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[PATCH] leds: flash: leds-qcom-flash: Fix registry access after re-bind

by Krzysztof Kozlowski

Driver in probe() updates each of 'reg_field' with 'reg_base': for (i = 0; i < REG_MAX_COUNT; i++) regs[i].reg += reg_base; 'reg_field' array (under variable 'regs' above) is statically allocated, this each re-bind would add another 'reg_base' leading to bogus register addresses. Constify the local 'reg_field' array and duplicate it in probe to solve this. Fixes: 96a2e242a5dc ("leds: flash: Add driver to support flash LED module in QCOM PMICs") Cc: <stable(a)vger.kernel.org> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org> --- This is a nice example why constifying static memory is useful. --- drivers/leds/flash/leds-qcom-flash.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/leds/flash/leds-qcom-flash.c b/drivers/leds/flash/leds-qcom-flash.c index b4c19be51c4d..b8a48c15d797 100644 --- a/drivers/leds/flash/leds-qcom-flash.c +++ b/drivers/leds/flash/leds-qcom-flash.c @@ -117,7 +117,7 @@ enum { REG_MAX_COUNT, }; -static struct reg_field mvflash_3ch_regs[REG_MAX_COUNT] = { +static const struct reg_field mvflash_3ch_regs[REG_MAX_COUNT] = { REG_FIELD(0x08, 0, 7), /* status1 */ REG_FIELD(0x09, 0, 7), /* status2 */ REG_FIELD(0x0a, 0, 7), /* status3 */ @@ -132,7 +132,7 @@ static struct reg_field mvflash_3ch_regs[REG_MAX_COUNT] = { REG_FIELD(0x58, 0, 2), /* therm_thrsh3 */ }; -static struct reg_field mvflash_4ch_regs[REG_MAX_COUNT] = { +static const struct reg_field mvflash_4ch_regs[REG_MAX_COUNT] = { REG_FIELD(0x06, 0, 7), /* status1 */ REG_FIELD(0x07, 0, 6), /* status2 */ REG_FIELD(0x09, 0, 7), /* status3 */ @@ -854,11 +854,17 @@ static int qcom_flash_led_probe(struct platform_device *pdev) if (val == FLASH_SUBTYPE_3CH_PM8150_VAL || val == FLASH_SUBTYPE_3CH_PMI8998_VAL) { flash_data->hw_type = QCOM_MVFLASH_3CH; flash_data->max_channels = 3; - regs = mvflash_3ch_regs; + regs = devm_kmemdup(dev, mvflash_3ch_regs, sizeof(mvflash_3ch_regs), + GFP_KERNEL); + if (!regs) + return -ENOMEM; } else if (val == FLASH_SUBTYPE_4CH_VAL) { flash_data->hw_type = QCOM_MVFLASH_4CH; flash_data->max_channels = 4; - regs = mvflash_4ch_regs; + regs = devm_kmemdup(dev, mvflash_4ch_regs, sizeof(mvflash_3ch_regs), + GFP_KERNEL); + if (!regs) + return -ENOMEM; rc = regmap_read(regmap, reg_base + FLASH_REVISION_REG, &val); if (rc < 0) { @@ -880,6 +886,7 @@ static int qcom_flash_led_probe(struct platform_device *pdev) dev_err(dev, "Failed to allocate regmap field, rc=%d\n", rc); return rc; } + devm_kfree(dev, regs); /* devm_regmap_field_bulk_alloc() makes copies */ platform_set_drvdata(pdev, flash_data); mutex_init(&flash_data->lock); -- 2.45.2

1 month, 1 week

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[PATCH v3] drm/xe/sched: stop re-submitting signalled jobs

