September 2024 - Linux-stable-mirror

[PATCH 1/1] iommu/vt-d: Prevent boot failure with devices requiring ATS

by Lu Baolu

SOC-integrated devices on some platforms require their PCI ATS enabled for operation when the IOMMU is in scalable mode. Those devices are reported via ACPI/SATC table with the ATC_REQUIRED bit set in the Flags field. The PCI subsystem offers the 'pci=noats' kernel command to disable PCI ATS on all devices. Using 'pci=noat' with devices that require PCI ATS can cause a conflict, leading to boot failure, especially if the device is a graphics device. To prevent this issue, check PCI ATS support before enumerating the IOMMU devices. If any device requires PCI ATS, but PCI ATS is disabled by 'pci=noats', switch the IOMMU to operate in legacy mode to ensure successful booting. Fixes: 97f2f2c5317f ("iommu/vt-d: Enable ATS for the devices in SATC table") Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/12036 Cc: stable(a)vger.kernel.org Signed-off-by: Lu Baolu <baolu.lu(a)linux.intel.com> --- drivers/iommu/intel/iommu.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 4aa070cf56e7..8f275e046e91 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -3127,10 +3127,26 @@ int dmar_iommu_notify_scope_dev(struct dmar_pci_notify_info *info) (void *)satc + satc->header.length, satc->segment, satcu->devices, satcu->devices_cnt); - if (ret > 0) - break; - else if (ret < 0) + if (ret < 0) return ret; + + if (ret > 0) { + /* + * The device requires PCI/ATS when the IOMMU + * works in the scalable mode. If PCI/ATS is + * disabled using the pci=noats kernel parameter, + * the IOMMU will default to legacy mode. Users + * are informed of this change. + */ + if (intel_iommu_sm && satcu->atc_required && + !pci_ats_supported(info->dev)) { + pci_warn(info->dev, + "PCI/ATS not supported, system working in IOMMU legacy mode\n"); + intel_iommu_sm = 0; + } + + break; + } } else if (info->event == BUS_NOTIFY_REMOVED_DEVICE) { if (dmar_remove_dev_scope(info, satc->segment, satcu->devices, satcu->devices_cnt)) -- 2.34.1

1 year, 3 months

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[PATCH 00/11] arm64: qcom: set of fixes for SM8350 platform

by Dmitry Baryshkov

A set of fixes that target stability of the SM8350 platform. Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org> --- Dmitry Baryshkov (11): clk: qcom: dispcc-sm8250: use CLK_SET_RATE_PARENT for branch clocks clk: qcom: dispcc-sm8250: use special function for Lucid 5LPE PLL drm/msm/dsi: correct programming sequence for SM8350 / SM8450 interconnect: qcom: sm8350: drop DISP nodes interconnect: qcom: sm8450: drop DISP nodes dt-bindings: interconnect: qcom,sm8350: drop DISP nodes dt-bindings: interconnect: qcom,sm8450: drop DISP nodes interconnect: qcom: sm8250: Enable sync_state arm64: dts: qcom: sm8350: add MDSS registers interconnect arm64: dts: qcom: sm8350: add refgen regulator arm64: defconfig: build CONFIG_REGULATOR_QCOM_REFGEN as module arch/arm64/boot/dts/qcom/sm8350.dtsi | 16 ++- arch/arm64/configs/defconfig | 1 + drivers/clk/qcom/clk-alpha-pll.c | 52 +++++++++ drivers/clk/qcom/clk-alpha-pll.h | 2 + drivers/clk/qcom/dispcc-sm8250.c | 12 +- drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c | 12 +- drivers/interconnect/qcom/sm8350.c | 155 +------------------------ drivers/interconnect/qcom/sm8350.h | 10 -- drivers/interconnect/qcom/sm8450.c | 145 ----------------------- drivers/interconnect/qcom/sm8450.h | 12 -- include/dt-bindings/interconnect/qcom,sm8350.h | 10 -- include/dt-bindings/interconnect/qcom,sm8450.h | 10 -- 12 files changed, 91 insertions(+), 346 deletions(-) --- base-commit: 668d33c9ff922c4590c58754ab064aaf53c387dd change-id: 20240804-sm8350-fixes-9e731f79c56f Best regards, -- Dmitry Baryshkov <dmitry.baryshkov(a)linaro.org>

