- Linux-stable-mirror - lists.linaro.org

Fwd: Request to add mainline merged patch to stable kernels

by JP Dehollain

Hi Greg, thanks for looking into this.. The full commit hash is 807221d3c5ff6e3c91ff57bc82a0b7a541462e20 Note: apologies if you received this multiple times, the previous one got bounced due to html Cheers, JP ________________________________ From: Greg KH <gregkh(a)linuxfoundation.org> Sent: Tuesday, December 23, 2025 6:39:22 PM To: JP Dehollain <jpdehollain(a)gmail.com> Cc: stable(a)vger.kernel.org <stable(a)vger.kernel.org> Subject: Re: Request to add mainline merged patch to stable kernels On Tue, Dec 23, 2025 at 04:05:24PM +1100, JP Dehollain wrote: > Hello, > I recently used the patch misc: rtsx_pci: Add separate CD/WP pin > polarity reversal support with commit ID 807221d, to fix a bug causing > the cardreader driver to always load sd cards in read-only mode. > On the suggestion of the driver maintainer, I am requesting that this > patch be applied to all stable kernel versions, as it is currently > only applied to >=6.18. > Thanks, > JP > What is the git id of the commit you are looking to have backported? thanks, greg k-h

1 day, 15 hours

1
0
0 0

[PATCH] ARM: dts: integrator: Fix DMA ranges mismatch warning on IM-PD1

by Kuan-Wei Chiu

When compiling the device tree for the Integrator/AP with IM-PD1, the following warning is observed regarding the display controller node: arch/arm/boot/dts/arm/integratorap-im-pd1.dts:251.3-14: Warning (dma_ranges_format): /bus@c0000000/bus@c0000000/display@1000000:dma-ranges: empty "dma-ranges" property but its #address-cells (2) differs from /bus@c0000000/bus@c0000000 (1) The display node specifies an empty "dma-ranges" property, intended to describe a 1:1 identity mapping. However, the node lacks explicit "#address-cells" and "#size-cells" properties. In this case, the device tree compiler defaults the address cells to 2 (64-bit), which conflicts with the parent bus configuration (32-bit, 1 cell). Fix this by explicitly defining "#address-cells" and "#size-cells" as 1. This matches the 32-bit architecture of the Integrator platform and ensures the address translation range is correctly parsed by the compiler. Fixes: 7bea67a99430 ("ARM: dts: integrator: Fix DMA ranges") Cc: stable(a)vger.kernel.org Signed-off-by: Kuan-Wei Chiu <visitorckw(a)gmail.com> --- arch/arm/boot/dts/arm/integratorap-im-pd1.dts | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/arm/boot/dts/arm/integratorap-im-pd1.dts b/arch/arm/boot/dts/arm/integratorap-im-pd1.dts index db13e09f2fab..6d90d9a42dc9 100644 --- a/arch/arm/boot/dts/arm/integratorap-im-pd1.dts +++ b/arch/arm/boot/dts/arm/integratorap-im-pd1.dts @@ -248,6 +248,8 @@ display@1000000 { /* 640x480 16bpp @ 25.175MHz is 36827428 bytes/s */ max-memory-bandwidth = <40000000>; memory-region = <&impd1_ram>; + #address-cells = <1>; + #size-cells = <1>; dma-ranges; port@0 { -- 2.52.0.177.g9f829587af-goog

1 day, 16 hours

3
2
0 0

[PATCH v1 0/3] mm: mm_cid static initialization fixes

by Mathieu Desnoyers

Hi Andrew, Here are 2 fixes for missing mm_cid fields for init_mm and efi_mm static initialization. The renaming of cpu_bitmap to flexible_array (patch 2) is needed for patch 3. Those are relevant for mainline, with CC stable. They are based on v6.19-rc2. Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: stable(a)vger.kernel.org Cc: linux-mm(a)kvack.org Mathieu Desnoyers (3): mm: Add missing static initializer for init_mm::mm_cid.lock mm: Rename cpu_bitmap field to flexible_array mm: Take into account mm_cid size for mm_struct static definitions drivers/firmware/efi/efi.c | 2 +- include/linux/mm_types.h | 18 +++++++++++++----- mm/init-mm.c | 5 ++++- 3 files changed, 18 insertions(+), 7 deletions(-) -- 2.39.5

1 day, 20 hours

1
3
0 0

[report] Performance regressions introduced via "cpuidle: menu: Remove iowait influence" on 6.12.y

by ALOK TIWARI

Hi, I’m reporting a performance regression of up to 6% sequential I/O vdbench regression observed on 6.12.y kernel. While running performance benchmarks on v6.12.60 kernel the sequential I/O vdbench metrics are showing a 5-6% performance regression when compared to v6.12.48 Bisect root cause commit ======================== - commit b39b62075ab4 ("cpuidle: menu: Remove iowait influence") Things work fine again when the previously removed performance-multiplier code is added back. Test details ============ The system is connected to a number of disks in disk array using multipathing and directio configuration in the vdbench profile. wd=wd1,sd=sd*,rdpct=0,seekpct=sequential,xfersize=128k rd=128k64T,wd=wd1,iorate=max,elapsed=600,interval=1,warmup=300,threads=64 Thanks, Alok

2 days

2
2
0 0

[PATCH v3] virtio: console: fix lost wakeup when device is written and polled

by Lorenz Bauer

A process issuing blocking writes to a virtio console may get stuck indefinitely if another thread polls the device. Here is how to trigger the bug: - Thread A writes to the port until the virtqueue is full. - Thread A calls wait_port_writable() and goes to sleep, waiting on port->waitqueue. - The host processes some of the write, marks buffers as used and raises an interrupt. - Before the interrupt is serviced, thread B executes port_fops_poll(). This calls reclaim_consumed_buffers() via will_write_block() and consumes all used buffers. - The interrupt is serviced. vring_interrupt() finds no used buffers via more_used() and returns without waking port->waitqueue. - Thread A is still in wait_event(port->waitqueue), waiting for a wakeup that never arrives. The crux is that invoking reclaim_consumed_buffers() may cause vring_interrupt() to omit wakeups. Fix this by calling reclaim_consumed_buffers() in out_int() before waking. This is similar to the call to discard_port_data() in in_intr() which also frees buffer from a non-sleepable context. This in turn guarantees that port->outvq_full is up to date when handling polling. Since in_intr() already populates port->inbuf we use that to avoid changing reader state. Cc: stable(a)vger.kernel.org Signed-off-by: Lorenz Bauer <lmb(a)isovalent.com> --- As far as I can tell all currently maintained stable series kernels need this commit. Applies and builds cleanly on 5.10.247, verified to fix the issue. --- Changes in v3: - Use spin_lock_irq in port_fops_poll (Arnd) - Use spin_lock in out_intr (Arnd) - Link to v2: https://lore.kernel.org/r/20251222-virtio-console-lost-wakeup-v2-1-5de93cb3… Changes in v2: - Call reclaim_consumed_buffers() in out_intr instead of issuing another wake. - Link to v1: https://lore.kernel.org/r/20251215-virtio-console-lost-wakeup-v1-1-79a5c578… --- drivers/char/virtio_console.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 088182e54debd6029ea2c2a5542d7a28500e67b8..e6048e04c3b23d008caa2a1d31d4ac6b2841045f 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -971,10 +971,17 @@ static __poll_t port_fops_poll(struct file *filp, poll_table *wait) return EPOLLHUP; } ret = 0; - if (!will_read_block(port)) + + spin_lock_irq(&port->inbuf_lock); + if (port->inbuf) ret |= EPOLLIN | EPOLLRDNORM; - if (!will_write_block(port)) + spin_unlock_irq(&port->inbuf_lock); + + spin_lock_irq(&port->outvq_lock); + if (!port->outvq_full) ret |= EPOLLOUT; + spin_unlock_irq(&port->outvq_lock); + if (!port->host_connected) ret |= EPOLLHUP; @@ -1705,6 +1712,10 @@ static void out_intr(struct virtqueue *vq) return; } + spin_lock(&port->outvq_lock); + reclaim_consumed_buffers(port); + spin_unlock(&port->outvq_lock); + wake_up_interruptible(&port->waitqueue); } --- base-commit: d358e5254674b70f34c847715ca509e46eb81e6f change-id: 20251215-virtio-console-lost-wakeup-0f566c5cd35f Best regards, -- Lorenz Bauer <lmb(a)isovalent.com>

2 days, 2 hours

1
0
0 0

[PATCH RESEND v5 0/3] phy: qcom: edp: Add missing ref clock to x1e80100

by Abel Vesa

According to documentation, the DP PHY on x1e80100 has another clock called ref. The current X Elite devices supported upstream work fine without this clock, because the boot firmware leaves this clock enabled. But we should not rely on that. Also, when it comes to power management, this clock needs to be also disabled on suspend. So even though this change breaks the ABI, it is needed in order to make we disable this clock on runtime PM, when that is going to be enabled in the driver. So rework the driver to allow different number of clocks, fix the dt-bindings schema and add the clock to the DT node as well. Signed-off-by: Abel Vesa <abel.vesa(a)linaro.org> --- Changes in v5: - Picked-up Bjorn's R-b tags. - Replaced "parse" with "get" on clocks acquiring failure. - Link to v4: https://lore.kernel.org/r/20251029-phy-qcom-edp-add-missing-refclk-v4-0-adb… Changes in v4: - Picked Dmitry's R-b tag for the driver patch - Added x1e80100 substring to subject of dts patch - Link to v3 (resend): https://lore.kernel.org/r/20251014-phy-qcom-edp-add-missing-refclk-v3-0-078… Changes in v3 (resend) - picked-up Krzysztof's R-b tag for bindings patch - Link to v3: https://lore.kernel.org/r/20250909-phy-qcom-edp-add-missing-refclk-v3-0-4ec… Changes in v3: - Use dev_err_probe() on clocks parsing failure. - Explain why the ABI break is necessary. - Drop the extra 'clk' suffix from the clock name. So ref instead of refclk. - Link to v2: https://lore.kernel.org/r/20250903-phy-qcom-edp-add-missing-refclk-v2-0-d88… Changes in v2: - Fix schema by adding the minItems, as suggested by Krzysztof. - Use devm_clk_bulk_get_all, as suggested by Konrad. - Rephrase the commit messages to reflect the flexible number of clocks. - Link to v1: https://lore.kernel.org/r/20250730-phy-qcom-edp-add-missing-refclk-v1-0-6f7… --- Abel Vesa (3): dt-bindings: phy: qcom-edp: Add missing clock for X Elite phy: qcom: edp: Make the number of clocks flexible arm64: dts: qcom: x1e80100: Add missing TCSR ref clock to the DP PHYs .../devicetree/bindings/phy/qcom,edp-phy.yaml | 28 +++++++++++++++++++++- arch/arm64/boot/dts/qcom/hamoa.dtsi | 12 ++++++---- drivers/phy/qualcomm/phy-qcom-edp.c | 16 ++++++------- 3 files changed, 43 insertions(+), 13 deletions(-) --- base-commit: 131f3d9446a6075192cdd91f197989d98302faa6 change-id: 20250730-phy-qcom-edp-add-missing-refclk-5ab82828f8e7 Best regards, -- Abel Vesa <abel.vesa(a)oss.qualcomm.com>