by Matthew Auld

Customer is reporting a really subtle issue where we get random DMAR faults, hangs and other nasties for kernel migration jobs when stressing stuff like s2idle/s3/s4. The explosions seems to happen somewhere after resuming the system with splats looking something like: PM: suspend exit rfkill: input handler disabled xe 0000:00:02.0: [drm] GT0: Engine reset: engine_class=bcs, logical_mask: 0x2, guc_id=0 xe 0000:00:02.0: [drm] GT0: Timedout job: seqno=24496, lrc_seqno=24496, guc_id=0, flags=0x13 in no process [-1] xe 0000:00:02.0: [drm] GT0: Kernel-submitted job timed out The likely cause appears to be a race between suspend cancelling the worker that processes the free_job()'s, such that we still have pending jobs to be freed after the cancel. Following from this, on resume the pending_list will now contain at least one already complete job, but it looks like we call drm_sched_resubmit_jobs(), which will then call run_job() on everything still on the pending_list. But if the job was already complete, then all the resources tied to the job, like the bb itself, any memory that is being accessed, the iommu mappings etc. might be long gone since those are usually tied to the fence signalling. This scenario can be seen in ftrace when running a slightly modified xe_pm (kernel was only modified to inject artificial latency into free_job to make the race easier to hit): xe_sched_job_run: dev=0000:00:02.0, fence=0xffff888276cc8540, seqno=0, lrc_seqno=0, gt=0, guc_id=0, batch_addr=0x000000146910 ... xe_exec_queue_stop: dev=0000:00:02.0, 3:0x2, gt=0, width=1, guc_id=0, guc_state=0x0, flags=0x13 xe_exec_queue_stop: dev=0000:00:02.0, 3:0x2, gt=0, width=1, guc_id=1, guc_state=0x0, flags=0x4 xe_exec_queue_stop: dev=0000:00:02.0, 4:0x1, gt=1, width=1, guc_id=0, guc_state=0x0, flags=0x3 xe_exec_queue_stop: dev=0000:00:02.0, 1:0x1, gt=1, width=1, guc_id=1, guc_state=0x0, flags=0x3 xe_exec_queue_stop: dev=0000:00:02.0, 4:0x1, gt=1, width=1, guc_id=2, guc_state=0x0, flags=0x3 xe_exec_queue_resubmit: dev=0000:00:02.0, 3:0x2, gt=0, width=1, guc_id=0, guc_state=0x0, flags=0x13 xe_sched_job_run: dev=0000:00:02.0, fence=0xffff888276cc8540, seqno=0, lrc_seqno=0, gt=0, guc_id=0, batch_addr=0x000000146910 ... ..... xe_exec_queue_memory_cat_error: dev=0000:00:02.0, 3:0x2, gt=0, width=1, guc_id=0, guc_state=0x3, flags=0x13 So the job_run() is clearly triggered twice for the same job, even though the first must have already signalled to completion during suspend. We can also see a CAT error after the re-submit. To prevent this try to call xe_sched_stop() to forcefully remove anything on the pending_list that has already signalled, before we re-submit. v2: - Make sure to re-arm the fence callbacks with sched_start(). v3 (Matt B): - Stop using drm_sched_resubmit_jobs(), which appears to be deprecated and just open-code a simple loop such that we skip calling run_job() and anything already signalled. Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4856 Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs") Signed-off-by: Matthew Auld <matthew.auld(a)intel.com> Cc: Thomas Hellström <thomas.hellstrom(a)linux.intel.com> Cc: Matthew Brost <matthew.brost(a)intel.com> Cc: William Tseng <william.tseng(a)intel.com> Cc: <stable(a)vger.kernel.org> # v6.8+ --- drivers/gpu/drm/xe/xe_gpu_scheduler.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xe/xe_gpu_scheduler.h b/drivers/gpu/drm/xe/xe_gpu_scheduler.h index c250ea773491..308061f0cf37 100644 --- a/drivers/gpu/drm/xe/xe_gpu_scheduler.h +++ b/drivers/gpu/drm/xe/xe_gpu_scheduler.h @@ -51,7 +51,15 @@ static inline void xe_sched_tdr_queue_imm(struct xe_gpu_scheduler *sched) static inline void xe_sched_resubmit_jobs(struct xe_gpu_scheduler *sched) { - drm_sched_resubmit_jobs(&sched->base); + struct drm_sched_job *s_job; + + list_for_each_entry(s_job, &sched->base.pending_list, list) { + struct drm_sched_fence *s_fence = s_job->s_fence; + struct dma_fence *hw_fence = s_fence->parent; + + if (hw_fence && !dma_fence_is_signaled(hw_fence)) + sched->base.ops->run_job(s_job); + } } static inline bool -- 2.49.0

1 month, 1 week

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[PATCH] net: ch9200: fix uninitialised access during mii_nway_restart

by Qasim Ijaz

In mii_nway_restart() the code attempts to call mii->mdio_read which is ch9200_mdio_read(). ch9200_mdio_read() utilises a local buffer called "buff", which is initialised with control_read(). However "buff" is conditionally initialised inside control_read(): if (err == size) { memcpy(data, buf, size); } If the condition of "err == size" is not met, then "buff" remains uninitialised. Once this happens the uninitialised "buff" is accessed and returned during ch9200_mdio_read(): return (buff[0] | buff[1] << 8); The problem stems from the fact that ch9200_mdio_read() ignores the return value of control_read(), leading to uinit-access of "buff". To fix this we should check the return value of control_read() and return early on error. Reported-by: syzbot <syzbot+3361c2d6f78a3e0892f9(a)syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=3361c2d6f78a3e0892f9 Tested-by: syzbot <syzbot+3361c2d6f78a3e0892f9(a)syzkaller.appspotmail.com> Fixes: 4a476bd6d1d9 ("usbnet: New driver for QinHeng CH9200 devices") Cc: stable(a)vger.kernel.org Signed-off-by: Qasim Ijaz <qasdev00(a)gmail.com> --- drivers/net/usb/ch9200.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/net/usb/ch9200.c b/drivers/net/usb/ch9200.c index f69d9b902da0..a206ffa76f1b 100644 --- a/drivers/net/usb/ch9200.c +++ b/drivers/net/usb/ch9200.c @@ -178,6 +178,7 @@ static int ch9200_mdio_read(struct net_device *netdev, int phy_id, int loc) { struct usbnet *dev = netdev_priv(netdev); unsigned char buff[2]; + int ret; netdev_dbg(netdev, "%s phy_id:%02x loc:%02x\n", __func__, phy_id, loc); @@ -185,8 +186,10 @@ static int ch9200_mdio_read(struct net_device *netdev, int phy_id, int loc) if (phy_id != 0) return -ENODEV; - control_read(dev, REQUEST_READ, 0, loc * 2, buff, 0x02, - CONTROL_TIMEOUT_MS); + ret = control_read(dev, REQUEST_READ, 0, loc * 2, buff, 0x02, + CONTROL_TIMEOUT_MS); + if (ret < 0) + return ret; return (buff[0] | buff[1] << 8); } -- 2.39.5