1 year, 3 months

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[PATCH] cxl/region: Fix logic for finding a free cxl decoder

by Zijun Hu

From: Zijun Hu <quic_zijuhu(a)quicinc.com> match_free_decoder()'s logic for finding a free cxl decoder depends on a prerequisite that all child decoders are sorted by ID in ascending order but the prerequisite may not be guaranteed, fix by finding a free cxl decoder with minimal ID. Fixes: 384e624bb211 ("cxl/region: Attach endpoint decoders") Closes: https://lore.kernel.org/all/cdfc6f98-1aa0-4cb5-bd7d-93256552c39b@icloud.com/ Cc: stable(a)vger.kernel.org Signed-off-by: Zijun Hu <quic_zijuhu(a)quicinc.com> --- drivers/cxl/core/region.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 21ad5f242875..b9607b4fc40b 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -797,21 +797,26 @@ static size_t show_targetN(struct cxl_region *cxlr, char *buf, int pos) static int match_free_decoder(struct device *dev, void *data) { struct cxl_decoder *cxld; - int *id = data; + struct cxl_decoder *target_cxld; + struct device **target_device = data; if (!is_switch_decoder(dev)) return 0; cxld = to_cxl_decoder(dev); - - /* enforce ordered allocation */ - if (cxld->id != *id) + if (cxld->region) return 0; - if (!cxld->region) - return 1; - - (*id)++; + if (!*target_device) { + *target_device = get_device(dev); + return 0; + } + /* enforce ordered allocation */ + target_cxld = to_cxl_decoder(*target_device); + if (cxld->id < target_cxld->id) { + put_device(*target_device); + *target_device = get_device(dev); + } return 0; } @@ -839,8 +844,7 @@ cxl_region_find_decoder(struct cxl_port *port, struct cxl_endpoint_decoder *cxled, struct cxl_region *cxlr) { - struct device *dev; - int id = 0; + struct device *dev = NULL; if (port == cxled_to_port(cxled)) return &cxled->cxld; @@ -849,7 +853,8 @@ cxl_region_find_decoder(struct cxl_port *port, dev = device_find_child(&port->dev, &cxlr->params, match_auto_decoder); else - dev = device_find_child(&port->dev, &id, match_free_decoder); + /* Need to put_device(@dev) after use */ + device_for_each_child(&port->dev, &dev, match_free_decoder); if (!dev) return NULL; /* --- base-commit: 67784a74e258a467225f0e68335df77acd67b7ab change-id: 20240903-fix_cxld-4f6575a90619 Best regards, -- Zijun Hu <quic_zijuhu(a)quicinc.com>

1 year, 3 months

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[for-linus][PATCH 6/6] eventfs: Use list_del_rcu() for SRCU protected list variable

