Linaro-mm-sig

linaro-mm-sig@lists.linaro.org

19 participants
7032 discussions

by Mina Almasry

* TL;DR: Device memory TCP (devmem TCP) is a proposal for transferring data to and/or from device memory efficiently, without bouncing the data to a host memory buffer. * Problem: A large amount of data transfers have device memory as the source and/or destination. Accelerators drastically increased the volume of such transfers. Some examples include: - ML accelerators transferring large amounts of training data from storage into GPU/TPU memory. In some cases ML training setup time can be as long as 50% of TPU compute time, improving data transfer throughput & efficiency can help improving GPU/TPU utilization. - Distributed training, where ML accelerators, such as GPUs on different hosts, exchange data among them. - Distributed raw block storage applications transfer large amounts of data with remote SSDs, much of this data does not require host processing. Today, the majority of the Device-to-Device data transfers the network are implemented as the following low level operations: Device-to-Host copy, Host-to-Host network transfer, and Host-to-Device copy. The implementation is suboptimal, especially for bulk data transfers, and can put significant strains on system resources, such as host memory bandwidth, PCIe bandwidth, etc. One important reason behind the current state is the kernel’s lack of semantics to express device to network transfers. * Proposal: In this patch series we attempt to optimize this use case by implementing socket APIs that enable the user to: 1. send device memory across the network directly, and 2. receive incoming network packets directly into device memory. Packet _payloads_ go directly from the NIC to device memory for receive and from device memory to NIC for transmit. Packet _headers_ go to/from host memory and are processed by the TCP/IP stack normally. The NIC _must_ support header split to achieve this. Advantages: - Alleviate host memory bandwidth pressure, compared to existing network-transfer + device-copy semantics. - Alleviate PCIe BW pressure, by limiting data transfer to the lowest level of the PCIe tree, compared to traditional path which sends data through the root complex. With this proposal we're able to reach ~96.6% line rate speeds with data sent and received directly from/to device memory. * Patch overview: ** Part 1: struct paged device memory Currently the standard for device memory sharing is DMABUF, which doesn't generate struct pages. On the other hand, networking stack (skbs, drivers, and page pool) operate on pages. We have 2 options: 1. Generate struct pages for dmabuf device memory, or, 2. Modify the networking stack to understand a new memory type. This proposal implements option #1. We implement a small framework to generate struct pages for an sg_table returned from dma_buf_map_attachment(). The support added here should be generic and easily extended to other use cases interested in struct paged device memory. We use this framework to generate pages that can be used in the networking stack. ** Part 2: recvmsg() & sendmsg() APIs We define user APIs for the user to send and receive these dmabuf pages. ** part 3: support for unreadable skb frags Dmabuf pages are not accessible by the host; we implement changes throughput the networking stack to correctly handle skbs with unreadable frags. ** part 4: page pool support We piggy back on Jakub's page pool memory providers idea: https://github.com/kuba-moo/linux/tree/pp-providers It allows the page pool to define a memory provider that provides the page allocation and freeing. It helps abstract most of the device memory TCP changes from the driver. This is not strictly necessary, the driver can choose to allocate dmabuf pages and use them directly without going through the page pool (if acceptable to their maintainers). Not included with this RFC is the GVE devmem TCP support, just to simplify the review. Code available here if desired: https://github.com/mina/linux/tree/tcpdevmem This RFC is built on top of v6.4-rc7 with Jakub's pp-providers changes cherry-picked. * NIC dependencies: 1. (strict) Devmem TCP require the NIC to support header split, i.e. the capability to split incoming packets into a header + payload and to put each into a separate buffer. Devmem TCP works by using dmabuf pages for the packet payload, and host memory for the packet headers. 2. (optional) Devmem TCP works better with flow steering support & RSS support, i.e. the NIC's ability to steer flows into certain rx queues. This allows the sysadmin to enable devmem TCP on a subset of the rx queues, and steer devmem TCP traffic onto these queues and non devmem TCP elsewhere. The NIC I have access to with these properties is the GVE with DQO support running in Google Cloud, but any NIC that supports these features would suffice. I may be able to help reviewers bring up devmem TCP on their NICs. * Testing: The series includes a udmabuf kselftest that show a simple use case of devmem TCP and validates the entire data path end to end without a dependency on a specific dmabuf provider. Not included in this series is our devmem TCP benchmark, which transfers data to/from GPU dmabufs directly. With this implementation & benchmark we're able to reach ~96.6% line rate speeds with 4 GPU/NIC pairs running bi-direction traffic, with all the packet payloads going straight to the GPU memory (no host buffer bounce). ** Test Setup Kernel: v6.4-rc7, with this RFC and Jakub's memory provider API cherry-picked locally. Hardware: Google Cloud A3 VMs. NIC: GVE with header split & RSS & flow steering support. Benchmark: custom devmem TCP benchmark not yet open sourced. Mina Almasry (10): dma-buf: add support for paged attachment mappings dma-buf: add support for NET_RX pages dma-buf: add support for NET_TX pages net: add support for skbs with unreadable frags tcp: implement recvmsg() RX path for devmem TCP net: add SO_DEVMEM_DONTNEED setsockopt to release RX pages tcp: implement sendmsg() TX path for for devmem tcp selftests: add ncdevmem, netcat for devmem TCP memory-provider: updates core provider API for devmem TCP memory-provider: add dmabuf devmem provider drivers/dma-buf/dma-buf.c | 444 ++++++++++++++++ include/linux/dma-buf.h | 142 +++++ include/linux/netdevice.h | 1 + include/linux/skbuff.h | 34 +- include/linux/socket.h | 1 + include/net/page_pool.h | 21 + include/net/sock.h | 4 + include/net/tcp.h | 6 +- include/uapi/asm-generic/socket.h | 6 + include/uapi/linux/dma-buf.h | 12 + include/uapi/linux/uio.h | 10 + net/core/datagram.c | 3 + net/core/page_pool.c | 111 +++- net/core/skbuff.c | 81 ++- net/core/sock.c | 47 ++ net/ipv4/tcp.c | 262 +++++++++- net/ipv4/tcp_input.c | 13 +- net/ipv4/tcp_ipv4.c | 8 + net/ipv4/tcp_output.c | 5 +- net/packet/af_packet.c | 4 +- tools/testing/selftests/net/.gitignore | 1 + tools/testing/selftests/net/Makefile | 1 + tools/testing/selftests/net/ncdevmem.c | 693 +++++++++++++++++++++++++ 23 files changed, 1868 insertions(+), 42 deletions(-) create mode 100644 tools/testing/selftests/net/ncdevmem.c -- 2.41.0.390.g38632f3daf-goog