1 month, 1 week

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[PATCH] net: af_key: Add error check in set_sadb_address()

by Wentao Liang

The function set_sadb_address() calls the function pfkey_sockaddr_fill(), but does not check its return value. A proper implementation can be found in set_sadb_kmaddress(). Add an error check for set_sadb_address(), return error code if the function fails. Fixes: e5b56652c11b ("key: Share common code path to fill sockaddr{}.") Cc: stable(a)vger.kernel.org # v2.6 Signed-off-by: Wentao Liang <vulab(a)iscas.ac.cn> --- net/key/af_key.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/net/key/af_key.c b/net/key/af_key.c index c56bb4f451e6..537c9604e356 100644 --- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -3474,15 +3474,17 @@ static int set_sadb_address(struct sk_buff *skb, int sasize, int type, switch (type) { case SADB_EXT_ADDRESS_SRC: addr->sadb_address_prefixlen = sel->prefixlen_s; - pfkey_sockaddr_fill(&sel->saddr, 0, - (struct sockaddr *)(addr + 1), - sel->family); + if (!pfkey_sockaddr_fill(&sel->saddr, 0, + (struct sockaddr *)(addr + 1), + sel->family)) + return -EINVAL; break; case SADB_EXT_ADDRESS_DST: addr->sadb_address_prefixlen = sel->prefixlen_d; - pfkey_sockaddr_fill(&sel->daddr, 0, - (struct sockaddr *)(addr + 1), - sel->family); + if (!pfkey_sockaddr_fill(&sel->daddr, 0, + (struct sockaddr *)(addr + 1), + sel->family)) + return -EINVAL; break; default: return -EINVAL; -- 2.42.0.windows.2

1 month, 1 week

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[PATCH 2/5] LoongArch: KVM: Check interrupt route from physical cpu with eiointc

by Bibo Mao

With eiointc interrupt controller, physical cpu id is set for irq route. However function kvm_get_vcpu() is used to get destination vCPU when delivering irq. With API kvm_get_vcpu(), logical cpu is used. With API kvm_get_vcpu_by_cpuid(), vCPU can be searched from physical cpu id. Cc: stable(a)vger.kernel.org Fixes: 3956a52bc05b ("LoongArch: KVM: Add EIOINTC read and write functions") Signed-off-by: Bibo Mao <maobibo(a)loongson.cn> --- arch/loongarch/kvm/intc/eiointc.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c index d2c521b0e923..0b648c56b0c3 100644 --- a/arch/loongarch/kvm/intc/eiointc.c +++ b/arch/loongarch/kvm/intc/eiointc.c @@ -9,7 +9,8 @@ static void eiointc_set_sw_coreisr(struct loongarch_eiointc *s) { - int ipnum, cpu, irq_index, irq_mask, irq; + int ipnum, cpu, irq_index, irq_mask, irq, cpuid; + struct kvm_vcpu *vcpu; for (irq = 0; irq < EIOINTC_IRQS; irq++) { ipnum = s->ipmap.reg_u8[irq / 32]; @@ -20,7 +21,12 @@ static void eiointc_set_sw_coreisr(struct loongarch_eiointc *s) irq_index = irq / 32; irq_mask = BIT(irq & 0x1f); - cpu = s->coremap.reg_u8[irq]; + cpuid = s->coremap.reg_u8[irq]; + vcpu = kvm_get_vcpu_by_cpuid(s->kvm, cpuid); + if (vcpu == NULL) + continue; + + cpu = vcpu->vcpu_id; if (!!(s->coreisr.reg_u32[cpu][irq_index] & irq_mask)) set_bit(irq, s->sw_coreisr[cpu][ipnum]); else @@ -68,17 +74,23 @@ static void eiointc_update_irq(struct loongarch_eiointc *s, int irq, int level) static inline void eiointc_update_sw_coremap(struct loongarch_eiointc *s, int irq, u64 val, u32 len, bool notify) { - int i, cpu; + int i, cpu, cpuid; + struct kvm_vcpu *vcpu; for (i = 0; i < len; i++) { - cpu = val & 0xff; + cpuid = val & 0xff; val = val >> 8; if (!(s->status & BIT(EIOINTC_ENABLE_CPU_ENCODE))) { - cpu = ffs(cpu) - 1; - cpu = (cpu >= 4) ? 0 : cpu; + cpuid = ffs(cpuid) - 1; + cpuid = (cpuid >= 4) ? 0 : cpuid; } + vcpu = kvm_get_vcpu_by_cpuid(s->kvm, cpuid); + if (vcpu == NULL) + continue; + + cpu = vcpu->vcpu_id; if (s->sw_coremap[irq + i] == cpu) continue; -- 2.39.3

