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* Re: [PATCH] tty: serial: cpm_uart: Fix behaviour for non existing GPIOs
From: Linus Walleij @ 2020-06-10 11:18 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Greg Kroah-Hartman, linuxppc-dev@lists.ozlabs.org list,
	linux-kernel@vger.kernel.org, open list:SERIAL DRIVERS,
	Jiri Slaby
In-Reply-To: <bafd8df9e743c433196c727293c5015620fae2b8.1591428452.git.christophe.leroy@csgroup.eu>

Hi Christophe!

On Sat, Jun 6, 2020 at 9:30 AM Christophe Leroy
<christophe.leroy@csgroup.eu> wrote:


>                 gpiod = devm_gpiod_get_index(dev, NULL, i, GPIOD_ASIS);
>
> -               if (gpiod) {
> +               if (!IS_ERR_OR_NULL(gpiod)) {
>                         if (i == GPIO_RTS || i == GPIO_DTR)
>                                 ret = gpiod_direction_output(gpiod, 0);
>                         else

This code, and the way descriptors are used in the driver leads
me to believe that the right solution is to use the optional
call with a hard error check:

gpiod = devm_gpiod_get_index_optional(...);

if (IS_ERR(gpiod))
    return PTR_ERR(gpiod);

if (gpiod) {
... followed by the old code ...

This makes sure that the array member is left NULL if there is no
GPIO on this line, and all other errors, such as -EPROBE_DEFER
which currently absolutely does not work, will lead to us properly
exiting with an error.

Yours,
Linus Walleij

^ permalink raw reply

* Re: [PATCH 0/6] consolidate PowerPC instruction encoding macros
From: Michael Ellerman @ 2020-06-10 10:50 UTC (permalink / raw)
  To: Balamuruhan S
  Cc: christophe.leroy, ravi.bangoria, jniethe5, Balamuruhan S, paulus,
	sandipan, naveen.n.rao, linuxppc-dev
In-Reply-To: <20200526081523.92463-1-bala24@linux.ibm.com>

Balamuruhan S <bala24@linux.ibm.com> writes:
> ppc-opcode.h have base instruction encoding wrapped with stringify_in_c()
> for raw encoding to have compatibility. But there are redundant macros for
> base instruction encodings in bpf, instruction emulation test infrastructure
> and powerpc selftests.
>
> Currently PPC_INST_* macros are used for encoding instruction opcode and PPC_*
> for raw instuction encoding, this rfc patchset introduces PPC_RAW_* macros for
> base instruction encoding and reuse it from elsewhere. With this change we can
> avoid redundant macro definitions in multiple files and start adding new
> instructions in ppc-opcode.h in future.

Sorry this series collided with the prefixed instruction support and I
didn't have time to resolve the conflicts.

Can you please rebase on top of current mainline and resend.

cheers

^ permalink raw reply

* Re: [PATCH 1/6] powerpc/ppc-opcode: introduce PPC_RAW_* macros for base instruction encoding
From: Michael Ellerman @ 2020-06-10 10:50 UTC (permalink / raw)
  To: Balamuruhan S
  Cc: christophe.leroy, ravi.bangoria, jniethe5, Balamuruhan S, paulus,
	sandipan, naveen.n.rao, linuxppc-dev
In-Reply-To: <20200526081523.92463-2-bala24@linux.ibm.com>

Balamuruhan S <bala24@linux.ibm.com> writes:
> Introduce PPC_RAW_* macros to have all the bare encoding of ppc
> instructions. Move `VSX_XX*()` and `TMRN()` macros up to reuse it.
>
> Signed-off-by: Balamuruhan S <bala24@linux.ibm.com>
> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> ---
>  arch/powerpc/include/asm/ppc-opcode.h | 183 ++++++++++++++++++++++++--
>  1 file changed, 175 insertions(+), 8 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h
> index 2a39c716c343..e3540be1fc17 100644
> --- a/arch/powerpc/include/asm/ppc-opcode.h
> +++ b/arch/powerpc/include/asm/ppc-opcode.h
> @@ -431,6 +431,181 @@
>  #define __PPC_EH(eh)	0
>  #endif
>  
> +/* Base instruction encoding */
> +#define PPC_RAW_CP_ABORT		(PPC_INST_CP_ABORT)
> +#define PPC_RAW_COPY(a, b)		(PPC_INST_COPY | ___PPC_RA(a) | \
> +						___PPC_RB(b))
> +#define PPC_RAW_DARN(t, l)		(PPC_INST_DARN | ___PPC_RT(t) | \
> +						(((l) & 0x3) << 16))

I know you're copying the existing formatting by wrapping these lines,
but please don't.

It hurts rather than improves readability.

For a line like the one above, just let it be long, eg:

#define PPC_RAW_DARN(t, l)		(PPC_INST_DARN | ___PPC_RT(t) | (((l) & 0x3) << 16))

Yeah it's 91 columns but who cares.

For the really long ones like:

> +#define PPC_RAW_TLBIE_5(rb, rs, ric, prs, r) \
> +					(PPC_INST_TLBIE | \
> +						___PPC_RB(rb) | \
> +						___PPC_RS(rs) | \
> +						___PPC_RIC(ric) | \
> +						___PPC_PRS(prs) | \
> +						___PPC_R(r))

I think this is the best option:

#define PPC_RAW_TLBIE_5(rb, rs, ric, prs, r) \
	(PPC_INST_TLBIE | ___PPC_RB(rb) | ___PPC_RS(rs) | ___PPC_RIC(ric) | ___PPC_PRS(prs) | ___PPC_R(r))


Which is long, but I don't think wrapping it helps.

If we didn't have those ridiculous ___PPC_RX macros it would be a bit
shorter, but I guess that's a rework for another day.


cheers

^ permalink raw reply

* [RFC PATCH v2 3/3] ASoC: fsl_asrc_dma: Reuse the dma channel if available in Back-End
From: Shengjiu Wang @ 2020-06-10 10:05 UTC (permalink / raw)
  To: lars, perex, tiwai, lgirdwood, broonie, timur, nicoleotsuka,
	Xiubo.Lee, festevam, alsa-devel, linux-kernel, linuxppc-dev
In-Reply-To: <cover.1591783089.git.shengjiu.wang@nxp.com>

The dma channel has been requested by Back-End cpu dai driver already.
If fsl_asrc_dma requests dma chan with same dma:tx symlink, then
there will be below warning with SDMA.

[   48.174236] fsl-esai-dai 2024000.esai: Cannot create DMA dma:tx symlink

or with EDMA the request operation will fail for EDMA channel
can only be requested once.

So If we can reuse the dma channel of Back-End, then the issue can be
fixed.

In order to get the dma channel which is already requested in Back-End.
we use the exported two functions (snd_soc_lookup_component_nolocked
and soc_component_to_pcm). If we can get the dma channel, then reuse it,
if can't, then request a new one.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 sound/soc/fsl/fsl_asrc_common.h |  2 ++
 sound/soc/fsl/fsl_asrc_dma.c    | 52 +++++++++++++++++++++++++--------
 2 files changed, 42 insertions(+), 12 deletions(-)

diff --git a/sound/soc/fsl/fsl_asrc_common.h b/sound/soc/fsl/fsl_asrc_common.h
index 77665b15c8db..09512bc79b80 100644
--- a/sound/soc/fsl/fsl_asrc_common.h
+++ b/sound/soc/fsl/fsl_asrc_common.h
@@ -32,6 +32,7 @@ enum asrc_pair_index {
  * @dma_chan: inputer and output DMA channels
  * @dma_data: private dma data
  * @pos: hardware pointer position
+ * @req_dma_chan_dev_to_dev: flag for release dev_to_dev chan
  * @private: pair private area
  */
 struct fsl_asrc_pair {
@@ -45,6 +46,7 @@ struct fsl_asrc_pair {
 	struct dma_chan *dma_chan[2];
 	struct imx_dma_data dma_data;
 	unsigned int pos;
+	bool req_dma_chan_dev_to_dev;
 
 	void *private;
 };
diff --git a/sound/soc/fsl/fsl_asrc_dma.c b/sound/soc/fsl/fsl_asrc_dma.c
index d6a3fc5f87e5..5ecb77d466d3 100644
--- a/sound/soc/fsl/fsl_asrc_dma.c
+++ b/sound/soc/fsl/fsl_asrc_dma.c
@@ -133,6 +133,7 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	struct snd_dmaengine_dai_dma_data *dma_params_fe = NULL;
 	struct snd_dmaengine_dai_dma_data *dma_params_be = NULL;
+	struct dma_chan *tmp_chan = NULL, *tmp_chan_new = NULL;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct fsl_asrc_pair *pair = runtime->private_data;
 	struct fsl_asrc *asrc = pair->asrc;
@@ -142,7 +143,6 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 	int stream = substream->stream;
 	struct imx_dma_data *tmp_data;
 	struct snd_soc_dpcm *dpcm;
-	struct dma_chan *tmp_chan;
 	struct device *dev_be;
 	u8 dir = tx ? OUT : IN;
 	dma_cap_mask_t mask;
@@ -152,6 +152,7 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 	for_each_dpcm_be(rtd, stream, dpcm) {
 		struct snd_soc_pcm_runtime *be = dpcm->be;
 		struct snd_pcm_substream *substream_be;
+		struct snd_soc_component *component_be;
 		struct snd_soc_dai *dai = asoc_rtd_to_cpu(be, 0);
 
 		if (dpcm->fe != rtd)
@@ -160,6 +161,9 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 		substream_be = snd_soc_dpcm_get_substream(be, stream);
 		dma_params_be = snd_soc_dai_get_dma_data(dai, substream_be);
 		dev_be = dai->dev;
+		component_be = snd_soc_lookup_component_nolocked(dev_be, SND_DMAENGINE_PCM_DRV_NAME);
+		if (component_be)
+			tmp_chan = soc_component_to_pcm(component_be)->chan[substream->stream];
 		break;
 	}
 
