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[PATCH OLK-6.6 00/19] Memory access profiler(SPE) driven NUMA balancing and damon
by Ze Zuo 18 May '25

18 May '25

Hi, In Arm processors, there is a hardware PMU (Performance Monitoring Unit) facility called Statistical Profiling Extension (SPE) that can gather memory access metrics. In this patchset, SPE is exploited as an access information sampling approach to drive NUMA balancing. This sampling approach is introducedto replace the method based on address space scanning and hint faults with the access information provided by the hardware. With this, it is no longer necessary for NUMA balancing to scan over the address space periodically and rely on task-to-page association built by NUMA hint faults. Instead, the access samples obtained from hardware PMU are fed to NUMA balancing as equivalents to page fault. Except for the replaced sampling approach, the rest of the NUMA balancing policy is retained to do pages and tasks migrations according to the samples. Profiling based on SPE is an valid alternative sampling approach in NUMA balancing for the optimal page and task placement. This can be also extended to other architectures as long as there is a hardware PMU that supports memory access profiling. An abstract layer mem_sampling is introduced to reserve support for other kernel features and different types of hardware PMU. To help evaluate performance of this approach in system, syctl interfaces are added to enable/disable hardware mem sampling. NUMA balancing sampling approach can be also switched back to hint-faults- based approach dynamically. TODOs Currently, SPE for NUMA balance does not support PMD-level page migration, but it will be supported in later version. Ze Zuo (19): mm_monitor/mm_spe: Introduce standalone SPE profiling framework mm_monitor/mm_spe: Init per-CPU buffers and SPE state mm_monitor/mm_spe: Add PMU based memory sampling abstract layer mm_monitor/mm_spe: Introduce arm_spe_user to abstract SPE usage mm/mem_sampling: Add eBPF interface for memory access tracing mm/mem_sampling: Add sched switch hook to control sampling state sched: Enable per-process mem_sampling from sched switch path mm/mem_sampling:: Add proc and cmdline interface to control sampling enable mm/numa: Use mem_sampling framework for NUMA balancing mm/numa: Enable mem_sampling-based access tracking for NUMA balancing mm/mem_sampling: Add sysctl control for NUMA balancing integration mm/numa: Add tracepoints for access sampling and NUMA page migration mm/damon/vaddr: Support hardware-assisted memory access sampling mm/damon/vaddr: Extend mem_sampling sysctl to support DAMON mm/damon/vaddr: Add demotion interface for migrating cold pages to target nodemask arm-spe: Boost SPE add TLB hot page and remote access tracking arm-spe: Add kernel cmdline option to enable SPE boost arm-spe: Export boost SPE sampling info via tracefs tracepoint config: Enable memory sampling based pmu for numa balance and damon by default arch/arm64/configs/openeuler_defconfig | 4 + drivers/Kconfig | 2 + drivers/Makefile | 2 + drivers/arm/Kconfig | 2 + drivers/arm/mm_monitor/Kconfig | 20 + drivers/arm/mm_monitor/Makefile | 2 + drivers/arm/mm_monitor/mm_spe.c | 537 +++++++++++++++ drivers/arm/mm_monitor/mm_spe.h | 102 +++ drivers/arm/mm_monitor/spe-decoder/Makefile | 2 + .../mm_monitor/spe-decoder/arm-spe-decoder.c | 224 +++++++ .../mm_monitor/spe-decoder/arm-spe-decoder.h | 75 +++ .../spe-decoder/arm-spe-pkt-decoder.c | 227 +++++++ .../spe-decoder/arm-spe-pkt-decoder.h | 158 +++++ drivers/perf/arm_pmu_acpi.c | 31 + drivers/perf/arm_spe_pmu.c | 112 +++- include/linux/damon.h | 8 + include/linux/mem_sampling.h | 125 ++++ include/linux/mempolicy.h | 2 + include/linux/migrate_mode.h | 1 + include/linux/mm_types.h | 4 + include/trace/events/kmem.h | 112 ++++ include/trace/events/migrate.h | 3 +- kernel/fork.c | 3 + kernel/sched/core.c | 2 + kernel/sched/fair.c | 13 + mm/Kconfig | 28 + mm/Makefile | 1 + mm/damon/Kconfig | 14 + mm/damon/core.c | 34 + mm/damon/sysfs-schemes.c | 40 ++ mm/damon/vaddr.c | 127 ++++ mm/mem_sampling.c | 614 ++++++++++++++++++ mm/mempolicy.c | 146 +++++ 33 files changed, 2775 insertions(+), 2 deletions(-) create mode 100644 drivers/arm/Kconfig create mode 100644 drivers/arm/mm_monitor/Kconfig create mode 100644 drivers/arm/mm_monitor/Makefile create mode 100644 drivers/arm/mm_monitor/mm_spe.c create mode 100644 drivers/arm/mm_monitor/mm_spe.h create mode 100644 drivers/arm/mm_monitor/spe-decoder/Makefile create mode 100644 drivers/arm/mm_monitor/spe-decoder/arm-spe-decoder.c create mode 100644 drivers/arm/mm_monitor/spe-decoder/arm-spe-decoder.h create mode 100644 drivers/arm/mm_monitor/spe-decoder/arm-spe-pkt-decoder.c create mode 100644 drivers/arm/mm_monitor/spe-decoder/arm-spe-pkt-decoder.h create mode 100644 include/linux/mem_sampling.h create mode 100644 mm/mem_sampling.c -- 2.25.1