1 month, 1 week

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[PATCH 1/5] LoongArch: KVM: Fix interrupt route update with eiointc

by Bibo Mao

With function eiointc_update_sw_coremap(), there is forced assignment like val = *(u64 *)pvalue. Parameter pvalue may be pointer to char type or others, there is problem with forced assignment with u64 type. Here the detailed value is passed rather address pointer. Cc: stable(a)vger.kernel.org Fixes: 3956a52bc05b ("LoongArch: KVM: Add EIOINTC read and write functions") Signed-off-by: Bibo Mao <maobibo(a)loongson.cn> --- arch/loongarch/kvm/intc/eiointc.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c index f39929d7bf8a..d2c521b0e923 100644 --- a/arch/loongarch/kvm/intc/eiointc.c +++ b/arch/loongarch/kvm/intc/eiointc.c @@ -66,10 +66,9 @@ static void eiointc_update_irq(struct loongarch_eiointc *s, int irq, int level) } static inline void eiointc_update_sw_coremap(struct loongarch_eiointc *s, - int irq, void *pvalue, u32 len, bool notify) + int irq, u64 val, u32 len, bool notify) { int i, cpu; - u64 val = *(u64 *)pvalue; for (i = 0; i < len; i++) { cpu = val & 0xff; @@ -398,7 +397,7 @@ static int loongarch_eiointc_writeb(struct kvm_vcpu *vcpu, irq = offset - EIOINTC_COREMAP_START; index = irq; s->coremap.reg_u8[index] = data; - eiointc_update_sw_coremap(s, irq, (void *)&data, sizeof(data), true); + eiointc_update_sw_coremap(s, irq, data, sizeof(data), true); break; default: ret = -EINVAL; @@ -484,7 +483,7 @@ static int loongarch_eiointc_writew(struct kvm_vcpu *vcpu, irq = offset - EIOINTC_COREMAP_START; index = irq >> 1; s->coremap.reg_u16[index] = data; - eiointc_update_sw_coremap(s, irq, (void *)&data, sizeof(data), true); + eiointc_update_sw_coremap(s, irq, data, sizeof(data), true); break; default: ret = -EINVAL; @@ -570,7 +569,7 @@ static int loongarch_eiointc_writel(struct kvm_vcpu *vcpu, irq = offset - EIOINTC_COREMAP_START; index = irq >> 2; s->coremap.reg_u32[index] = data; - eiointc_update_sw_coremap(s, irq, (void *)&data, sizeof(data), true); + eiointc_update_sw_coremap(s, irq, data, sizeof(data), true); break; default: ret = -EINVAL; @@ -656,7 +655,7 @@ static int loongarch_eiointc_writeq(struct kvm_vcpu *vcpu, irq = offset - EIOINTC_COREMAP_START; index = irq >> 3; s->coremap.reg_u64[index] = data; - eiointc_update_sw_coremap(s, irq, (void *)&data, sizeof(data), true); + eiointc_update_sw_coremap(s, irq, data, sizeof(data), true); break; default: ret = -EINVAL; @@ -809,7 +808,7 @@ static int kvm_eiointc_ctrl_access(struct kvm_device *dev, for (i = 0; i < (EIOINTC_IRQS / 4); i++) { start_irq = i * 4; eiointc_update_sw_coremap(s, start_irq, - (void *)&s->coremap.reg_u32[i], sizeof(u32), false); + s->coremap.reg_u32[i], sizeof(u32), false); } break; default: -- 2.39.3

1 month, 1 week

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[PATCH] net: ethernet: rtsn: Fix a null pointer dereference in rtsn_probe()

by Haoxiang Li

Add check for the return value of rcar_gen4_ptp_alloc() to prevent potential null pointer dereference. Fixes: b0d3969d2b4d ("net: ethernet: rtsn: Add support for Renesas Ethernet-TSN") Cc: stable(a)vger.kernel.org Signed-off-by: Haoxiang Li <haoxiang_li2024(a)163.com> --- drivers/net/ethernet/renesas/rtsn.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/ethernet/renesas/rtsn.c b/drivers/net/ethernet/renesas/rtsn.c index 6b3f7fca8d15..f5df3374d279 100644 --- a/drivers/net/ethernet/renesas/rtsn.c +++ b/drivers/net/ethernet/renesas/rtsn.c @@ -1260,6 +1260,10 @@ static int rtsn_probe(struct platform_device *pdev) priv->pdev = pdev; priv->ndev = ndev; priv->ptp_priv = rcar_gen4_ptp_alloc(pdev); + if (!priv->ptp_priv) { + ret = -ENOMEM; + goto error_free; + } spin_lock_init(&priv->lock); platform_set_drvdata(pdev, priv); -- 2.25.1