by Steven Rostedt

From: Steven Rostedt <rostedt(a)goodmis.org> Chi Zhiling reported: We found a null pointer accessing in tracefs[1], the reason is that the variable 'ei_child' is set to LIST_POISON1, that means the list was removed in eventfs_remove_rec. so when access the ei_child->is_freed, the panic triggered. by the way, the following script can reproduce this panic loop1 (){ while true do echo "p:kp submit_bio" > /sys/kernel/debug/tracing/kprobe_events echo "" > /sys/kernel/debug/tracing/kprobe_events done } loop2 (){ while true do tree /sys/kernel/debug/tracing/events/kprobes/ done } loop1 & loop2 [1]: [ 1147.959632][T17331] Unable to handle kernel paging request at virtual address dead000000000150 [ 1147.968239][T17331] Mem abort info: [ 1147.971739][T17331] ESR = 0x0000000096000004 [ 1147.976172][T17331] EC = 0x25: DABT (current EL), IL = 32 bits [ 1147.982171][T17331] SET = 0, FnV = 0 [ 1147.985906][T17331] EA = 0, S1PTW = 0 [ 1147.989734][T17331] FSC = 0x04: level 0 translation fault [ 1147.995292][T17331] Data abort info: [ 1147.998858][T17331] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 1148.005023][T17331] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 1148.010759][T17331] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 1148.016752][T17331] [dead000000000150] address between user and kernel address ranges [ 1148.024571][T17331] Internal error: Oops: 0000000096000004 [#1] SMP [ 1148.030825][T17331] Modules linked in: team_mode_loadbalance team nlmon act_gact cls_flower sch_ingress bonding tls macvlan dummy ib_core bridge stp llc veth amdgpu amdxcp mfd_core gpu_sched drm_exec drm_buddy radeon crct10dif_ce video drm_suballoc_helper ghash_ce drm_ttm_helper sha2_ce ttm sha256_arm64 i2c_algo_bit sha1_ce sbsa_gwdt cp210x drm_display_helper cec sr_mod cdrom drm_kms_helper binfmt_misc sg loop fuse drm dm_mod nfnetlink ip_tables autofs4 [last unloaded: tls] [ 1148.072808][T17331] CPU: 3 PID: 17331 Comm: ls Tainted: G W ------- ---- 6.6.43 #2 [ 1148.081751][T17331] Source Version: 21b3b386e948bedd29369af66f3e98ab01b1c650 [ 1148.088783][T17331] Hardware name: Greatwall GW-001M1A-FTF/GW-001M1A-FTF, BIOS KunLun BIOS V4.0 07/16/2020 [ 1148.098419][T17331] pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 1148.106060][T17331] pc : eventfs_iterate+0x2c0/0x398 [ 1148.111017][T17331] lr : eventfs_iterate+0x2fc/0x398 [ 1148.115969][T17331] sp : ffff80008d56bbd0 [ 1148.119964][T17331] x29: ffff80008d56bbf0 x28: ffff001ff5be2600 x27: 0000000000000000 [ 1148.127781][T17331] x26: ffff001ff52ca4e0 x25: 0000000000009977 x24: dead000000000100 [ 1148.135598][T17331] x23: 0000000000000000 x22: 000000000000000b x21: ffff800082645f10 [ 1148.143415][T17331] x20: ffff001fddf87c70 x19: ffff80008d56bc90 x18: 0000000000000000 [ 1148.151231][T17331] x17: 0000000000000000 x16: 0000000000000000 x15: ffff001ff52ca4e0 [ 1148.159048][T17331] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 [ 1148.166864][T17331] x11: 0000000000000000 x10: 0000000000000000 x9 : ffff8000804391d0 [ 1148.174680][T17331] x8 : 0000000180000000 x7 : 0000000000000018 x6 : 0000aaab04b92862 [ 1148.182498][T17331] x5 : 0000aaab04b92862 x4 : 0000000080000000 x3 : 0000000000000068 [ 1148.190314][T17331] x2 : 000000000000000f x1 : 0000000000007ea8 x0 : 0000000000000001 [ 1148.198131][T17331] Call trace: [ 1148.201259][T17331] eventfs_iterate+0x2c0/0x398 [ 1148.205864][T17331] iterate_dir+0x98/0x188 [ 1148.210036][T17331] __arm64_sys_getdents64+0x78/0x160 [ 1148.215161][T17331] invoke_syscall+0x78/0x108 [ 1148.219593][T17331] el0_svc_common.constprop.0+0x48/0xf0 [ 1148.224977][T17331] do_el0_svc+0x24/0x38 [ 1148.228974][T17331] el0_svc+0x40/0x168 [ 1148.232798][T17331] el0t_64_sync_handler+0x120/0x130 [ 1148.237836][T17331] el0t_64_sync+0x1a4/0x1a8 [ 1148.242182][T17331] Code: 54ffff6c f9400676 910006d6 f9000676 (b9405300) [ 1148.248955][T17331] ---[ end trace 0000000000000000 ]--- The issue is that list_del() is used on an SRCU protected list variable before the synchronization occurs. This can poison the list pointers while there is a reader iterating the list. This is simply fixed by using list_del_rcu() that is specifically made for this purpose. Link: https://lore.kernel.org/linux-trace-kernel/20240829085025.3600021-1-chizhil… Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Link: https://lore.kernel.org/20240904131605.640d42b1@gandalf.local.home Fixes: 43aa6f97c2d03 ("eventfs: Get rid of dentry pointers without refcounts") Reported-by: Chi Zhiling <chizhiling(a)kylinos.cn> Tested-by: Chi Zhiling <chizhiling(a)kylinos.cn> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- fs/tracefs/event_inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 01e99e98457d..8705c77a9e75 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -862,7 +862,7 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, int level) list_for_each_entry(ei_child, &ei->children, list) eventfs_remove_rec(ei_child, level + 1); - list_del(&ei->list); + list_del_rcu(&ei->list); free_ei(ei); } -- 2.43.0