2 days, 2 hours

1
3
0 0

[PATCH v6.1 0/2] x86/mm/pat: fix VM_PAT handling

by Ajay Kaher

[PATCH v6.1 1/2]: required to backport [PATCH v6.1 2/2]. [PATCH v6.1 2/2]: backport to fix VM_PAT handling when fork() fails in copy_page_range(). arch/x86/mm/pat/memtype.c | 50 +++++++++++++++++++++++---------------- include/linux/pgtable.h | 31 ++++++++++++++++++------ kernel/fork.c | 4 ++++ mm/memory.c | 10 ++++---- mm/mremap.c | 2 +- 5 files changed, 62 insertions(+), 35 deletions(-) -- 2.40.4

2 days, 3 hours

1
2
0 0

[PATCH] usb: cdns3: fix a null pointer dereference in cdns3_gadget_ep_queue()

by Haoxiang Li

If cdns3_gadget_ep_alloc_request() fails, a null pointer dereference occurs. Add a check to prevent it. Found by code review and compiled on ubuntu 20.04. Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver") Cc: stable(a)vger.kernel.org Signed-off-by: Haoxiang Li <lihaoxiang(a)isrc.iscas.ac.cn> --- drivers/usb/cdns3/cdns3-gadget.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c index 168707213ed9..cc2421a34588 100644 --- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -2659,6 +2659,8 @@ static int cdns3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request, struct cdns3_request *priv_req; zlp_request = cdns3_gadget_ep_alloc_request(ep, GFP_ATOMIC); + if (!zlp_request) + return -ENOMEM; zlp_request->buf = priv_dev->zlp_buf; zlp_request->length = 0; -- 2.25.1

2 days, 3 hours

2
1
0 0

[PATCH] usb: cdns2: fix a null pointer dereference in cdns2_gadget_ep_queue()

by Haoxiang Li

If cdns2_gadget_ep_alloc_request() fails, a null pointer dereference occurs. Add a check to prevent it. Fixes: 3eb1f1efe204 ("usb: cdns2: Add main part of Cadence USBHS driver") Cc: stable(a)vger.kernel.org Signed-off-by: Haoxiang Li <lihaoxiang(a)isrc.iscas.ac.cn> --- drivers/usb/gadget/udc/cdns2/cdns2-gadget.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c b/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c index 9b53daf76583..c5b9dae743d8 100644 --- a/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c +++ b/drivers/usb/gadget/udc/cdns2/cdns2-gadget.c @@ -1725,6 +1725,8 @@ static int cdns2_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request, struct cdns2_request *preq; zlp_request = cdns2_gadget_ep_alloc_request(ep, GFP_ATOMIC); + if (!zlp_request) + return -ENOMEM; zlp_request->buf = pdev->zlp_buf; zlp_request->length = 0; -- 2.25.1

2 days, 3 hours

2
1
0 0

[PATCH] drm/msm/dpu: Add missing NULL pointer check for pingpong interface

by Nikolay Kuratov

It is checked almost always in dpu_encoder_phys_wb_setup_ctl(), but in a single place the check is missing. Also use convenient locals instead of phys_enc->* where available. Cc: stable(a)vger.kernel.org Fixes: d7d0e73f7de33 ("drm/msm/dpu: introduce the dpu_encoder_phys_* for writeback") Signed-off-by: Nikolay Kuratov <kniv(a)yandex-team.ru> --- drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c index 46f348972a97..6d28f2281c76 100644 --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_wb.c @@ -247,14 +247,12 @@ static void dpu_encoder_phys_wb_setup_ctl(struct dpu_encoder_phys *phys_enc) if (hw_cdm) intf_cfg.cdm = hw_cdm->idx; - if (phys_enc->hw_pp->merge_3d && phys_enc->hw_pp->merge_3d->ops.setup_3d_mode) - phys_enc->hw_pp->merge_3d->ops.setup_3d_mode(phys_enc->hw_pp->merge_3d, - mode_3d); + if (hw_pp && hw_pp->merge_3d && hw_pp->merge_3d->ops.setup_3d_mode) + hw_pp->merge_3d->ops.setup_3d_mode(hw_pp->merge_3d, mode_3d); /* setup which pp blk will connect to this wb */ - if (hw_pp && phys_enc->hw_wb->ops.bind_pingpong_blk) - phys_enc->hw_wb->ops.bind_pingpong_blk(phys_enc->hw_wb, - phys_enc->hw_pp->idx); + if (hw_pp && hw_wb->ops.bind_pingpong_blk) + hw_wb->ops.bind_pingpong_blk(hw_wb, hw_pp->idx); phys_enc->hw_ctl->ops.setup_intf_cfg(phys_enc->hw_ctl, &intf_cfg); } else if (phys_enc->hw_ctl && phys_enc->hw_ctl->ops.setup_intf_cfg) { -- 2.34.1

2 days, 4 hours

2
3
0 0

[PATCH V2 0/2] LoongArch: KVM: fix "unreliable stack" issue

by Xianglai Li

When starting multi-core loongarch virtualization on loongarch physical machine, loading livepatch on the physical machine will cause an error similar to the following: [ 411.686289] livepatch: klp_try_switch_task: CPU 31/KVM:3116 has an unreliable stack The specific test steps are as follows: 1.Start a multi-core virtual machine on a physical machine 2.Enter the following command on the physical machine to turn on the debug switch: echo "file kernel/livepatch/transition.c +p" > /sys/kernel/debug/\ dynamic_debug/control 3.Load livepatch: modprobe livepatch-sample Through the above steps, similar prints can be viewed in dmesg. The reason for this issue is that the code of the kvm_exc_entry function was copied in the function kvm_loongarch_env_init. When the cpu needs to execute kvm_exc_entry, it will switch to the copied address for execution. The new address of the kvm_exc_entry function cannot be recognized in ORC, which eventually leads to the arch_stack_walk_reliable function returning an error and printing an exception message. To solve the above problems, we directly compile the switch.S file into the kernel instead of the module. In this way, the function kvm_exc_entry will no longer need to be copied. changlog: V2<-V1: 1.Rollback the modification of function parameter types such as kvm_save_fpu. In the asm-prototypes.h header file, only the parameter types it depends on are included Cc: Huacai Chen <chenhuacai(a)kernel.org> Cc: WANG Xuerui <kernel(a)xen0n.name> Cc: Tianrui Zhao <zhaotianrui(a)loongson.cn> Cc: Bibo Mao <maobibo(a)loongson.cn> Cc: Charlie Jenkins <charlie(a)rivosinc.com> Cc: Xianglai Li <lixianglai(a)loongson.cn> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: stable(a)vger.kernel.org Xianglai Li (2): LoongArch: KVM: Compile the switch.S file directly into the kernel LoongArch: KVM: fix "unreliable stack" issue arch/loongarch/Kbuild | 2 +- arch/loongarch/include/asm/asm-prototypes.h | 21 +++++++++++++ arch/loongarch/include/asm/kvm_host.h | 3 -- arch/loongarch/kvm/Makefile | 2 +- arch/loongarch/kvm/main.c | 35 ++------------------- arch/loongarch/kvm/switch.S | 24 +++++++++++--- 6 files changed, 45 insertions(+), 42 deletions(-) base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8 -- 2.39.1

2 days, 4 hours

4
12
0 0

[PATCH] drm/vmwgfx: Fix an error return check in vmw_compat_shader_add()

by Haoxiang Li

In vmw_compat_shader_add(), the return value check of vmw_shader_alloc() is not proper. Modify the check for the return pointer 'res'. Found by code review and compiled on ubuntu 20.04. Fixes: 18e4a4669c50 ("drm/vmwgfx: Fix compat shader namespace") Cc: stable(a)vger.kernel.org Signed-off-by: Haoxiang Li <lihaoxiang(a)isrc.iscas.ac.cn> --- drivers/gpu/drm/vmwgfx/vmwgfx_shader.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c b/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c index 69dfe69ce0f8..7ed938710342 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_shader.c @@ -923,8 +923,10 @@ int vmw_compat_shader_add(struct vmw_private *dev_priv, ttm_bo_unreserve(&buf->tbo); res = vmw_shader_alloc(dev_priv, buf, size, 0, shader_type); - if (unlikely(ret != 0)) + if (IS_ERR(res)) { + ret = PTR_ERR(res); goto no_reserve; + } ret = vmw_cmdbuf_res_add(man, vmw_cmdbuf_res_shader, vmw_shader_key(user_key, shader_type), -- 2.25.1