3 years

[PATCH v2] dma-buf: Fix the typo in DMA-BUF statistics doc

by Luc Ma

From: Luc Ma <luc(a)sietium.com> The kernel-doc for DMA-BUF statistics mentions /sys/kernel/dma-buf/buffers but the correct path is /sys/kernel/dmabuf/buffers instead. Signed-off-by: Luc Ma <luc(a)sietium.com> Reviewed-by: Javier Martinez Canillas <javierm(a)redhat.com> --- drivers/dma-buf/dma-buf-sysfs-stats.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.c b/drivers/dma-buf/dma-buf-sysfs-stats.c index 6cfbbf0720bd..b5b62e40ccc1 100644 --- a/drivers/dma-buf/dma-buf-sysfs-stats.c +++ b/drivers/dma-buf/dma-buf-sysfs-stats.c @@ -33,7 +33,7 @@ * into their address space. This necessitated the creation of the DMA-BUF sysfs * statistics interface to provide per-buffer information on production systems. * - * The interface at ``/sys/kernel/dma-buf/buffers`` exposes information about + * The interface at ``/sys/kernel/dmabuf/buffers`` exposes information about * every DMA-BUF when ``CONFIG_DMABUF_SYSFS_STATS`` is enabled. * * The following stats are exposed by the interface: -- 2.25.1