1 year, 3 months

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[for-linus][PATCH 5/6] tracing: Avoid possible softlockup in tracing_iter_reset()

by Steven Rostedt

From: Zheng Yejian <zhengyejian(a)huaweicloud.com> In __tracing_open(), when max latency tracers took place on the cpu, the time start of its buffer would be updated, then event entries with timestamps being earlier than start of the buffer would be skipped (see tracing_iter_reset()). Softlockup will occur if the kernel is non-preemptible and too many entries were skipped in the loop that reset every cpu buffer, so add cond_resched() to avoid it. Cc: stable(a)vger.kernel.org Fixes: 2f26ebd549b9a ("tracing: use timestamp to determine start of latency traces") Link: https://lore.kernel.org/20240827124654.3817443-1-zhengyejian@huaweicloud.com Suggested-by: Steven Rostedt <rostedt(a)goodmis.org> Signed-off-by: Zheng Yejian <zhengyejian(a)huaweicloud.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/trace.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index ebe7ce2f5f4a..edf6bc817aa1 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3958,6 +3958,8 @@ void tracing_iter_reset(struct trace_iterator *iter, int cpu) break; entries++; ring_buffer_iter_advance(buf_iter); + /* This could be a big loop */ + cond_resched(); } per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = entries; -- 2.43.0

1 year, 3 months

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[for-linus][PATCH 4/6] tracing/osnoise: Use a cpumask to know what threads are kthreads

