Re: [PATCH v1] misc: fastrpc: Reassign memory ownership only for remote heap

[Srinivas Kandagatla]

On 21/03/2023 10:21, Ekansh Gupta wrote:
> The userspace map request for remote heap allocates CMA memory.
> The ownership of this memory needs to be reassigned to proper
> owners to allow access from the protection domain running on
> DSP. This reassigning of ownership is not correct if done for
> any other supported flags.
>
> When any other flag is requested from userspace, fastrpc is
> trying to reassign the ownership of memory and this reassignment
> is getting skipped for remote heap request which is incorrect.
> Add proper flag check to reassign the memory only if remote heap
> is requested.
>
> Fixes: 532ad70c6d44 ("misc: fastrpc: Add mmap request assigning for static PD pool")
> Cc: stable <stable@xxxxxxxxxx>
> Tested-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>
> Signed-off-by: Ekansh Gupta <quic_ekangupt@xxxxxxxxxxx>

Thanks for fixing this,  without this fix the code inside if condition 
was a dead code.


Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>


--srini
> ---
>   drivers/misc/fastrpc.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
> index a701132..9b88132 100644
> --- a/drivers/misc/fastrpc.c
> +++ b/drivers/misc/fastrpc.c
> @@ -1892,7 +1892,7 @@ static int fastrpc_req_mmap(struct fastrpc_user *fl, char __user *argp)
>   	req.vaddrout = rsp_msg.vaddr;
>   
>   	/* Add memory to static PD pool, protection thru hypervisor */
> -	if (req.flags != ADSP_MMAP_REMOTE_HEAP_ADDR && fl->cctx->vmcount) {
> +	if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR && fl->cctx->vmcount) {
>   		struct qcom_scm_vmperm perm;
>   
>   		perm.vmid = QCOM_SCM_VMID_HLOS;