3 years

[PATCH v2] scsi: lpfc: Fix potential deadlock on &ndlp->lock

by Chengfeng Ye

As &ndlp->lock is acquired by timer lpfc_els_retry_delay() under softirq context, process context code acquiring the lock &ndlp->lock should disable irq or bh, otherwise deadlock could happen if the timer preempt the execution while the lock is held in process context on the same CPU. The two lock acquisition inside lpfc_cleanup_pending_mbox() does not disable irq or softirq. [Deadlock Scenario] lpfc_cmpl_els_fdisc() -> lpfc_cleanup_pending_mbox() -> spin_lock(&ndlp->lock); <irq> -> lpfc_els_retry_delay() -> lpfc_nlp_get() -> spin_lock_irqsave(&ndlp->lock, flags); (deadlock here) This flaw was found by an experimental static analysis tool I am developing for irq-related deadlock. The patch fix the potential deadlock by spin_lock_irq() to disable irq. Signed-off-by: Chengfeng Ye <dg573847474(a)gmail.com> --- drivers/scsi/lpfc/lpfc_sli.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index 58d10f8f75a7..8555f6bb9742 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -21049,9 +21049,9 @@ lpfc_cleanup_pending_mbox(struct lpfc_vport *vport) mb->mbox_flag |= LPFC_MBX_IMED_UNREG; restart_loop = 1; spin_unlock_irq(&phba->hbalock); - spin_lock(&ndlp->lock); + spin_lock_irq(&ndlp->lock); ndlp->nlp_flag &= ~NLP_IGNR_REG_CMPL; - spin_unlock(&ndlp->lock); + spin_unlock_irq(&ndlp->lock); spin_lock_irq(&phba->hbalock); break; } @@ -21067,9 +21067,9 @@ lpfc_cleanup_pending_mbox(struct lpfc_vport *vport) ndlp = (struct lpfc_nodelist *)mb->ctx_ndlp; mb->ctx_ndlp = NULL; if (ndlp) { - spin_lock(&ndlp->lock); + spin_lock_irq(&ndlp->lock); ndlp->nlp_flag &= ~NLP_IGNR_REG_CMPL; - spin_unlock(&ndlp->lock); + spin_unlock_irq(&ndlp->lock); lpfc_nlp_put(ndlp); } } -- 2.17.1

3 years

[PATCH] scsi: lpfc: Fix potential deadlock on &ndlp->lock

by Chengfeng Ye

As &ndlp->lock is acquired by timer lpfc_els_retry_delay() under softirq context, process context code acquiring the lock &phba->hbalock should disable irq or bh, otherwise deadlock could happen if the timer preempt the execution while the lock is held in process context on the same CPU. The two lock acquisition inside lpfc_cleanup_pending_mbox() does not disable irq or softirq. [Deadlock Scenario] lpfc_cmpl_els_fdisc() -> lpfc_cleanup_pending_mbox() -> spin_lock(&ndlp->lock); <irq> -> lpfc_els_retry_delay() -> lpfc_nlp_get() -> spin_lock_irqsave(&ndlp->lock, flags); (deadlock here) This flaw was found by an experimental static analysis tool I am developing for irq-related deadlock. The patch fix the potential deadlock by spin_lock_irq() to disable irq. Signed-off-by: Chengfeng Ye <dg573847474(a)gmail.com> --- drivers/scsi/lpfc/lpfc_sli.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index 58d10f8f75a7..8555f6bb9742 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -21049,9 +21049,9 @@ lpfc_cleanup_pending_mbox(struct lpfc_vport *vport) mb->mbox_flag |= LPFC_MBX_IMED_UNREG; restart_loop = 1; spin_unlock_irq(&phba->hbalock); - spin_lock(&ndlp->lock); + spin_lock_irq(&ndlp->lock); ndlp->nlp_flag &= ~NLP_IGNR_REG_CMPL; - spin_unlock(&ndlp->lock); + spin_unlock_irq(&ndlp->lock); spin_lock_irq(&phba->hbalock); break; } @@ -21067,9 +21067,9 @@ lpfc_cleanup_pending_mbox(struct lpfc_vport *vport) ndlp = (struct lpfc_nodelist *)mb->ctx_ndlp; mb->ctx_ndlp = NULL; if (ndlp) { - spin_lock(&ndlp->lock); + spin_lock_irq(&ndlp->lock); ndlp->nlp_flag &= ~NLP_IGNR_REG_CMPL; - spin_unlock(&ndlp->lock); + spin_unlock_irq(&ndlp->lock); lpfc_nlp_put(ndlp); } } -- 2.17.1