by Steven Rostedt

From: Steven Rostedt <rostedt(a)goodmis.org> The start_kthread() and stop_thread() code was not always called with the interface_lock held. This means that the kthread variable could be unexpectedly changed causing the kthread_stop() to be called on it when it should not have been, leading to: while true; do rtla timerlat top -u -q & PID=$!; sleep 5; kill -INT $PID; sleep 0.001; kill -TERM $PID; wait $PID; done Causing the following OOPS: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 5 UID: 0 PID: 885 Comm: timerlatu/5 Not tainted 6.11.0-rc4-test-00002-gbc754cc76d1b-dirty #125 a533010b71dab205ad2f507188ce8c82203b0254 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:hrtimer_active+0x58/0x300 Code: 48 c1 ee 03 41 54 48 01 d1 48 01 d6 55 53 48 83 ec 20 80 39 00 0f 85 30 02 00 00 49 8b 6f 30 4c 8d 75 10 4c 89 f0 48 c1 e8 03 <0f> b6 3c 10 4c 89 f0 83 e0 07 83 c0 03 40 38 f8 7c 09 40 84 ff 0f RSP: 0018:ffff88811d97f940 EFLAGS: 00010202 RAX: 0000000000000002 RBX: ffff88823c6b5b28 RCX: ffffed10478d6b6b RDX: dffffc0000000000 RSI: ffffed10478d6b6c RDI: ffff88823c6b5b28 RBP: 0000000000000000 R08: ffff88823c6b5b58 R09: ffff88823c6b5b60 R10: ffff88811d97f957 R11: 0000000000000010 R12: 00000000000a801d R13: ffff88810d8b35d8 R14: 0000000000000010 R15: ffff88823c6b5b28 FS: 0000000000000000(0000) GS:ffff88823c680000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561858ad7258 CR3: 000000007729e001 CR4: 0000000000170ef0 Call Trace: <TASK> ? die_addr+0x40/0xa0 ? exc_general_protection+0x154/0x230 ? asm_exc_general_protection+0x26/0x30 ? hrtimer_active+0x58/0x300 ? __pfx_mutex_lock+0x10/0x10 ? __pfx_locks_remove_file+0x10/0x10 hrtimer_cancel+0x15/0x40 timerlat_fd_release+0x8e/0x1f0 ? security_file_release+0x43/0x80 __fput+0x372/0xb10 task_work_run+0x11e/0x1f0 ? _raw_spin_lock+0x85/0xe0 ? __pfx_task_work_run+0x10/0x10 ? poison_slab_object+0x109/0x170 ? do_exit+0x7a0/0x24b0 do_exit+0x7bd/0x24b0 ? __pfx_migrate_enable+0x10/0x10 ? __pfx_do_exit+0x10/0x10 ? __pfx_read_tsc+0x10/0x10 ? ktime_get+0x64/0x140 ? _raw_spin_lock_irq+0x86/0xe0 do_group_exit+0xb0/0x220 get_signal+0x17ba/0x1b50 ? vfs_read+0x179/0xa40 ? timerlat_fd_read+0x30b/0x9d0 ? __pfx_get_signal+0x10/0x10 ? __pfx_timerlat_fd_read+0x10/0x10 arch_do_signal_or_restart+0x8c/0x570 ? __pfx_arch_do_signal_or_restart+0x10/0x10 ? vfs_read+0x179/0xa40 ? ksys_read+0xfe/0x1d0 ? __pfx_ksys_read+0x10/0x10 syscall_exit_to_user_mode+0xbc/0x130 do_syscall_64+0x74/0x110 ? __pfx___rseq_handle_notify_resume+0x10/0x10 ? __pfx_ksys_read+0x10/0x10 ? fpregs_restore_userregs+0xdb/0x1e0 ? fpregs_restore_userregs+0xdb/0x1e0 ? syscall_exit_to_user_mode+0x116/0x130 ? do_syscall_64+0x74/0x110 ? do_syscall_64+0x74/0x110 ? do_syscall_64+0x74/0x110 entry_SYSCALL_64_after_hwframe+0x71/0x79 RIP: 0033:0x7ff0070eca9c Code: Unable to access opcode bytes at 0x7ff0070eca72. RSP: 002b:00007ff006dff8c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007ff0070eca9c RDX: 0000000000000400 RSI: 00007ff006dff9a0 RDI: 0000000000000003 RBP: 00007ff006dffde0 R08: 0000000000000000 R09: 00007ff000000ba0 R10: 00007ff007004b08 R11: 0000000000000246 R12: 0000000000000003 R13: 00007ff006dff9a0 R14: 0000000000000007 R15: 0000000000000008 </TASK> Modules linked in: snd_hda_intel snd_intel_dspcfg snd_intel_sdw_acpi snd_hda_codec snd_hwdep snd_hda_core ---[ end trace 0000000000000000 ]--- This is because it would mistakenly call kthread_stop() on a user space thread making it "exit" before it actually exits. Since kthreads are created based on global behavior, use a cpumask to know when kthreads are running and that they need to be shutdown before proceeding to do new work. Link: https://lore.kernel.org/all/20240820130001.124768-1-tglozar@redhat.com/ This was debugged by using the persistent ring buffer: Link: https://lore.kernel.org/all/20240823013902.135036960@goodmis.org/ Note, locking was originally used to fix this, but that proved to cause too many deadlocks to work around: https://lore.kernel.org/linux-trace-kernel/20240823102816.5e55753b@gandalf.… Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Cc: "Luis Claudio R. Goncalves" <lgoncalv(a)redhat.com> Link: https://lore.kernel.org/20240904103428.08efdf4c@gandalf.local.home Fixes: e88ed227f639e ("tracing/timerlat: Add user-space interface") Reported-by: Tomas Glozar <tglozar(a)redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/trace_osnoise.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c index 400a72cd6ab5..8543d941b870 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -1614,6 +1614,7 @@ static int run_osnoise(void) static struct cpumask osnoise_cpumask; static struct cpumask save_cpumask; +static struct cpumask kthread_cpumask; /* * osnoise_sleep - sleep until the next period @@ -1677,6 +1678,7 @@ static inline int osnoise_migration_pending(void) */ mutex_lock(&interface_lock); this_cpu_osn_var()->kthread = NULL; + cpumask_clear_cpu(smp_processor_id(), &kthread_cpumask); mutex_unlock(&interface_lock); return 1; @@ -1949,9 +1951,10 @@ static void stop_kthread(unsigned int cpu) kthread = per_cpu(per_cpu_osnoise_var, cpu).kthread; if (kthread) { - if (test_bit(OSN_WORKLOAD, &osnoise_options)) { + if (cpumask_test_and_clear_cpu(cpu, &kthread_cpumask) && + !WARN_ON(!test_bit(OSN_WORKLOAD, &osnoise_options))) { kthread_stop(kthread); - } else { + } else if (!WARN_ON(test_bit(OSN_WORKLOAD, &osnoise_options))) { /* * This is a user thread waiting on the timerlat_fd. We need * to close all users, and the best way to guarantee this is @@ -2023,6 +2026,7 @@ static int start_kthread(unsigned int cpu) } per_cpu(per_cpu_osnoise_var, cpu).kthread = kthread; + cpumask_set_cpu(cpu, &kthread_cpumask); return 0; } @@ -2050,8 +2054,16 @@ static int start_per_cpu_kthreads(void) */ cpumask_and(current_mask, cpu_online_mask, &osnoise_cpumask); - for_each_possible_cpu(cpu) + for_each_possible_cpu(cpu) { + if (cpumask_test_and_clear_cpu(cpu, &kthread_cpumask)) { + struct task_struct *kthread; + + kthread = per_cpu(per_cpu_osnoise_var, cpu).kthread; + if (!WARN_ON(!kthread)) + kthread_stop(kthread); + } per_cpu(per_cpu_osnoise_var, cpu).kthread = NULL; + } for_each_cpu(cpu, current_mask) { retval = start_kthread(cpu); -- 2.43.0

