From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6B99942A15E; Tue, 7 Jul 2026 07:23:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783409021; cv=none; b=in3LiP2oBPvT6BdVwY/MHaHnNuk+osM0bMJMJ8oAPgoMuaQiMXtwFJQ56Dvp801LAFNqEiyHXp78Fb5XUQzrjcbSp6g0qVFfpFHAs6h4HS5B+9x6ADnE85vzYmPShokqR2ChbOGN6m/gfxv/LD9v1EHcTm5sixM5Cy9/gU/uvIo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783409021; c=relaxed/simple; bh=oyI/WNr9SV7QM/SDr5ee52ZGvpRMKK5eA0P6o/DaW1U=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ErKdsEX18ulv4DzdXYoOZb0sUp0judOy51roIMObxNYFpd4UWGLJiKRiuZH1kzDQ8EV+wB/k0UNlPtkVpnAAEXaYX+yEbXvqmx9lsP6ELIu31D4EG/qWQO9FvI+05DOdcmc4JqNdHCycDH6hK9gmcKYtpcGytoyHWVOPh7p3DQA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZO9SUlUV; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZO9SUlUV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 408971F00A3A; Tue, 7 Jul 2026 07:23:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783409007; bh=M7vIsXzvnm+ZS0aSjN5l0MsfSQvRk4hbYLWiRFeHBGs=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ZO9SUlUVsBjTStfEDnasivCovJQsJqvqG0yWim8d7uG6+PZ+vzIRQhVTJlGfTN9py 8kd5QxUSpZ6nvxHgFe04c3ZyCwysx2Ed3QDzsFDOroo4DKMOsAtwsZsFsV6keHZFfM V0xmEz2YZemm1+OPW9o/F1/4nI1HfHas7DgWXZe6HlNS6yAwt4sN544N14jHVooM7k WsFVGHKkfvmdJ3GQL/jnTplXJ5PGL4NWla7YIzbO/eUP5QrTJz3NEpUIJCWwDfy4qm d0jnNHLoOrR6ppkYHV/qNSrtGvFrp5omMC/XYvxWCgjODozGdU7MMuD2PSXm86+IIU weeZLIkbZcIRQ== Message-ID: <6de7ec43-5757-43f0-b8d8-34a692a36d1b@kernel.org> Date: Tue, 7 Jul 2026 08:23:23 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v9] misc: fastrpc: Allocate entire reserved memory for Audio PD in probe To: Jianping Li , Srinivas Kandagatla , Ekansh Gupta Cc: Arnd Bergmann , Greg Kroah-Hartman , Abel Vesa , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, quic_chennak@quicinc.com, stable@kernel.org References: <20260707061733.495-1-jianping.li@oss.qualcomm.com> Content-Language: en-US From: Srinivas Kandagatla In-Reply-To: <20260707061733.495-1-jianping.li@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/7/26 7:17 AM, Jianping Li wrote: > Allocating and freeing Audio PD memory from userspace is unsafe because > the kernel cannot reliably determine when the DSP has finished using the > memory. Userspace may free buffers while they are still in use by the DSP, > and remote free requests cannot be safely trusted. > > Additionally, the current implementation allows userspace to repeatedly > grow the Audio PD heap, but does not support shrinking it. This can lead > to unbounded memory usage over time, effectively causing a memory leak. > > Fix this by allocating the entire Audio PD reserved-memory region during > rpmsg probe and tying its lifetime to the rpmsg channel. This removes > userspace-controlled alloc/free and ensures that memory is reclaimed only > when the DSP process is torn down. > > Add explicit validation for remote_heap presence and size before sending > the memory to DSP, and fail early if the reserved-memory region is > missing or incomplete. > > Fixes: 0871561055e66 ("misc: fastrpc: Add support for audiopd") > Cc: stable@kernel.org > Signed-off-by: Jianping Li > --- > drivers/misc/fastrpc.c | 119 +++++++++++++++++++++++------------------ > 1 file changed, 66 insertions(+), 53 