3 years

[PATCH 0/9] Add DRM driver for StarFive SoC JH7110

by Keith Zhao

Hi, This series is a DRM driver for StarFive SoC JH7110, which includes a display controller driver for Verisilicon DC8200 and an HMDI driver. We use GEM framework for buffer management and allocate memory by using DMA APIs. The JH7110 display subsystem includes a display controller Verisilicon DC8200 and an HDMI transmitter. The HDMI TX IP is designed for transmitting video and audio data from DC8200 to a display device. The HDMI TX IP consists of the digital controller and the physical layer. This series does not support HDMI audio driver. Keith Zhao (9): dt-bindings: display: Add yamls for JH7110 display subsystem riscv: dts: starfive: jh7110: add dc&hdmi controller node drm/verisilicon: Add basic drm driver drm/verisilicon: Add gem driver for JH7110 SoC drm/verisilicon: Add mode config funcs drm/verisilicon: Add drm crtc funcs drm/verisilicon: Add drm plane funcs drm/verisilicon: Add verisilicon dc controller driver drm/verisilicon: Add starfive hdmi driver .../display/verisilicon/starfive-hdmi.yaml | 93 + .../display/verisilicon/verisilicon-dc.yaml | 110 + .../display/verisilicon/verisilicon-drm.yaml | 42 + .../devicetree/bindings/vendor-prefixes.yaml | 2 + MAINTAINERS | 9 + .../jh7110-starfive-visionfive-2.dtsi | 87 + arch/riscv/boot/dts/starfive/jh7110.dtsi | 46 + drivers/gpu/drm/Kconfig | 2 + drivers/gpu/drm/Makefile | 1 + drivers/gpu/drm/verisilicon/Kconfig | 24 + drivers/gpu/drm/verisilicon/Makefile | 13 + drivers/gpu/drm/verisilicon/starfive_hdmi.c | 928 ++++++++ drivers/gpu/drm/verisilicon/starfive_hdmi.h | 296 +++ drivers/gpu/drm/verisilicon/vs_crtc.c | 388 ++++ drivers/gpu/drm/verisilicon/vs_crtc.h | 74 + drivers/gpu/drm/verisilicon/vs_dc.c | 1040 +++++++++ drivers/gpu/drm/verisilicon/vs_dc.h | 62 + drivers/gpu/drm/verisilicon/vs_dc_hw.c | 2008 +++++++++++++++++ drivers/gpu/drm/verisilicon/vs_dc_hw.h | 496 ++++ drivers/gpu/drm/verisilicon/vs_drv.c | 301 +++ drivers/gpu/drm/verisilicon/vs_drv.h | 52 + drivers/gpu/drm/verisilicon/vs_fb.c | 181 ++ drivers/gpu/drm/verisilicon/vs_fb.h | 15 + drivers/gpu/drm/verisilicon/vs_gem.c | 372 +++ drivers/gpu/drm/verisilicon/vs_gem.h | 72 + drivers/gpu/drm/verisilicon/vs_plane.c | 440 ++++ drivers/gpu/drm/verisilicon/vs_plane.h | 74 + drivers/gpu/drm/verisilicon/vs_type.h | 72 + include/uapi/drm/drm_fourcc.h | 83 + include/uapi/drm/vs_drm.h | 50 + 30 files changed, 7433 insertions(+) create mode 100644 Documentation/devicetree/bindings/display/verisilicon/starfive-hdmi.yaml create mode 100644 Documentation/devicetree/bindings/display/verisilicon/verisilicon-dc.yaml create mode 100644 Documentation/devicetree/bindings/display/verisilicon/verisilicon-drm.yaml create mode 100644 drivers/gpu/drm/verisilicon/Kconfig create mode 100644 drivers/gpu/drm/verisilicon/Makefile create mode 100644 drivers/gpu/drm/verisilicon/starfive_hdmi.c create mode 100644 drivers/gpu/drm/verisilicon/starfive_hdmi.h create mode 100644 drivers/gpu/drm/verisilicon/vs_crtc.c create mode 100644 drivers/gpu/drm/verisilicon/vs_crtc.h create mode 100644 drivers/gpu/drm/verisilicon/vs_dc.c create mode 100644 drivers/gpu/drm/verisilicon/vs_dc.h create mode 100644 drivers/gpu/drm/verisilicon/vs_dc_hw.c create mode 100644 drivers/gpu/drm/verisilicon/vs_dc_hw.h create mode 100644 drivers/gpu/drm/verisilicon/vs_drv.c create mode 100644 drivers/gpu/drm/verisilicon/vs_drv.h create mode 100644 drivers/gpu/drm/verisilicon/vs_fb.c create mode 100644 drivers/gpu/drm/verisilicon/vs_fb.h create mode 100644 drivers/gpu/drm/verisilicon/vs_gem.c create mode 100644 drivers/gpu/drm/verisilicon/vs_gem.h create mode 100644 drivers/gpu/drm/verisilicon/vs_plane.c create mode 100644 drivers/gpu/drm/verisilicon/vs_plane.h create mode 100644 drivers/gpu/drm/verisilicon/vs_type.h create mode 100644 include/uapi/drm/vs_drm.h -- 2.34.1

