<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/mips/net, branch v4.0</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>module: remove mod arg from module_free, rename module_memfree().</title>
<updated>2015-01-20T01:08:33+00:00</updated>
<author>
<name>Rusty Russell</name>
<email>rusty@rustcorp.com.au</email>
</author>
<published>2015-01-19T22:37:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=be1f221c0445a4157d177197c236f888d3581914'/>
<id>be1f221c0445a4157d177197c236f888d3581914</id>
<content type='text'>
Nothing needs the module pointer any more, and the next patch will
call it from RCU, where the module itself might no longer exist.
Removing the arg is the safest approach.

This just codifies the use of the module_alloc/module_free pattern
which ftrace and bpf use.

Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Mikael Starvik &lt;starvik@axis.com&gt;
Cc: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Chris Metcalf &lt;cmetcalf@ezchip.com&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: x86@kernel.org
Cc: Ananth N Mavinakayanahalli &lt;ananth@in.ibm.com&gt;
Cc: Anil S Keshavamurthy &lt;anil.s.keshavamurthy@intel.com&gt;
Cc: Masami Hiramatsu &lt;masami.hiramatsu.pt@hitachi.com&gt;
Cc: linux-cris-kernel@axis.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: nios2-dev@lists.rocketboards.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Cc: netdev@vger.kernel.org
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Nothing needs the module pointer any more, and the next patch will
call it from RCU, where the module itself might no longer exist.
Removing the arg is the safest approach.

This just codifies the use of the module_alloc/module_free pattern
which ftrace and bpf use.

Signed-off-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Acked-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Mikael Starvik &lt;starvik@axis.com&gt;
Cc: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Chris Metcalf &lt;cmetcalf@ezchip.com&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: x86@kernel.org
Cc: Ananth N Mavinakayanahalli &lt;ananth@in.ibm.com&gt;
Cc: Anil S Keshavamurthy &lt;anil.s.keshavamurthy@intel.com&gt;
Cc: Masami Hiramatsu &lt;masami.hiramatsu.pt@hitachi.com&gt;
Cc: linux-cris-kernel@axis.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: nios2-dev@lists.rocketboards.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Cc: netdev@vger.kernel.org
</pre>
</div>
</content>
</entry>
<entry>
<title>mips: bpf: Fix broken BPF_MOD</title>
<updated>2014-12-09T01:22:30+00:00</updated>
<author>
<name>Denis Kirjanov</name>
<email>kda@linux-powerpc.org</email>
</author>
<published>2014-12-01T09:57:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2e46477a12f6fd273e31a220b155d66e8352198c'/>
<id>2e46477a12f6fd273e31a220b155d66e8352198c</id>
<content type='text'>
Remove optimize_div() from BPF_MOD | BPF_K case
since we don't know the dividend and fix the
emit_mod() by reading the mod operation result from HI register

Signed-off-by: Denis Kirjanov &lt;kda@linux-powerpc.org&gt;
Reviewed-by: Markos Chandras &lt;markos.chandras@imgtec.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove optimize_div() from BPF_MOD | BPF_K case
since we don't know the dividend and fix the
emit_mod() by reading the mod operation result from HI register

Signed-off-by: Denis Kirjanov &lt;kda@linux-powerpc.org&gt;
Reviewed-by: Markos Chandras &lt;markos.chandras@imgtec.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus</title>
<updated>2014-10-18T21:24:36+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-10-18T21:24:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=857b50f5d0eed113428c864e927289d8f5f2b864'/>
<id>857b50f5d0eed113428c864e927289d8f5f2b864</id>
<content type='text'>
Pull MIPS updates from Ralf Baechle:
 "This is the MIPS pull request for the next kernel:

   - Zubair's patch series adds CMA support for MIPS.  Doing so it also
     touches ARM64 and x86.
   - remove the last instance of IRQF_DISABLED from arch/mips
   - updates to two of the MIPS defconfig files.
   - cleanup of how cache coherency bits are handled on MIPS and
     implement support for write-combining.
   - platform upgrades for Alchemy
   - move MIPS DTS files to arch/mips/boot/dts/"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (24 commits)
  MIPS: ralink: remove deprecated IRQF_DISABLED
  MIPS: pgtable.h: Implement the pgprot_writecombine function for MIPS
  MIPS: cpu-probe: Set the write-combine CCA value on per core basis
  MIPS: pgtable-bits: Define the CCA bit for WC writes on Ingenic cores
  MIPS: pgtable-bits: Move the CCA bits out of the core's ifdef blocks
  MIPS: DMA: Add cma support
  x86: use generic dma-contiguous.h
  arm64: use generic dma-contiguous.h
  asm-generic: Add dma-contiguous.h
  MIPS: BPF: Add new emit_long_instr macro
  MIPS: ralink: Move device-trees to arch/mips/boot/dts/
  MIPS: Netlogic: Move device-trees to arch/mips/boot/dts/
  MIPS: sead3: Move device-trees to arch/mips/boot/dts/
  MIPS: Lantiq: Move device-trees to arch/mips/boot/dts/
  MIPS: Octeon: Move device-trees to arch/mips/boot/dts/
  MIPS: Add support for building device-tree binaries
  MIPS: Create common infrastructure for building built-in device-trees
  MIPS: SEAD3: Enable DEVTMPFS
  MIPS: SEAD3: Regenerate defconfigs
  MIPS: Alchemy: DB1300: Add touch penirq support
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull MIPS updates from Ralf Baechle:
 "This is the MIPS pull request for the next kernel:

   - Zubair's patch series adds CMA support for MIPS.  Doing so it also
     touches ARM64 and x86.
   - remove the last instance of IRQF_DISABLED from arch/mips
   - updates to two of the MIPS defconfig files.
   - cleanup of how cache coherency bits are handled on MIPS and
     implement support for write-combining.
   - platform upgrades for Alchemy
   - move MIPS DTS files to arch/mips/boot/dts/"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (24 commits)
  MIPS: ralink: remove deprecated IRQF_DISABLED
  MIPS: pgtable.h: Implement the pgprot_writecombine function for MIPS
  MIPS: cpu-probe: Set the write-combine CCA value on per core basis
  MIPS: pgtable-bits: Define the CCA bit for WC writes on Ingenic cores
  MIPS: pgtable-bits: Move the CCA bits out of the core's ifdef blocks
  MIPS: DMA: Add cma support
  x86: use generic dma-contiguous.h
  arm64: use generic dma-contiguous.h
  asm-generic: Add dma-contiguous.h
  MIPS: BPF: Add new emit_long_instr macro
  MIPS: ralink: Move device-trees to arch/mips/boot/dts/
  MIPS: Netlogic: Move device-trees to arch/mips/boot/dts/
  MIPS: sead3: Move device-trees to arch/mips/boot/dts/
  MIPS: Lantiq: Move device-trees to arch/mips/boot/dts/
  MIPS: Octeon: Move device-trees to arch/mips/boot/dts/
  MIPS: Add support for building device-tree binaries
  MIPS: Create common infrastructure for building built-in device-trees
  MIPS: SEAD3: Enable DEVTMPFS
  MIPS: SEAD3: Regenerate defconfigs
  MIPS: Alchemy: DB1300: Add touch penirq support
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>next: mips: bpf: Fix build failure</title>
<updated>2014-09-30T20:54:51+00:00</updated>
<author>
<name>Guenter Roeck</name>
<email>linux@roeck-us.net</email>
</author>
<published>2014-09-30T16:39:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=72d099e2571b3b1bcf8cddb917f0cde4e60c354d'/>
<id>72d099e2571b3b1bcf8cddb917f0cde4e60c354d</id>
<content type='text'>
Fix:

arch/mips/net/bpf_jit.c: In function 'build_body':
arch/mips/net/bpf_jit.c:762:6: error: unused variable 'tmp'
cc1: all warnings being treated as errors
make[2]: *** [arch/mips/net/bpf_jit.o] Error 1

Seen when building mips:allmodconfig in -next since next-20140924.

Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fix:

arch/mips/net/bpf_jit.c: In function 'build_body':
arch/mips/net/bpf_jit.c:762:6: error: unused variable 'tmp'
cc1: all warnings being treated as errors
make[2]: *** [arch/mips/net/bpf_jit.o] Error 1

Seen when building mips:allmodconfig in -next since next-20140924.

Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2014-09-23T16:09:27+00:00</updated>
<author>
<name>David S. Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2014-09-23T16:09:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1f6d80358dc9bbbeb56cb43384fa11fd645d9289'/>
<id>1f6d80358dc9bbbeb56cb43384fa11fd645d9289</id>
<content type='text'>
Conflicts:
	arch/mips/net/bpf_jit.c
	drivers/net/can/flexcan.c

Both the flexcan and MIPS bpf_jit conflicts were cases of simple
overlapping changes.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:
	arch/mips/net/bpf_jit.c
	drivers/net/can/flexcan.c

Both the flexcan and MIPS bpf_jit conflicts were cases of simple
overlapping changes.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: BPF: Add new emit_long_instr macro</title>
<updated>2014-09-22T11:35:51+00:00</updated>
<author>
<name>Markos Chandras</name>
<email>markos.chandras@imgtec.com</email>
</author>
<published>2014-07-23T09:00:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=39bcb7969a84aab3dcdb857b261a87d5d888f5a7'/>
<id>39bcb7969a84aab3dcdb857b261a87d5d888f5a7</id>
<content type='text'>
This macro uses the capitalized UASM_* macros to emit 32 or 64-bit
instructions depending on the kernel configurations. This allows
us to remove a few CONFIG_64BIT ifdefs from the code.

Signed-off-by: Markos Chandras &lt;markos.chandras@imgtec.com&gt;
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7446/
Signed-off-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This macro uses the capitalized UASM_* macros to emit 32 or 64-bit
instructions depending on the kernel configurations. This allows
us to remove a few CONFIG_64BIT ifdefs from the code.

Signed-off-by: Markos Chandras &lt;markos.chandras@imgtec.com&gt;
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7446/
Signed-off-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Use WSBH/DSBH/DSHD on Loongson 3A</title>
<updated>2014-09-22T11:35:46+00:00</updated>
<author>
<name>Chen Jie</name>
<email>chenj@lemote.com</email>
</author>
<published>2014-08-15T08:56:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3c09bae43ba92a07a6a7b7d42360deb32d289cc0'/>
<id>3c09bae43ba92a07a6a7b7d42360deb32d289cc0</id>
<content type='text'>
Signed-off-by: chenj &lt;chenj@lemote.com&gt;
Cc: linux-mips@linux-mips.org
Cc: chenhc@lemote.com
Patchwork: https://patchwork.linux-mips.org/patch/7542/
Patchwork: https://patchwork.linux-mips.org/patch/7550/
Signed-off-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: chenj &lt;chenj@lemote.com&gt;
Cc: linux-mips@linux-mips.org
Cc: chenhc@lemote.com
Patchwork: https://patchwork.linux-mips.org/patch/7542/
Patchwork: https://patchwork.linux-mips.org/patch/7550/
Signed-off-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: filter: constify detection of pkt_type_offset</title>
<updated>2014-09-13T21:07:21+00:00</updated>
<author>
<name>Hannes Frederic Sowa</name>
<email>hannes@stressinduktion.org</email>
</author>
<published>2014-09-12T12:04:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=233577a22089facf5271ab5e845b2262047c971f'/>
<id>233577a22089facf5271ab5e845b2262047c971f</id>
<content type='text'>
Currently we have 2 pkt_type_offset functions doing the same thing and
spread across the architecture files. Remove those and replace them
with a PKT_TYPE_OFFSET macro helper which gets the constant value from a
zero sized sk_buff member right in front of the bitfield with offsetof.
This new offset marker does not change size of struct sk_buff.

Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Markos Chandras &lt;markos.chandras@imgtec.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Cc: Alexei Starovoitov &lt;alexei.starovoitov@gmail.com&gt;
Signed-off-by: Denis Kirjanov &lt;kda@linux-powerpc.org&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Acked-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Acked-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently we have 2 pkt_type_offset functions doing the same thing and
spread across the architecture files. Remove those and replace them
with a PKT_TYPE_OFFSET macro helper which gets the constant value from a
zero sized sk_buff member right in front of the bitfield with offsetof.
This new offset marker does not change size of struct sk_buff.

Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Markos Chandras &lt;markos.chandras@imgtec.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Cc: Alexei Starovoitov &lt;alexei.starovoitov@gmail.com&gt;
Signed-off-by: Denis Kirjanov &lt;kda@linux-powerpc.org&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Acked-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Acked-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: bpf: be friendly to kmemcheck</title>
<updated>2014-09-09T23:58:56+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>dborkman@redhat.com</email>
</author>
<published>2014-09-08T06:04:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=286aad3c4014ca825c447e07e24f8929e6d266d2'/>
<id>286aad3c4014ca825c447e07e24f8929e6d266d2</id>
<content type='text'>
Reported by Mikulas Patocka, kmemcheck currently barks out a
false positive since we don't have special kmemcheck annotation
for bitfields used in bpf_prog structure.