@@ -205,10 +209,14 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 	 */
 	if (!asrc->use_edma) {
 		/* Get DMA request of Back-End */
-		tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx");
+		if (!tmp_chan) {
+			tmp_chan_new = dma_request_slave_channel(dev_be, tx ? "tx" : "rx");
+			tmp_chan = tmp_chan_new;
+		}
 		tmp_data = tmp_chan->private;
 		pair->dma_data.dma_request = tmp_data->dma_request;
-		dma_release_channel(tmp_chan);
+		if (tmp_chan_new)
+			dma_release_channel(tmp_chan_new);
 
 		/* Get DMA request of Front-End */
 		tmp_chan = asrc->get_dma_channel(pair, dir);
@@ -220,9 +228,26 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 
 		pair->dma_chan[dir] =
 			dma_request_channel(mask, filter, &pair->dma_data);
+		pair->req_dma_chan_dev_to_dev = true;
 	} else {
-		pair->dma_chan[dir] =
-			asrc->get_dma_channel(pair, dir);
+		/*
+		 * With EDMA, there is two dma channels can be used for p2p,
+		 * one is from ASRC, one is from another peripheral
+		 * (ESAI or SAI). Previously we select the dma channel of ASRC,
+		 * but find an issue for ideal ratio case, there is no control
+		 * for data copy speed, the speed is faster than sample
+		 * frequency.
+		 *
+		 * So we switch to use dma channel of peripheral (ESAI or SAI),
+		 * that copy speed of DMA is controlled by data consumption
+		 * speed in the peripheral FIFO.
+		 */
+		pair->req_dma_chan_dev_to_dev = false;
+		pair->dma_chan[dir] = tmp_chan;
+		if (!pair->dma_chan[dir]) {
+			pair->dma_chan[dir] = dma_request_slave_channel(dev_be, tx ? "tx" : "rx");
+			pair->req_dma_chan_dev_to_dev = true;
+		}
 	}
 
 	if (!pair->dma_chan[dir]) {
@@ -261,7 +286,8 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 	ret = dmaengine_slave_config(pair->dma_chan[dir], &config_be);
 	if (ret) {
 		dev_err(dev, "failed to config DMA channel for Back-End\n");
-		dma_release_channel(pair->dma_chan[dir]);
+		if (pair->req_dma_chan_dev_to_dev)
+			dma_release_channel(pair->dma_chan[dir]);
 		return ret;
 	}
 
@@ -273,19 +299,21 @@ static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 static int fsl_asrc_dma_hw_free(struct snd_soc_component *component,
 				struct snd_pcm_substream *substream)
 {
+	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct fsl_asrc_pair *pair = runtime->private_data;
+	u8 dir = tx ? OUT : IN;
 
 	snd_pcm_set_runtime_buffer(substream, NULL);
 
-	if (pair->dma_chan[IN])
-		dma_release_channel(pair->dma_chan[IN]);
+	if (pair->dma_chan[!dir])
+		dma_release_channel(pair->dma_chan[!dir]);
 
-	if (pair->dma_chan[OUT])
-		dma_release_channel(pair->dma_chan[OUT]);
+	if (pair->dma_chan[dir] && pair->req_dma_chan_dev_to_dev)
+		dma_release_channel(pair->dma_chan[dir]);
 
-	pair->dma_chan[IN] = NULL;
-	pair->dma_chan[OUT] = NULL;
+	pair->dma_chan[!dir] = NULL;
+	pair->dma_chan[dir] = NULL;
 
 	return 0;
 }
-- 
2.21.0


^ permalink raw reply related

* [RFC PATCH v2 2/3] ASoC: dmaengine_pcm: export soc_component_to_pcm
From: Shengjiu Wang @ 2020-06-10 10:05 UTC (permalink / raw)
  To: lars, perex, tiwai, lgirdwood, broonie, timur, nicoleotsuka,
	Xiubo.Lee, festevam, alsa-devel, linux-kernel, linuxppc-dev
In-Reply-To: <cover.1591783089.git.shengjiu.wang@nxp.com>

In DPCM case, Front-End needs to get the dma chan which has
been requested by Back-End and reuse it.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 include/sound/dmaengine_pcm.h         | 11 +++++++++++
 sound/soc/soc-generic-dmaengine-pcm.c | 12 ------------
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/include/sound/dmaengine_pcm.h b/include/sound/dmaengine_pcm.h
index b65220685920..8c5e38180fb0 100644
--- a/include/sound/dmaengine_pcm.h
+++ b/include/sound/dmaengine_pcm.h
@@ -161,4 +161,15 @@ int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
 
 #define SND_DMAENGINE_PCM_DRV_NAME "snd_dmaengine_pcm"
 
+struct dmaengine_pcm {
+	struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
+	const struct snd_dmaengine_pcm_config *config;
+	struct snd_soc_component component;
+	unsigned int flags;
+};
+
+static inline struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p)
+{
+	return container_of(p, struct dmaengine_pcm, component);
+}
 #endif
diff --git a/sound/soc/soc-generic-dmaengine-pcm.c b/sound/soc/soc-generic-dmaengine-pcm.c
index f728309a0833..80a4e71f2d95 100644
--- a/sound/soc/soc-generic-dmaengine-pcm.c
+++ b/sound/soc/soc-generic-dmaengine-pcm.c
@@ -21,18 +21,6 @@
  */
 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
 
-struct dmaengine_pcm {
-	struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
-	const struct snd_dmaengine_pcm_config *config;
-	struct snd_soc_component component;
-	unsigned int flags;
-};
-
-static struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p)
-{
-	return container_of(p, struct dmaengine_pcm, component);
-}
-
 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
 	struct snd_pcm_substream *substream)
 {
-- 
2.21.0


^ permalink raw reply related

* [RFC PATCH v2 0/3] ASoC: fsl_asrc_dma: Reuse the dma channel if available in Back-End
From: Shengjiu Wang @ 2020-06-10 10:05 UTC (permalink / raw)
  To: lars, perex, tiwai, lgirdwood, broonie, timur, nicoleotsuka,
	Xiubo.Lee, festevam, alsa-devel, linux-kernel, linuxppc-dev

Reuse the dma channel if available in Back-End

Shengjiu Wang (3):
  ASoC: soc-card: export snd_soc_lookup_component_nolocked
  ASoC: dmaengine_pcm: export soc_component_to_pcm
  ASoC: fsl_asrc_dma: Reuse the dma channel if available in Back-End

changes in v2:
- update according to Mark's comments and split the patch


 include/sound/dmaengine_pcm.h         | 11 ++++++
 include/sound/soc.h                   |  2 ++
 sound/soc/fsl/fsl_asrc_common.h       |  2 ++
 sound/soc/fsl/fsl_asrc_dma.c          | 52 ++++++++++++++++++++-------
 sound/soc/soc-core.c                  |  3 +-
 sound/soc/soc-generic-dmaengine-pcm.c | 12 -------
 6 files changed, 57 insertions(+), 25 deletions(-)

-- 
2.21.0


^ permalink raw reply

* [RFC PATCH v2 1/3] ASoC: soc-card: export snd_soc_lookup_component_nolocked
From: Shengjiu Wang @ 2020-06-10 10:05 UTC (permalink / raw)
  To: lars, perex, tiwai, lgirdwood, broonie, timur, nicoleotsuka,
	Xiubo.Lee, festevam, alsa-devel, linux-kernel, linuxppc-dev
In-Reply-To: <cover.1591783089.git.shengjiu.wang@nxp.com>

snd_soc_lookup_component_nolocked can be used for the DPCM case
that Front-End needs to get the unused platform component but
added by Back-End cpu dai driver.

If the component is gotten, then we can get the dma chan created
by Back-End component and reused it in Front-End.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 include/sound/soc.h  | 2 ++
 sound/soc/soc-core.c | 3 ++-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/sound/soc.h b/include/sound/soc.h
index 74868436ac79..565612a8d690 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -444,6 +444,8 @@ int devm_snd_soc_register_component(struct device *dev,
 			 const struct snd_soc_component_driver *component_driver,
 			 struct snd_soc_dai_driver *dai_drv, int num_dai);
 void snd_soc_unregister_component(struct device *dev);
+struct snd_soc_component *snd_soc_lookup_component_nolocked(struct device *dev,
+							    const char *driver_name);
 struct snd_soc_component *snd_soc_lookup_component(struct device *dev,
 						   const char *driver_name);
 
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index b07eca2c6ccc..d4c73e86d058 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -310,7 +310,7 @@ struct snd_soc_component *snd_soc_rtdcom_lookup(struct snd_soc_pcm_runtime *rtd,
 }
 EXPORT_SYMBOL_GPL(snd_soc_rtdcom_lookup);
 
-static struct snd_soc_component
+struct snd_soc_component
 *snd_soc_lookup_component_nolocked(struct device *dev, const char *driver_name)
 {
 	struct snd_soc_component *component;
@@ -329,6 +329,7 @@ static struct snd_soc_component
 
 	return found_component;
 }
+EXPORT_SYMBOL_GPL(snd_soc_lookup_component_nolocked);
 
 struct snd_soc_component *snd_soc_lookup_component(struct device *dev,
 						   const char *driver_name)
-- 
2.21.0


^ permalink raw reply related

* Re: [PATCH] powerpc/kprobes: Use probe_address() to read instructions
From: Michael Ellerman @ 2020-06-10 10:12 UTC (permalink / raw)
  To: Christoph Hellwig, Michael Ellerman
  Cc: Christophe Leroy, linux-kernel, Paul Mackerras, naveen.n.rao,
	linuxppc-dev
In-Reply-To: <20200609055320.GA14237@infradead.org>

Christoph Hellwig <hch@infradead.org> writes:
> On Tue, Jun 09, 2020 at 03:28:38PM +1000, Michael Ellerman wrote:
>> On Mon, 24 Feb 2020 18:02:10 +0000 (UTC), Christophe Leroy wrote:
>> > In order to avoid Oopses, use probe_address() to read the
>> > instruction at the address where the trap happened.
>> 
>> Applied to powerpc/next.
>> 
>> [1/1] powerpc/kprobes: Use probe_address() to read instructions
>>       https://git.kernel.org/powerpc/c/9ed5df69b79a22b40b20bc2132ba2495708b19c4
>
> probe_addresss has been renamed to get_kernel_nofault in the -mm
> queue that Andrew sent off to Linus last night.

