<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/arm, branch v4.15</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc</title>
<updated>2018-01-19T19:21:31+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-01-19T19:21:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6ec8765f55cc3e2d6543dfe64ebfd9b2ff327fa4'/>
<id>6ec8765f55cc3e2d6543dfe64ebfd9b2ff327fa4</id>
<content type='text'>
Pull ARM SoC fixes from Arnd Bergmann:
 "We have various small DT fixes, and one important regression fix:

  The recent device tree bugfixes that were intended to address issues
  that 'dtc' started warning about in 4.15 fixed various USB PHY device
  nodes, but it turns out that we had code that depended on those nodes
  being incorrect and the probe failing with a particular error code.
  With the workaround we can also deal with correct device nodes.

  The DT fixes include:

   - Allwinner A10 and A20 had the display pipeline set up incorrectly
     (introduced in v4.15)

   - The Altera PMU lacked an interrupt-parent (never worked)

   - Pin muxing on the Openblocks A7 (never worked)

   - Clocks might get set up wrong on Armada 7K/8K (4.15 regression)

  We now have additional device tree patches to address all the
  remaining warnings introduced in 4.15, but decided to queue them for
  4.16 instead, to avoid risking another regression like the USB PHY
  thing mentioned above.

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  phy: work around 'phys' references to usb-nop-xceiv devices
  ARM: sunxi_defconfig: Enable CMA
  arm64: dts: socfpga: add missing interrupt-parent
  ARM: dts: sun[47]i: Fix display backend 1 output to TCON0 remote endpoint
  ARM64: dts: marvell: armada-cp110: Fix clock resources for various node
  ARM: dts: da850-lcdk: Remove leading 0x and 0s from unit address
  ARM: dts: kirkwood: fix pin-muxing of MPP7 on OpenBlocks A7
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ARM SoC fixes from Arnd Bergmann:
 "We have various small DT fixes, and one important regression fix:

  The recent device tree bugfixes that were intended to address issues
  that 'dtc' started warning about in 4.15 fixed various USB PHY device
  nodes, but it turns out that we had code that depended on those nodes
  being incorrect and the probe failing with a particular error code.
  With the workaround we can also deal with correct device nodes.

  The DT fixes include:

   - Allwinner A10 and A20 had the display pipeline set up incorrectly
     (introduced in v4.15)

   - The Altera PMU lacked an interrupt-parent (never worked)

   - Pin muxing on the Openblocks A7 (never worked)

   - Clocks might get set up wrong on Armada 7K/8K (4.15 regression)

  We now have additional device tree patches to address all the
  remaining warnings introduced in 4.15, but decided to queue them for
  4.16 instead, to avoid risking another regression like the USB PHY
  thing mentioned above.

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  phy: work around 'phys' references to usb-nop-xceiv devices
  ARM: sunxi_defconfig: Enable CMA
  arm64: dts: socfpga: add missing interrupt-parent
  ARM: dts: sun[47]i: Fix display backend 1 output to TCON0 remote endpoint
  ARM64: dts: marvell: armada-cp110: Fix clock resources for various node
  ARM: dts: da850-lcdk: Remove leading 0x and 0s from unit address
  ARM: dts: kirkwood: fix pin-muxing of MPP7 on OpenBlocks A7
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: sunxi_defconfig: Enable CMA</title>
<updated>2018-01-19T15:08:08+00:00</updated>
<author>
<name>Maxime Ripard</name>
<email>maxime.ripard@free-electrons.com</email>
</author>
<published>2018-01-19T13:32:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c13e7f313da33d1488355440f1a10feb1897480a'/>
<id>c13e7f313da33d1488355440f1a10feb1897480a</id>
<content type='text'>
The DRM driver most notably, but also out of tree drivers (for now) like
the VPU or GPU drivers, are quite big consumers of large, contiguous memory
buffers. However, the sunxi_defconfig doesn't enable CMA in order to
mitigate that, which makes them almost unusable.

Enable it to make sure it somewhat works.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Maxime Ripard &lt;maxime.ripard@free-electrons.com&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The DRM driver most notably, but also out of tree drivers (for now) like
the VPU or GPU drivers, are quite big consumers of large, contiguous memory
buffers. However, the sunxi_defconfig doesn't enable CMA in order to
mitigate that, which makes them almost unusable.