1 month, 1 week

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[alternative-merged] mm-contig_alloc-fix-alloc_contig_range-when-__gfp_comp-and-order-max_order.patch removed from -mm tree

by Andrew Morton

The quilt patch titled Subject: mm/contig_alloc: fix alloc_contig_range when __GFP_COMP and order < MAX_ORDER has been removed from the -mm tree. Its filename was mm-contig_alloc-fix-alloc_contig_range-when-__gfp_comp-and-order-max_order.patch This patch was dropped because an alternative patch was or shall be merged ------------------------------------------------------ From: Jinjiang Tu <tujinjiang(a)huawei.com> Subject: mm/contig_alloc: fix alloc_contig_range when __GFP_COMP and order < MAX_ORDER Date: Mon, 21 Apr 2025 09:36:20 +0800 When calling alloc_contig_range() with __GFP_COMP and the order of requested pfn range is pageblock_order, less than MAX_ORDER, I triggered WARNING as follows: PFN range: requested [2150105088, 2150105600), allocated [2150105088, 2150106112) WARNING: CPU: 3 PID: 580 at mm/page_alloc.c:6877 alloc_contig_range+0x280/0x340 alloc_contig_range() marks pageblocks of the requested pfn range to be isolated, migrate these pages if they are in use and will be freed to MIGRATE_ISOLATED freelist. Suppose two alloc_contig_range() calls at the same time and the requested pfn range are [0x80280000, 0x80280200) and [0x80280200, 0x80280400) respectively. Suppose the two memory range are in use, then alloc_contig_range() will migrate and free these pages to MIGRATE_ISOLATED freelist. __free_one_page() will merge MIGRATE_ISOLATE buddy to larger buddy, resulting in a MAX_ORDER buddy. Finally, find_large_buddy() in alloc_contig_range() returns a MAX_ORDER buddy and results in WARNING. To fix it, call free_contig_range() to free the excess pfn range. Link: https://lkml.kernel.org/r/20250421013620.459740-1-tujinjiang@huawei.com Fixes: e98337d11bbd ("mm/contig_alloc: support __GFP_COMP") Signed-off-by: Jinjiang Tu <tujinjiang(a)huawei.com> Reviewed-by: Zi Yan <ziy(a)nvidia.com> Cc: David Hildenbrand <david(a)redhat.com> Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com> Cc: Yu Zhao <yuzhao(a)google.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> --- mm/page_alloc.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) --- a/mm/page_alloc.c~mm-contig_alloc-fix-alloc_contig_range-when-__gfp_comp-and-order-max_order +++ a/mm/page_alloc.c @@ -6693,6 +6693,7 @@ int alloc_contig_range_noprof(unsigned l .alloc_contig = true, }; INIT_LIST_HEAD(&cc.migratepages); + bool is_range_aligned; gfp_mask = current_gfp_context(gfp_mask); if (__alloc_contig_verify_gfp_mask(gfp_mask, (gfp_t *)&cc.gfp_mask)) @@ -6781,7 +6782,14 @@ int alloc_contig_range_noprof(unsigned l goto done; } - if (!(gfp_mask & __GFP_COMP)) { + /* + * With __GFP_COMP and the requested order < MAX_PAGE_ORDER, + * isolated free pages can have higher order than the requested + * one. Use split_free_pages() to free out of range pages. + */ + is_range_aligned = is_power_of_2(end - start); + if (!(gfp_mask & __GFP_COMP) || + (is_range_aligned && ilog2(end - start) < MAX_PAGE_ORDER)) { split_free_pages(cc.freepages, gfp_mask); /* Free head and tail (if any) */ @@ -6789,7 +6797,15 @@ int alloc_contig_range_noprof(unsigned l free_contig_range(outer_start, start - outer_start); if (end != outer_end) free_contig_range(end, outer_end - end); - } else if (start == outer_start && end == outer_end && is_power_of_2(end - start)) { + + outer_start = start; + outer_end = end; + + if (!(gfp_mask & __GFP_COMP)) + goto done; + } + + if (start == outer_start && end == outer_end && is_range_aligned) { struct page *head = pfn_to_page(start); int order = ilog2(end - start); _ Patches currently in -mm which might be from tujinjiang(a)huawei.com are