2 days, 4 hours

1
0
0 0

[PATCH] media: iris: Add missing platform data entries for SM8750

by Dikshita Agarwal

Two platform-data fields for SM8750 were missed: - get_vpu_buffer_size = iris_vpu33_buf_size Without this, the driver fails to allocate the required internal buffers, leading to basic decode/encode failures during session bring-up. - max_core_mbps = ((7680 * 4320) / 256) * 60 Without this capability exposed, capability checks are incomplete and v4l2-compliance for encoder fails. Fixes: a5925a2ce077 ("media: iris: add VPU33 specific encoding buffer calculation") Fixes: a6882431a138 ("media: iris: Add support for ENUM_FRAMESIZES/FRAMEINTERVALS for encoder") Cc: stable(a)vger.kernel.org Signed-off-by: Dikshita Agarwal <dikshita.agarwal(a)oss.qualcomm.com> --- drivers/media/platform/qcom/iris/iris_platform_gen2.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/media/platform/qcom/iris/iris_platform_gen2.c b/drivers/media/platform/qcom/iris/iris_platform_gen2.c index c1989240c248601c34b84f508f1b72d72f81260a..00d1d55463179429f2ae7554546dcbe4fb1431cc 100644 --- a/drivers/media/platform/qcom/iris/iris_platform_gen2.c +++ b/drivers/media/platform/qcom/iris/iris_platform_gen2.c @@ -915,6 +915,7 @@ const struct iris_platform_data sm8750_data = { .get_instance = iris_hfi_gen2_get_instance, .init_hfi_command_ops = iris_hfi_gen2_command_ops_init, .init_hfi_response_ops = iris_hfi_gen2_response_ops_init, + .get_vpu_buffer_size = iris_vpu33_buf_size, .vpu_ops = &iris_vpu35_ops, .set_preset_registers = iris_set_sm8550_preset_registers, .icc_tbl = sm8550_icc_table, @@ -945,6 +946,7 @@ const struct iris_platform_data sm8750_data = { .num_vpp_pipe = 4, .max_session_count = 16, .max_core_mbpf = NUM_MBS_8K * 2, + .max_core_mbps = ((7680 * 4320) / 256) * 60, .dec_input_config_params_default = sm8550_vdec_input_config_params_default, .dec_input_config_params_default_size = --- base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8 change-id: 20251217-iris-sm8750-fix-2d42a133058d Best regards, -- Dikshita Agarwal <dikshita.agarwal(a)oss.qualcomm.com>

2 days, 4 hours

3
2
0 0

[PATCH v5.10-v6.1] drm/vmwgfx: Fix a null-ptr access in the cursor snooper

by Shivani Agarwal

From: Zack Rusin <zack.rusin(a)broadcom.com> [ Upstream commit 5ac2c0279053a2c5265d46903432fb26ae2d0da2 ] Check that the resource which is converted to a surface exists before trying to use the cursor snooper on it. vmw_cmd_res_check allows explicit invalid (SVGA3D_INVALID_ID) identifiers because some svga commands accept SVGA3D_INVALID_ID to mean "no surface", unfortunately functions that accept the actual surfaces as objects might (and in case of the cursor snooper, do not) be able to handle null objects. Make sure that we validate not only the identifier (via the vmw_cmd_res_check) but also check that the actual resource exists before trying to do something with it. Fixes unchecked null-ptr reference in the snooping code. Signed-off-by: Zack Rusin <zack.rusin(a)broadcom.com> Fixes: c0951b797e7d ("drm/vmwgfx: Refactor resource management") Reported-by: Kuzey Arda Bulut <kuzeyardabulut(a)gmail.com> Cc: Broadcom internal kernel review list <bcm-kernel-feedback-list(a)broadcom.com> Cc: dri-devel(a)lists.freedesktop.org Reviewed-by: Ian Forbes <ian.forbes(a)broadcom.com> Link: https://lore.kernel.org/r/20250917153655.1968583-1-zack.rusin@broadcom.com Signed-off-by: Sasha Levin <sashal(a)kernel.org> [Shivani: Modified to apply on v5.10.y-v6.1.y] Signed-off-by: Shivani Agarwal <shivani.agarwal(a)broadcom.com> --- drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c index 0d12d6af6..5d3827b5d 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_execbuf.c @@ -1507,6 +1507,7 @@ static int vmw_cmd_dma(struct vmw_private *dev_priv, SVGA3dCmdHeader *header) { struct vmw_buffer_object *vmw_bo = NULL; + struct vmw_resource *res; struct vmw_surface *srf = NULL; VMW_DECLARE_CMD_VAR(*cmd, SVGA3dCmdSurfaceDMA); int ret; @@ -1542,18 +1543,24 @@ static int vmw_cmd_dma(struct vmw_private *dev_priv, dirty = (cmd->body.transfer == SVGA3D_WRITE_HOST_VRAM) ? VMW_RES_DIRTY_SET : 0; - ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface, - dirty, user_surface_converter, - &cmd->body.host.sid, NULL); + ret = vmw_cmd_res_check(dev_priv, sw_context, vmw_res_surface, dirty, + user_surface_converter, &cmd->body.host.sid, + NULL); if (unlikely(ret != 0)) { if (unlikely(ret != -ERESTARTSYS)) VMW_DEBUG_USER("could not find surface for DMA.\n"); return ret; } - srf = vmw_res_to_srf(sw_context->res_cache[vmw_res_surface].res); + res = sw_context->res_cache[vmw_res_surface].res; + if (!res) { + VMW_DEBUG_USER("Invalid DMA surface.\n"); + return -EINVAL; + } - vmw_kms_cursor_snoop(srf, sw_context->fp->tfile, &vmw_bo->base, header); + srf = vmw_res_to_srf(res); + vmw_kms_cursor_snoop(srf, sw_context->fp->tfile, &vmw_bo->base, + header); return 0; } -- 2.40.4

2 days, 4 hours

1
0
0 0

[PATCH 1/1] phy: tegra: xusb: Explicitly configure HS_DISCON_LEVEL to 0x7

by Wayne Chang

The USB2 Bias Pad Control register manages analog parameters for signal detection. Previously, the HS_DISCON_LEVEL relied on hardware reset values, which may lead to the detection failure. Explicitly configure HS_DISCON_LEVEL to 0x7. This ensures the disconnect threshold is sufficient to guarantee reliable detection. Fixes: bbf711682cd5 ("phy: tegra: xusb: Add Tegra186 support") Cc: stable(a)vger.kernel.org Signed-off-by: Wayne Chang <waynec(a)nvidia.com> --- drivers/phy/tegra/xusb-tegra186.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/phy/tegra/xusb-tegra186.c b/drivers/phy/tegra/xusb-tegra186.c index e818f6c3980e..bec9616c4a2e 100644 --- a/drivers/phy/tegra/xusb-tegra186.c +++ b/drivers/phy/tegra/xusb-tegra186.c @@ -84,6 +84,7 @@ #define XUSB_PADCTL_USB2_BIAS_PAD_CTL0 0x284 #define BIAS_PAD_PD BIT(11) #define HS_SQUELCH_LEVEL(x) (((x) & 0x7) << 0) +#define HS_DISCON_LEVEL(x) (((x) & 0x7) << 3) #define XUSB_PADCTL_USB2_BIAS_PAD_CTL1 0x288 #define USB2_TRK_START_TIMER(x) (((x) & 0x7f) << 12) @@ -623,6 +624,8 @@ static void tegra186_utmi_bias_pad_power_on(struct tegra_xusb_padctl *padctl) value &= ~BIAS_PAD_PD; value &= ~HS_SQUELCH_LEVEL(~0); value |= HS_SQUELCH_LEVEL(priv->calib.hs_squelch); + value &= ~HS_DISCON_LEVEL(~0); + value |= HS_DISCON_LEVEL(0x7); padctl_writel(padctl, value, XUSB_PADCTL_USB2_BIAS_PAD_CTL0); udelay(1); -- 2.25.1

2 days, 6 hours

2
1
0 0

[PATCH] ocfs2: Add check for total number of chains in chain list

by Prithvi Tambewagh

The functions ocfs2_reserve_suballoc_bits(), ocfs2_block_group_alloc(), ocfs2_block_group_alloc_contig() and ocfs2_find_smallest_chain() trust the on-disk values related to the allocation chain. However, KASAN bug was triggered in these functions, and the kernel panicked when accessing redzoned memory. This occurred due to the corrupted value of `cl_count` field of `struct ocfs2_chain_list`. Upon analysis, the value of `cl_count` was observed to be overwhemingly large, due to which the code accessed redzoned memory. The fix introduces an if statement which validates value of `cl_count` (both lower and upper bounds). Lower bound check ensures the value of `cl_count` is not zero and upper bound check ensures that the value of `cl_count` is in the range such that it has a value less than the total size of struct ocfs2_chain_list and maximum number of chains that can be present, so as to fill one block. Reported-by: syzbot+af14efe17dfa46173239(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=af14efe17dfa46173239 Tested-by: syzbot+af14efe17dfa46173239(a)syzkaller.appspotmail.com Cc: stable(a)vger.kernel.org Signed-off-by: Prithvi Tambewagh <activprithvi(a)gmail.com> --- fs/ocfs2/suballoc.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c index f7b483f0de2a..7ea63e9cc4f8 100644 --- a/fs/ocfs2/suballoc.c +++ b/fs/ocfs2/suballoc.c @@ -671,6 +671,21 @@ static int ocfs2_block_group_alloc(struct ocfs2_super *osb, BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode)); cl = &fe->id2.i_chain; + unsigned int block_size = osb->sb->s_blocksize; + unsigned int max_cl_count = + (block_size - offsetof(struct ocfs2_chain_list, cl_recs)) / + sizeof(struct ocfs2_chain_rec); + + if (!le16_to_cpu(cl->cl_count) || + le16_to_cpu(cl->cl_count) > max_cl_count) { + ocfs2_error(osb->sb, + "Invalid chain list: cl_count %u " + "exceeds max %u", + le16_to_cpu(cl->cl_count), max_cl_count); + status = -EIO; + goto bail; + } + status = ocfs2_reserve_clusters_with_limit(osb, le16_to_cpu(cl->cl_cpg), max_block, flags, &ac); base-commit: 36c254515dc6592c44db77b84908358979dd6b50 -- 2.34.1