That commit above is actually already in mainline, I was just _really_
behind on sending the patch notifications.

cheers

^ permalink raw reply

* [PATCH v3 38/41] powerpc/selftest/ptrace-pkey: Update the test to mark an invalid pkey correctly
From: Aneesh Kumar K.V @ 2020-06-10  9:52 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 .../selftests/powerpc/ptrace/ptrace-pkey.c    | 30 ++++++++-----------
 1 file changed, 12 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
index f9216c7a1829..bc33d748d95b 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
@@ -66,11 +66,6 @@ static int sys_pkey_alloc(unsigned long flags, unsigned long init_access_rights)
 	return syscall(__NR_pkey_alloc, flags, init_access_rights);
 }
 
-static int sys_pkey_free(int pkey)
-{
-	return syscall(__NR_pkey_free, pkey);
-}
-
 static int child(struct shared_info *info)
 {
 	unsigned long reg;
@@ -100,7 +95,11 @@ static int child(struct shared_info *info)
 
 	info->amr1 |= 3ul << pkeyshift(pkey1);
 	info->amr2 |= 3ul << pkeyshift(pkey2);
-	info->invalid_amr |= info->amr2 | 3ul << pkeyshift(pkey3);
+	/*
+	 * invalid amr value where we try to force write
+	 * things which are deined by a uamor setting.
+	 */
+	info->invalid_amr = info->amr2 | (~0x0UL & ~info->expected_uamor);
 
 	if (disable_execute)
 		info->expected_iamr |= 1ul << pkeyshift(pkey1);
@@ -111,17 +110,12 @@ static int child(struct shared_info *info)
 
 	info->expected_uamor |= 3ul << pkeyshift(pkey1) |
 				3ul << pkeyshift(pkey2);
-	info->invalid_iamr |= 1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2);
-	info->invalid_uamor |= 3ul << pkeyshift(pkey1);
-
 	/*
-	 * We won't use pkey3. We just want a plausible but invalid key to test
-	 * whether ptrace will let us write to AMR bits we are not supposed to.
-	 *
-	 * This also tests whether the kernel restores the UAMOR permissions
-	 * after a key is freed.
+	 * Create an IAMR value different from expected value.
+	 * Kernel will reject an IAMR and UAMOR change.
 	 */
-	sys_pkey_free(pkey3);
+	info->invalid_iamr = info->expected_iamr | (1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2));
+	info->invalid_uamor = info->expected_uamor & ~(0x3ul << pkeyshift(pkey1));
 
 	printf("%-30s AMR: %016lx pkey1: %d pkey2: %d pkey3: %d\n",
 	       user_write, info->amr1, pkey1, pkey2, pkey3);
@@ -196,9 +190,9 @@ static int parent(struct shared_info *info, pid_t pid)
 	PARENT_SKIP_IF_UNSUPPORTED(ret, &info->child_sync);
 	PARENT_FAIL_IF(ret, &info->child_sync);
 
-	info->amr1 = info->amr2 = info->invalid_amr = regs[0];
-	info->expected_iamr = info->invalid_iamr = regs[1];
-	info->expected_uamor = info->invalid_uamor = regs[2];
+	info->amr1 = info->amr2 = regs[0];
+	info->expected_iamr = regs[1];
+	info->expected_uamor = regs[2];
 
 	/* Wake up child so that it can set itself up. */
 	ret = prod_child(&info->child_sync);
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 41/41] powerpc/book3s64/hash/kup: Don't hardcode kup key
From: Aneesh Kumar K.V @ 2020-06-10  9:52 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Make KUAP/KUEP key a variable and also check whether the platform
limit the max key such that we can't use the key for KUAP/KEUP.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 .../powerpc/include/asm/book3s/64/hash-pkey.h | 22 +--------
 arch/powerpc/include/asm/book3s/64/kup.h      |  1 +
 arch/powerpc/mm/book3s64/pkeys.c              | 46 +++++++++++++++++--
 3 files changed, 43 insertions(+), 26 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/hash-pkey.h b/arch/powerpc/include/asm/book3s/64/hash-pkey.h
index 9f44e208f036..ff9907c72ee3 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-pkey.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-pkey.h
@@ -2,9 +2,7 @@
 #ifndef _ASM_POWERPC_BOOK3S_64_HASH_PKEY_H
 #define _ASM_POWERPC_BOOK3S_64_HASH_PKEY_H
 
-/*  We use key 3 for KERNEL */
-#define HASH_DEFAULT_KERNEL_KEY (HPTE_R_KEY_BIT0 | HPTE_R_KEY_BIT1)
-
+u64 pte_to_hpte_pkey_bits(u64 pteflags, unsigned long flags);
 static inline u64 hash__vmflag_to_pte_pkey_bits(u64 vm_flags)
 {
 	return (((vm_flags & VM_PKEY_BIT0) ? H_PTE_PKEY_BIT0 : 0x0UL) |
@@ -14,24 +12,6 @@ static inline u64 hash__vmflag_to_pte_pkey_bits(u64 vm_flags)
 		((vm_flags & VM_PKEY_BIT4) ? H_PTE_PKEY_BIT4 : 0x0UL));
 }
 
-static inline u64 pte_to_hpte_pkey_bits(u64 pteflags, unsigned long flags)
-{
-	unsigned long pte_pkey;
-
-	pte_pkey = (((pteflags & H_PTE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL) |
-		    ((pteflags & H_PTE_PKEY_BIT3) ? HPTE_R_KEY_BIT3 : 0x0UL) |
-		    ((pteflags & H_PTE_PKEY_BIT2) ? HPTE_R_KEY_BIT2 : 0x0UL) |
-		    ((pteflags & H_PTE_PKEY_BIT1) ? HPTE_R_KEY_BIT1 : 0x0UL) |
-		    ((pteflags & H_PTE_PKEY_BIT0) ? HPTE_R_KEY_BIT0 : 0x0UL));
-
-	if (mmu_has_feature(MMU_FTR_KUAP) || mmu_has_feature(MMU_FTR_KUEP)) {
-		if ((pte_pkey == 0) && (flags & HPTE_USE_KERNEL_KEY))
-			return HASH_DEFAULT_KERNEL_KEY;
-	}
-
-	return pte_pkey;
-}
-
 static inline u16 hash__pte_to_pkey_bits(u64 pteflags)
 {
 	return (((pteflags & H_PTE_PKEY_BIT4) ? 0x10 : 0x0UL) |
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 44a80fa94079..56afb3bb9055 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -172,6 +172,7 @@
 extern u64 default_uamor;
 extern u64 default_amr;
 extern u64 default_iamr;
+extern int kup_key;
 
 /*
  * For kernel thread that doesn't have thread.regs return
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 5d320ac2ba04..8ab2c377f315 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -29,6 +29,10 @@ u64 default_uamor = ~0x0UL;
  * We pick key 2 because 0 is special key and 1 is reserved as per ISA.
  */
 static int execute_only_key = 2;
+/*
+ * key used to implement KUAP/KUEP with hash translation.
+ */
+int kup_key = 3;
 
 
 #define AMR_BITS_PER_PKEY 2
@@ -169,6 +173,18 @@ void __init pkey_early_init_devtree(void)
 		default_uamor &= ~(0x3ul << pkeyshift(execute_only_key));
 	}
 
+	if (unlikely(max_pkey <= kup_key)) {
+		/*
+		 * Insufficient number of keys to support
+		 * KUAP/KUEP feature.
+		 */
+		kup_key = -1;
+	} else {
+		/*  handle key which is used by kernel for KAUP */
+		reserved_allocation_mask |= (0x1 << kup_key);
+		default_uamor &= ~(0x3ul << pkeyshift(kup_key));
+	}
+
 	/*
 	 * Allow access for only key 0. And prevent any other modification.
 	 */
@@ -189,9 +205,6 @@ void __init pkey_early_init_devtree(void)
 	reserved_allocation_mask |= (0x1 << 1);
 	default_uamor &= ~(0x3ul << pkeyshift(1));
 
-	/*  handle key 3 which is used by kernel for KAUP */
-	reserved_allocation_mask |= (0x1 << 3);
-	default_uamor &= ~(0x3ul << pkeyshift(3));
 