1 year, 3 months

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[for-linus][PATCH 3/6] tracing/timerlat: Only clear timer if a kthread exists

by Steven Rostedt

From: Steven Rostedt <rostedt(a)goodmis.org> The timerlat tracer can use user space threads to check for osnoise and timer latency. If the program using this is killed via a SIGTERM, the threads are shutdown one at a time and another tracing instance can start up resetting the threads before they are fully closed. That causes the hrtimer assigned to the kthread to be shutdown and freed twice when the dying thread finally closes the file descriptors, causing a use-after-free bug. Only cancel the hrtimer if the associated thread is still around. Note, this is just a quick fix that can be backported to stable. A real fix is to have a better synchronization between the shutdown of old threads and the starting of new ones. Link: https://lore.kernel.org/all/20240820130001.124768-1-tglozar@redhat.com/ Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com> Cc: "Luis Claudio R. Goncalves" <lgoncalv(a)redhat.com> Link: https://lore.kernel.org/20240903111642.35292e70@gandalf.local.home Fixes: e88ed227f639e ("tracing/timerlat: Add user-space interface") Reported-by: Tomas Glozar <tglozar(a)redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/trace_osnoise.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c index 66a871553d4a..400a72cd6ab5 100644 --- a/kernel/trace/trace_osnoise.c +++ b/kernel/trace/trace_osnoise.c @@ -265,6 +265,8 @@ static inline void tlat_var_reset(void) */ for_each_cpu(cpu, cpu_online_mask) { tlat_var = per_cpu_ptr(&per_cpu_timerlat_var, cpu); + if (tlat_var->kthread) + hrtimer_cancel(&tlat_var->timer); memset(tlat_var, 0, sizeof(*tlat_var)); } } @@ -2579,7 +2581,8 @@ static int timerlat_fd_release(struct inode *inode, struct file *file) osn_var = per_cpu_ptr(&per_cpu_osnoise_var, cpu); tlat_var = per_cpu_ptr(&per_cpu_timerlat_var, cpu); - hrtimer_cancel(&tlat_var->timer); + if (tlat_var->kthread) + hrtimer_cancel(&tlat_var->timer); memset(tlat_var, 0, sizeof(*tlat_var)); osn_var->sampling = 0; -- 2.43.0

1 year, 3 months

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[for-linus][PATCH 2/6] tracing: Fix memory leak in fgraph storage selftest

by Steven Rostedt

From: "Masami Hiramatsu (Google)" <mhiramat(a)kernel.org> With ftrace boot-time selftest, kmemleak reported some memory leaks in the new test case for function graph storage for multiple tracers. unreferenced object 0xffff888005060080 (size 32): comm "swapper/0", pid 1, jiffies 4294676440 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 20 10 06 05 80 88 ff ff ........ ....... 54 0c 1e 81 ff ff ff ff 00 00 00 00 00 00 00 00 T............... backtrace (crc 7c93416c): [<000000000238ee6f>] __kmalloc_cache_noprof+0x11f/0x2a0 [<0000000033d2b6c5>] enter_record+0xe8/0x150 [<0000000054c38424>] match_records+0x1cd/0x230 [<00000000c775b63d>] ftrace_set_hash+0xff/0x380 [<000000007bf7208c>] ftrace_set_filter+0x70/0x90 [<00000000a5c08dda>] test_graph_storage_multi+0x2e/0xf0 [<000000006ba028ca>] trace_selftest_startup_function_graph+0x1e8/0x260 [<00000000a715d3eb>] run_tracer_selftest+0x111/0x190 [<00000000395cbf90>] register_tracer+0xdf/0x1f0 [<0000000093e67f7b>] do_one_initcall+0x141/0x3b0 [<00000000c591b682>] do_initcall_level+0x82/0xa0 [<000000004e4c6600>] do_initcalls+0x43/0x70 [<0000000034f3c4e4>] kernel_init_freeable+0x170/0x1f0 [<00000000c7a5dab2>] kernel_init+0x1a/0x1a0 [<00000000ea105947>] ret_from_fork+0x3a/0x50 [<00000000a1932e84>] ret_from_fork_asm+0x1a/0x30 ... This means filter hash allocated for the fixtures are not correctly released after the test. Free those hash lists after tests are done and split the loop for initialize fixture and register fixture for rollback. Fixes: dd120af2d5f8 ("ftrace: Add multiple fgraph storage selftest") Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/172411539857.28895.13119957560263401102.stgit@devno… Signed-off-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/trace_selftest.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 97f1e4bc47dc..c4ad7cd7e778 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -942,7 +942,7 @@ static __init int test_graph_storage_multi(void) { struct fgraph_fixture *fixture; bool printed = false; - int i, ret; + int i, j, ret; pr_cont("PASSED\n"); pr_info("Testing multiple fgraph storage on a function: "); @@ -953,22 +953,35 @@ static __init int test_graph_storage_multi(void) if (ret && ret != -ENODEV) { pr_cont("*Could not set filter* "); printed = true; - goto out; + goto out2; } + } + for (j = 0; j < ARRAY_SIZE(store_bytes); j++) { + fixture = &store_bytes[j]; ret = register_ftrace_graph(&fixture->gops); if (ret) { pr_warn("Failed to init store_bytes fgraph tracing\n"); printed = true; - goto out; + goto out1; } } DYN_FTRACE_TEST_NAME(); -out: +out1: + while (--j >= 0) { + fixture = &store_bytes[j]; + unregister_ftrace_graph(&fixture->gops); + + if (fixture->error_str && !printed) { + pr_cont("*** %s ***", fixture->error_str); + printed = true; + } + } +out2: while (--i >= 0) { fixture = &store_bytes[i]; - unregister_ftrace_graph(&fixture->gops); + ftrace_free_filter(&fixture->gops.ops); if (fixture->error_str && !printed) { pr_cont("*** %s ***", fixture->error_str); -- 2.43.0