2 days, 6 hours

3
2
0 0

[PATCH] platform/x86: intel_telemetry: Fix swapped arrays in PSS output

by Kaushlendra Kumar

The LTR blocking statistics and wakeup event counters are incorrectly cross-referenced during debugfs output rendering. The code populates pss_ltr_blkd[] with LTR blocking data and pss_s0ix_wakeup[] with wakeup data, but the display loops reference the wrong arrays. This causes the "LTR Blocking Status" section to print wakeup events and the "Wakes Status" section to print LTR blockers, misleading power management analysis and S0ix residency debugging. Fix by aligning array usage with the intended output section labels. Fixes: 87bee290998d ("platform:x86: Add Intel Telemetry Debugfs interfaces") Cc: stable(a)vger.kernel.org Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar(a)intel.com> --- drivers/platform/x86/intel/telemetry/debugfs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/platform/x86/intel/telemetry/debugfs.c b/drivers/platform/x86/intel/telemetry/debugfs.c index 70e5736c44c7..189c61ff7ff0 100644 --- a/drivers/platform/x86/intel/telemetry/debugfs.c +++ b/drivers/platform/x86/intel/telemetry/debugfs.c @@ -449,7 +449,7 @@ static int telem_pss_states_show(struct seq_file *s, void *unused) for (index = 0; index < debugfs_conf->pss_ltr_evts; index++) { seq_printf(s, "%-32s\t%u\n", debugfs_conf->pss_ltr_data[index].name, - pss_s0ix_wakeup[index]); + pss_ltr_blkd[index]); } seq_puts(s, "\n--------------------------------------\n"); @@ -459,7 +459,7 @@ static int telem_pss_states_show(struct seq_file *s, void *unused) for (index = 0; index < debugfs_conf->pss_wakeup_evts; index++) { seq_printf(s, "%-32s\t%u\n", debugfs_conf->pss_wakeup[index].name, - pss_ltr_blkd[index]); + pss_s0ix_wakeup[index]); } return 0; -- 2.34.1

2 days, 10 hours

1
0
0 0

[PATCH v2 0/2] iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device

by Jinhui Guo

Hi, all We hit hard-lockups when the Intel IOMMU waits indefinitely for an ATS invalidation that cannot complete, especially under GDR high-load conditions. 1. Hard-lock when a passthrough PCIe NIC with ATS enabled link-down in Intel IOMMU non-scalable mode. Two scenarios exist: NIC link-down with an explicit link-down event and link-down without any event. a) NIC link-down with an explicit link-dow event. Call Trace: qi_submit_sync qi_flush_dev_iotlb __context_flush_dev_iotlb.part.0 domain_context_clear_one_cb pci_for_each_dma_alias device_block_translation blocking_domain_attach_dev iommu_deinit_device __iommu_group_remove_device iommu_release_device iommu_bus_notifier blocking_notifier_call_chain bus_notify device_del pci_remove_bus_device pci_stop_and_remove_bus_device pciehp_unconfigure_device pciehp_disable_slot pciehp_handle_presence_or_link_change pciehp_ist b) NIC link-down without an event - hard-lock on VM destroy. Call Trace: qi_submit_sync qi_flush_dev_iotlb __context_flush_dev_iotlb.part.0 domain_context_clear_one_cb pci_for_each_dma_alias device_block_translation blocking_domain_attach_dev __iommu_attach_device __iommu_device_set_domain __iommu_group_set_domain_internal iommu_detach_group vfio_iommu_type1_detach_group vfio_group_detach_container vfio_group_fops_release __fput 2. Hard-lock when a passthrough PCIe NIC with ATS enabled link-down in Intel IOMMU scalable mode; NIC link-down without an event hard-locks on VM destroy. Call Trace: qi_submit_sync qi_flush_dev_iotlb intel_pasid_tear_down_entry device_block_translation blocking_domain_attach_dev __iommu_attach_device __iommu_device_set_domain __iommu_group_set_domain_internal iommu_detach_group vfio_iommu_type1_detach_group vfio_group_detach_container vfio_group_fops_release __fput Fix both issues with two patches: 1. Skip dev-IOTLB flush for inaccessible devices in __context_flush_dev_iotlb() using pci_device_is_present(). 2. Use pci_device_is_present() instead of pci_dev_is_disconnected() to decide when to skip ATS invalidation in devtlb_invalidation_with_pasid(). Best Regards, Jinhui --- v1: https://lore.kernel.org/all/20251210171431.1589-1-guojinhui.liam@bytedance.… Changelog in v1 -> v2 (suggested by Baolu Lu) - Simplify the pci_device_is_present() check in __context_flush_dev_iotlb(). - Add Cc: stable(a)vger.kernel.org to both patches. Jinhui Guo (2): iommu/vt-d: Skip dev-iotlb flush for inaccessible PCIe device without scalable mode iommu/vt-d: Flush dev-IOTLB only when PCIe device is accessible in scalable mode drivers/iommu/intel/pasid.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) -- 2.20.1

2 days, 10 hours

3
7
0 0

Backport request for commit 5326ab737a47 ("virtio_console: fix order of fields cols and rows")

by Filip Hejsek

Hi, I would like to request backporting 5326ab737a47 ("virtio_console: fix order of fields cols and rows") to all LTS kernels. I'm working on QEMU patches that add virtio console size support. Without the fix, rows and columns will be swapped. As far as I know, there are no device implementations that use the wrong order and would by broken by the fix. Note: A previous version [1] of the patch contained "Cc: stable" and "Fixes:" tags, but they seem to have been accidentally left out from the final version. [1]: https://lore.kernel.org/all/20250320172654.624657-1-maxbr@linux.ibm.com/ Thanks, Filip Hejsek

2 days, 15 hours

2
7
0 0

[PATCH RESEND v3 1/4] mm/hugetlb: fix hugetlb_pmd_shared()

by David Hildenbrand (Red Hat)

We switched from (wrongly) using the page count to an independent shared count. Now, shared page tables have a refcount of 1 (excluding speculative references) and instead use ptdesc->pt_share_count to identify sharing. We didn't convert hugetlb_pmd_shared(), so right now, we would never detect a shared PMD table as such, because sharing/unsharing no longer touches the refcount of a PMD table. Page migration, like mbind() or migrate_pages() would allow for migrating folios mapped into such shared PMD tables, even though the folios are not exclusive. In smaps we would account them as "private" although they are "shared", and we would be wrongly setting the PM_MMAP_EXCLUSIVE in the pagemap interface. Fix it by properly using ptdesc_pmd_is_shared() in hugetlb_pmd_shared(). Fixes: 59d9094df3d7 ("mm: hugetlb: independent PMD page table shared count") Reviewed-by: Rik van Riel <riel(a)surriel.com> Reviewed-by: Lance Yang <lance.yang(a)linux.dev> Tested-by: Lance Yang <lance.yang(a)linux.dev> Reviewed-by: Harry Yoo <harry.yoo(a)oracle.com> Tested-by: Laurence Oberman <loberman(a)redhat.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Acked-by: Oscar Salvador <osalvador(a)suse.de> Cc: <stable(a)vger.kernel.org> Cc: Liu Shixin <liushixin2(a)huawei.com> Signed-off-by: David Hildenbrand (Red Hat) <david(a)kernel.org> --- include/linux/hugetlb.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 019a1c5281e4e..03c8725efa289 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -1326,7 +1326,7 @@ static inline __init void hugetlb_cma_reserve(int order) #ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING static inline bool hugetlb_pmd_shared(pte_t *pte) { - return page_count(virt_to_page(pte)) > 1; + return ptdesc_pmd_is_shared(virt_to_ptdesc(pte)); } #else static inline bool hugetlb_pmd_shared(pte_t *pte) -- 2.52.0

2 days, 15 hours

1
0
0 0

[PATCH v3 3/3] mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather

by David Hildenbrand (Red Hat)