 	/*
 	 * Prevent the usage of OS reserved keys. Update UAMOR
@@ -220,7 +233,7 @@ void __init pkey_early_init_devtree(void)
 #ifdef CONFIG_PPC_KUEP
 void __init setup_kuep(bool disabled)
 {
-	if (disabled)
+	if (disabled || kup_key == -1)
 		return;
 	/*
 	 * On hash if PKEY feature is not enabled, disable KUAP too.
@@ -246,7 +259,7 @@ void __init setup_kuep(bool disabled)
 #ifdef CONFIG_PPC_KUAP
 void __init setup_kuap(bool disabled)
 {
-	if (disabled)
+	if (disabled || kup_key == -1)
 		return;
 	/*
 	 * On hash if PKEY feature is not enabled, disable KUAP too.
@@ -449,3 +462,26 @@ void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm)
 	mm_pkey_allocation_map(mm) = mm_pkey_allocation_map(oldmm);
 	mm->context.execute_only_pkey = oldmm->context.execute_only_pkey;
 }
+
+u64 pte_to_hpte_pkey_bits(u64 pteflags, unsigned long flags)
+{
+	unsigned long pte_pkey;
+
+	pte_pkey = (((pteflags & H_PTE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL) |
+		    ((pteflags & H_PTE_PKEY_BIT3) ? HPTE_R_KEY_BIT3 : 0x0UL) |
+		    ((pteflags & H_PTE_PKEY_BIT2) ? HPTE_R_KEY_BIT2 : 0x0UL) |
+		    ((pteflags & H_PTE_PKEY_BIT1) ? HPTE_R_KEY_BIT1 : 0x0UL) |
+		    ((pteflags & H_PTE_PKEY_BIT0) ? HPTE_R_KEY_BIT0 : 0x0UL));
+
+	if (mmu_has_feature(MMU_FTR_KUAP) || mmu_has_feature(MMU_FTR_KUEP)) {
+		if ((pte_pkey == 0) &&
+		    (flags & HPTE_USE_KERNEL_KEY) && (kup_key != -1)) {
+			u64 vm_flag = pkey_to_vmflag_bits(kup_key);
+			u64 pte_flag = hash__vmflag_to_pte_pkey_bits(vm_flag);
+			return pte_to_hpte_pkey_bits(pte_flag, 0);
+		}
+	}
+
+	return pte_pkey;
+}
+
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 17/41] powerpc/book3s64/kuap: Move KUAP related function outside radix
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

The next set of patches adds support for kuap with hash translation.
In preparation for that rename/move kuap related functions to
non radix names.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 .../asm/book3s/64/{kup-radix.h => kup.h}       |  6 +++---
 arch/powerpc/include/asm/kup.h                 |  2 +-
 arch/powerpc/kernel/syscall_64.c               |  2 +-
 arch/powerpc/mm/book3s64/pkeys.c               | 18 ++++++++++++++++++
 arch/powerpc/mm/book3s64/radix_pgtable.c       | 18 ------------------
 5 files changed, 23 insertions(+), 23 deletions(-)
 rename arch/powerpc/include/asm/book3s/64/{kup-radix.h => kup.h} (97%)

diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup.h
similarity index 97%
rename from arch/powerpc/include/asm/book3s/64/kup-radix.h
rename to arch/powerpc/include/asm/book3s/64/kup.h
index 3ee1ec60be84..dff1fef765fa 100644
--- a/arch/powerpc/include/asm/book3s/64/kup-radix.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -1,6 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H
-#define _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H
+#ifndef _ASM_POWERPC_BOOK3S_64_KUP_H
+#define _ASM_POWERPC_BOOK3S_64_KUP_H
 
 #include <linux/const.h>
 #include <asm/reg.h>
@@ -182,4 +182,4 @@ static inline unsigned long kuap_get_and_check_amr(void)
 
 #endif /* __ASSEMBLY__ */
 
-#endif /* _ASM_POWERPC_BOOK3S_64_KUP_RADIX_H */
+#endif /* _ASM_POWERPC_BOOK3S_64_KUP_H */
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index c745ee41ad66..015f51b02741 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -15,7 +15,7 @@
 #define KUAP_CURRENT		(KUAP_CURRENT_READ | KUAP_CURRENT_WRITE)
 
 #ifdef CONFIG_PPC64
-#include <asm/book3s/64/kup-radix.h>
+#include <asm/book3s/64/kup.h>
 #endif
 #ifdef CONFIG_PPC_8xx
 #include <asm/nohash/32/kup-8xx.h>
diff --git a/arch/powerpc/kernel/syscall_64.c b/arch/powerpc/kernel/syscall_64.c
index 79edba3ab312..7e560a01afa4 100644
--- a/arch/powerpc/kernel/syscall_64.c
+++ b/arch/powerpc/kernel/syscall_64.c
@@ -2,7 +2,7 @@
 
 #include <linux/err.h>
 #include <asm/asm-prototypes.h>
-#include <asm/book3s/64/kup-radix.h>
+#include <asm/book3s/64/kup.h>
 #include <asm/cputime.h>
 #include <asm/hw_irq.h>
 #include <asm/kprobes.h>
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 810118123e70..e923be3b52e7 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -198,6 +198,24 @@ void __init pkey_early_init_devtree(void)
 	return;
 }
 
+#ifdef CONFIG_PPC_KUAP
+void __init setup_kuap(bool disabled)
+{
+	if (disabled || !early_radix_enabled())
+		return;
+
+	if (smp_processor_id() == boot_cpuid) {
+		pr_info("Activating Kernel Userspace Access Prevention\n");
+		cur_cpu_spec->mmu_features |= MMU_FTR_RADIX_KUAP;
+	}
+
+	/* Make sure userspace can't change the AMR */
+	mtspr(SPRN_UAMOR, 0);
+	mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
+	isync();
+}
+#endif
+
 void pkey_mm_init(struct mm_struct *mm)
 {
 	if (!mmu_has_feature(MMU_FTR_PKEY))
diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 8acb96de0e48..7ebaf35ec21d 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -532,24 +532,6 @@ void setup_kuep(bool disabled)
 }
 #endif
 
-#ifdef CONFIG_PPC_KUAP
-void setup_kuap(bool disabled)
-{
-	if (disabled || !early_radix_enabled())
-		return;
-
-	if (smp_processor_id() == boot_cpuid) {
-		pr_info("Activating Kernel Userspace Access Prevention\n");
-		cur_cpu_spec->mmu_features |= MMU_FTR_RADIX_KUAP;
-	}
-
-	/* Make sure userspace can't change the AMR */
-	mtspr(SPRN_UAMOR, 0);
-	mtspr(SPRN_AMR, AMR_KUAP_BLOCKED);
-	isync();
-}
-#endif
-
 void __init radix__early_init_mmu(void)
 {
 	unsigned long lpcr;
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 40/41] powerpc/book3s64/keys/kuap: Reset AMR/IAMR values on kexec
From: Aneesh Kumar K.V @ 2020-06-10  9:52 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

We can kexec into a kernel that doesn't use memory keys for kernel
mapping (such as an older kernel which doesn't support kuap/kuep with hash
translation). We need to make sure we reset the AMR/IAMR value on kexec
otherwise, the new kernel will use key 0 for kernel mapping and the old
AMR value prevents access to key 0.

This patch also removes reset if IAMR and AMOR in kexec_sequence. Reset of AMOR
is not needed and the IAMR reset is partial (it doesn't do the reset
on secondary cpus) and is redundant with this patch.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/kup.h | 20 ++++++++++++++++++++
 arch/powerpc/include/asm/kup.h           | 14 ++++++++++++++
 arch/powerpc/kernel/misc_64.S            | 14 --------------
 arch/powerpc/kexec/core_64.c             |  3 +++
 arch/powerpc/mm/book3s64/pgtable.c       |  3 +++
 5 files changed, 40 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index f38748e1e37e..44a80fa94079 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -341,6 +341,26 @@ static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
 	return !!(error_code & DSISR_KEYFAULT);
 }
 
+#define reset_kuap reset_kuap
+static inline void reset_kuap(void)
+{
+	if (mmu_has_feature(MMU_FTR_KUAP)) {
+		mtspr(SPRN_AMR, 0);
+		/*  Do we need isync()? We are going via a kexec reset */
+		isync();
+	}
+}
+
+#define reset_kuep reset_kuep
+static inline void reset_kuep(void)
+{
+	if (mmu_has_feature(MMU_FTR_KUEP)) {
+		mtspr(SPRN_IAMR, 0);
+		/*  Do we need isync()? We are going via a kexec reset */
+		isync();
+	}
+}
+
 #else /* CONFIG_PPC_MEM_KEYS */
 static inline void kuap_restore_user_amr(struct pt_regs *regs)
 {
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index a29f69bbf6ec..c7ab7310f230 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -113,6 +113,20 @@ static inline void prevent_current_write_to_user(void)
 	prevent_user_access(NULL, NULL, ~0UL, KUAP_CURRENT_WRITE);
 }
 
+#ifndef reset_kuap
+#define reset_kuap reset_kuap
+static inline void reset_kuap(void)
+{
+}
+#endif
+
+#ifndef reset_kuep
+#define reset_kuep reset_kuep
+static inline void reset_kuep(void)
+{
+}
+#endif
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_KUAP_H_ */
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 1864605eca29..7bb46ad98207 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -413,20 +413,6 @@ _GLOBAL(kexec_sequence)
 	li	r0,0
 	std	r0,16(r1)
 
-BEGIN_FTR_SECTION
-	/*
-	 * This is the best time to turn AMR/IAMR off.
-	 * key 0 is used in radix for supervisor<->user
-	 * protection, but on hash key 0 is reserved
-	 * ideally we want to enter with a clean state.
-	 * NOTE, we rely on r0 being 0 from above.
-	 */
-	mtspr	SPRN_IAMR,r0
-BEGIN_FTR_SECTION_NESTED(42)
-	mtspr	SPRN_AMOR,r0
-END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42)
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-
 	/* save regs for local vars on new stack.
 	 * yes, we won't go back, but ...
 	 */
diff --git a/arch/powerpc/kexec/core_64.c b/arch/powerpc/kexec/core_64.c
index b4184092172a..a124715f33ea 100644
--- a/arch/powerpc/kexec/core_64.c
+++ b/arch/powerpc/kexec/core_64.c
@@ -152,6 +152,9 @@ static void kexec_smp_down(void *arg)
 	if (ppc_md.kexec_cpu_down)
 		ppc_md.kexec_cpu_down(0, 1);
 