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[openeuler:openEuler-1.0-LTS 1640/1640] kismet: WARNING: unmet direct dependencies detected for UACCE when selected by CRYPTO_DEV_HISI_QM
by kernel test robot 18 May '25

18 May '25

tree: https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS head: 9f24885126c03082a677c4d607a2e3502781c858 commit: c89f49b5f6b23b319f338f7e9e7e9b077ec8f5ff [1640/1640] crypto: hisilicon delete invlaid api and config config: arm64-kismet-CONFIG_UACCE-CONFIG_CRYPTO_DEV_HISI_QM-0-0 (https://download.01.org/0day-ci/archive/20250518/202505180330.wT5fsdK9-lkp@…) reproduce: (https://download.01.org/0day-ci/archive/20250518/202505180330.wT5fsdK9-lkp@…) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp(a)intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202505180330.wT5fsdK9-lkp@intel.com/ kismet warnings: (new ones prefixed by >>) >> kismet: WARNING: unmet direct dependencies detected for UACCE when selected by CRYPTO_DEV_HISI_QM WARNING: unmet direct dependencies detected for PINCTRL_EXYNOS Depends on [n]: PINCTRL [=y] && OF [=y] && GPIOLIB [=n] && (ARCH_EXYNOS [=y] || ARCH_S5PV210) Selected by [y]: - ARCH_EXYNOS [=y] WARNING: unmet direct dependencies detected for UACCE Depends on [n]: IOMMU_API [=n] Selected by [y]: - CRYPTO_DEV_HISI_QM [=y] && CRYPTO [=y] && CRYPTO_HW [=y] && ARM64 [=y] && PCI [=y] -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki

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[PATCH openEuler-1.0-LTS] dm crypt: add cond_resched() to dmcrypt_write()
by Zheng Qixing 17 May '25

17 May '25

From: Mikulas Patocka <mpatocka(a)redhat.com> stable inclusion from stable-v4.19.280 commit 7b9f8efb5fc888dd938d2964e705b8e00f1dc0f6 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IC5DGE CVE: CVE-2023-53051 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… ------------------ commit fb294b1c0ba982144ca467a75e7d01ff26304e2b upstream. The loop in dmcrypt_write may be running for unbounded amount of time, thus we need cond_resched() in it. This commit fixes the following warning: [ 3391.153255][ C12] watchdog: BUG: soft lockup - CPU#12 stuck for 23s! [dmcrypt_write/2:2897] ... [ 3391.387210][ C12] Call trace: [ 3391.390338][ C12] blk_attempt_bio_merge.part.6+0x38/0x158 [ 3391.395970][ C12] blk_attempt_plug_merge+0xc0/0x1b0 [ 3391.401085][ C12] blk_mq_submit_bio+0x398/0x550 [ 3391.405856][ C12] submit_bio_noacct+0x308/0x380 [ 3391.410630][ C12] dmcrypt_write+0x1e4/0x208 [dm_crypt] [ 3391.416005][ C12] kthread+0x130/0x138 [ 3391.419911][ C12] ret_from_fork+0x10/0x18 Reported-by: yangerkun <yangerkun(a)huawei.com> Fixes: dc2676210c42 ("dm crypt: offload writes to thread") Cc: stable(a)vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka(a)redhat.com> Signed-off-by: Mike Snitzer <snitzer(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Zheng Qixing <zhengqixing(a)huawei.com> --- drivers/md/dm-crypt.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index fee23d3e2eba..be1ec17a0a4e 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1661,6 +1661,7 @@ static int dmcrypt_write(void *data) io = crypt_io_from_node(rb_first(&write_tree)); rb_erase(&io->rb_node, &write_tree); kcryptd_io_write(io); + cond_resched(); } while (!RB_EMPTY_ROOT(&write_tree)); blk_finish_plug(&plug); } -- 2.39.2