We currently have jited:1, len:31 and thus when accessing len
while CONFIG_KMEMCHECK enabled, kmemcheck throws a warning that
we're reading uninitialized memory.

As we don't need the whole bit universe for pages member, we
can just split it to u16 and use a bool flag for jited instead
of a bitfield.

Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Acked-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Reported by Mikulas Patocka, kmemcheck currently barks out a
false positive since we don't have special kmemcheck annotation
for bitfields used in bpf_prog structure.

We currently have jited:1, len:31 and thus when accessing len
while CONFIG_KMEMCHECK enabled, kmemcheck throws a warning that
we're reading uninitialized memory.

As we don't need the whole bit universe for pages member, we
can just split it to u16 and use a bool flag for jited instead
of a bitfield.

Signed-off-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Signed-off-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Acked-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: bpf: make eBPF interpreter images read-only</title>
<updated>2014-09-05T19:02:48+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>dborkman@redhat.com</email>
</author>
<published>2014-09-02T20:53:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=60a3b2253c413cf601783b070507d7dd6620c954'/>
<id>60a3b2253c413cf601783b070507d7dd6620c954</id>
<content type='text'>
With eBPF getting more extended and exposure to user space is on it's way,
hardening the memory range the interpreter uses to steer its command flow
seems appropriate.  This patch moves the to be interpreted bytecode to
read-only pages.

In case we execute a corrupted BPF interpreter image for some reason e.g.
caused by an attacker which got past a verifier stage, it would not only
provide arbitrary read/write memory access but arbitrary function calls
as well. After setting up the BPF interpreter image, its contents do not
change until destruction time, thus we can setup the image on immutable
made pages in order to mitigate modifications to that code. The idea
is derived from commit 314beb9bcabf ("x86: bpf_jit_comp: secure bpf jit
against spraying attacks").

This is possible because bpf_prog is not part of sk_filter anymore.
After setup bpf_prog cannot be altered during its life-time. This prevents
any modifications to the entire bpf_prog structure (incl. function/JIT
image pointer).

Every eBPF program (including classic BPF that are migrated) have to call
bpf_prog_select_runtime() to select either interpreter or a JIT image
as a last setup step, and they all are being freed via bpf_prog_free(),
including non-JIT. Therefore, we can easily integrate this into the
eBPF life-time, plus since we directly allocate a bpf_prog, we have no
performance penalty.

Tested with seccomp and test_bpf testsuite in JIT/non-JIT mode and manual
inspection of kernel_page_tables.  Brad Spengler proposed the same idea
via Twitter during development of this patch.

Joint work with Hannes Frederic Sowa.

Suggested-by: Brad Spengler &lt;spender@grsecurity.net&gt;
Signed-off-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Cc: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With eBPF getting more extended and exposure to user space is on it's way,
hardening the memory range the interpreter uses to steer its command flow
seems appropriate.  This patch moves the to be interpreted bytecode to
read-only pages.

In case we execute a corrupted BPF interpreter image for some reason e.g.
caused by an attacker which got past a verifier stage, it would not only
provide arbitrary read/write memory access but arbitrary function calls
as well. After setting up the BPF interpreter image, its contents do not
change until destruction time, thus we can setup the image on immutable
made pages in order to mitigate modifications to that code. The idea
is derived from commit 314beb9bcabf ("x86: bpf_jit_comp: secure bpf jit
against spraying attacks").

This is possible because bpf_prog is not part of sk_filter anymore.
After setup bpf_prog cannot be altered during its life-time. This prevents
any modifications to the entire bpf_prog structure (incl. function/JIT
image pointer).

Every eBPF program (including classic BPF that are migrated) have to call
bpf_prog_select_runtime() to select either interpreter or a JIT image
as a last setup step, and they all are being freed via bpf_prog_free(),
including non-JIT. Therefore, we can easily integrate this into the
eBPF life-time, plus since we directly allocate a bpf_prog, we have no
performance penalty.

Tested with seccomp and test_bpf testsuite in JIT/non-JIT mode and manual
inspection of kernel_page_tables.  Brad Spengler proposed the same idea
via Twitter during development of this patch.

Joint work with Hannes Frederic Sowa.

Suggested-by: Brad Spengler &lt;spender@grsecurity.net&gt;
Signed-off-by: Daniel Borkmann &lt;dborkman@redhat.com&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Cc: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Acked-by: Alexei Starovoitov &lt;ast@plumgrid.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
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