+	reset_kuap();
+	reset_kuep();
+
 	kexec_smp_wait();
 	/* NOTREACHED */
 }
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index c58ad1049909..9673f4b74c9a 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -165,6 +165,9 @@ void mmu_cleanup_all(void)
 		radix__mmu_cleanup_all();
 	else if (mmu_hash_ops.hpte_clear_all)
 		mmu_hash_ops.hpte_clear_all();
+
+	reset_kuap();
+	reset_kuep();
 }
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 39/41] powerpc/selftest/ptrace-pkey: IAMR and uamor cannot be updated by ptrace
From: Aneesh Kumar K.V @ 2020-06-10  9:52 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Both IAMR and uamor are privileged and cannot be updated by userspace. Hence
we also don't allow ptrace interface to update them. Don't update them in the
test. Also expected_iamr is only changed if we can allocate a  DISABLE_EXECUTE
pkey.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
index bc33d748d95b..5c3c8222de46 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
@@ -101,15 +101,12 @@ static int child(struct shared_info *info)
 	 */
 	info->invalid_amr = info->amr2 | (~0x0UL & ~info->expected_uamor);
 
+	/*
+	 * if PKEY_DISABLE_EXECUTE succeeded we should update the expected_iamr
+	 */
 	if (disable_execute)
 		info->expected_iamr |= 1ul << pkeyshift(pkey1);
-	else
-		info->expected_iamr &= ~(1ul << pkeyshift(pkey1));
-
-	info->expected_iamr &= ~(1ul << pkeyshift(pkey2) | 1ul << pkeyshift(pkey3));
 
-	info->expected_uamor |= 3ul << pkeyshift(pkey1) |
-				3ul << pkeyshift(pkey2);
 	/*
 	 * Create an IAMR value different from expected value.
 	 * Kernel will reject an IAMR and UAMOR change.
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 37/41] powerpc/selftest/ptrave-pkey: Rename variables to make it easier to follow code
From: Aneesh Kumar K.V @ 2020-06-10  9:52 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Rename variable to indicate that they are invalid values which we will use to
test ptrace update of pkeys.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 .../selftests/powerpc/ptrace/ptrace-pkey.c    | 26 +++++++++----------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
index bdbbbe8431e0..f9216c7a1829 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-pkey.c
@@ -44,7 +44,7 @@ struct shared_info {
 	unsigned long amr2;
 
 	/* AMR value that ptrace should refuse to write to the child. */
-	unsigned long amr3;
+	unsigned long invalid_amr;
 
 	/* IAMR value the parent expects to read from the child. */
 	unsigned long expected_iamr;
@@ -57,8 +57,8 @@ struct shared_info {
 	 * (even though they're valid ones) because userspace doesn't have
 	 * access to those registers.
 	 */
-	unsigned long new_iamr;
-	unsigned long new_uamor;
+	unsigned long invalid_iamr;
+	unsigned long invalid_uamor;
 };
 
 static int sys_pkey_alloc(unsigned long flags, unsigned long init_access_rights)
@@ -100,7 +100,7 @@ static int child(struct shared_info *info)
 
 	info->amr1 |= 3ul << pkeyshift(pkey1);
 	info->amr2 |= 3ul << pkeyshift(pkey2);
-	info->amr3 |= info->amr2 | 3ul << pkeyshift(pkey3);
+	info->invalid_amr |= info->amr2 | 3ul << pkeyshift(pkey3);
 
 	if (disable_execute)
 		info->expected_iamr |= 1ul << pkeyshift(pkey1);
@@ -111,8 +111,8 @@ static int child(struct shared_info *info)
 
 	info->expected_uamor |= 3ul << pkeyshift(pkey1) |
 				3ul << pkeyshift(pkey2);
-	info->new_iamr |= 1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2);
-	info->new_uamor |= 3ul << pkeyshift(pkey1);
+	info->invalid_iamr |= 1ul << pkeyshift(pkey1) | 1ul << pkeyshift(pkey2);
+	info->invalid_uamor |= 3ul << pkeyshift(pkey1);
 
 	/*
 	 * We won't use pkey3. We just want a plausible but invalid key to test
@@ -196,9 +196,9 @@ static int parent(struct shared_info *info, pid_t pid)
 	PARENT_SKIP_IF_UNSUPPORTED(ret, &info->child_sync);
 	PARENT_FAIL_IF(ret, &info->child_sync);
 
-	info->amr1 = info->amr2 = info->amr3 = regs[0];
-	info->expected_iamr = info->new_iamr = regs[1];
-	info->expected_uamor = info->new_uamor = regs[2];
+	info->amr1 = info->amr2 = info->invalid_amr = regs[0];
+	info->expected_iamr = info->invalid_iamr = regs[1];
+	info->expected_uamor = info->invalid_uamor = regs[2];
 
 	/* Wake up child so that it can set itself up. */
 	ret = prod_child(&info->child_sync);
@@ -234,10 +234,10 @@ static int parent(struct shared_info *info, pid_t pid)
 		return ret;
 
 	/* Write invalid AMR value in child. */
-	ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->amr3, 1);
+	ret = ptrace_write_regs(pid, NT_PPC_PKEY, &info->invalid_amr, 1);
 	PARENT_FAIL_IF(ret, &info->child_sync);
 
-	printf("%-30s AMR: %016lx\n", ptrace_write_running, info->amr3);
+	printf("%-30s AMR: %016lx\n", ptrace_write_running, info->invalid_amr);
 
 	/* Wake up child so that it can verify it didn't change. */
 	ret = prod_child(&info->child_sync);
@@ -249,7 +249,7 @@ static int parent(struct shared_info *info, pid_t pid)
 
 	/* Try to write to IAMR. */
 	regs[0] = info->amr1;
-	regs[1] = info->new_iamr;
+	regs[1] = info->invalid_iamr;
 	ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 2);
 	PARENT_FAIL_IF(!ret, &info->child_sync);
 
@@ -257,7 +257,7 @@ static int parent(struct shared_info *info, pid_t pid)
 	       ptrace_write_running, regs[0], regs[1]);
 
 	/* Try to write to IAMR and UAMOR. */
-	regs[2] = info->new_uamor;
+	regs[2] = info->invalid_uamor;
 	ret = ptrace_write_regs(pid, NT_PPC_PKEY, regs, 3);
 	PARENT_FAIL_IF(!ret, &info->child_sync);
 
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 36/41] powerpc/book3s64/keys: Print information during boot.
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/mm/book3s64/pkeys.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index bb127e4e2dd2..5d320ac2ba04 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -207,6 +207,7 @@ void __init pkey_early_init_devtree(void)
 	 */
 	initial_allocation_mask |= reserved_allocation_mask;
 
+	pr_info("Enabling Memory keys with max key count %d", max_pkey);
 err_out:
 	/*
 	 * Setup uamor on boot cpu
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 35/41] powerpc/book3s64/hash/kuep: Enable KUEP on hash
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/mm/book3s64/pkeys.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index e94585fad5c4..bb127e4e2dd2 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -219,7 +219,12 @@ void __init pkey_early_init_devtree(void)
 #ifdef CONFIG_PPC_KUEP
 void __init setup_kuep(bool disabled)
 {
-	if (disabled || !early_radix_enabled())
+	if (disabled)
+		return;
+	/*
+	 * On hash if PKEY feature is not enabled, disable KUAP too.
+	 */
+	if (!early_radix_enabled() && !early_mmu_has_feature(MMU_FTR_PKEY))
 		return;
 
 	if (smp_processor_id() == boot_cpuid) {
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 34/41] powerpc/book3s64/hash/kuap: Enable kuap on hash
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/mm/book3s64/pkeys.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 0f4fc2876fc8..e94585fad5c4 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -240,7 +240,12 @@ void __init setup_kuep(bool disabled)
 #ifdef CONFIG_PPC_KUAP
 void __init setup_kuap(bool disabled)
 {
-	if (disabled || !early_radix_enabled())
+	if (disabled)
+		return;
+	/*
+	 * On hash if PKEY feature is not enabled, disable KUAP too.
+	 */
+	if (!early_radix_enabled() && !early_mmu_has_feature(MMU_FTR_PKEY))
 		return;
 
 	if (smp_processor_id() == boot_cpuid) {
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 33/41] powerpc/book3s64/kuep: Use Key 3 to implement KUEP with hash translation.
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Radix use IAMR Key 0 and hash translation use IAMR key 3.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/kup.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 6d7c2de0d7f6..f38748e1e37e 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -7,7 +7,7 @@
 
 #define AMR_KUAP_BLOCK_READ	UL(0x5455555555555555)
 #define AMR_KUAP_BLOCK_WRITE	UL(0xa8aaaaaaaaaaaaaa)
-#define AMR_KUEP_BLOCKED	(1UL << 62)
+#define AMR_KUEP_BLOCKED	UL(0x5455555555555555)
 #define AMR_KUAP_BLOCKED	(AMR_KUAP_BLOCK_READ | AMR_KUAP_BLOCK_WRITE)
 
 #ifdef __ASSEMBLY__
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 32/41] powerpc/book3s64/kuap: Use Key 3 to implement KUAP with hash translation.
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Radix use AMR Key 0 and hash translation use AMR key 3.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/kup.h | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 64774ebf78c9..6d7c2de0d7f6 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -5,11 +5,10 @@
 #include <linux/const.h>
 #include <asm/reg.h>
 
-#define AMR_KUAP_BLOCK_READ	UL(0x4000000000000000)
-#define AMR_KUAP_BLOCK_WRITE	UL(0x8000000000000000)
+#define AMR_KUAP_BLOCK_READ	UL(0x5455555555555555)
+#define AMR_KUAP_BLOCK_WRITE	UL(0xa8aaaaaaaaaaaaaa)
 #define AMR_KUEP_BLOCKED	(1UL << 62)
 #define AMR_KUAP_BLOCKED	(AMR_KUAP_BLOCK_READ | AMR_KUAP_BLOCK_WRITE)
-#define AMR_KUAP_SHIFT		62
 