deletions(-) > > diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c > index d86e79134c68..1ec37e6c68a2 100644 > --- a/drivers/misc/fastrpc.c > +++ b/drivers/misc/fastrpc.c > @@ -276,6 +276,8 @@ struct fastrpc_channel_ctx { > struct kref refcount; > /* Flag if dsp attributes are cached */ > bool valid_attributes; > + /* Flag if audio PD init mem was allocated */ > + bool audio_init_mem; > u32 dsp_attributes[FASTRPC_MAX_DSP_ATTRIBUTES]; > struct fastrpc_device *secure_fdevice; > struct fastrpc_device *fdevice; > @@ -1344,15 +1346,24 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl, > struct fastrpc_init_create_static init; > struct fastrpc_invoke_args *args; > struct fastrpc_phy_page pages[1]; > + struct fastrpc_channel_ctx *cctx = fl->cctx; > char *name; > int err; > - bool scm_done = false; > struct { > int client_id; > u32 namelen; > u32 pageslen; > } inbuf; > u32 sc; > + unsigned long flags; > + > + if (!cctx->remote_heap || !cctx->remote_heap->dma_addr || > + !cctx->remote_heap->size) { if remote heap is a mandatory for ADSP or SDSP then this should be enforced at binding level and even at driver probe level. > + err = -ENOMEM; > + dev_err(fl->sctx->dev, > + "remote heap memory region is not added\n"); > + return err; > + } > > args = kzalloc_objs(*args, FASTRPC_CREATE_STATIC_PROCESS_NARGS); > if (!args) > @@ -1376,31 +1387,6 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl, > inbuf.client_id = fl->client_id; > inbuf.namelen = init.namelen; > inbuf.pageslen = 0; > - if (!fl->cctx->remote_heap) { > - err = fastrpc_remote_heap_alloc(fl, fl->sctx->dev, init.memlen, > - &fl->cctx->remote_heap); > - if (err) > - goto err_name; > - > - /* Map if we have any heap VMIDs associated with this ADSP Static Process. */ > - if (fl->cctx->vmcount) { > - u64 src_perms = BIT(QCOM_SCM_VMID_HLOS); > - > - err = qcom_scm_assign_mem(fl->cctx->remote_heap->dma_addr, > - (u64)fl->cctx->remote_heap->size, > - &src_perms, > - fl->cctx->vmperms, fl->cctx->vmcount); > - if (err) { > - dev_err(fl->sctx->dev, > - "Failed to assign memory with dma_addr %pad size 0x%llx err %d\n", > - &fl->cctx->remote_heap->dma_addr, > - fl->cctx->remote_heap->size, err); > - goto err_map; > - } > - scm_done = true; > - inbuf.pageslen = 1; > - } > - } > > fl->pd = USER_PD; > > @@ -1412,8 +1398,24 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl, > args[1].length = inbuf.namelen; > args[1].fd = -1; > > - pages[0].addr = fl->cctx->remote_heap->dma_addr; > - pages[0].size = fl->cctx->remote_heap->size; > + /* > + * Audio PD is a static PD and retains the remote heap > + * information across daemon restarts. Therefore only > + * the first attach should provide heap information to > + * DSP. Subsequent attaches reuse the previously > + * initialized memory pool. > + */ > + spin_lock_irqsave(&cctx->lock, flags); > + if (!cctx->audio_init_mem) { > + pages[0].addr = cctx->remote_heap->dma_addr; > + pages[0].size = cctx->remote_heap->size; > + cctx->audio_init_mem = true; > + inbuf.pageslen = 1; > + } else { > + pages[0].addr = 0; > + pages[0].size = 0; > + } > + spin_unlock_irqrestore(&cctx->lock, flags); > > args[2].ptr = (u64)(uintptr_t) pages; > args[2].length = sizeof(*pages); > @@ -1431,27 +1433,7 @@ static int fastrpc_init_create_static_process(struct