1 year, 3 months

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[PATCH 8/8] serial: qcom-geni: fix polled console corruption

by Johan Hovold

The polled UART operations are used by the kernel debugger (KDB, KGDB), which can interrupt the kernel at any point in time. The current Qualcomm GENI implementation does not really work when there is on-going serial output as it inadvertently "hijacks" the current tx command, which can result in both the initial debugger output being corrupted as well as the corruption of any on-going serial output (up to 4k characters) when execution resumes: 0190: abcdefghijklmnopqrstuvwxyz0123456789 0190: abcdefghijklmnopqrstuvwxyz0123456789 0191: abcdefghijklmnop[ 50.825552] sysrq: DEBUG qrstuvwxyz0123456789 0191: abcdefghijklmnopqrstuvwxyz0123456789 Entering kdb (current=0xffff53510b4cd280, pid 640) on processor 2 due to Keyboard Entry [2]kdb> go omlji3h3h2g2g1f1f0e0ezdzdycycxbxbwawav :t72r2rp o9n976k5j5j4i4i3h3h2g2g1f1f0e0ezdzdycycxbxbwawavu:t7t8s8s8r2r2q0q0p o9n9n8ml6k6k5j5j4i4i3h3h2g2g1f1f0e0ezdzdycycxbxbwawav v u:u:t9t0s4s4rq0p o9n9n8m8m7l7l6k6k5j5j40q0p p o o9n9n8m8m7l7l6k6k5j5j4i4i3h3h2g2g1f1f0e0ezdzdycycxbxbwawav :t8t9s4s4r4r4q0q0p Fix this by making sure that the polled output implementation waits for the tx fifo to drain before cancelling any on-going longer transfers. As the polled code cannot take any locks, leave the state variables as they are and instead make sure that the interrupt handler always starts a new tx command when there is data in the write buffer. Since the debugger can interrupt the interrupt handler when it is writing data to the tx fifo, it is currently not possible to fully prevent losing up to 64 bytes of tty output on resume. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Cc: stable(a)vger.kernel.org # 4.17 Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/tty/serial/qcom_geni_serial.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index fbed143c90a3..cf8bafd99a09 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -145,6 +145,7 @@ static const struct uart_ops qcom_geni_uart_pops; static struct uart_driver qcom_geni_console_driver; static struct uart_driver qcom_geni_uart_driver; +static void __qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport); static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport); static inline struct qcom_geni_serial_port *to_dev_port(struct uart_port *uport) @@ -403,13 +404,14 @@ static int qcom_geni_serial_get_char(struct uart_port *uport) static void qcom_geni_serial_poll_put_char(struct uart_port *uport, unsigned char c) { - writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG); + if (qcom_geni_serial_main_active(uport)) { + qcom_geni_serial_poll_tx_done(uport); + __qcom_geni_serial_cancel_tx_cmd(uport); + } + writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); qcom_geni_serial_setup_tx(uport, 1); - WARN_ON(!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, - M_TX_FIFO_WATERMARK_EN, true)); writel(c, uport->membase + SE_GENI_TX_FIFOn); - writel(M_TX_FIFO_WATERMARK_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); qcom_geni_serial_poll_tx_done(uport); } #endif @@ -688,13 +690,10 @@ static void qcom_geni_serial_stop_tx_fifo(struct uart_port *uport) writel(irq_en, uport->membase + SE_GENI_M_IRQ_EN); } -static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport) +static void __qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport) { struct qcom_geni_serial_port *port = to_dev_port(uport); - if (!qcom_geni_serial_main_active(uport)) - return; - geni_se_cancel_m_cmd(&port->se); if (!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_CMD_CANCEL_EN, true)) { @@ -704,6 +703,16 @@ static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport) writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); } writel(M_CMD_CANCEL_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); +} + +static void qcom_geni_serial_cancel_tx_cmd(struct uart_port *uport) +{ + struct qcom_geni_serial_port *port = to_dev_port(uport); + + if (!qcom_geni_serial_main_active(uport)) + return; + + __qcom_geni_serial_cancel_tx_cmd(uport); port->tx_remaining = 0; port->tx_queued = 0; @@ -930,7 +939,7 @@ static void qcom_geni_serial_handle_tx_fifo(struct uart_port *uport, if (!chunk) goto out_write_wakeup; - if (!port->tx_remaining) { + if (!active) { qcom_geni_serial_setup_tx(uport, pending); port->tx_remaining = pending; port->tx_queued = 0; -- 2.44.2