 #ifdef __ASSEMBLY__
 
@@ -75,8 +74,8 @@
 #ifdef CONFIG_PPC_KUAP_DEBUG
 	BEGIN_MMU_FTR_SECTION_NESTED(67)
 	mfspr	\gpr1, SPRN_AMR
-	li	\gpr2, (AMR_KUAP_BLOCKED >> AMR_KUAP_SHIFT)
-	sldi	\gpr2, \gpr2, AMR_KUAP_SHIFT
+	/* Prevent access to userspace using any key values */
+	LOAD_REG_IMMEDIATE(\gpr2, AMR_KUAP_BLOCKED)
 999:	tdne	\gpr1, \gpr2
 	EMIT_BUG_ENTRY 999b, __FILE__, __LINE__, (BUGFLAG_WARNING | BUGFLAG_ONCE)
 	END_MMU_FTR_SECTION_NESTED_IFSET(MMU_FTR_KUAP, 67)
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 31/41] powerpc/book3s64/kuap: Improve error reporting with KUAP
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

With hash translation use DSISR_KEYFAULT to identify a wrong access.
With Radix we look at the AMR value and type of fault.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/32/kup.h     |  4 +--
 arch/powerpc/include/asm/book3s/64/kup.h     | 28 ++++++++++++++++----
 arch/powerpc/include/asm/kup.h               |  4 +--
 arch/powerpc/include/asm/nohash/32/kup-8xx.h |  4 +--
 arch/powerpc/mm/fault.c                      |  2 +-
 5 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index 32fd4452e960..b18cd931e325 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -177,8 +177,8 @@ static inline void restore_user_access(unsigned long flags)
 		allow_user_access(to, to, end - addr, KUAP_READ_WRITE);
 }
 
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
+				  bool is_write, unsigned long error_code)
 {
 	unsigned long begin = regs->kuap & 0xf0000000;
 	unsigned long end = regs->kuap << 28;
diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 252ba198e2ec..64774ebf78c9 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -317,13 +317,31 @@ static inline void restore_user_access(unsigned long flags)
 	set_kuap(flags);
 }
 
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+#define RADIX_KUAP_BLOCK_READ	UL(0x4000000000000000)
+#define RADIX_KUAP_BLOCK_WRITE	UL(0x8000000000000000)
+
+static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
+				  bool is_write, unsigned long error_code)
 {
-	return WARN(mmu_has_feature(MMU_FTR_KUAP) &&
-		    (regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)),
-		    "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
+	if (!mmu_has_feature(MMU_FTR_KUAP))
+		return false;
+
+	if (radix_enabled()) {
+		/*
+		 * Will be a storage protection fault.
+		 * Only check the details of AMR[0]
+		 */
+		return WARN((regs->kuap & (is_write ? RADIX_KUAP_BLOCK_WRITE : RADIX_KUAP_BLOCK_READ)),
+			    "Bug: %s fault blocked by AMR!", is_write ? "Write" : "Read");
+	}
+	/*
+	 * We don't want to WARN here because userspace can setup
+	 * keys such that a kernel access to user address can cause
+	 * fault
+	 */
+	return !!(error_code & DSISR_KEYFAULT);
 }
+
 #else /* CONFIG_PPC_MEM_KEYS */
 static inline void kuap_restore_user_amr(struct pt_regs *regs)
 {
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 015f51b02741..a29f69bbf6ec 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -59,8 +59,8 @@ static inline void prevent_user_access(void __user *to, const void __user *from,
 				       unsigned long size, unsigned long dir) { }
 static inline unsigned long prevent_user_access_return(void) { return 0UL; }
 static inline void restore_user_access(unsigned long flags) { }
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
+				  bool is_write, unsigned long error_code)
 {
 	return false;
 }
diff --git a/arch/powerpc/include/asm/nohash/32/kup-8xx.h b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
index 85ed2390fb99..c401e4e404d4 100644
--- a/arch/powerpc/include/asm/nohash/32/kup-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/kup-8xx.h
@@ -60,8 +60,8 @@ static inline void restore_user_access(unsigned long flags)
 	mtspr(SPRN_MD_AP, flags);
 }
 
-static inline bool
-bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write)
+static inline bool bad_kuap_fault(struct pt_regs *regs, unsigned long address,
+				  bool is_write, unsigned long error_code)
 {
 	return WARN(!((regs->kuap ^ MD_APG_KUAP) & 0xf0000000),
 		    "Bug: fault blocked by AP register !");
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 2393ed9d84bb..785c3e32c4e7 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -260,7 +260,7 @@ static bool bad_kernel_fault(struct pt_regs *regs, unsigned long error_code,
 
 	// Read/write fault in a valid region (the exception table search passed
 	// above), but blocked by KUAP is bad, it can never succeed.
-	if (bad_kuap_fault(regs, address, is_write))
+	if (bad_kuap_fault(regs, address, is_write, error_code))
 		return true;
 
 	// What's left? Kernel fault on user in well defined regions (extable
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 30/41] powerpc/book3s64/kuap: Restrict access to userspace based on userspace AMR
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

If an application has configured address protection such that read/write is
denied using pkey even the kernel should receive a FAULT on accessing the same.

This patch use user AMR value stored in pt_regs.kuap to achieve the same.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/kup.h | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 9a7d1ec51fb6..252ba198e2ec 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -279,14 +279,20 @@ static inline void set_kuap(unsigned long value)
 static __always_inline void allow_user_access(void __user *to, const void __user *from,
 					      unsigned long size, unsigned long dir)
 {
+	unsigned long thread_amr = 0;
+
 	// This is written so we can resolve to a single case at build time
 	BUILD_BUG_ON(!__builtin_constant_p(dir));
+
+	if (mmu_has_feature(MMU_FTR_PKEY))
+		thread_amr = current_thread_amr();
+
 	if (dir == KUAP_READ)
-		set_kuap(AMR_KUAP_BLOCK_WRITE);
+		set_kuap(thread_amr | AMR_KUAP_BLOCK_WRITE);
 	else if (dir == KUAP_WRITE)
-		set_kuap(AMR_KUAP_BLOCK_READ);
+		set_kuap(thread_amr | AMR_KUAP_BLOCK_READ);
 	else if (dir == KUAP_READ_WRITE)
-		set_kuap(0);
+		set_kuap(thread_amr);
 	else
 		BUILD_BUG();
 }
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 29/41] powerpc/book3s64/pkeys: Don't update SPRN_AMR when in kernel mode.
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Now that kernel correctly store/restore userspace AMR/IAMR values, avoid
manipulating AMR and IAMR from the kernel on behalf of userspace.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/kup.h | 23 ++++++++
 arch/powerpc/include/asm/processor.h     |  5 --
 arch/powerpc/kernel/process.c            |  4 --
 arch/powerpc/kernel/traps.c              |  6 --
 arch/powerpc/mm/book3s64/pkeys.c         | 71 ++++--------------------
 5 files changed, 34 insertions(+), 75 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index 58397ee18a03..9a7d1ec51fb6 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -174,6 +174,29 @@ extern u64 default_uamor;
 extern u64 default_amr;
 extern u64 default_iamr;
 
+/*
+ * For kernel thread that doesn't have thread.regs return
+ * default AMR/IAMR values.
+ */
+static inline u64 current_thread_amr(void)
+{
+	if (current->thread.regs)
+		return current->thread.regs->kuap;
+	return AMR_KUAP_BLOCKED;
+}
+
+static inline u64 current_thread_iamr(void)
+{
+	if (current->thread.regs)
+		return current->thread.regs->kuep;
+	return AMR_KUEP_BLOCKED;
+}
+
+static inline u64 read_uamor(void)
+{
+	return default_uamor;
+}
+
 static inline void kuap_restore_user_amr(struct pt_regs *regs)
 {
 	if (!mmu_has_feature(MMU_FTR_PKEY))
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 52a67835057a..bac4258a34b1 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -234,11 +234,6 @@ struct thread_struct {
 	struct thread_vr_state ckvr_state; /* Checkpointed VR state */
 	unsigned long	ckvrsave; /* Checkpointed VRSAVE */
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
-#ifdef CONFIG_PPC_MEM_KEYS
-	unsigned long	amr;
-	unsigned long	iamr;
-	unsigned long	uamor;
-#endif
 #ifdef CONFIG_KVM_BOOK3S_32_HANDLER
 	void*		kvm_shadow_vcpu; /* KVM internal data */
 #endif /* CONFIG_KVM_BOOK3S_32_HANDLER */
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 340e473e8738..7eb6598375f1 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -585,7 +585,6 @@ static void save_all(struct task_struct *tsk)
 		__giveup_spe(tsk);
 
 	msr_check_and_clear(msr_all_available);
-	thread_pkey_regs_save(&tsk->thread);
 }
 
 void flush_all_to_thread(struct task_struct *tsk)
@@ -1109,8 +1108,6 @@ static inline void save_sprs(struct thread_struct *t)
 		t->tar = mfspr(SPRN_TAR);
 	}
 #endif
-
-	thread_pkey_regs_save(t);
 }
 
 static inline void restore_sprs(struct thread_struct *old_thread,
@@ -1151,7 +1148,6 @@ static inline void restore_sprs(struct thread_struct *old_thread,
 		mtspr(SPRN_TIDR, new_thread->tidr);
 #endif
 
-	thread_pkey_regs_restore(new_thread, old_thread);
 }
 
 struct task_struct *__switch_to(struct task_struct *prev,
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 067e501f2202..e441e8eacfbc 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -348,12 +348,6 @@ static bool exception_common(int signr, struct pt_regs *regs, int code,
 
 	current->thread.trap_nr = code;
 
-	/*
-	 * Save all the pkey registers AMR/IAMR/UAMOR. Eg: Core dumps need
-	 * to capture the content, if the task gets killed.
-	 */
-	thread_pkey_regs_save(&current->thread);
-
 	return true;
 }
 
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 5012b57af808..0f4fc2876fc8 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -264,40 +264,17 @@ void pkey_mm_init(struct mm_struct *mm)
 	mm->context.execute_only_pkey = execute_only_key;
 }
 