3 years

[PATCH 6.1 026/183] dma-buf/dma-resv: Stop leaking on krealloc() failure

by Greg Kroah-Hartman

From: Ville Syrjälä <ville.syrjala(a)linux.intel.com> commit 05abb3be91d8788328231ee02973ab3d47f5e3d2 upstream. Currently dma_resv_get_fences() will leak the previously allocated array if the fence iteration got restarted and the krealloc_array() fails. Free the old array by hand, and make sure we still clear the returned *fences so the caller won't end up accessing freed memory. Some (but not all) of the callers of dma_resv_get_fences() seem to still trawl through the array even when dma_resv_get_fences() failed. And let's zero out *num_fences as well for good measure. Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Christian König <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Fixes: d3c80698c9f5 ("dma-buf: use new iterator in dma_resv_get_fences v3") Signed-off-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com> Reviewed-by: Christian König <christian.koenig(a)amd.com> Cc: stable(a)vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20230713194745.1751-1-ville.s… Signed-off-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-resv.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -566,6 +566,7 @@ int dma_resv_get_fences(struct dma_resv dma_resv_for_each_fence_unlocked(&cursor, fence) { if (dma_resv_iter_is_restarted(&cursor)) { + struct dma_fence **new_fences; unsigned int count; while (*num_fences) @@ -574,13 +575,17 @@ int dma_resv_get_fences(struct dma_resv count = cursor.num_fences + 1; /* Eventually re-allocate the array */ - *fences = krealloc_array(*fences, count, - sizeof(void *), - GFP_KERNEL); - if (count && !*fences) { + new_fences = krealloc_array(*fences, count, + sizeof(void *), + GFP_KERNEL); + if (count && !new_fences) { + kfree(*fences); + *fences = NULL; + *num_fences = 0; dma_resv_iter_end(&cursor); return -ENOMEM; } + *fences = new_fences; } (*fences)[(*num_fences)++] = dma_fence_get(fence);

3 years

[PATCH 6.4 043/227] dma-buf/dma-resv: Stop leaking on krealloc() failure

by Greg Kroah-Hartman

From: Ville Syrjälä <ville.syrjala(a)linux.intel.com> commit 05abb3be91d8788328231ee02973ab3d47f5e3d2 upstream. Currently dma_resv_get_fences() will leak the previously allocated array if the fence iteration got restarted and the krealloc_array() fails. Free the old array by hand, and make sure we still clear the returned *fences so the caller won't end up accessing freed memory. Some (but not all) of the callers of dma_resv_get_fences() seem to still trawl through the array even when dma_resv_get_fences() failed. And let's zero out *num_fences as well for good measure. Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Christian König <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Fixes: d3c80698c9f5 ("dma-buf: use new iterator in dma_resv_get_fences v3") Signed-off-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com> Reviewed-by: Christian König <christian.koenig(a)amd.com> Cc: stable(a)vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20230713194745.1751-1-ville.s… Signed-off-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-resv.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -571,6 +571,7 @@ int dma_resv_get_fences(struct dma_resv dma_resv_for_each_fence_unlocked(&cursor, fence) { if (dma_resv_iter_is_restarted(&cursor)) { + struct dma_fence **new_fences; unsigned int count; while (*num_fences) @@ -579,13 +580,17 @@ int dma_resv_get_fences(struct dma_resv count = cursor.num_fences + 1; /* Eventually re-allocate the array */ - *fences = krealloc_array(*fences, count, - sizeof(void *), - GFP_KERNEL); - if (count && !*fences) { + new_fences = krealloc_array(*fences, count, + sizeof(void *), + GFP_KERNEL); + if (count && !new_fences) { + kfree(*fences); + *fences = NULL; + *num_fences = 0; dma_resv_iter_end(&cursor); return -ENOMEM; } + *fences = new_fences; } (*fences)[(*num_fences)++] = dma_fence_get(fence);

3 years

Patch "dma-buf/dma-resv: Stop leaking on krealloc() failure" has been added to the 6.4-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled dma-buf/dma-resv: Stop leaking on krealloc() failure to the 6.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: dma-buf-dma-resv-stop-leaking-on-krealloc-failure.patch and it can be found in the queue-6.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From 05abb3be91d8788328231ee02973ab3d47f5e3d2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala(a)linux.intel.com> Date: Thu, 13 Jul 2023 22:47:45 +0300 Subject: dma-buf/dma-resv: Stop leaking on krealloc() failure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ville Syrjälä <ville.syrjala(a)linux.intel.com> commit 05abb3be91d8788328231ee02973ab3d47f5e3d2 upstream. Currently dma_resv_get_fences() will leak the previously allocated array if the fence iteration got restarted and the krealloc_array() fails. Free the old array by hand, and make sure we still clear the returned *fences so the caller won't end up accessing freed memory. Some (but not all) of the callers of dma_resv_get_fences() seem to still trawl through the array even when dma_resv_get_fences() failed. And let's zero out *num_fences as well for good measure. Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Christian König <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Fixes: d3c80698c9f5 ("dma-buf: use new iterator in dma_resv_get_fences v3") Signed-off-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com> Reviewed-by: Christian König <christian.koenig(a)amd.com> Cc: stable(a)vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20230713194745.1751-1-ville.s… Signed-off-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-resv.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -571,6 +571,7 @@ int dma_resv_get_fences(struct dma_resv dma_resv_for_each_fence_unlocked(&cursor, fence) { if (dma_resv_iter_is_restarted(&cursor)) { + struct dma_fence **new_fences; unsigned int count; while (*num_fences) @@ -579,13 +580,17 @@ int dma_resv_get_fences(struct dma_resv count = cursor.num_fences + 1; /* Eventually re-allocate the array */ - *fences = krealloc_array(*fences, count, - sizeof(void *), - GFP_KERNEL); - if (count && !*fences) { + new_fences = krealloc_array(*fences, count, + sizeof(void *), + GFP_KERNEL); + if (count && !new_fences) { + kfree(*fences); + *fences = NULL; + *num_fences = 0; dma_resv_iter_end(&cursor); return -ENOMEM; } + *fences = new_fences; } (*fences)[(*num_fences)++] = dma_fence_get(fence); Patches currently in stable-queue which might be from ville.syrjala(a)linux.intel.com are queue-6.4/dma-buf-dma-resv-stop-leaking-on-krealloc-failure.patch

3 years

Patch "dma-buf/dma-resv: Stop leaking on krealloc() failure" has been added to the 6.1-stable tree

by gregkh＠linuxfoundation.org

This is a note to let you know that I've just added the patch titled dma-buf/dma-resv: Stop leaking on krealloc() failure to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=sum… The filename of the patch is: dma-buf-dma-resv-stop-leaking-on-krealloc-failure.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable(a)vger.kernel.org> know about it. From 05abb3be91d8788328231ee02973ab3d47f5e3d2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala(a)linux.intel.com> Date: Thu, 13 Jul 2023 22:47:45 +0300 Subject: dma-buf/dma-resv: Stop leaking on krealloc() failure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ville Syrjälä <ville.syrjala(a)linux.intel.com> commit 05abb3be91d8788328231ee02973ab3d47f5e3d2 upstream. Currently dma_resv_get_fences() will leak the previously allocated array if the fence iteration got restarted and the krealloc_array() fails. Free the old array by hand, and make sure we still clear the returned *fences so the caller won't end up accessing freed memory. Some (but not all) of the callers of dma_resv_get_fences() seem to still trawl through the array even when dma_resv_get_fences() failed. And let's zero out *num_fences as well for good measure. Cc: Sumit Semwal <sumit.semwal(a)linaro.org> Cc: Christian König <christian.koenig(a)amd.com> Cc: linux-media(a)vger.kernel.org Cc: dri-devel(a)lists.freedesktop.org Cc: linaro-mm-sig(a)lists.linaro.org Fixes: d3c80698c9f5 ("dma-buf: use new iterator in dma_resv_get_fences v3") Signed-off-by: Ville Syrjälä <ville.syrjala(a)linux.intel.com> Reviewed-by: Christian König <christian.koenig(a)amd.com> Cc: stable(a)vger.kernel.org Link: https://patchwork.freedesktop.org/patch/msgid/20230713194745.1751-1-ville.s… Signed-off-by: Christian König <christian.koenig(a)amd.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/dma-buf/dma-resv.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -566,6 +566,7 @@ int dma_resv_get_fences(struct dma_resv dma_resv_for_each_fence_unlocked(&cursor, fence) { if (dma_resv_iter_is_restarted(&cursor)) { + struct dma_fence **new_fences; unsigned int count; while (*num_fences) @@ -574,13 +575,17 @@ int dma_resv_get_fences(struct dma_resv count = cursor.num_fences + 1; /* Eventually re-allocate the array */ - *fences = krealloc_array(*fences, count, - sizeof(void *), - GFP_KERNEL); - if (count && !*fences) { + new_fences = krealloc_array(*fences, count, + sizeof(void *), + GFP_KERNEL); + if (count && !new_fences) { + kfree(*fences); + *fences = NULL; + *num_fences = 0; dma_resv_iter_end(&cursor); return -ENOMEM; } + *fences = new_fences; } (*fences)[(*num_fences)++] = dma_fence_get(fence); Patches currently in stable-queue which might be from ville.syrjala(a)linux.intel.com are queue-6.1/dma-buf-dma-resv-stop-leaking-on-krealloc-failure.patch

3 years

[PATCH] dma-buf: remove unintended hyphen in the sysfs path

by Luc Ma

From: Luc Ma <luc(a)sietium.com> Signed-off-by: Luc Ma <luc(a)sietium.com> --- drivers/dma-buf/dma-buf-sysfs-stats.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/dma-buf/dma-buf-sysfs-stats.c b/drivers/dma-buf/dma-buf-sysfs-stats.c index 6cfbbf0720bd..b5b62e40ccc1 100644 --- a/drivers/dma-buf/dma-buf-sysfs-stats.c +++ b/drivers/dma-buf/dma-buf-sysfs-stats.c @@ -33,7 +33,7 @@ * into their address space. This necessitated the creation of the DMA-BUF sysfs * statistics interface to provide per-buffer information on production systems. * - * The interface at ``/sys/kernel/dma-buf/buffers`` exposes information about + * The interface at ``/sys/kernel/dmabuf/buffers`` exposes information about * every DMA-BUF when ``CONFIG_DMABUF_SYSFS_STATS`` is enabled. * * The following stats are exposed by the interface: -- 2.25.1

3 years

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