Enable it to make sure it somewhat works.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Maxime Ripard &lt;maxime.ripard@free-electrons.com&gt;
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm</title>
<updated>2018-01-18T18:57:59+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2018-01-18T18:57:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=dda3e15231b35840fe6f0973f803cc70ddb86281'/>
<id>dda3e15231b35840fe6f0973f803cc70ddb86281</id>
<content type='text'>
Pull ARM fixes from Russell King:
 "These are the ARM BPF fixes as discussed earlier this week"

* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: net: bpf: clarify tail_call index
  ARM: net: bpf: fix LDX instructions
  ARM: net: bpf: fix register saving
  ARM: net: bpf: correct stack layout documentation
  ARM: net: bpf: move stack documentation
  ARM: net: bpf: fix stack alignment
  ARM: net: bpf: fix tail call jumps
  ARM: net: bpf: avoid 'bx' instruction on non-Thumb capable CPUs
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull ARM fixes from Russell King:
 "These are the ARM BPF fixes as discussed earlier this week"

* 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: net: bpf: clarify tail_call index
  ARM: net: bpf: fix LDX instructions
  ARM: net: bpf: fix register saving
  ARM: net: bpf: correct stack layout documentation
  ARM: net: bpf: move stack documentation
  ARM: net: bpf: fix stack alignment
  ARM: net: bpf: fix tail call jumps
  ARM: net: bpf: avoid 'bx' instruction on non-Thumb capable CPUs
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: net: bpf: clarify tail_call index</title>
<updated>2018-01-17T19:39:10+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2018-01-13T12:11:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=091f02483df7b56615b524491f404e574c5e0668'/>
<id>091f02483df7b56615b524491f404e574c5e0668</id>
<content type='text'>
As per 90caccdd8cc0 ("bpf: fix bpf_tail_call() x64 JIT"), the index used
for array lookup is defined to be 32-bit wide. Update a misleading
comment that suggests it is 64-bit wide.

Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As per 90caccdd8cc0 ("bpf: fix bpf_tail_call() x64 JIT"), the index used
for array lookup is defined to be 32-bit wide. Update a misleading
comment that suggests it is 64-bit wide.

Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: net: bpf: fix LDX instructions</title>
<updated>2018-01-17T19:38:21+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2018-01-13T21:06:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ec19e02b343db991d2d1610c409efefebf4e2ca9'/>
<id>ec19e02b343db991d2d1610c409efefebf4e2ca9</id>
<content type='text'>
When the source and destination register are identical, our JIT does not
generate correct code, which leads to kernel oopses.

Fix this by (a) generating more efficient code, and (b) making use of
the temporary earlier if we will overwrite the address register.

Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When the source and destination register are identical, our JIT does not
generate correct code, which leads to kernel oopses.

Fix this by (a) generating more efficient code, and (b) making use of
the temporary earlier if we will overwrite the address register.

Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: net: bpf: fix register saving</title>
<updated>2018-01-17T19:38:07+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2018-01-13T22:38:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=02088d9b392f605c892894b46aa8c83e3abd0115'/>
<id>02088d9b392f605c892894b46aa8c83e3abd0115</id>
<content type='text'>
When an eBPF program tail-calls another eBPF program, it enters it after
the prologue to avoid having complex stack manipulations.  This can lead
to kernel oopses, and similar.

Resolve this by always using a fixed stack layout, a CPU register frame
pointer, and using this when reloading registers before returning.

Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When an eBPF program tail-calls another eBPF program, it enters it after
the prologue to avoid having complex stack manipulations.  This can lead
to kernel oopses, and similar.

Resolve this by always using a fixed stack layout, a CPU register frame
pointer, and using this when reloading registers before returning.

Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: net: bpf: correct stack layout documentation</title>
<updated>2018-01-17T19:36:43+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2018-01-13T22:51:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=0005e55a79cfda88199e41a406a829c88d708c67'/>
<id>0005e55a79cfda88199e41a406a829c88d708c67</id>
<content type='text'>
The stack layout documentation incorrectly suggests that the BPF JIT
scratch space starts immediately below BPF_FP. This is not correct,
so let's fix the documentation to reflect reality.

Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The stack layout documentation incorrectly suggests that the BPF JIT
scratch space starts immediately below BPF_FP. This is not correct,
so let's fix the documentation to reflect reality.

Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: net: bpf: move stack documentation</title>
<updated>2018-01-17T19:36:43+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2018-01-13T21:26:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=70ec3a6c2c11e4b0e107a65de943a082f9aff351'/>
<id>70ec3a6c2c11e4b0e107a65de943a082f9aff351</id>
<content type='text'>
Move the stack documentation towards the top of the file, where it's
relevant for things like the register layout.

Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Move the stack documentation towards the top of the file, where it's
relevant for things like the register layout.

Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: net: bpf: fix stack alignment</title>
<updated>2018-01-17T19:36:43+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2018-01-13T16:10:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d1220efd23484c72c82d5471f05daeb35b5d1916'/>
<id>d1220efd23484c72c82d5471f05daeb35b5d1916</id>
<content type='text'>
As per 2dede2d8e925 ("ARM EABI: stack pointer must be 64-bit aligned
after a CPU exception") the stack should be aligned to a 64-bit boundary
on EABI systems.  Ensure that the eBPF JIT appropraitely aligns the
stack.

Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As per 2dede2d8e925 ("ARM EABI: stack pointer must be 64-bit aligned
after a CPU exception") the stack should be aligned to a 64-bit boundary
on EABI systems.  Ensure that the eBPF JIT appropraitely aligns the
stack.

Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: net: bpf: fix tail call jumps</title>
<updated>2018-01-17T19:35:51+00:00</updated>
<author>
<name>Russell King</name>
<email>rmk+kernel@armlinux.org.uk</email>
</author>
<published>2018-01-13T11:39:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f4483f2cc1fdc03488c8a1452e545545ae5bda93'/>
<id>f4483f2cc1fdc03488c8a1452e545545ae5bda93</id>
<content type='text'>
When a tail call fails, it is documented that the tail call should
continue execution at the following instruction.  An example tail call
sequence is:

  12: (85) call bpf_tail_call#12
  13: (b7) r0 = 0
  14: (95) exit

The ARM assembler for the tail call in this case ends up branching to
instruction 14 instead of instruction 13, resulting in the BPF filter
returning a non-zero value:

  178:	ldr	r8, [sp, #588]	; insn 12
  17c:	ldr	r6, [r8, r6]
  180:	ldr	r8, [sp, #580]
  184:	cmp	r8, r6
  188:	bcs	0x1e8
  18c:	ldr	r6, [sp, #524]
  190:	ldr	r7, [sp, #528]
  194:	cmp	r7, #0
  198:	cmpeq	r6, #32
  19c:	bhi	0x1e8
  1a0:	adds	r6, r6, #1
  1a4:	adc	r7, r7, #0
  1a8:	str	r6, [sp, #524]
  1ac:	str	r7, [sp, #528]
  1b0:	mov	r6, #104
  1b4:	ldr	r8, [sp, #588]
  1b8:	add	r6, r8, r6
  1bc:	ldr	r8, [sp, #580]
  1c0:	lsl	r7, r8, #2
  1c4:	ldr	r6, [r6, r7]
  1c8:	cmp	r6, #0
  1cc:	beq	0x1e8
  1d0:	mov	r8, #32
  1d4:	ldr	r6, [r6, r8]
  1d8:	add	r6, r6, #44
  1dc:	bx	r6
  1e0:	mov	r0, #0		; insn 13
  1e4:	mov	r1, #0
  1e8:	add	sp, sp, #596	; insn 14
  1ec:	pop	{r4, r5, r6, r7, r8, sl, pc}

For other sequences, the tail call could end up branching midway through
the following BPF instructions, or maybe off the end of the function,
leading to unknown behaviours.

Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When a tail call fails, it is documented that the tail call should
continue execution at the following instruction.  An example tail call
sequence is:

  12: (85) call bpf_tail_call#12
  13: (b7) r0 = 0
  14: (95) exit

The ARM assembler for the tail call in this case ends up branching to
instruction 14 instead of instruction 13, resulting in the BPF filter
returning a non-zero value:

  178:	ldr	r8, [sp, #588]	; insn 12
  17c:	ldr	r6, [r8, r6]
  180:	ldr	r8, [sp, #580]
  184:	cmp	r8, r6
  188:	bcs	0x1e8
  18c:	ldr	r6, [sp, #524]
  190:	ldr	r7, [sp, #528]
  194:	cmp	r7, #0
  198:	cmpeq	r6, #32
  19c:	bhi	0x1e8
  1a0:	adds	r6, r6, #1
  1a4:	adc	r7, r7, #0
  1a8:	str	r6, [sp, #524]
  1ac:	str	r7, [sp, #528]
  1b0:	mov	r6, #104
  1b4:	ldr	r8, [sp, #588]
  1b8:	add	r6, r8, r6
  1bc:	ldr	r8, [sp, #580]
  1c0:	lsl	r7, r8, #2
  1c4:	ldr	r6, [r6, r7]
  1c8:	cmp	r6, #0
  1cc:	beq	0x1e8
  1d0:	mov	r8, #32
  1d4:	ldr	r6, [r6, r8]
  1d8:	add	r6, r6, #44
  1dc:	bx	r6
  1e0:	mov	r0, #0		; insn 13
  1e4:	mov	r1, #0
  1e8:	add	sp, sp, #596	; insn 14
  1ec:	pop	{r4, r5, r6, r7, r8, sl, pc}

For other sequences, the tail call could end up branching midway through
the following BPF instructions, or maybe off the end of the function,
leading to unknown behaviours.

Fixes: 39c13c204bb1 ("arm: eBPF JIT compiler")
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
</pre>
</div>
</content>
</entry>
</feed>