-static inline u64 read_amr(void)
+static inline void update_current_thread_amr(u64 value)
 {
-	return mfspr(SPRN_AMR);
+	current->thread.regs->kuap = value;
 }
 
-static inline void write_amr(u64 value)
-{
-	mtspr(SPRN_AMR, value);
-}
-
-static inline u64 read_iamr(void)
-{
-	if (static_branch_unlikely(&execute_pkey_disabled))
-		return 0x0UL;
-
-	return mfspr(SPRN_IAMR);
-}
-
-static inline void write_iamr(u64 value)
+static inline void update_current_thread_iamr(u64 value)
 {
 	if (static_branch_unlikely(&execute_pkey_disabled))
 		return;
 
-	mtspr(SPRN_IAMR, value);
-}
-
-static inline u64 read_uamor(void)
-{
-	return mfspr(SPRN_UAMOR);
-}
-
-static inline void write_uamor(u64 value)
-{
-	mtspr(SPRN_UAMOR, value);
+	current->thread.regs->kuep = value;
 }
 
 static bool is_pkey_enabled(int pkey)
@@ -314,20 +291,21 @@ static bool is_pkey_enabled(int pkey)
 	return !!(uamor_pkey_bits);
 }
 
+/*  FIXME!! what happens to other threads AMR value? */
 static inline void init_amr(int pkey, u8 init_bits)
 {
 	u64 new_amr_bits = (((u64)init_bits & 0x3UL) << pkeyshift(pkey));
-	u64 old_amr = read_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
+	u64 old_amr = current_thread_amr() & ~((u64)(0x3ul) << pkeyshift(pkey));
 
-	write_amr(old_amr | new_amr_bits);
+	update_current_thread_amr(old_amr | new_amr_bits);
 }
 
 static inline void init_iamr(int pkey, u8 init_bits)
 {
 	u64 new_iamr_bits = (((u64)init_bits & 0x1UL) << pkeyshift(pkey));
-	u64 old_iamr = read_iamr() & ~((u64)(0x1ul) << pkeyshift(pkey));
+	u64 old_iamr = current_thread_iamr() & ~((u64)(0x1ul) << pkeyshift(pkey));
 
-	write_iamr(old_iamr | new_iamr_bits);
+	update_current_thread_iamr(old_iamr | new_iamr_bits);
 }
 
 /*
@@ -360,33 +338,6 @@ int __arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
 	return 0;
 }
 
-void thread_pkey_regs_save(struct thread_struct *thread)
-{
-	if (!mmu_has_feature(MMU_FTR_PKEY))
-		return;
-
-	/*
-	 * TODO: Skip saving registers if @thread hasn't used any keys yet.
-	 */
-	thread->amr = read_amr();
-	thread->iamr = read_iamr();
-	thread->uamor = read_uamor();
-}
-
-void thread_pkey_regs_restore(struct thread_struct *new_thread,
-			      struct thread_struct *old_thread)
-{
-	if (!mmu_has_feature(MMU_FTR_PKEY))
-		return;
-
-	if (old_thread->amr != new_thread->amr)
-		write_amr(new_thread->amr);
-	if (old_thread->iamr != new_thread->iamr)
-		write_iamr(new_thread->iamr);
-	if (old_thread->uamor != new_thread->uamor)
-		write_uamor(new_thread->uamor);
-}
-
 int execute_only_pkey(struct mm_struct *mm)
 {
 	if (static_branch_likely(&execute_pkey_disabled))
@@ -440,10 +391,10 @@ static bool pkey_access_permitted(int pkey, bool write, bool execute)
 		return true;
 
 	pkey_shift = pkeyshift(pkey);
-	if (execute && !(read_iamr() & (IAMR_EX_BIT << pkey_shift)))
+	if (execute && !(current_thread_iamr() & (IAMR_EX_BIT << pkey_shift)))
 		return true;
 
-	amr = read_amr(); /* Delay reading amr until absolutely needed */
+	amr = current_thread_amr();
 	return ((!write && !(amr & (AMR_RD_BIT << pkey_shift))) ||
 		(write &&  !(amr & (AMR_WR_BIT << pkey_shift))));
 }
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 28/41] powerpc/ptrace-view: Use pt_regs values instead of thread_struct based one.
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

We will remove thread.amr/iamr/uamor in a later patch

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/kernel/ptrace/ptrace-view.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/kernel/ptrace/ptrace-view.c b/arch/powerpc/kernel/ptrace/ptrace-view.c
index caeb5822a8f4..878764d0ee4c 100644
--- a/arch/powerpc/kernel/ptrace/ptrace-view.c
+++ b/arch/powerpc/kernel/ptrace/ptrace-view.c
@@ -488,14 +488,25 @@ static int pkey_active(struct task_struct *target, const struct user_regset *reg
 static int pkey_get(struct task_struct *target, const struct user_regset *regset,
 		    unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf)
 {
-	BUILD_BUG_ON(TSO(amr) + sizeof(unsigned long) != TSO(iamr));
-	BUILD_BUG_ON(TSO(iamr) + sizeof(unsigned long) != TSO(uamor));
+	int ret;
 
 	if (!arch_pkeys_enabled())
 		return -ENODEV;
 
-	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &target->thread.amr,
-				   0, ELF_NPKEY * sizeof(unsigned long));
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &target->thread.regs->kuap,
+				  0, 1 * sizeof(unsigned long));
+	if (ret)
+		goto err_out;
+
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &target->thread.regs->kuep,
+				  1 * sizeof(unsigned long), 2 * sizeof(unsigned long));
+	if (ret)
+		goto err_out;
+
+	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &default_uamor,
+				  2 * sizeof(unsigned long), 3 * sizeof(unsigned long));
+err_out:
+	return ret;
 }
 
 static int pkey_set(struct task_struct *target, const struct user_regset *regset,
@@ -518,8 +529,8 @@ static int pkey_set(struct task_struct *target, const struct user_regset *regset
 		return ret;
 
 	/* UAMOR determines which bits of the AMR can be set from userspace. */
-	target->thread.amr = (new_amr & target->thread.uamor) |
-			     (target->thread.amr & ~target->thread.uamor);
+	target->thread.regs->kuap = (new_amr & default_uamor) |
+		(target->thread.regs->kuap & ~default_uamor);
 
 	return 0;
 }
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 05/41] powerpc/book3s64/pkeys: Simplify the key initialization
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

Add documentation explaining the execute_only_key. The reservation and initialization mask
details are also explained in this patch.

No functional change in this patch.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/mm/book3s64/pkeys.c | 186 ++++++++++++++++++-------------
 1 file changed, 107 insertions(+), 79 deletions(-)

diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index d60e6bfa3e03..3db0b3cfc322 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -15,48 +15,71 @@
 DEFINE_STATIC_KEY_TRUE(pkey_disabled);
 int  pkeys_total;		/* Total pkeys as per device tree */
 u32  initial_allocation_mask;   /* Bits set for the initially allocated keys */
-u32  reserved_allocation_mask;  /* Bits set for reserved keys */
+/*
+ *  Keys marked in the reservation list cannot be allocated by  userspace
+ */
+u32  reserved_allocation_mask;
 static bool pkey_execute_disable_supported;
-static bool pkeys_devtree_defined;	/* property exported by device tree */
-static u64 pkey_amr_mask;		/* Bits in AMR not to be touched */
-static u64 pkey_iamr_mask;		/* Bits in AMR not to be touched */
-static u64 pkey_uamor_mask;		/* Bits in UMOR not to be touched */
+static u64 default_amr;
+static u64 default_iamr;
+/* Allow all keys to be modified by default */
+static u64 default_uamor = ~0x0UL;
+/*
+ * Key used to implement PROT_EXEC mmap. Denies READ/WRITE
+ * We pick key 2 because 0 is special key and 1 is reserved as per ISA.
+ */
 static int execute_only_key = 2;
 
+
 #define AMR_BITS_PER_PKEY 2
 #define AMR_RD_BIT 0x1UL
 #define AMR_WR_BIT 0x2UL
 #define IAMR_EX_BIT 0x1UL
-#define PKEY_REG_BITS (sizeof(u64)*8)
+#define PKEY_REG_BITS (sizeof(u64) * 8)
 #define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey+1) * AMR_BITS_PER_PKEY))
 
-static void scan_pkey_feature(void)
+static int scan_pkey_feature(void)
 {
 	u32 vals[2];
+	int pkeys_total = 0;
 	struct device_node *cpu;
 
+	/*
+	 * Pkey is not supported with Radix translation.
+	 */
+	if (radix_enabled())
+		return 0;
+
 	cpu = of_find_node_by_type(NULL, "cpu");
 	if (!cpu)
-		return;
+		return 0;
 
 	if (of_property_read_u32_array(cpu,
-			"ibm,processor-storage-keys", vals, 2))
-		return;
+				       "ibm,processor-storage-keys", vals, 2) == 0) {
+		/*
+		 * Since any pkey can be used for data or execute, we will
+		 * just treat all keys as equal and track them as one entity.
+		 */
+		pkeys_total = vals[0];
+		/*  Should we check for IAMR support FIXME!! */
+	} else {
+		/*
+		 * Let's assume 32 pkeys on P8 bare metal, if its not defined by device
+		 * tree. We make this exception since skiboot forgot to expose this
+		 * property on power8.
+		 */
+		if (!firmware_has_feature(FW_FEATURE_LPAR) &&
+		    cpu_has_feature(CPU_FTRS_POWER8))
+			pkeys_total = 32;
+	}
 