1 month, 1 week

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[for-next][PATCH 02/10] ring-buffer: Do not trigger WARN_ON() due to a commit_overrun

by Steven Rostedt

From: Steven Rostedt <rostedt(a)goodmis.org> When reading a memory mapped buffer the reader page is just swapped out with the last page written in the write buffer. If the reader page is the same as the commit buffer (the buffer that is currently being written to) it was assumed that it should never have missed events. If it does, it triggers a WARN_ON_ONCE(). But there just happens to be one scenario where this can legitimately happen. That is on a commit_overrun. A commit overrun is when an interrupt preempts an event being written to the buffer and then the interrupt adds so many new events that it fills and wraps the buffer back to the commit. Any new events would then be dropped and be reported as "missed_events". In this case, the next page to read is the commit buffer and after the swap of the reader page, the reader page will be the commit buffer, but this time there will be missed events and this triggers the following warning: ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1127 at kernel/trace/ring_buffer.c:7357 ring_buffer_map_get_reader+0x49a/0x780 Modules linked in: kvm_intel kvm irqbypass CPU: 2 UID: 0 PID: 1127 Comm: trace-cmd Not tainted 6.15.0-rc7-test-00004-g478bc2824b45-dirty #564 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:ring_buffer_map_get_reader+0x49a/0x780 Code: 00 00 00 48 89 fe 48 c1 ee 03 80 3c 2e 00 0f 85 ec 01 00 00 4d 3b a6 a8 00 00 00 0f 85 8a fd ff ff 48 85 c0 0f 84 55 fe ff ff <0f> 0b e9 4e fe ff ff be 08 00 00 00 4c 89 54 24 58 48 89 54 24 50 RSP: 0018:ffff888121787dc0 EFLAGS: 00010002 RAX: 00000000000006a2 RBX: ffff888100062800 RCX: ffffffff8190cb49 RDX: ffff888126934c00 RSI: 1ffff11020200a15 RDI: ffff8881010050a8 RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffed1024d26982 R10: ffff888126934c17 R11: ffff8881010050a8 R12: ffff888126934c00 R13: ffff8881010050b8 R14: ffff888101005000 R15: ffff888126930008 FS: 00007f95c8cd7540(0000) GS:ffff8882b576e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f95c8de4dc0 CR3: 0000000128452002 CR4: 0000000000172ef0 Call Trace: <TASK> ? __pfx_ring_buffer_map_get_reader+0x10/0x10 tracing_buffers_ioctl+0x283/0x370 __x64_sys_ioctl+0x134/0x190 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f95c8de48db Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007ffe037ba110 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007ffe037bb2b0 RCX: 00007f95c8de48db RDX: 0000000000000000 RSI: 0000000000005220 RDI: 0000000000000006 RBP: 00007ffe037ba180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe037bb6f8 R14: 00007f95c9065000 R15: 00005575c7492c90 </TASK> irq event stamp: 5080 hardirqs last enabled at (5079): [<ffffffff83e0adb0>] _raw_spin_unlock_irqrestore+0x50/0x70 hardirqs last disabled at (5080): [<ffffffff83e0aa83>] _raw_spin_lock_irqsave+0x63/0x70 softirqs last enabled at (4182): [<ffffffff81516122>] handle_softirqs+0x552/0x710 softirqs last disabled at (4159): [<ffffffff815163f7>] __irq_exit_rcu+0x107/0x210 ---[ end trace 0000000000000000 ]--- The above was triggered by running on a kernel with both lockdep and KASAN as well as kmemleak enabled and executing the following command: # perf record -o perf-test.dat -a -- trace-cmd record --nosplice -e all -p function hackbench 50 With perf interjecting a lot of interrupts and trace-cmd enabling all events as well as function tracing, with lockdep, KASAN and kmemleak enabled, it could cause an interrupt preempting an event being written to add enough events to wrap the buffer. trace-cmd was modified to have --nosplice use mmap instead of reading the buffer. The way to differentiate this case from the normal case of there only being one page written to where the swap of the reader page received that one page (which is the commit page), check if the tail page is on the reader page. The difference between the commit page and the tail page is that the tail page is where new writes go to, and the commit page holds the first write that hasn't been committed yet. In the case of an interrupt preempting the write of an event and filling the buffer, it would move the tail page but not the commit page. Have the warning only trigger if the tail page is also on the reader page, and also print out the number of events dropped by a commit overrun as that can not yet be safely added to the page so that the reader can see there were events dropped. Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Cc: Vincent Donnefort <vdonnefort(a)google.com> Link: https://lore.kernel.org/20250528121555.2066527e@gandalf.local.home Fixes: fe832be05a8ee ("ring-buffer: Have mmapped ring buffer keep track of missed events") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/ring_buffer.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index ca1a8e706004..683aa57870fe 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -7285,8 +7285,8 @@ int ring_buffer_map_get_reader(struct trace_buffer *buffer, int cpu) /* Check if any events were dropped */ missed_events = cpu_buffer->lost_events; - if (cpu_buffer->reader_page != cpu_buffer->commit_page) { - if (missed_events) { + if (missed_events) { + if (cpu_buffer->reader_page != cpu_buffer->commit_page) { struct buffer_data_page *bpage = reader->page; unsigned int commit; /* @@ -7307,13 +7307,23 @@ int ring_buffer_map_get_reader(struct trace_buffer *buffer, int cpu) local_add(RB_MISSED_STORED, &bpage->commit); } local_add(RB_MISSED_EVENTS, &bpage->commit); + } else if (!WARN_ONCE(cpu_buffer->reader_page == cpu_buffer->tail_page, + "Reader on commit with %ld missed events", + missed_events)) { + /* + * There shouldn't be any missed events if the tail_page + * is on the reader page. But if the tail page is not on the + * reader page and the commit_page is, that would mean that + * there's a commit_overrun (an interrupt preempted an + * addition of an event and then filled the buffer + * with new events). In this case it's not an + * error, but it should still be reported. + * + * TODO: Add missed events to the page for user space to know. + */ + pr_info("Ring buffer [%d] commit overrun lost %ld events at timestamp:%lld\n", + cpu, missed_events, cpu_buffer->reader_page->page->time_stamp); } - } else { - /* - * There really shouldn't be any missed events if the commit - * is on the reader page. - */ - WARN_ON_ONCE(missed_events); } cpu_buffer->lost_events = 0; -- 2.47.2