fastrpc_user *fl, > > return 0; > err_invoke: > - if (fl->cctx->vmcount && scm_done) { > - u64 src_perms = 0; > - struct qcom_scm_vmperm dst_perms; > - u32 i; > - > - for (i = 0; i < fl->cctx->vmcount; i++) > - src_perms |= BIT(fl->cctx->vmperms[i].vmid); > - > - dst_perms.vmid = QCOM_SCM_VMID_HLOS; > - dst_perms.perm = QCOM_SCM_PERM_RWX; > - err = qcom_scm_assign_mem(fl->cctx->remote_heap->dma_addr, > - (u64)fl->cctx->remote_heap->size, > - &src_perms, &dst_perms, 1); > - if (err) > - dev_err(fl->sctx->dev, "Failed to assign memory dma_addr %pad size 0x%llx err %d\n", > - &fl->cctx->remote_heap->dma_addr, fl->cctx->remote_heap->size, err); > - } > -err_map: > - fastrpc_buf_free(fl->cctx->remote_heap); > - fl->cctx->remote_heap = NULL; > -err_name: > + cctx->audio_init_mem = false; You are ignoring my comments that I have provided in the last version. > kfree(name); > err: > kfree(args); > @@ -2418,12 +2400,23 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev) > } > } > > - if (domain_id == SDSP_DOMAIN_ID) { > + if (domain_id == SDSP_DOMAIN_ID || domain_id == ADSP_DOMAIN_ID) { > struct resource res; > u64 src_perms; > > err = of_reserved_mem_region_to_resource(rdev->of_node, 0, &res); > if (!err) { > + if (domain_id == ADSP_DOMAIN_ID) { > + data->remote_heap = > + kzalloc_obj(*data->remote_heap, GFP_KERNEL); > + if (!data->remote_heap) { > + err = -ENOMEM; > + goto err_free_data; > + } > + > + data->remote_heap->dma_addr = res.start; > + data->remote_heap->size = resource_size(&res); > + } > src_perms = BIT(QCOM_SCM_VMID_HLOS); > > err = qcom_scm_assign_mem(res.start, resource_size(&res), &src_perms, > @@ -2431,7 +2424,6 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev) > if (err) > goto err_free_data; > } > - > } > > secure_dsp = !(of_property_read_bool(rdev->of_node, "qcom,non-secure-domain")); > @@ -2490,6 +2482,7 @@ static int fastrpc_rpmsg_probe(struct rpmsg_device *rpdev) > misc_deregister(&data->secure_fdevice->miscdev); > > err_free_data: > + kfree(data->remote_heap); > kfree(data); > return err; > } > @@ -2512,6 +2505,7 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev) > struct fastrpc_buf *buf, *b; > struct fastrpc_user *user; > unsigned long flags; > + int err; > > /* No invocations past this point */ > spin_lock_irqsave(&cctx->lock, flags); > @@ -2529,8 +2523,27 @@ static void fastrpc_rpmsg_remove(struct rpmsg_device *rpdev) > list_for_each_entry_safe(buf, b, &cctx->invoke_interrupted_mmaps, node) > list_del(&buf->node); > > - if (cctx->remote_heap) > - fastrpc_buf_free(cctx->remote_heap); > + if (cctx->remote_heap && cctx->vmcount) { > + u64 src_perms = 0; > + struct qcom_scm_vmperm dst_perms; > + > + for (u32 i = 0; i < cctx->vmcount; i++) > + src_perms |= BIT(cctx->vmperms[i].vmid); > + > + dst_perms.vmid = QCOM_SCM_VMID_HLOS; > + dst_perms.perm = QCOM_SCM_PERM_RWX; > + > + err = qcom_scm_assign_mem(cctx->remote_heap->dma_addr, > + cctx->remote_heap->size, &src_perms, > + &dst_perms, 1); > + if (err) > + dev_err(&rpdev->dev, > + "Failed to assign memory back to HLOS: dma_addr %pad size %#llx err %d\n", > + &cctx->remote_heap->dma_addr, cctx->remote_heap->size, err); > + } > + > + kfree(cctx->remote_heap); > + cctx->remote_heap = NULL; > > of_platform_depopulate(&rpdev->dev); >