1 year, 3 months

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[PATCH 2/8] serial: qcom-geni: fix false console tx restart

by Johan Hovold

Commit 663abb1a7a7f ("tty: serial: qcom_geni_serial: Fix UART hang") addressed an issue with stalled tx after the console code interrupted the last bytes of a tx command by reenabling the watermark interrupt if there is data in write buffer. This can however break software flow control by re-enabling tx after the user has stopped it. Address the original issue by not clearing the CMD_DONE flag after polling for command completion. This allows the interrupt handler to start another transfer when the CMD_DONE interrupt has not been disabled due to flow control. Fixes: c4f528795d1a ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP") Fixes: 663abb1a7a7f ("tty: serial: qcom_geni_serial: Fix UART hang") Cc: stable(a)vger.kernel.org # 4.17 Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/tty/serial/qcom_geni_serial.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index e1926124339d..0af4a93c0af5 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -314,18 +314,16 @@ static void qcom_geni_serial_setup_tx(struct uart_port *uport, u32 xmit_size) static void qcom_geni_serial_poll_tx_done(struct uart_port *uport) { int done; - u32 irq_clear = M_CMD_DONE_EN; done = qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_CMD_DONE_EN, true); if (!done) { writel(M_GENI_CMD_ABORT, uport->membase + SE_GENI_M_CMD_CTRL_REG); - irq_clear |= M_CMD_ABORT_EN; qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_CMD_ABORT_EN, true); + writel(M_CMD_ABORT_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); } - writel(irq_clear, uport->membase + SE_GENI_M_IRQ_CLEAR); } static void qcom_geni_serial_abort_rx(struct uart_port *uport) @@ -386,6 +384,7 @@ static void qcom_geni_serial_poll_put_char(struct uart_port *uport, unsigned char c) { writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG); + writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); qcom_geni_serial_setup_tx(uport, 1); WARN_ON(!qcom_geni_serial_poll_bit(uport, SE_GENI_M_IRQ_STATUS, M_TX_FIFO_WATERMARK_EN, true)); @@ -430,6 +429,7 @@ __qcom_geni_serial_console_write(struct uart_port *uport, const char *s, } writel(DEF_TX_WM, uport->membase + SE_GENI_TX_WATERMARK_REG); + writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_CLEAR); qcom_geni_serial_setup_tx(uport, bytes_to_send); for (i = 0; i < count; ) { size_t chars_to_write = 0; @@ -471,7 +471,6 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s, bool locked = true; unsigned long flags; u32 geni_status; - u32 irq_en; WARN_ON(co->index < 0 || co->index >= GENI_UART_CONS_PORTS); @@ -503,12 +502,6 @@ static void qcom_geni_serial_console_write(struct console *co, const char *s, * has been sent, in which case we need to look for done first. */ qcom_geni_serial_poll_tx_done(uport); - - if (!kfifo_is_empty(&uport->state->port.xmit_fifo)) { - irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN); - writel(irq_en | M_TX_FIFO_WATERMARK_EN, - uport->membase + SE_GENI_M_IRQ_EN); - } } __qcom_geni_serial_console_write(uport, s, count); -- 2.44.2

1 year, 3 months

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