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[for-next][PATCH 01/10] ring-buffer: Move cpus_read_lock() outside of buffer->mutex

by Steven Rostedt

From: Steven Rostedt <rostedt(a)goodmis.org> Running a modified trace-cmd record --nosplice where it does a mmap of the ring buffer when '--nosplice' is set, caused the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 6.15.0-rc7-test-00002-gfb7d03d8a82f #551 Not tainted ------------------------------------------------------ trace-cmd/1113 is trying to acquire lock: ffff888100062888 (&buffer->mutex){+.+.}-{4:4}, at: ring_buffer_map+0x11c/0xe70 but task is already holding lock: ffff888100a5f9f8 (&cpu_buffer->mapping_lock){+.+.}-{4:4}, at: ring_buffer_map+0xcf/0xe70 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (&cpu_buffer->mapping_lock){+.+.}-{4:4}: __mutex_lock+0x192/0x18c0 ring_buffer_map+0xcf/0xe70 tracing_buffers_mmap+0x1c4/0x3b0 __mmap_region+0xd8d/0x1f70 do_mmap+0x9d7/0x1010 vm_mmap_pgoff+0x20b/0x390 ksys_mmap_pgoff+0x2e9/0x440 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #4 (&mm->mmap_lock){++++}-{4:4}: __might_fault+0xa5/0x110 _copy_to_user+0x22/0x80 _perf_ioctl+0x61b/0x1b70 perf_ioctl+0x62/0x90 __x64_sys_ioctl+0x134/0x190 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #3 (&cpuctx_mutex){+.+.}-{4:4}: __mutex_lock+0x192/0x18c0 perf_event_init_cpu+0x325/0x7c0 perf_event_init+0x52a/0x5b0 start_kernel+0x263/0x3e0 x86_64_start_reservations+0x24/0x30 x86_64_start_kernel+0x95/0xa0 common_startup_64+0x13e/0x141 -> #2 (pmus_lock){+.+.}-{4:4}: __mutex_lock+0x192/0x18c0 perf_event_init_cpu+0xb7/0x7c0 cpuhp_invoke_callback+0x2c0/0x1030 __cpuhp_invoke_callback_range+0xbf/0x1f0 _cpu_up+0x2e7/0x690 cpu_up+0x117/0x170 cpuhp_bringup_mask+0xd5/0x120 bringup_nonboot_cpus+0x13d/0x170 smp_init+0x2b/0xf0 kernel_init_freeable+0x441/0x6d0 kernel_init+0x1e/0x160 ret_from_fork+0x34/0x70 ret_from_fork_asm+0x1a/0x30 -> #1 (cpu_hotplug_lock){++++}-{0:0}: cpus_read_lock+0x2a/0xd0 ring_buffer_resize+0x610/0x14e0 __tracing_resize_ring_buffer.part.0+0x42/0x120 tracing_set_tracer+0x7bd/0xa80 tracing_set_trace_write+0x132/0x1e0 vfs_write+0x21c/0xe80 ksys_write+0xf9/0x1c0 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e -> #0 (&buffer->mutex){+.+.}-{4:4}: __lock_acquire+0x1405/0x2210 lock_acquire+0x174/0x310 __mutex_lock+0x192/0x18c0 ring_buffer_map+0x11c/0xe70 tracing_buffers_mmap+0x1c4/0x3b0 __mmap_region+0xd8d/0x1f70 do_mmap+0x9d7/0x1010 vm_mmap_pgoff+0x20b/0x390 ksys_mmap_pgoff+0x2e9/0x440 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e other info that might help us debug this: Chain exists of: &buffer->mutex --> &mm->mmap_lock --> &cpu_buffer->mapping_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&cpu_buffer->mapping_lock); lock(&mm->mmap_lock); lock(&cpu_buffer->mapping_lock); lock(&buffer->mutex); *** DEADLOCK *** 2 locks held by trace-cmd/1113: #0: ffff888106b847e0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x192/0x390 #1: ffff888100a5f9f8 (&cpu_buffer->mapping_lock){+.+.