change time */
    ^~~~~~~~~~~~~~~
  usr/include/asm-generic/msgbuf.h:41:2: error: unknown type name `__kernel_pid_t'
    __kernel_pid_t msg_lspid; /* pid of last msgsnd */
    ^~~~~~~~~~~~~~
  usr/include/asm-generic/msgbuf.h:42:2: error: unknown type name `__kernel_pid_t'
    __kernel_pid_t msg_lrpid; /* last receive pid */
    ^~~~~~~~~~~~~~

It is just a matter of missing include directive.

Include &lt;asm/ipcbuf.h&gt; to make it self-contained, and add it to
the compile-test coverage.

Link: http://lkml.kernel.org/r/20191030063855.9989-2-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