As reported, ever since commit 1013af4f585f ("mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race") we can end up in some situations where we perform so many IPI broadcasts when unsharing hugetlb PMD page tables that it severely regresses some workloads. In particular, when we fork()+exit(), or when we munmap() a large area backed by many shared PMD tables, we perform one IPI broadcast per unshared PMD table. There are two optimizations to be had: (1) When we process (unshare) multiple such PMD tables, such as during exit(), it is sufficient to send a single IPI broadcast (as long as we respect locking rules) instead of one per PMD table. Locking prevents that any of these PMD tables could get reused before we drop the lock. (2) When we are not the last sharer (> 2 users including us), there is no need to send the IPI broadcast. The shared PMD tables cannot become exclusive (fully unshared) before an IPI will be broadcasted by the last sharer. Concurrent GUP-fast could walk into a PMD table just before we unshared it. It could then succeed in grabbing a page from the shared page table even after munmap() etc succeeded (and supressed an IPI). But there is not difference compared to GUP-fast just sleeping for a while after grabbing the page and re-enabling IRQs. Most importantly, GUP-fast will never walk into page tables that are no-longer shared, because the last sharer will issue an IPI broadcast. (if ever required, checking whether the PUD changed in GUP-fast after grabbing the page like we do in the PTE case could handle this) So let's rework PMD sharing TLB flushing + IPI sync to use the mmu_gather infrastructure so we can implement these optimizations and demystify the code at least a bit. Extend the mmu_gather infrastructure to be able to deal with our special hugetlb PMD table sharing implementation. To make initialization of the mmu_gather easier when working on a single VMA (in particular, when dealing with hugetlb), provide tlb_gather_mmu_vma(). We'll consolidate the handling for (full) unsharing of PMD tables in tlb_unshare_pmd_ptdesc() and tlb_flush_unshared_tables(), and track in "struct mmu_gather" whether we had (full) unsharing of PMD tables. Because locking is very special (concurrent unsharing+reuse must be prevented), we disallow deferring flushing to tlb_finish_mmu() and instead require an explicit earlier call to tlb_flush_unshared_tables(). From hugetlb code, we call huge_pmd_unshare_flush() where we make sure that the expected lock protecting us from concurrent unsharing+reuse is still held. Check with a VM_WARN_ON_ONCE() in tlb_finish_mmu() that tlb_flush_unshared_tables() was properly called earlier. Document it all properly. Notes about tlb_remove_table_sync_one() interaction with unsharing: There are two fairly tricky things: (1) tlb_remove_table_sync_one() is a NOP on architectures without CONFIG_MMU_GATHER_RCU_TABLE_FREE. Here, the assumption is that the previous TLB flush would send an IPI to all relevant CPUs. Careful: some architectures like x86 only send IPIs to all relevant CPUs when tlb->freed_tables is set. The relevant architectures should be selecting MMU_GATHER_RCU_TABLE_FREE, but x86 might not do that in stable kernels and it might have been problematic before this patch. Also, the arch flushing behavior (independent of IPIs) is different when tlb->freed_tables is set. Do we have to enlighten them to also take care of tlb->unshared_tables? So far we didn't care, so hopefully we are fine. Of course, we could be setting tlb->freed_tables as well, but that might then unnecessarily flush too much, because the semantics of tlb->freed_tables are a bit fuzzy. This patch changes nothing in this regard. (2) tlb_remove_table_sync_one() is not a NOP on architectures with CONFIG_MMU_GATHER_RCU_TABLE_FREE that actually don't need a sync. Take x86 as an example: in the common case (!pv, !X86_FEATURE_INVLPGB) we still issue IPIs during TLB flushes and don't actually need the second tlb_remove_table_sync_one(). This optimized can be implemented on top of this, by checking e.g., in tlb_remove_table_sync_one() whether we really need IPIs. But as described in (1), it really must honor tlb->freed_tables then to send IPIs to all relevant CPUs. Notes on TLB flushing changes: (1) Flushing for non-shared PMD tables We're converting from flush_hugetlb_tlb_range() to tlb_remove_huge_tlb_entry(). Given that we properly initialize the MMU gather in tlb_gather_mmu_vma() to be hugetlb aware, similar to __unmap_hugepage_range(), that should be fine. (2) Flushing for shared PMD tables We're converting from various things (flush_hugetlb_tlb_range(), tlb_flush_pmd_range(), flush_tlb_range()) to tlb_flush_pmd_range(). tlb_flush_pmd_range() achieves the same that tlb_remove_huge_tlb_entry() would achieve in these scenarios. Note that tlb_remove_huge_tlb_entry() also calls __tlb_remove_tlb_entry(), however that is only implemented on powerpc, which does not support PMD table sharing. Similar to (1), tlb_gather_mmu_vma() should make sure that TLB flushing keeps on working as expected. Further, note that the ptdesc_pmd_pts_dec() in huge_pmd_share() is not a concern, as we are holding the i_mmap_lock the whole time, preventing concurrent unsharing. That ptdesc_pmd_pts_dec() usage will be removed separately as a cleanup later. There are plenty more cleanups to be had, but they have to wait until this is fixed. Fixes: 1013af4f585f ("mm/hugetlb: fix huge_pmd_unshare() vs GUP-fast race") Reported-by: Uschakow, Stanislav" <suschako(a)amazon.de> Closes: https://lore.kernel.org/all/4d3878531c76479d9f8ca9789dc6485d@amazon.de/ Tested-by: Laurence Oberman <loberman(a)redhat.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: David Hildenbrand (Red Hat) <david(a)kernel.org> --- include/asm-generic/tlb.h | 77 +++++++++++++++++++++++- include/linux/hugetlb.h | 15 +++-- include/linux/mm_types.h | 1 + mm/hugetlb.c | 123 ++++++++++++++++++++++---------------- mm/mmu_gather.c | 33 ++++++++++ mm/rmap.c | 25 +++++--- 6 files changed, 208 insertions(+), 66 deletions(-) diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h index 1fff717cae510..4d679d2a206b4 100644 --- a/include/asm-generic/tlb.h +++ b/include/asm-generic/tlb.h @@ -46,7 +46,8 @@ * * The mmu_gather API consists of: * - * - tlb_gather_mmu() / tlb_gather_mmu_fullmm() / tlb_finish_mmu() + * - tlb_gather_mmu() / tlb_gather_mmu_fullmm() / tlb_gather_mmu_vma() / + * tlb_finish_mmu() * * start and finish a mmu_gather * @@ -364,6 +365,20 @@ struct mmu_gather { unsigned int vma_huge : 1; unsigned int vma_pfn : 1; + /* + * Did we unshare (unmap) any shared page tables? For now only + * used for hugetlb PMD table sharing. + */ + unsigned int unshared_tables : 1; + + /* + * Did we unshare any page tables such that they are now exclusive + * and could get reused+modified by the new owner? When setting this + * flag, "unshared_tables" will be set as well. For now only used + * for hugetlb PMD table sharing. + */ + unsigned int fully_unshared_tables : 1; + unsigned int batch_count; #ifndef CONFIG_MMU_GATHER_NO_GATHER @@ -400,6 +415,7 @@ static inline void __tlb_reset_range(struct mmu_gather *tlb) tlb->cleared_pmds = 0; tlb->cleared_puds = 0; tlb->cleared_p4ds = 0; + tlb->unshared_tables = 0; /* * Do not reset mmu_gather::vma_* fields here, we do not * call into tlb_start_vma() again to set them if there is an @@ -484,7 +500,7 @@ static inline void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb) * these bits. */ if (!(tlb->freed_tables || tlb->cleared_ptes || tlb->cleared_pmds || - tlb->cleared_puds || tlb->cleared_p4ds)) + tlb->cleared_puds || tlb->cleared_p4ds || tlb->unshared_tables)) return; tlb_flush(tlb); @@ -773,6 +789,63 @@ static inline bool huge_pmd_needs_flush(pmd_t oldpmd, pmd_t newpmd) } #endif +#ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING +static inline void tlb_unshare_pmd_ptdesc(struct mmu_gather *tlb, struct ptdesc *pt, + unsigned long addr) +{ + /* + * The caller must make sure that concurrent unsharing + exclusive + * reuse is impossible until tlb_flush_unshared_tables() was called. + */ + VM_WARN_ON_ONCE(!ptdesc_pmd_is_shared(pt)); + ptdesc_pmd_pts_dec(pt); + + /* Clearing a PUD pointing at a PMD table with PMD leaves. */ + tlb_flush_pmd_range(tlb, addr & PUD_MASK, PUD_SIZE); + + /* + * If the page table is now exclusively owned, we fully unshared + * a page table. + */ + if (!ptdesc_pmd_is_shared(pt)) + tlb->fully_unshared_tables = true; + tlb->unshared_tables = true; +} + +static inline void tlb_flush_unshared_tables(struct mmu_gather *tlb) +{ + /* + * As soon as the caller drops locks to allow for reuse of + * previously-shared tables, these tables could get modified and + * even reused outside of hugetlb context, so we have to make sure that + * any page table walkers (incl. TLB, GUP-fast) are aware of that + * change. + * + * Even if we are not fully unsharing a PMD table, we must + * flush the TLB for the unsharer now. + */ + if (tlb->unshared_tables) + tlb_flush_mmu_tlbonly(tlb); + + /* + * Similarly, we must make sure that concurrent GUP-fast will not + * walk previously-shared page tables that are getting modified+reused + * elsewhere. So broadcast an IPI to wait for any concurrent GUP-fast. + * + * We only perform this when we are the last sharer of a page table, + * as the IPI will reach all CPUs: any GUP-fast. + * + * Note that on configs where tlb_remove_table_sync_one() is a NOP, + * the expectation is that the tlb_flush_mmu_tlbonly() would have issued + * required IPIs already for us. + */ + if (tlb->fully_unshared_tables) { + tlb_remove_table_sync_one(); + tlb->fully_unshared_tables = false; + } +} +#endif /* CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING */ + #endif /* CONFIG_MMU */ #endif /* _ASM_GENERIC__TLB_H */ diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 03c8725efa289..e51b8ef0cebd9 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -240,8 +240,9 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma, pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, unsigned long sz); unsigned long hugetlb_mask_last_page(struct hstate *h); -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep); +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep); +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma); void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, unsigned long *start, unsigned long *end); @@ -300,13 +301,17 @@ static inline struct address_space *hugetlb_folio_mapping_lock_write( return NULL; } -static inline int huge_pmd_unshare(struct mm_struct *mm, - struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +static inline int huge_pmd_unshare(struct mmu_gather *tlb, + struct vm_area_struct *vma, unsigned long addr, pte_t *ptep) { return 0; } +static inline void huge_pmd_unshare_flush(struct mmu_gather *tlb, + struct vm_area_struct *vma) +{ +} + static inline void adjust_range_if_pmd_sharing_possible( struct vm_area_struct *vma, unsigned long *start, unsigned long *end) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 42af2292951d4..d1053b2c1f800 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -1522,6 +1522,7 @@ static inline unsigned int mm_cid_size(void) struct mmu_gather; extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm); extern void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm); +void tlb_gather_mmu_vma(struct mmu_gather *tlb, struct vm_area_struct *vma); extern void tlb_finish_mmu(struct mmu_gather *tlb); struct vm_fault; diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 3c77cdef12a32..2609b6d58f99e 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -5096,7 +5096,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, unsigned long last_addr_mask; pte_t *src_pte, *dst_pte; struct mmu_notifier_range range; - bool shared_pmd = false; + struct mmu_gather tlb; mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, old_addr, old_end); @@ -5106,6 +5106,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, * range. */ flush_cache_range(vma, range.start, range.end); + tlb_gather_mmu_vma(&tlb, vma); mmu_notifier_invalidate_range_start(&range); last_addr_mask = hugetlb_mask_last_page(h); @@ -5122,8 +5123,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, if (huge_pte_none(huge_ptep_get(mm, old_addr, src_pte))) continue; - if (huge_pmd_unshare(mm, vma, old_addr, src_pte)) { - shared_pmd = true; + if (huge_pmd_unshare(&tlb, vma, old_addr, src_pte)) { old_addr |= last_addr_mask; new_addr |= last_addr_mask; continue; @@ -5134,15 +5134,16 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma, break; move_huge_pte(vma, old_addr, new_addr, src_pte, dst_pte, sz); + tlb_remove_huge_tlb_entry(h, &tlb, src_pte, old_addr); } - if (shared_pmd) - flush_hugetlb_tlb_range(vma, range.start, range.end); - else - flush_hugetlb_tlb_range(vma, old_end - len, old_end); + tlb_flush_mmu_tlbonly(&tlb); + huge_pmd_unshare_flush(&tlb, vma); + mmu_notifier_invalidate_range_end(&range); i_mmap_unlock_write(mapping); hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); return len + old_addr - old_end; } @@ -5161,7 +5162,6 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, unsigned long sz = huge_page_size(h); bool adjust_reservation; unsigned long last_addr_mask; - bool force_flush = false; WARN_ON(!is_vm_hugetlb_page(vma)); BUG_ON(start & ~huge_page_mask(h)); @@ -5184,10 +5184,8 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, } ptl = huge_pte_lock(h, mm, ptep); - if (huge_pmd_unshare(mm, vma, address, ptep)) { + if (huge_pmd_unshare(tlb, vma, address, ptep)) { spin_unlock(ptl); - tlb_flush_pmd_range(tlb, address & PUD_MASK, PUD_SIZE); - force_flush = true; address |= last_addr_mask; continue; } @@ -5303,14 +5301,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma, } tlb_end_vma(tlb, vma); - /* - * There is nothing protecting a previously-shared page table that we - * unshared through huge_pmd_unshare() from getting freed after we - * release i_mmap_rwsem, so flush the TLB now. If huge_pmd_unshare() - * succeeded, flush the range corresponding to the pud. - */ - if (force_flush) - tlb_flush_mmu_tlbonly(tlb); + huge_pmd_unshare_flush(tlb, vma); } void __hugetlb_zap_begin(struct vm_area_struct *vma, @@ -6409,11 +6400,11 @@ long hugetlb_change_protection(struct vm_area_struct *vma, pte_t pte; struct hstate *h = hstate_vma(vma); long pages = 0, psize = huge_page_size(h); - bool shared_pmd = false; struct mmu_notifier_range range; unsigned long last_addr_mask; bool uffd_wp = cp_flags & MM_CP_UFFD_WP; bool uffd_wp_resolve = cp_flags & MM_CP_UFFD_WP_RESOLVE; + struct mmu_gather tlb; /* * In the case of shared PMDs, the area to flush could be beyond @@ -6426,6 +6417,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma, BUG_ON(address >= end); flush_cache_range(vma, range.start, range.end); + tlb_gather_mmu_vma(&tlb, vma); mmu_notifier_invalidate_range_start(&range); hugetlb_vma_lock_write(vma); @@ -6452,7 +6444,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma, } } ptl = huge_pte_lock(h, mm, ptep); - if (huge_pmd_unshare(mm, vma, address, ptep)) { + if (huge_pmd_unshare(&tlb, vma, address, ptep)) { /* * When uffd-wp is enabled on the vma, unshare * shouldn't happen at all. Warn about it if it @@ -6461,7 +6453,6 @@ long hugetlb_change_protection(struct vm_area_struct *vma, WARN_ON_ONCE(uffd_wp || uffd_wp_resolve); pages++; spin_unlock(ptl); - shared_pmd = true; address |= last_addr_mask; continue; } @@ -6522,22 +6513,16 @@ long hugetlb_change_protection(struct vm_area_struct *vma, pte = huge_pte_clear_uffd_wp(pte); huge_ptep_modify_prot_commit(vma, address, ptep, old_pte, pte); pages++; + tlb_remove_huge_tlb_entry(h, &tlb, ptep, address); } next: spin_unlock(ptl); cond_resched(); } - /* - * There is nothing protecting a previously-shared page table that we - * unshared through huge_pmd_unshare() from getting freed after we - * release i_mmap_rwsem, so flush the TLB now. If huge_pmd_unshare() - * succeeded, flush the range corresponding to the pud. - */ - if (shared_pmd) - flush_hugetlb_tlb_range(vma, range.start, range.end); - else - flush_hugetlb_tlb_range(vma, start, end); + + tlb_flush_mmu_tlbonly(&tlb); + huge_pmd_unshare_flush(&tlb, vma); /* * No need to call mmu_notifier_arch_invalidate_secondary_tlbs() we are * downgrading page table protection not changing it to point to a new @@ -6548,6 +6533,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma, i_mmap_unlock_write(vma->vm_file->f_mapping); hugetlb_vma_unlock_write(vma); mmu_notifier_invalidate_range_end(&range); + tlb_finish_mmu(&tlb); return pages > 0 ? (pages << h->order) : pages; } @@ -6904,18 +6890,27 @@ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, return pte; } -/* - * unmap huge page backed by shared pte. +/** + * huge_pmd_unshare - Unmap a pmd table if it is shared by multiple users + * @tlb: the current mmu_gather. + * @vma: the vma covering the pmd table. + * @addr: the address we are trying to unshare. + * @ptep: pointer into the (pmd) page table. + * + * Called with the page table lock held, the i_mmap_rwsem held in write mode + * and the hugetlb vma lock held in write mode. * - * Called with page table lock held. + * Note: The caller must call huge_pmd_unshare_flush() before dropping the + * i_mmap_rwsem. * - * returns: 1 successfully unmapped a shared pte page - * 0 the underlying pte page is not shared, or it is the last user + * Returns: 1 if it was a shared PMD table and it got unmapped, or 0 if it + * was not a shared PMD table. */ -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) { unsigned long sz = huge_page_size(hstate_vma(vma)); + struct mm_struct *mm = vma->vm_mm; pgd_t *pgd = pgd_offset(mm, addr); p4d_t *p4d = p4d_offset(pgd, addr); pud_t *pud = pud_offset(p4d, addr); @@ -6927,18 +6922,36 @@ int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, i_mmap_assert_write_locked(vma->vm_file->f_mapping); hugetlb_vma_assert_locked(vma); pud_clear(pud); - /* - * Once our caller drops the rmap lock, some other process might be - * using this page table as a normal, non-hugetlb page table. - * Wait for pending gup_fast() in other threads to finish before letting - * that happen. - */ - tlb_remove_table_sync_one(); - ptdesc_pmd_pts_dec(virt_to_ptdesc(ptep)); + + tlb_unshare_pmd_ptdesc(tlb, virt_to_ptdesc(ptep), addr); + mm_dec_nr_pmds(mm); return 1; } +/* + * huge_pmd_unshare_flush - Complete a sequence of huge_pmd_unshare() calls + * @tlb: the current mmu_gather. + * @vma: the vma covering the pmd table. + * + * Perform necessary TLB flushes or IPI broadcasts to synchronize PMD table + * unsharing with concurrent page table walkers. + * + * This function must be called after a sequence of huge_pmd_unshare() + * calls while still holding the i_mmap_rwsem. + */ +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + /* + * We must synchronize page table unsharing such that nobody will + * try reusing a previously-shared page table while it might still + * be in use by previous sharers (TLB, GUP_fast). + */ + i_mmap_assert_write_locked(vma->vm_file->f_mapping); + + tlb_flush_unshared_tables(tlb); +} + #else /* !CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING */ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, @@ -6947,12 +6960,16 @@ pte_t *huge_pmd_share(struct mm_struct *mm, struct vm_area_struct *vma, return NULL; } -int huge_pmd_unshare(struct mm_struct *mm, struct vm_area_struct *vma, - unsigned long addr, pte_t *ptep) +int huge_pmd_unshare(struct mmu_gather *tlb, struct vm_area_struct *vma, + unsigned long addr, pte_t *ptep) { return 0; } +void huge_pmd_unshare_flush(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ +} + void adjust_range_if_pmd_sharing_possible(struct vm_area_struct *vma, unsigned long *start, unsigned long *end) { @@ -7219,6 +7236,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, unsigned long sz = huge_page_size(h); struct mm_struct *mm = vma->vm_mm; struct mmu_notifier_range range; + struct mmu_gather tlb; unsigned long address; spinlock_t *ptl; pte_t *ptep; @@ -7230,6 +7248,8 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, return; flush_cache_range(vma, start, end); + tlb_gather_mmu_vma(&tlb, vma); + /* * No need to call adjust_range_if_pmd_sharing_possible(), because * we have already done the PUD_SIZE alignment. @@ -7248,10 +7268,10 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, if (!ptep) continue; ptl = huge_pte_lock(h, mm, ptep); - huge_pmd_unshare(mm, vma, address, ptep); + huge_pmd_unshare(&tlb, vma, address, ptep); spin_unlock(ptl); } - flush_hugetlb_tlb_range(vma, start, end); + huge_pmd_unshare_flush(&tlb, vma); if (take_locks) { i_mmap_unlock_write(vma->vm_file->f_mapping); hugetlb_vma_unlock_write(vma); @@ -7261,6 +7281,7 @@ static void hugetlb_unshare_pmds(struct vm_area_struct *vma, * Documentation/mm/mmu_notifier.rst. */ mmu_notifier_invalidate_range_end(&range); + tlb_finish_mmu(&tlb); } /* diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c index 247e3f9db6c7a..cd32c2dbf501b 100644 --- a/mm/mmu_gather.c +++ b/mm/mmu_gather.c @@ -10,6 +10,7 @@ #include <linux/swap.h> #include <linux/rmap.h> #include <linux/pgalloc.h> +#include <linux/hugetlb.h> #include <asm/tlb.h> @@ -426,6 +427,7 @@ static void __tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, #endif tlb->vma_pfn = 0; + tlb->fully_unshared_tables = 0; __tlb_reset_range(tlb); inc_tlb_flush_pending(tlb->mm); } @@ -459,6 +461,31 @@ void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm) __tlb_gather_mmu(tlb, mm, true); } +/** + * tlb_gather_mmu - initialize an mmu_gather structure for operating on a single + * VMA + * @tlb: the mmu_gather structure to initialize + * @vma: the vm_area_struct + * + * Called to initialize an (on-stack) mmu_gather structure for operating on + * a single VMA. In contrast to tlb_gather_mmu(), calling this function will + * not require another call to tlb_start_vma(). In contrast to tlb_start_vma(), + * this function will *not* call flush_cache_range(). + * + * For hugetlb VMAs, this function will also initialize the mmu_gather + * page_size accordingly, not requiring a separate call to + * tlb_change_page_size(). + * + */ +void tlb_gather_mmu_vma(struct mmu_gather *tlb, struct vm_area_struct *vma) +{ + tlb_gather_mmu(tlb, vma->vm_mm); + tlb_update_vma_flags(tlb, vma); + if (is_vm_hugetlb_page(vma)) + /* All entries have the same size. */ + tlb_change_page_size(tlb, huge_page_size(hstate_vma(vma))); +} + /** * tlb_finish_mmu - finish an mmu_gather structure * @tlb: the mmu_gather structure to finish @@ -468,6 +495,12 @@ void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm) */ void tlb_finish_mmu(struct mmu_gather *tlb) { + /* + * We expect an earlier huge_pmd_unshare_flush() call to sort this out, + * due to complicated locking requirements with page table unsharing. + */ + VM_WARN_ON_ONCE(tlb->fully_unshared_tables); + /* * If there are parallel threads are doing PTE changes on same range * under non-exclusive lock (e.g., mmap_lock read-side) but defer TLB diff --git a/mm/rmap.c b/mm/rmap.c index 748f48727a162..7b9879ef442d9 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -76,7 +76,7 @@ #include <linux/mm_inline.h> #include <linux/oom.h> -#include <asm/tlbflush.h> +#include <asm/tlb.h> #define CREATE_TRACE_POINTS #include <trace/events/migrate.h> @@ -2008,13 +2008,17 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, * if unsuccessful. */ if (!anon) { + struct mmu_gather tlb; + VM_BUG_ON(!(flags & TTU_RMAP_LOCKED)); if (!hugetlb_vma_trylock_write(vma)) goto walk_abort; - if (huge_pmd_unshare(mm, vma, address, pvmw.pte)) { + + tlb_gather_mmu_vma(&tlb, vma); + if (huge_pmd_unshare(&tlb, vma, address, pvmw.pte)) { hugetlb_vma_unlock_write(vma); - flush_tlb_range(vma, - range.start, range.end); + huge_pmd_unshare_flush(&tlb, vma); + tlb_finish_mmu(&tlb); /* * The PMD table was unmapped, * consequently unmapping the folio. @@ -2022,6 +2026,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma, goto walk_done; } hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); } pteval = huge_ptep_clear_flush(vma, address, pvmw.pte); if (pte_dirty(pteval)) @@ -2398,17 +2403,20 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, * fail if unsuccessful. */ if (!anon) { + struct mmu_gather tlb; + VM_BUG_ON(!(flags & TTU_RMAP_LOCKED)); if (!hugetlb_vma_trylock_write(vma)) { page_vma_mapped_walk_done(&pvmw); ret = false; break; } - if (huge_pmd_unshare(mm, vma, address, pvmw.pte)) { - hugetlb_vma_unlock_write(vma); - flush_tlb_range(vma, - range.start, range.end); + tlb_gather_mmu_vma(&tlb, vma); + if (huge_pmd_unshare(&tlb, vma, address, pvmw.pte)) { + hugetlb_vma_unlock_write(vma); + huge_pmd_unshare_flush(&tlb, vma); + tlb_finish_mmu(&tlb); /* * The PMD table was unmapped, * consequently unmapping the folio. @@ -2417,6 +2425,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma, break; } hugetlb_vma_unlock_write(vma); + tlb_finish_mmu(&tlb); } /* Nuke the hugetlb page table entry */ pteval = huge_ptep_clear_flush(vma, address, pvmw.pte); -- 2.52.0