 	/*
-	 * Since any pkey can be used for data or execute, we will just treat
-	 * all keys as equal and track them as one entity.
+	 * Adjust the upper limit, based on the number of bits supported by
+	 * arch-neutral code.
 	 */
-	pkeys_total = vals[0];
-	pkeys_devtree_defined = true;
-}
-
-static inline bool pkey_mmu_enabled(void)
-{
-	if (firmware_has_feature(FW_FEATURE_LPAR))
-		return pkeys_total;
-	else
-		return cpu_has_feature(CPU_FTR_PKEY);
+	pkeys_total = min_t(int, pkeys_total,
+			    ((ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT) + 1));
+	return pkeys_total;
 }
 
 static int pkey_initialize(void)
@@ -80,31 +103,13 @@ static int pkey_initialize(void)
 				!= (sizeof(u64) * BITS_PER_BYTE));
 
 	/* scan the device tree for pkey feature */
-	scan_pkey_feature();
-
-	/*
-	 * Let's assume 32 pkeys on P8 bare metal, if its not defined by device
-	 * tree. We make this exception since skiboot forgot to expose this
-	 * property on power8.
-	 */
-	if (!pkeys_devtree_defined && !firmware_has_feature(FW_FEATURE_LPAR) &&
-			cpu_has_feature(CPU_FTRS_POWER8))
-		pkeys_total = 32;
-
-	/*
-	 * Adjust the upper limit, based on the number of bits supported by
-	 * arch-neutral code.
-	 */
-	pkeys_total = min_t(int, pkeys_total,
-			((ARCH_VM_PKEY_FLAGS >> VM_PKEY_SHIFT)+1));
-
-	if (!pkey_mmu_enabled() || radix_enabled() || !pkeys_total)
-		static_branch_enable(&pkey_disabled);
-	else
+	pkeys_total = scan_pkey_feature();
+	if (pkeys_total)
 		static_branch_disable(&pkey_disabled);
-
-	if (static_branch_likely(&pkey_disabled))
+	else {
+		static_branch_enable(&pkey_disabled);
 		return 0;
+	}
 
 	/*
 	 * The device tree cannot be relied to indicate support for
@@ -118,48 +123,71 @@ static int pkey_initialize(void)
 #ifdef CONFIG_PPC_4K_PAGES
 	/*
 	 * The OS can manage only 8 pkeys due to its inability to represent them
-	 * in the Linux 4K PTE.
+	 * in the Linux 4K PTE. Mark all other keys reserved.
 	 */
 	os_reserved = pkeys_total - 8;
 #else
 	os_reserved = 0;
 #endif
-	/*
-	 * key 1 is recommended not to be used. PowerISA(3.0) page 1015,
-	 * programming note.
-	 */
-	reserved_allocation_mask = (0x1 << 1) | (0x1 << execute_only_key);
-
-	/* register mask is in BE format */
-	pkey_amr_mask = ~0x0ul;
-	pkey_amr_mask &= ~(0x3ul << pkeyshift(0));
-
-	pkey_iamr_mask = ~0x0ul;
-	pkey_iamr_mask &= ~(0x3ul << pkeyshift(0));
-	pkey_iamr_mask &= ~(0x3ul << pkeyshift(execute_only_key));
-
-	pkey_uamor_mask = ~0x0ul;
-	pkey_uamor_mask &= ~(0x3ul << pkeyshift(0));
-	pkey_uamor_mask &= ~(0x3ul << pkeyshift(execute_only_key));
-
-	/* mark the rest of the keys as reserved and hence unavailable */
-	for (i = (pkeys_total - os_reserved); i < pkeys_total; i++) {
-		reserved_allocation_mask |= (0x1 << i);
-		pkey_uamor_mask &= ~(0x3ul << pkeyshift(i));
-	}
-	initial_allocation_mask = reserved_allocation_mask | (0x1 << 0);
 
 	if (unlikely((pkeys_total - os_reserved) <= execute_only_key)) {
 		/*
 		 * Insufficient number of keys to support
 		 * execute only key. Mark it unavailable.
-		 * Any AMR, UAMOR, IAMR bit set for
-		 * this key is irrelevant since this key
-		 * can never be allocated.
 		 */
 		execute_only_key = -1;
+	} else {
+		/*
+		 * Mark the execute_only_pkey as not available for
+		 * user allocation via pkey_alloc.
+		 */
+		reserved_allocation_mask |= (0x1 << execute_only_key);
+
+		/*
+		 * Deny READ/WRITE for execute_only_key.
+		 * Allow execute in IAMR.
+		 */
+		default_amr  |= (0x3ul << pkeyshift(execute_only_key));
+		default_iamr &= ~(0x3ul << pkeyshift(execute_only_key));
+
+		/*
+		 * Clear the uamor bits for this key.
+		 */
+		default_uamor &= ~(0x3ul << pkeyshift(execute_only_key));
 	}
 
+	/*
+	 * Allow access for only key 0. And prevent any other modification.
+	 */
+	default_amr   &= ~(0x3ul << pkeyshift(0));
+	default_iamr  &= ~(0x3ul << pkeyshift(0));
+	default_uamor &= ~(0x3ul << pkeyshift(0));
+	/*
+	 * key 0 is special in that we want to consider it an allocated
+	 * key which is preallocated. We don't allow changing AMR bits
+	 * w.r.t key 0. But one can pkey_free(key0)
+	 */
+	initial_allocation_mask |= (0x1 << 0);
+
+	/*
+	 * key 1 is recommended not to be used. PowerISA(3.0) page 1015,
+	 * programming note.
+	 */
+	reserved_allocation_mask |= (0x1 << 1);
+
+	/*
+	 * Prevent the usage of OS reserved the keys. Update UAMOR
+	 * for those keys.
+	 */
+	for (i = (pkeys_total - os_reserved); i < pkeys_total; i++) {
+		reserved_allocation_mask |= (0x1 << i);
+		default_uamor &= ~(0x3ul << pkeyshift(i));
+	}
+	/*
+	 * Prevent the allocation of reserved keys too.
+	 */
+	initial_allocation_mask |= reserved_allocation_mask;
+
 	return 0;
 }
 
@@ -301,13 +329,13 @@ void thread_pkey_regs_init(struct thread_struct *thread)
 	if (static_branch_likely(&pkey_disabled))
 		return;
 
-	thread->amr = pkey_amr_mask;
-	thread->iamr = pkey_iamr_mask;
-	thread->uamor = pkey_uamor_mask;
+	thread->amr   = default_amr;
+	thread->iamr  = default_iamr;
+	thread->uamor = default_uamor;
 
-	write_uamor(pkey_uamor_mask);
-	write_amr(pkey_amr_mask);
-	write_iamr(pkey_iamr_mask);
+	write_amr(default_amr);
+	write_iamr(default_iamr);
+	write_uamor(default_uamor);
 }
 
 int __execute_only_pkey(struct mm_struct *mm)
-- 
2.26.2


^ permalink raw reply related

* [PATCH v3 27/41] powerpc/book3s64/pkeys: Reset userspace AMR correctly on exec
From: Aneesh Kumar K.V @ 2020-06-10  9:51 UTC (permalink / raw)
  To: linuxppc-dev, mpe; +Cc: Aneesh Kumar K.V, linuxram, bauerman
In-Reply-To: <20200610095204.608183-1-aneesh.kumar@linux.ibm.com>

On fork, we inherit from the parent and on exec, we should switch to default_amr values.

Also, avoid changing the AMR register value within the kernel. The kernel now runs with
different AMR values.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 arch/powerpc/include/asm/book3s/64/kup.h |  2 ++
 arch/powerpc/kernel/process.c            |  6 +++++-
 arch/powerpc/mm/book3s64/pkeys.c         | 18 ++----------------
 3 files changed, 9 insertions(+), 17 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/kup.h b/arch/powerpc/include/asm/book3s/64/kup.h
index f26f3fad5872..58397ee18a03 100644
--- a/arch/powerpc/include/asm/book3s/64/kup.h
+++ b/arch/powerpc/include/asm/book3s/64/kup.h
@@ -171,6 +171,8 @@
 #include <asm/ptrace.h>
 
 extern u64 default_uamor;
+extern u64 default_amr;
+extern u64 default_iamr;
 
 static inline void kuap_restore_user_amr(struct pt_regs *regs)
 {
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index dbce0b1daf2f..340e473e8738 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1485,6 +1485,11 @@ void arch_setup_new_exec(void)
 		current->thread.regs = regs - 1;
 	}
 
+#ifdef CONFIG_PPC_MEM_KEYS
+	current->thread.regs->kuap  = default_amr;
+	current->thread.regs->kuep  = default_iamr;
+#endif
+
 }
 #else
 void arch_setup_new_exec(void)
@@ -1839,7 +1844,6 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 	current->thread.load_tm = 0;
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
-	thread_pkey_regs_init(&current->thread);
 }
 EXPORT_SYMBOL(start_thread);
 
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 976f65f27324..5012b57af808 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -20,8 +20,8 @@ int  max_pkey;			/* Maximum key value supported */
  */
 u32  reserved_allocation_mask;
 static u32  initial_allocation_mask;   /* Bits set for the initially allocated keys */
-static u64 default_amr;
-static u64 default_iamr;
+u64 default_amr;
+u64 default_iamr;
 /* Allow all keys to be modified by default */
 u64 default_uamor = ~0x0UL;
 /*
@@ -387,20 +387,6 @@ void thread_pkey_regs_restore(struct thread_struct *new_thread,
 		write_uamor(new_thread->uamor);
 }
 
-void thread_pkey_regs_init(struct thread_struct *thread)
-{
-	if (!mmu_has_feature(MMU_FTR_PKEY))
-		return;
-
-	thread->amr   = default_amr;
-	thread->iamr  = default_iamr;
-	thread->uamor = default_uamor;
-
-	write_amr(default_amr);
-	write_iamr(default_iamr);
-	write_uamor(default_uamor);
-}
-
 int execute_only_pkey(struct mm_struct *mm)
 {
 	if (static_branch_likely(&execute_pkey_disabled))
-- 
2.26.2


^ permalink raw reply related


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