Re: [PATCH v4 1/5] remoteproc: Use u64 len for da_to_va

["Clément Leger" <cleger@kalray.eu>]

Hi Arnaud,

----- On 11 Feb, 2020, at 16:53, Arnaud Pouliquen arnaud.pouliquen@st.com wrote:

> On 2/10/20 5:22 PM, Clement Leger wrote:
>> With upcoming changes in elf loader for elf64 support, section size will
>> be a u64. When used with da_to_va, this will potentially lead to
>> overflow if using the current "int" type for len argument. Change
>> da_to_va prototype to use a u64 for len and fix all users of this
>> function.
>> 
>> Signed-off-by: Clement Leger <cleger@kalray.eu>
>> ---
>>  drivers/remoteproc/imx_rproc.c           | 11 ++++++-----
>>  drivers/remoteproc/keystone_remoteproc.c |  4 ++--
>>  drivers/remoteproc/qcom_q6v5_adsp.c      |  2 +-
>>  drivers/remoteproc/qcom_q6v5_mss.c       |  2 +-
>>  drivers/remoteproc/qcom_q6v5_pas.c       |  2 +-
>>  drivers/remoteproc/qcom_q6v5_wcss.c      |  2 +-
>>  drivers/remoteproc/qcom_wcnss.c          |  2 +-
>>  drivers/remoteproc/remoteproc_core.c     |  2 +-
>>  drivers/remoteproc/remoteproc_internal.h |  2 +-
>>  drivers/remoteproc/st_slim_rproc.c       |  4 ++--
>>  drivers/remoteproc/wkup_m3_rproc.c       |  4 ++--
>>  include/linux/remoteproc.h               |  2 +-
>>  12 files changed, 20 insertions(+), 19 deletions(-)
>> 
>> diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
>> index 3e72b6f38d4b..f497f5b49b18 100644
>> --- a/drivers/remoteproc/imx_rproc.c
>> +++ b/drivers/remoteproc/imx_rproc.c
>> @@ -186,7 +186,7 @@ static int imx_rproc_stop(struct rproc *rproc)
>>  }
>>  
>>  static int imx_rproc_da_to_sys(struct imx_rproc *priv, u64 da,
>> -			       int len, u64 *sys)
>> +			       u64 len, u64 *sys)
>>  {
>>  	const struct imx_rproc_dcfg *dcfg = priv->dcfg;
>>  	int i;
>> @@ -203,19 +203,19 @@ static int imx_rproc_da_to_sys(struct imx_rproc *priv, u64
>> da,
>>  		}
>>  	}
>>  
>> -	dev_warn(priv->dev, "Translation failed: da = 0x%llx len = 0x%x\n",
>> +	dev_warn(priv->dev, "Translation failed: da = 0x%llx len = 0x%llx\n",
>>  		 da, len);
>>  	return -ENOENT;
>>  }
>>  
>> -static void *imx_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
>> +static void *imx_rproc_da_to_va(struct rproc *rproc, u64 da, u64 len)
>>  {
>>  	struct imx_rproc *priv = rproc->priv;
>>  	void *va = NULL;
>>  	u64 sys;
>>  	int i;
>>  
>> -	if (len <= 0)
>> +	if (len == 0)
>>  		return NULL;
>>  
>>  	/*
>> @@ -235,7 +235,8 @@ static void *imx_rproc_da_to_va(struct rproc *rproc, u64 da,
>> int len)
>>  		}
>>  	}
>>  
>> -	dev_dbg(&rproc->dev, "da = 0x%llx len = 0x%x va = 0x%p\n", da, len, va);
>> +	dev_dbg(&rproc->dev, "da = 0x%llx len = 0x%llx va = 0x%p\n",
>> +		da, len, va);
>>  
>>  	return va;
>>  }
>> diff --git a/drivers/remoteproc/keystone_remoteproc.c
>> b/drivers/remoteproc/keystone_remoteproc.c
>> index 5c4658f00b3d..466093f48814 100644
>> --- a/drivers/remoteproc/keystone_remoteproc.c
>> +++ b/drivers/remoteproc/keystone_remoteproc.c
>> @@ -246,7 +246,7 @@ static void keystone_rproc_kick(struct rproc *rproc, int
>> vqid)
>>   * can be used either by the remoteproc core for loading (when using kernel
>>   * remoteproc loader), or by any rpmsg bus drivers.
>>   */
>> -static void *keystone_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
>> +static void *keystone_rproc_da_to_va(struct rproc *rproc, u64 da, u64 len)
>>  {
>>  	struct keystone_rproc *ksproc = rproc->priv;
>>  	void __iomem *va = NULL;
>> @@ -255,7 +255,7 @@ static void *keystone_rproc_da_to_va(struct rproc *rproc,
>> u64 da, int len)
>>  	size_t size;
>>  	int i;
>>  
>> -	if (len <= 0)
>> +	if (len == 0)
>>  		return NULL;
>>  
>>  	for (i = 0; i < ksproc->num_mems; i++) {
>> diff --git a/drivers/remoteproc/qcom_q6v5_adsp.c
>> b/drivers/remoteproc/qcom_q6v5_adsp.c
>> index e953886b2eb7..7518e67a49e5 100644
>> --- a/drivers/remoteproc/qcom_q6v5_adsp.c
>> +++ b/drivers/remoteproc/qcom_q6v5_adsp.c
>> @@ -270,7 +270,7 @@ static int adsp_stop(struct rproc *rproc)
>>  	return ret;
>>  }
>>  
>> -static void *adsp_da_to_va(struct rproc *rproc, u64 da, int len)
>> +static void *adsp_da_to_va(struct rproc *rproc, u64 da, u64 len)
>>  {
>>  	struct qcom_adsp *adsp = (struct qcom_adsp *)rproc->priv;
>>  	int offset;
>> diff --git a/drivers/remoteproc/qcom_q6v5_mss.c
>> b/drivers/remoteproc/qcom_q6v5_mss.c
>> index 471128a2e723..248febde6fc1 100644
>> --- a/drivers/remoteproc/qcom_q6v5_mss.c
>> +++ b/drivers/remoteproc/qcom_q6v5_mss.c
>> @@ -1148,7 +1148,7 @@ static int q6v5_stop(struct rproc *rproc)
>>  	return 0;
>>  }
>>  
>> -static void *q6v5_da_to_va(struct rproc *rproc, u64 da, int len)
>> +static void *q6v5_da_to_va(struct rproc *rproc, u64 da, u64 len)
>>  {
>>  	struct q6v5 *qproc = rproc->priv;
>>  	int offset;
>> diff --git a/drivers/remoteproc/qcom_q6v5_pas.c
>> b/drivers/remoteproc/qcom_q6v5_pas.c
>> index db4b3c4bacd7..cf2cd609c90d 100644
>> --- a/drivers/remoteproc/qcom_q6v5_pas.c
>> +++ b/drivers/remoteproc/qcom_q6v5_pas.c
>> @@ -159,7 +159,7 @@ static int adsp_stop(struct rproc *rproc)
>>  	return ret;
>>  }
>>  
>> -static void *adsp_da_to_va(struct rproc *rproc, u64 da, int len)
>> +static void *adsp_da_to_va(struct rproc *rproc, u64 da, u64 len)
>>  {
>>  	struct qcom_adsp *adsp = (struct qcom_adsp *)rproc->priv;
>>  	int offset;
>> diff --git a/drivers/remoteproc/qcom_q6v5_wcss.c
>> b/drivers/remoteproc/qcom_q6v5_wcss.c
>> index f93e1e4a1cc0..3a6b82a16961 100644
>> --- a/drivers/remoteproc/qcom_q6v5_wcss.c
>> +++ b/drivers/remoteproc/qcom_q6v5_wcss.c
>> @@ -406,7 +406,7 @@ static int q6v5_wcss_stop(struct rproc *rproc)
>>  	return 0;
>>  }
>>  
>> -static void *q6v5_wcss_da_to_va(struct rproc *rproc, u64 da, int len)
>> +static void *q6v5_wcss_da_to_va(struct rproc *rproc, u64 da, u64 len)
>>  {
>>  	struct q6v5_wcss *wcss = rproc->priv;
>>  	int offset;
>> diff --git a/drivers/remoteproc/qcom_wcnss.c b/drivers/remoteproc/qcom_wcnss.c
>> index dc135754bb9c..f893219e45a8 100644
>> --- a/drivers/remoteproc/qcom_wcnss.c
>> +++ b/drivers/remoteproc/qcom_wcnss.c
>> @@ -287,7 +287,7 @@ static int wcnss_stop(struct rproc *rproc)
>>  	return ret;
>>  }
>>  
>> -static void *wcnss_da_to_va(struct rproc *rproc, u64 da, int len)
>> +static void *wcnss_da_to_va(struct rproc *rproc, u64 da, u64 len)
>>  {
>>  	struct qcom_wcnss *wcnss = (struct qcom_wcnss *)rproc->priv;
>>  	int offset;
>> diff --git a/drivers/remoteproc/remoteproc_core.c
>> b/drivers/remoteproc/remoteproc_core.c
>> index 307df98347ba..9e6d3c6a60ee 100644
>> --- a/drivers/remoteproc/remoteproc_core.c
>> +++ b/drivers/remoteproc/remoteproc_core.c
>> @@ -185,7 +185,7 @@ EXPORT_SYMBOL(rproc_va_to_pa);
>>   * here the output of the DMA API for the carveouts, which should be more
>>   * correct.
>>   */
>> -void *rproc_da_to_va(struct rproc *rproc, u64 da, int len)
>> +void *rproc_da_to_va(struct rproc *rproc, u64 da, u64 len)
> 
> This function is exported, don't see any update in consequence...
> references:
> https://elixir.bootlin.com/linux/v5.6-rc1/ident/rproc_da_to_va
> For instance the function rproc_trace_read use it. it quite strange that my gcc
> does not warns for the cast but i suppose that some could.

Agreed, even if len should never have been a signed type since it can't be
negative. I will try to fix all callers.

> An indirect consequence is that the len field in rproc_mem_entry struct should
> probably been updated to u64 to be aligned.

Ok, I will do that once we settle on the type of len.

> 
> I'm still wondering about the use of size_t instead,which seems more rational
> from my window.
> So i you or Mathieu remember it was decided to use u64, please could remind me
> the arguments?

I tried to find the notes of a meeting we had for OpenAMP but I did not found
them. Anyway, the argument was coming from Tomas or someone else, (I can't
remember) talking about a 32 bits CPU executing code on a 64 bits accelerator.
In that case, the size_t type could fail due to being only 32bits on the host
CPU but larger than 4G.

However, I can't say if it's a real usecase or not... All I can say is
that keeping it open is probably better if one day somebody comes with such
architecture.

> As an alternative a check should be added for 32 bits processors to ensure that
> the size is not higher than
> its address range capability...

Agreed.
I was even thinking about a mecanism for remoteproc drivers to declare the type
of supported elfs files (such as EM_*, ELFCLASS* and other needed thing).
Or should it be supported by overriding .sanity_check in drivers  to reject
elf64 for instance ?

Since elf is a "specific format" and that rproc can support other formats,
I did not want to add a specific elf_sanity_check field to rproc ops.

Regards,

Clément

> 
> Regards
> Arnaud
> 
>>  {
>>  	struct rproc_mem_entry *carveout;
>>  	void *ptr = NULL;
>> diff --git a/drivers/remoteproc/remoteproc_internal.h
>> b/drivers/remoteproc/remoteproc_internal.h
>> index 493ef9262411..004867061721 100644
>> --- a/drivers/remoteproc/remoteproc_internal.h
>> +++ b/drivers/remoteproc/remoteproc_internal.h
>> @@ -50,7 +50,7 @@ void rproc_exit_sysfs(void);
>>  void rproc_free_vring(struct rproc_vring *rvring);
>>  int rproc_alloc_vring(struct rproc_vdev *rvdev, int i);
>>  
>> -void *rproc_da_to_va(struct rproc *rproc, u64 da, int len);
>> +void *rproc_da_to_va(struct rproc *rproc, u64 da, u64 len);
>>  phys_addr_t rproc_va_to_pa(void *cpu_addr);
>>  int rproc_trigger_recovery(struct rproc *rproc);
>>  
>> diff --git a/drivers/remoteproc/st_slim_rproc.c
>> b/drivers/remoteproc/st_slim_rproc.c
>> index 04492fead3c8..fc01cd879b60 100644
>> --- a/drivers/remoteproc/st_slim_rproc.c
>> +++ b/drivers/remoteproc/st_slim_rproc.c
>> @@ -174,7 +174,7 @@ static int slim_rproc_stop(struct rproc *rproc)
>>  	return 0;
>>  }
>>  
>> -static void *slim_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
>> +static void *slim_rproc_da_to_va(struct rproc *rproc, u64 da, u64 len)
>>  {
>>  	struct st_slim_rproc *slim_rproc = rproc->priv;
>>  	void *va = NULL;
>> @@ -191,7 +191,7 @@ static void *slim_rproc_da_to_va(struct rproc *rproc, u64
>> da, int len)
>>  		}
>>  	}
>>  
>> -	dev_dbg(&rproc->dev, "da = 0x%llx len = 0x%x va = 0x%pK\n",
>> +	dev_dbg(&rproc->dev, "da = 0x%llx len = 0x%llx va = 0x%pK\n",
>>  		da, len, va);
>>  
>>  	return va;
>> diff --git a/drivers/remoteproc/wkup_m3_rproc.c
>> b/drivers/remoteproc/wkup_m3_rproc.c
>> index 3984e585c847..91485b467407 100644
>> --- a/drivers/remoteproc/wkup_m3_rproc.c
>> +++ b/drivers/remoteproc/wkup_m3_rproc.c
>> @@ -80,14 +80,14 @@ static int wkup_m3_rproc_stop(struct rproc *rproc)
>>  	return 0;
>>  }
>>  
>> -static void *wkup_m3_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
>> +static void *wkup_m3_rproc_da_to_va(struct rproc *rproc, u64 da, u64 len)
>>  {
>>  	struct wkup_m3_rproc *wkupm3 = rproc->priv;
>>  	void *va = NULL;
>>  	int i;
>>  	u32 offset;
>>  
>> -	if (len <= 0)
>> +	if (len == 0)
>>  		return NULL;
>>  
>>  	for (i = 0; i < WKUPM3_MEM_MAX; i++) {
>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
>> index 16ad66683ad0..f84bd5fe0211 100644
>> --- a/include/linux/remoteproc.h
>> +++ b/include/linux/remoteproc.h
>> @@ -374,7 +374,7 @@ struct rproc_ops {
>>  	int (*start)(struct rproc *rproc);
>>  	int (*stop)(struct rproc *rproc);
>>  	void (*kick)(struct rproc *rproc, int vqid);
>> -	void * (*da_to_va)(struct rproc *rproc, u64 da, int len);
>> +	void * (*da_to_va)(struct rproc *rproc, u64 da, u64 len);
>>  	int (*parse_fw)(struct rproc *rproc, const struct firmware *fw);
>>  	int (*handle_rsc)(struct rproc *rproc, u32 rsc_type, void *rsc,
>>  			  int offset, int avail);