2 days, 16 hours

1
0
0 0

[PATCH 1/2] ublk: add UBLK_F_NO_AUTO_PART_SCAN feature flag

by Ming Lei

Add a new feature flag UBLK_F_NO_AUTO_PART_SCAN to allow users to suppress automatic partition scanning when starting a ublk device. This is useful for network-backed devices where partition scanning can cause issues: - Partition scan triggers synchronous I/O during device startup - If userspace server crashes during scan, recovery is problematic - For remotely-managed devices, partition probing may not be needed Users can manually trigger partition scanning later when appropriate using standard tools (e.g., partprobe, blockdev --rereadpt). Reported-by: Yoav Cohen <yoav(a)nvidia.com> Link: https://lore.kernel.org/linux-block/DM4PR12MB63280C5637917C071C2F0D65A9A8A@… Cc: stable(a)vger.kernel.org Signed-off-by: Ming Lei <ming.lei(a)redhat.com> --- - suggest to backport to stable, which is useful for avoiding problematic recovery, also the change is simple enough drivers/block/ublk_drv.c | 16 +++++++++++++--- include/uapi/linux/ublk_cmd.h | 8 ++++++++ 2 files changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 78f3e22151b9..ca6ec8ed443f 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -73,7 +73,8 @@ | UBLK_F_AUTO_BUF_REG \ | UBLK_F_QUIESCE \ | UBLK_F_PER_IO_DAEMON \ - | UBLK_F_BUF_REG_OFF_DAEMON) + | UBLK_F_BUF_REG_OFF_DAEMON \ + | UBLK_F_NO_AUTO_PART_SCAN) #define UBLK_F_ALL_RECOVERY_FLAGS (UBLK_F_USER_RECOVERY \ | UBLK_F_USER_RECOVERY_REISSUE \ @@ -2930,8 +2931,13 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, ublk_apply_params(ub); - /* don't probe partitions if any daemon task is un-trusted */ - if (ub->unprivileged_daemons) + /* + * Don't probe partitions if: + * - any daemon task is un-trusted, or + * - user explicitly requested to suppress partition scan + */ + if (ub->unprivileged_daemons || + (ub->dev_info.flags & UBLK_F_NO_AUTO_PART_SCAN)) set_bit(GD_SUPPRESS_PART_SCAN, &disk->state); ublk_get_device(ub); @@ -2947,6 +2953,10 @@ static int ublk_ctrl_start_dev(struct ublk_device *ub, if (ret) goto out_put_cdev; + /* allow user to probe partitions from userspace */ + if (!ub->unprivileged_daemons && + (ub->dev_info.flags & UBLK_F_NO_AUTO_PART_SCAN)) + clear_bit(GD_SUPPRESS_PART_SCAN, &disk->state); set_bit(UB_STATE_USED, &ub->state); out_put_cdev: diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index ec77dabba45b..0827db14a215 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -311,6 +311,14 @@ */ #define UBLK_F_BUF_REG_OFF_DAEMON (1ULL << 14) +/* + * If this feature is set, the kernel will not automatically scan for partitions + * when the device is started. This is useful for network-backed devices where + * partition scanning can cause deadlocks if the userspace server crashes during + * the scan. Users can manually trigger partition scanning later when appropriate. + */ +#define UBLK_F_NO_AUTO_PART_SCAN (1ULL << 15) + /* device state */ #define UBLK_S_DEV_DEAD 0 #define UBLK_S_DEV_LIVE 1 -- 2.47.0

