[PATCH v1] misc: fastrpc: Fix DSP capabilities request

[PATCH v1] misc: fastrpc: Fix DSP capabilities request

[Ekansh Gupta]

Incorrect remote arguments are getting passed when requesting for
capabilities from DSP. Also there is no requirement to update the
PD type as it might cause problems for any PD other than user PD.
In addition to this, the collected capability information is not
getting copied properly to user. Add changes to address these
problems and get correct DSP capabilities.

Fixes: 6c16fd8bdd40 ("misc: fastrpc: Add support to get DSP capabilities")
Cc: stable <stable@kernel.org>
Tested-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
Signed-off-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
---
 drivers/misc/fastrpc.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 30d4d04..776c596 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -1693,9 +1693,8 @@ static int fastrpc_get_info_from_dsp(struct fastrpc_user *fl, uint32_t *dsp_attr
 	args[0].length = sizeof(dsp_attr_buf_len);
 	args[0].fd = -1;
 	args[1].ptr = (u64)(uintptr_t)&dsp_attr_buf[1];
-	args[1].length = dsp_attr_buf_len;
+	args[1].length = dsp_attr_buf_len * sizeof(uint32_t);
 	args[1].fd = -1;
-	fl->pd = USER_PD;
 
 	return fastrpc_internal_invoke(fl, true, FASTRPC_DSP_UTILITIES_HANDLE,
 				       FASTRPC_SCALARS(0, 1, 1), args);
@@ -1723,7 +1722,7 @@ static int fastrpc_get_info_from_kernel(struct fastrpc_ioctl_capability *cap,
 	if (!dsp_attributes)
 		return -ENOMEM;
 
-	err = fastrpc_get_info_from_dsp(fl, dsp_attributes, FASTRPC_MAX_DSP_ATTRIBUTES_LEN);
+	err = fastrpc_get_info_from_dsp(fl, dsp_attributes, FASTRPC_MAX_DSP_ATTRIBUTES);
 	if (err == DSP_UNSUPPORTED_API) {
 		dev_info(&cctx->rpdev->dev,
 			 "Warning: DSP capabilities not supported on domain: %d\n", domain);
@@ -1776,7 +1775,7 @@ static int fastrpc_get_dsp_info(struct fastrpc_user *fl, char __user *argp)
 	if (err)
 		return err;
 
-	if (copy_to_user(argp, &cap.capability, sizeof(cap.capability)))
+	if (copy_to_user(argp, &cap, sizeof(cap)))
 		return -EFAULT;
 
 	return 0;
-- 
2.7.4

Re: [PATCH v1] misc: fastrpc: Fix DSP capabilities request

[Srinivas Kandagatla]

On 21/06/2023 07:28, Ekansh Gupta wrote:
> Incorrect remote arguments are getting passed when requesting for
> capabilities from DSP. Also there is no requirement to update the
> PD type as it might cause problems for any PD other than user PD.
> In addition to this, the collected capability information is not
> getting copied properly to user. Add changes to address these
> problems and get correct DSP capabilities.
> 
> Fixes: 6c16fd8bdd40 ("misc: fastrpc: Add support to get DSP capabilities")
> Cc: stable <stable@kernel.org>
> Tested-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
> Signed-off-by: Ekansh Gupta <quic_ekangupt@quicinc.com>
> ---
>   drivers/misc/fastrpc.c | 7 +++----
>   1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> index 30d4d04..776c596 100644
> --- a/drivers/misc/fastrpc.c
> +++ b/drivers/misc/fastrpc.c
> @@ -1693,9 +1693,8 @@ static int fastrpc_get_info_from_dsp(struct fastrpc_user *fl, uint32_t *dsp_attr
>   	args[0].length = sizeof(dsp_attr_buf_len);
>   	args[0].fd = -1;
>   	args[1].ptr = (u64)(uintptr_t)&dsp_attr_buf[1];

<--snip
> -	args[1].length = dsp_attr_buf_len;
> +	args[1].length = dsp_attr_buf_len * sizeof(uint32_t);
-->
>   	args[1].fd = -1;
> -	fl->pd = USER_PD;

this looks fine.
>   
>   	return fastrpc_internal_invoke(fl, true, FASTRPC_DSP_UTILITIES_HANDLE,
>   				       FASTRPC_SCALARS(0, 1, 1), args);
> @@ -1723,7 +1722,7 @@ static int fastrpc_get_info_from_kernel(struct fastrpc_ioctl_capability *cap,
>   	if (!dsp_attributes)
>   		return -ENOMEM;
>   

<-- snip
> -	err = fastrpc_get_info_from_dsp(fl, dsp_attributes, FASTRPC_MAX_DSP_ATTRIBUTES_LEN);
> +	err = fastrpc_get_info_from_dsp(fl, dsp_attributes, FASTRPC_MAX_DSP_ATTRIBUTES);

-->
Before this change we passed a value which is already multipled now we 
pass a value that will be mulitplied inside fastrpc_get_info_from_dsp, 
both will work, but I dont see any value in doing this change.


>   	if (err == DSP_UNSUPPORTED_API) {
>   		dev_info(&cctx->rpdev->dev,
>   			 "Warning: DSP capabilities not supported on domain: %d\n", domain);
> @@ -1776,7 +1775,7 @@ static int fastrpc_get_dsp_info(struct fastrpc_user *fl, char __user *argp)
>   	if (err)
>   		return err;
>   
> -	if (copy_to_user(argp, &cap.capability, sizeof(cap.capability)))
> +	if (copy_to_user(argp, &cap, sizeof(cap)))

Can you explain this change, and what is it fixing exactly?

--srini
>   		return -EFAULT;
>   
>   	return 0;