}-{4:4}, at: ring_buffer_map+0xcf/0xe70 stack backtrace: CPU: 5 UID: 0 PID: 1113 Comm: trace-cmd Not tainted 6.15.0-rc7-test-00002-gfb7d03d8a82f #551 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x6e/0xa0 print_circular_bug.cold+0x178/0x1be check_noncircular+0x146/0x160 __lock_acquire+0x1405/0x2210 lock_acquire+0x174/0x310 ? ring_buffer_map+0x11c/0xe70 ? ring_buffer_map+0x11c/0xe70 ? __mutex_lock+0x169/0x18c0 __mutex_lock+0x192/0x18c0 ? ring_buffer_map+0x11c/0xe70 ? ring_buffer_map+0x11c/0xe70 ? function_trace_call+0x296/0x370 ? __pfx___mutex_lock+0x10/0x10 ? __pfx_function_trace_call+0x10/0x10 ? __pfx___mutex_lock+0x10/0x10 ? _raw_spin_unlock+0x2d/0x50 ? ring_buffer_map+0x11c/0xe70 ? ring_buffer_map+0x11c/0xe70 ? __mutex_lock+0x5/0x18c0 ring_buffer_map+0x11c/0xe70 ? do_raw_spin_lock+0x12d/0x270 ? find_held_lock+0x2b/0x80 ? _raw_spin_unlock+0x2d/0x50 ? rcu_is_watching+0x15/0xb0 ? _raw_spin_unlock+0x2d/0x50 ? trace_preempt_on+0xd0/0x110 tracing_buffers_mmap+0x1c4/0x3b0 __mmap_region+0xd8d/0x1f70 ? ring_buffer_lock_reserve+0x99/0xff0 ? __pfx___mmap_region+0x10/0x10 ? ring_buffer_lock_reserve+0x99/0xff0 ? __pfx_ring_buffer_lock_reserve+0x10/0x10 ? __pfx_ring_buffer_lock_reserve+0x10/0x10 ? bpf_lsm_mmap_addr+0x4/0x10 ? security_mmap_addr+0x46/0xd0 ? lock_is_held_type+0xd9/0x130 do_mmap+0x9d7/0x1010 ? 0xffffffffc0370095 ? __pfx_do_mmap+0x10/0x10 vm_mmap_pgoff+0x20b/0x390 ? __pfx_vm_mmap_pgoff+0x10/0x10 ? 0xffffffffc0370095 ksys_mmap_pgoff+0x2e9/0x440 do_syscall_64+0x79/0x1c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fb0963a7de2 Code: 00 00 00 0f 1f 44 00 00 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 3b 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 5b 5d c3 0f 1f 00 48 8b 05 e1 9f 0d 00 64 RSP: 002b:00007ffdcc8fb878 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb0963a7de2 RDX: 0000000000000001 RSI: 0000000000001000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdcc8fbe68 R14: 00007fb096628000 R15: 00005633e01a5c90 </TASK> The issue is that cpus_read_lock() is taken within buffer->mutex. The memory mapped pages are taken with the mmap_lock held. The buffer->mutex is taken within the cpu_buffer->mapping_lock. There's quite a chain with all these locks, where the deadlock can be fixed by moving the cpus_read_lock() outside the taking of the buffer->mutex. Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Cc: Vincent Donnefort <vdonnefort(a)google.com> Link: https://lore.kernel.org/20250527105820.0f45d045@gandalf.local.home Fixes: 117c39200d9d7 ("ring-buffer: Introducing ring-buffer mapping functions") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/ring_buffer.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 3f9bf562beea..ca1a8e706004 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2849,6 +2849,12 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, if (nr_pages < 2) nr_pages = 2; + /* + * Keep CPUs from coming online while resizing to synchronize + * with new per CPU buffers being created. + */ + guard(cpus_read_lock)(); + /* prevent another thread from changing buffer sizes */ mutex_lock(&buffer->mutex); atomic_inc(&buffer->resizing); @@ -2893,7 +2899,6 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, cond_resched(); } - cpus_read_lock(); /* * Fire off all the required work handlers * We can't schedule on offline CPUs, but it's not necessary @@ -2933,7 +2938,6 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, cpu_buffer->nr_pages_to_update = 0; } - cpus_read_unlock(); } else { cpu_buffer = buffer->buffers[cpu_id]; @@ -2961,8 +2965,6 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, goto out_err; } - cpus_read_lock(); - /* Can't run something on an offline CPU. */ if (!cpu_online(cpu_id)) rb_update_pages(cpu_buffer); @@ -2981,7 +2983,6 @@ int ring_buffer_resize(struct trace_buffer *buffer, unsigned long size, } cpu_buffer->nr_pages_to_update = 0; - cpus_read_unlock(); } out: -- 2.47.2

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