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[PATCH OLK-6.6 v3 00/11] IPIV-BUGFIX for HIP12
by Jinqian Yang 17 May '25

17 May '25

Compared with the previous IPIV, the IPIV-BUGFIX has the following changes: 1. Use Kconfig to Control whether to enable IPIV. 2. Users use ioctl to control whether to enable IPIV. 3. Use the SMCCC interface for Guest OS to control whether to enable IPIV. 4. ensure that enable_ipiv_from_guest are the same before and after live migration 5. make sure vcpu_id == vcpu_idx. 6. the MPIDR cannot be changed When IPIV is enabled. 7. fix bug that ipiv enable is displayed on the host when "kvm-arm.vgic_v4_enable=0 kvm-arm.ipiv_enabled=1" is configured. 8. Add Exception Printing Jinqian Yang (5): arm64/config: add config to control whether enable IPIV feature KVM: arm64: fix live migration bug of IPIv KVM: arm64: using kvm_vgic_global_state for ipiv kvm: hisi: print error for IPIV arm64/kabi: use KABI_EXTEND to skip KABI check Zhou Wang (6): KVM: arm64: Introduce ipiv enable ioctl KVM: arm64: Document PV-sgi interface KVM: arm64: Implement PV_SGI related calls irqchip/gic: Add HiSilicon PV SGI support kvm: hisi: make sure vcpu_id and vcpu_idx have same value in IPIv kvm: hisi: Don't allow to change mpidr in IPIv Documentation/virt/kvm/arm/hypercalls.rst | 4 ++ Documentation/virt/kvm/arm/pvsgi.rst | 33 ++++++++++++++ arch/arm64/Kconfig | 13 ++++++ arch/arm64/configs/openeuler_defconfig | 1 + arch/arm64/include/asm/kvm_host.h | 3 ++ arch/arm64/include/uapi/asm/kvm.h | 5 +++ arch/arm64/kvm/arm.c | 36 +++++++++++---- arch/arm64/kvm/hisilicon/hisi_virt.c | 32 ++++++++++++- arch/arm64/kvm/hisilicon/hisi_virt.h | 20 +++++++-- arch/arm64/kvm/hypercalls.c | 26 +++++++++++ arch/arm64/kvm/sys_regs.c | 34 +++++++++----- arch/arm64/kvm/vgic/vgic-init.c | 42 ++++++++++++++--- arch/arm64/kvm/vgic/vgic-its.c | 19 ++++++++ arch/arm64/kvm/vgic/vgic-mmio-v3.c | 1 - drivers/irqchip/irq-gic-v3-its.c | 50 ++++++++++++++------- drivers/irqchip/irq-gic-v3.c | 55 ++++++++++++++++++----- include/linux/arm-smccc.h | 15 +++++++ include/linux/irqchip/arm-gic-v3.h | 10 +++++ include/linux/irqchip/arm-gic-v4.h | 5 ++- include/uapi/linux/kvm.h | 2 +- 20 files changed, 348 insertions(+), 58 deletions(-) create mode 100644 Documentation/virt/kvm/arm/pvsgi.rst -- 2.33.0

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[PATCH OLK-6.6 v3 00/11] IPIV-BUGFIX for HIP12
by Jinqian Yang 17 May '25

17 May '25

Compared with the previous IPIV, the IPIV-BUGFIX has the following changes: 1. Use Kconfig to Control whether to enable IPIV. 2. Users use ioctl to control whether to enable IPIV. 3. Use the SMCCC interface for Guest OS to control whether to enable IPIV. 4. ensure that enable_ipiv_from_guest are the same before and after live migration 5. make sure vcpu_id == vcpu_idx. 6. the MPIDR cannot be changed When IPIV is enabled. 7. fix bug that ipiv enable is displayed on the host when "kvm-arm.vgic_v4_enable=0 kvm-arm.ipiv_enabled=1" is configured. 8. Add Exception Printing Jinqian Yang (5): arm64/config: add config to control whether enable IPIV feature KVM: arm64: fix live migration bug of IPIv KVM: arm64: using kvm_vgic_global_state for ipiv kvm: hisi: print error for IPIV arm64/kabi: use KABI_EXTEND to skip KABI check Zhou Wang (6): KVM: arm64: Introduce ipiv enable ioctl KVM: arm64: Document PV-sgi interface KVM: arm64: Implement PV_SGI related calls irqchip/gic: Add HiSilicon PV SGI support kvm: hisi: make sure vcpu_id and vcpu_idx have same value in IPIv kvm: hisi: Don't allow to change mpidr in IPIv Documentation/virt/kvm/arm/hypercalls.rst | 4 ++ Documentation/virt/kvm/arm/pvsgi.rst | 33 ++++++++++++++ arch/arm64/Kconfig | 13 ++++++ arch/arm64/configs/openeuler_defconfig | 1 + arch/arm64/include/asm/kvm_host.h | 3 ++ arch/arm64/include/uapi/asm/kvm.h | 5 +++ arch/arm64/kvm/arm.c | 36 +++++++++++---- arch/arm64/kvm/hisilicon/hisi_virt.c | 32 ++++++++++++- arch/arm64/kvm/hisilicon/hisi_virt.h | 20 +++++++-- arch/arm64/kvm/hypercalls.c | 26 +++++++++++ arch/arm64/kvm/sys_regs.c | 34 +++++++++----- arch/arm64/kvm/vgic/vgic-init.c | 42 ++++++++++++++--- arch/arm64/kvm/vgic/vgic-its.c | 19 ++++++++ arch/arm64/kvm/vgic/vgic-mmio-v3.c | 1 - drivers/irqchip/irq-gic-v3-its.c | 50 ++++++++++++++------- drivers/irqchip/irq-gic-v3.c | 55 ++++++++++++++++++----- include/linux/arm-smccc.h | 15 +++++++ include/linux/irqchip/arm-gic-v3.h | 10 +++++ include/linux/irqchip/arm-gic-v4.h | 5 ++- include/uapi/linux/kvm.h | 2 +- 20 files changed, 348 insertions(+), 58 deletions(-) create mode 100644 Documentation/virt/kvm/arm/pvsgi.rst -- 2.33.0

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[PATCH OLK-6.6] drm/amd/display: prevent hang on link training fail
by Jinjie Ruan 17 May '25

17 May '25

From: Brendan Tam <Brendan.Tam(a)amd.com> stable inclusion from stable-v6.12.25 commit 0363c03672cd3191f037905bf981eb523a3b71b1 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IC6LSF CVE: CVE-2025-37870 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 8058061ed9d6bc259d1e678607b07d259342c08f upstream. [Why] When link training fails, the phy clock will be disabled. However, in enable_streams, it is assumed that link training succeeded and the mux selects the phy clock, causing a hang when a register write is made. [How] When enable_stream is hit, check if link training failed. If it did, fall back to the ref clock to avoid a hang and keep the system in a recoverable state. Reviewed-by: Dillon Varone <dillon.varone(a)amd.com> Signed-off-by: Brendan Tam <Brendan.Tam(a)amd.com> Signed-off-by: Aurabindo Pillai <aurabindo.pillai(a)amd.com> Tested-by: Daniel Wheeler <daniel.wheeler(a)amd.com> Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com> Cc: stable(a)vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Conflicts: drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c drivers/gpu/drm/amd/display/dc/hwss/dcn20/dcn20_hwseq.c drivers/gpu/drm/amd/display/dc/hwss/dcn401/dcn401_hwseq.c [The bug in dcn401_hwseq.c is not introduced and the dcn20_hwseq.c has changed the file path.] Signed-off-by: Jinjie Ruan <ruanjinjie(a)huawei.com> --- drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c index 509e0fd52491..8682c01b922a 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c @@ -2749,7 +2749,11 @@ void dcn20_enable_stream(struct pipe_ctx *pipe_ctx) dccg->funcs->set_dpstreamclk(dccg, DTBCLK0, tg->inst, dp_hpo_inst); phyd32clk = get_phyd32clk_src(link); - dccg->funcs->enable_symclk32_se(dccg, dp_hpo_inst, phyd32clk); + if (link->cur_link_settings.link_rate == LINK_RATE_UNKNOWN) { + dccg->funcs->disable_symclk32_se(dccg, dp_hpo_inst); + } else { + dccg->funcs->enable_symclk32_se(dccg, dp_hpo_inst, phyd32clk); + } } else { } if (hws->funcs.calculate_dccg_k1_k2_values && dc->res_pool->dccg->funcs->set_pixel_rate_div) { -- 2.34.1

2 1

[PATCH OLK-5.10] mfd: ene-kb3930: Fix a potential NULL pointer dereference
by Luo Gengkun 17 May '25

17 May '25

From: Chenyuan Yang <chenyuan0y(a)gmail.com> stable inclusion from stable-v5.10.237 commit ea07760676bba49319d553af80c239da053b5fb1 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IC5BIQ CVE: CVE-2025-23146 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 4cdf1d2a816a93fa02f7b6b5492dc7f55af2a199 upstream. The off_gpios could be NULL. Add missing check in the kb3930_probe(). This is similar to the issue fixed in commit b1ba8bcb2d1f ("backlight: hx8357: Fix potential NULL pointer dereference"). This was detected by our static analysis tool. Cc: stable(a)vger.kernel.org Fixes: ede6b2d1dfc0 ("mfd: ene-kb3930: Add driver for ENE KB3930 Embedded Controller") Suggested-by: Lee Jones <lee(a)kernel.org> Signed-off-by: Chenyuan Yang <chenyuan0y(a)gmail.com> Link: https://lore.kernel.org/r/20250224233736.1919739-1-chenyuan0y@gmail.com Signed-off-by: Lee Jones <lee(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Luo Gengkun <luogengkun2(a)huawei.com> --- drivers/mfd/ene-kb3930.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mfd/ene-kb3930.c b/drivers/mfd/ene-kb3930.c index 1c32ff586816..148b2c0523ee 100644 --- a/drivers/mfd/ene-kb3930.c +++ b/drivers/mfd/ene-kb3930.c @@ -162,7 +162,7 @@ static int kb3930_probe(struct i2c_client *client) devm_gpiod_get_array_optional(dev, "off", GPIOD_IN); if (IS_ERR(ddata->off_gpios)) return PTR_ERR(ddata->off_gpios); - if (ddata->off_gpios->ndescs < 2) { + if (ddata->off_gpios && ddata->off_gpios->ndescs < 2) { dev_err(dev, "invalid off-gpios property\n"); return -EINVAL; } -- 2.34.1

2 1

[PATCH OLK-6.6] mfd: ene-kb3930: Fix a potential NULL pointer dereference
by Luo Gengkun 17 May '25

17 May '25

From: Chenyuan Yang <chenyuan0y(a)gmail.com> stable inclusion from stable-v6.6.88 commit ea07760676bba49319d553af80c239da053b5fb1 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IC5BIQ CVE: CVE-2025-23146 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 4cdf1d2a816a93fa02f7b6b5492dc7f55af2a199 upstream. The off_gpios could be NULL. Add missing check in the kb3930_probe(). This is similar to the issue fixed in commit b1ba8bcb2d1f ("backlight: hx8357: Fix potential NULL pointer dereference"). This was detected by our static analysis tool. Cc: stable(a)vger.kernel.org Fixes: ede6b2d1dfc0 ("mfd: ene-kb3930: Add driver for ENE KB3930 Embedded Controller") Suggested-by: Lee Jones <lee(a)kernel.org> Signed-off-by: Chenyuan Yang <chenyuan0y(a)gmail.com> Link: https://lore.kernel.org/r/20250224233736.1919739-1-chenyuan0y@gmail.com Signed-off-by: Lee Jones <lee(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Luo Gengkun <luogengkun2(a)huawei.com> --- drivers/mfd/ene-kb3930.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mfd/ene-kb3930.c b/drivers/mfd/ene-kb3930.c index fa0ad2f14a39..9460a67acb0b 100644 --- a/drivers/mfd/ene-kb3930.c +++ b/drivers/mfd/ene-kb3930.c @@ -162,7 +162,7 @@ static int kb3930_probe(struct i2c_client *client) devm_gpiod_get_array_optional(dev, "off", GPIOD_IN); if (IS_ERR(ddata->off_gpios)) return PTR_ERR(ddata->off_gpios); - if (ddata->off_gpios->ndescs < 2) { + if (ddata->off_gpios && ddata->off_gpios->ndescs < 2) { dev_err(dev, "invalid off-gpios property\n"); return -EINVAL; } -- 2.34.1

2 1

[PATCH OLK-6.6] perf/core: Fix WARN_ON(!ctx) in __free_event() for partial init
by Luo Gengkun 17 May '25

17 May '25

From: Gabriel Shahrouzi <gshahrouzi(a)gmail.com> stable inclusion from stable-v6.6.89 commit 1fe9b92eede32574dbe05b5bdb6ad666b350bed0 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IC6M1S CVE: CVE-2025-37878 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit 0ba3a4ab76fd3367b9cb680cad70182c896c795c ] Move the get_ctx(child_ctx) call and the child_event->ctx assignment to occur immediately after the child event is allocated. Ensure that child_event->ctx is non-NULL before any subsequent error path within inherit_event calls free_event(), satisfying the assumptions of the cleanup code. Details: There's no clear Fixes tag, because this bug is a side-effect of multiple interacting commits over time (up to 15 years old), not a single regression. The code initially incremented refcount then assigned context immediately after the child_event was created. Later, an early validity check for child_event was added before the refcount/assignment. Even later, a WARN_ON_ONCE() cleanup check was added, assuming event->ctx is valid if the pmu_ctx is valid. The problem is that the WARN_ON_ONCE() could trigger after the initial check passed but before child_event->ctx was assigned, violating its precondition. The solution is to assign child_event->ctx right after its initial validation. This ensures the context exists for any subsequent checks or cleanup routines, resolving the WARN_ON_ONCE(). To resolve it, defer the refcount update and child_event->ctx assignment directly after child_event->pmu_ctx is set but before checking if the parent event is orphaned. The cleanup routine depends on event->pmu_ctx being non-NULL before it verifies event->ctx is non-NULL. This also maintains the author's original intent of passing in child_ctx to find_get_pmu_context before its refcount/assignment. [ mingo: Expanded the changelog from another email by Gabriel Shahrouzi. ] Reported-by: syzbot+ff3aa851d46ab82953a3(a)syzkaller.appspotmail.com Signed-off-by: Gabriel Shahrouzi <gshahrouzi(a)gmail.com> Signed-off-by: Ingo Molnar <mingo(a)kernel.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Ravi Bangoria <ravi.bangoria(a)amd.com> Cc: Kan Liang <kan.liang(a)linux.intel.com> Cc: Oleg Nesterov <oleg(a)redhat.com> Cc: Alexander Shishkin <alexander.shishkin(a)linux.intel.com> Link: https://lore.kernel.org/r/20250405203036.582721-1-gshahrouzi@gmail.com Closes: https://syzkaller.appspot.com/bug?extid=ff3aa851d46ab82953a3 Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Luo Gengkun <luogengkun2(a)huawei.com> --- kernel/events/core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 8b85a644fff1..d62ee4ac4c18 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -13376,6 +13376,9 @@ inherit_event(struct perf_event *parent_event, if (IS_ERR(child_event)) return child_event; + get_ctx(child_ctx); + child_event->ctx = child_ctx; + pmu_ctx = find_get_pmu_context(child_event->pmu, child_ctx, child_event); if (IS_ERR(pmu_ctx)) { free_event(child_event); @@ -13398,8 +13401,6 @@ inherit_event(struct perf_event *parent_event, return NULL; } - get_ctx(child_ctx); - /* * Make the child state follow the state of the parent event, * not its attr.disabled bit. We hold the parent's mutex, @@ -13420,7 +13421,6 @@ inherit_event(struct perf_event *parent_event, local64_set(&hwc->period_left, sample_period); } - child_event->ctx = child_ctx; child_event->overflow_handler = parent_event->overflow_handler; child_event->overflow_handler_context = parent_event->overflow_handler_context; -- 2.34.1

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[openeuler:openEuler-1.0-LTS 1639/1639] net/can/j1939/main.o: warning: objtool: missing symbol for section .exit.text
by kernel test robot 17 May '25

17 May '25

tree: https://gitee.com/openeuler/kernel.git openEuler-1.0-LTS head: 9f24885126c03082a677c4d607a2e3502781c858 commit: e0c2ee9edcacfdda0e806166eaec1310cdf9e324 [1639/1639] can: add support of SAE J1939 protocol config: x86_64-buildonly-randconfig-005-20250516 (https://download.01.org/0day-ci/archive/20250517/202505170752.BGWpf4BO-lkp@…) compiler: gcc-12 (Debian 12.2.0-14) 12.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250517/202505170752.BGWpf4BO-lkp@…) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp(a)intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202505170752.BGWpf4BO-lkp@intel.com/ All warnings (new ones prefixed by >>): >> net/can/j1939/main.o: warning: objtool: missing symbol for section .exit.text -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki

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