2 days, 17 hours

2
3
0 0

[alternative-merged] buildid-validate-page-backed-file-before-parsing-build-id.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: buildid: validate page-backed file before parsing build ID has been removed from the -mm tree. Its filename was buildid-validate-page-backed-file-before-parsing-build-id.patch This patch was dropped because an alternative patch was or shall be merged ------------------------------------------------------ From: Jinchao Wang <wangjinchao600(a)gmail.com> Subject: buildid: validate page-backed file before parsing build ID Date: Tue, 23 Dec 2025 18:32:07 +0800 __build_id_parse() only works on page-backed storage. Its helper paths eventually call mapping->a_ops->read_folio(), so explicitly reject VMAs that do not map a regular file or lack valid address_space operations. Link: https://lkml.kernel.org/r/20251223103214.2412446-1-wangjinchao600@gmail.com Fixes: ad41251c290d ("lib/buildid: implement sleepable build_id_parse() API") Signed-off-by: Jinchao Wang <wangjinchao600(a)gmail.com> Reported-by: <syzbot+e008db2ac01e282550ee(a)syzkaller.appspotmail.com> Tested-by: <syzbot+e008db2ac01e282550ee(a)syzkaller.appspotmail.com> Link: https://lkml.kernel.org/r/694a67ab.050a0220.19928e.001c.GAE@google.com Closes: https://lkml.kernel.org/r/693540fe.a70a0220.38f243.004c.GAE@google.com Cc: Axel Rasmussen <axelrasmussen(a)google.com> Cc: David Hildenbrand (Red Hat) <david(a)kernel.org> Cc: Johannes Weiner <hannes(a)cmpxchg.org> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Michal Hocko <mhocko(a)kernel.org> Cc: Qi Zheng <zhengqi.arch(a)bytedance.com> Cc: Shakeel Butt <shakeel.butt(a)linux.dev> Cc: Wei Xu <weixugc(a)google.com> Cc: Yuanchu Xie <yuanchu(a)google.com> Cc: Andrii Nakryiko <andrii(a)kernel.org> Cc: Eduard Zingerman <eddyz87(a)gmail.com> Cc: Omar Sandoval <osandov(a)fb.com> Cc: Deepanshu Kartikey <kartikey406(a)gmail.com> Cc: Alexei Starovoitov <ast(a)kernel.org> Cc: Daniel Borkman <daniel(a)iogearbox.net> Cc: Hao Luo <haoluo(a)google.com> Cc: Jiri Olsa <jolsa(a)kernel.org> Cc: John Fastabend <john.fastabend(a)gmail.com> Cc: KP Singh <kpsingh(a)kernel.org> Cc: Martin KaFai Lau <martin.lau(a)linux.dev> Cc: Song Liu <song(a)kernel.org> Cc: Stanislav Fomichev <sdf(a)fomichev.me> Cc: Yonghong Song <yonghong.song(a)linux.dev> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- lib/buildid.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/lib/buildid.c~buildid-validate-page-backed-file-before-parsing-build-id +++ a/lib/buildid.c @@ -288,7 +288,10 @@ static int __build_id_parse(struct vm_ar int ret; /* only works for page backed storage */ - if (!vma->vm_file) + if (!vma->vm_file || + !S_ISREG(file_inode(vma->vm_file)->i_mode) || + !vma->vm_file->f_mapping->a_ops || + !vma->vm_file->f_mapping->a_ops->read_folio) return -EINVAL; freader_init_from_file(&r, buf, sizeof(buf), vma->vm_file, may_fault); _ Patches currently in -mm which might be from wangjinchao600(a)gmail.com are

2 days, 18 hours

1
0
0 0

[merged mm-hotfixes-stable] mm-page_owner-fix-memory-leak-in-page_owner_stack_fops-release.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/page_owner: fix memory leak in page_owner_stack_fops->release() has been removed from the -mm tree. Its filename was mm-page_owner-fix-memory-leak-in-page_owner_stack_fops-release.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Ran Xiaokai <ran.xiaokai(a)zte.com.cn> Subject: mm/page_owner: fix memory leak in page_owner_stack_fops->release() Date: Fri, 19 Dec 2025 07:42:32 +0000 The page_owner_stack_fops->open() callback invokes seq_open_private(), therefore its corresponding ->release() callback must call seq_release_private(). Otherwise it will cause a memory leak of struct stack_print_ctx. Link: https://lkml.kernel.org/r/20251219074232.136482-1-ranxiaokai627@163.com Fixes: 765973a09803 ("mm,page_owner: display all stacks and their count") Signed-off-by: Ran Xiaokai <ran.xiaokai(a)zte.com.cn> Acked-by: Michal Hocko <mhocko(a)suse.com> Acked-by: Vlastimil Babka <vbabka(a)suse.cz> Cc: Andrey Konovalov <andreyknvl(a)gmail.com> Cc: Brendan Jackman <jackmanb(a)google.com> Cc: Johannes Weiner <hannes(a)cmpxchg.org> Cc: Marco Elver <elver(a)google.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Zi Yan <ziy(a)nvidia.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/page_owner.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/page_owner.c~mm-page_owner-fix-memory-leak-in-page_owner_stack_fops-release +++ a/mm/page_owner.c @@ -952,7 +952,7 @@ static const struct file_operations page .open = page_owner_stack_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release, + .release = seq_release_private, }; static int page_owner_threshold_get(void *data, u64 *val) _ Patches currently in -mm which might be from ran.xiaokai(a)zte.com.cn are

2 days, 18 hours

1
0
0 0

[merged mm-hotfixes-stable] mm-consider-non-anon-swap-cache-folios-in-folio_expected_ref_count.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm: consider non-anon swap cache folios in folio_expected_ref_count() has been removed from the -mm tree. Its filename was mm-consider-non-anon-swap-cache-folios-in-folio_expected_ref_count.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Bijan Tabatabai <bijan311(a)gmail.com> Subject: mm: consider non-anon swap cache folios in folio_expected_ref_count() Date: Tue, 16 Dec 2025 14:07:27 -0600 Currently, folio_expected_ref_count() only adds references for the swap cache if the folio is anonymous. However, according to the comment above the definition of PG_swapcache in enum pageflags, shmem folios can also have PG_swapcache set. This patch makes sure references for the swap cache are added if folio_test_swapcache(folio) is true. This issue was found when trying to hot-unplug memory in a QEMU/KVM virtual machine. When initiating hot-unplug when most of the guest memory is allocated, hot-unplug hangs partway through removal due to migration failures. The following message would be printed several times, and would be printed again about every five seconds: [ 49.641309] migrating pfn b12f25 failed ret:7 [ 49.641310] page: refcount:2 mapcount:0 mapping:0000000033bd8fe2 index:0x7f404d925 pfn:0xb12f25 [ 49.641311] aops:swap_aops [ 49.641313] flags: 0x300000000030508(uptodate|active|owner_priv_1|reclaim|swapbacked|node=0|zone=3) [ 49.641314] raw: 0300000000030508 ffffed312c4bc908 ffffed312c4bc9c8 0000000000000000 [ 49.641315] raw: 00000007f404d925 00000000000c823b 00000002ffffffff 0000000000000000 [ 49.641315] page dumped because: migration failure When debugging this, I found that these migration failures were due to __migrate_folio() returning -EAGAIN for a small set of folios because the expected reference count it calculates via folio_expected_ref_count() is one less than the actual reference count of the folios. Furthermore, all of the affected folios were not anonymous, but had the PG_swapcache flag set, inspiring this patch. After applying this patch, the memory hot-unplug behaves as expected. I tested this on a machine running Ubuntu 24.04 with kernel version 6.8.0-90-generic and 64GB of memory. The guest VM is managed by libvirt and runs Ubuntu 24.04 with kernel version 6.18 (though the head of the mm-unstable branch as a Dec 16, 2025 was also tested and behaves the same) and 48GB of memory. The libvirt XML definition for the VM can be found at [1]. CONFIG_MHP_DEFAULT_ONLINE_TYPE_ONLINE_MOVABLE is set in the guest kernel so the hot-pluggable memory is automatically onlined. Below are the steps to reproduce this behavior: 1) Define and start and virtual machine host$ virsh -c qemu:///system define ./test_vm.xml # test_vm.xml from [1] host$ virsh -c qemu:///system start test_vm 2) Setup swap in the guest guest$ sudo fallocate -l 32G /swapfile guest$ sudo chmod 0600 /swapfile guest$ sudo mkswap /swapfile guest$ sudo swapon /swapfile 3) Use alloc_data [2] to allocate most of the remaining guest memory guest$ ./alloc_data 45 4) In a separate guest terminal, monitor the amount of used memory guest$ watch -n1 free -h 5) When alloc_data has finished allocating, initiate the memory hot-unplug using the provided xml file [3] host$ virsh -c qemu:///system detach-device test_vm ./remove.xml --live After initiating the memory hot-unplug, you should see the amount of available memory in the guest decrease, and the amount of used swap data increase. If everything works as expected, when all of the memory is unplugged, there should be around 8.5-9GB of data in swap. If the unplugging is unsuccessful, the amount of used swap data will settle below that. If that happens, you should be able to see log messages in dmesg similar to the one posted above. Link: https://lkml.kernel.org/r/20251216200727.2360228-1-bijan311@gmail.com Link: https://github.com/BijanT/linux_patch_files/blob/main/test_vm.xml [1] Link: https://github.com/BijanT/linux_patch_files/blob/main/alloc_data.c [2] Link: https://github.com/BijanT/linux_patch_files/blob/main/remove.xml [3] Fixes: 86ebd50224c0 ("mm: add folio_expected_ref_count() for reference count calculation") Signed-off-by: Bijan Tabatabai <bijan311(a)gmail.com> Acked-by: David Hildenbrand (Red Hat) <david(a)kernel.org> Acked-by: Zi Yan <ziy(a)nvidia.com> Reviewed-by: Baolin Wang <baolin.wang(a)linux.alibaba.com> Cc: Liam Howlett <liam.howlett(a)oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes(a)oracle.com> Cc: Michal Hocko <mhocko(a)suse.com> Cc: Mike Rapoport <rppt(a)kernel.org> Cc: Shivank Garg <shivankg(a)amd.com> Cc: Suren Baghdasaryan <surenb(a)google.com> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Kairui Song <ryncsn(a)gmail.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- include/linux/mm.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) --- a/include/linux/mm.h~mm-consider-non-anon-swap-cache-folios-in-folio_expected_ref_count +++ a/include/linux/mm.h @@ -2459,10 +2459,10 @@ static inline int folio_expected_ref_cou if (WARN_ON_ONCE(page_has_type(&folio->page) && !folio_test_hugetlb(folio))) return 0; - if (folio_test_anon(folio)) { - /* One reference per page from the swapcache. */ - ref_count += folio_test_swapcache(folio) << order; - } else { + /* One reference per page from the swapcache. */ + ref_count += folio_test_swapcache(folio) << order; + + if (!folio_test_anon(folio)) { /* One reference per page from the pagecache. */ ref_count += !!folio->mapping << order; /* One reference from PG_private. */ _ Patches currently in -mm which might be from bijan311(a)gmail.com are

2 days, 18 hours

1
0
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror