- Oct 03, 2024
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Wei Li authored
The cpuhp online/offline processing race also exists in percpu-mode hwlat tracer in theory, apply the fix too. That is: T1 | T2 [CPUHP_ONLINE] | cpu_device_down() hwlat_hotplug_workfn() | | cpus_write_lock() | takedown_cpu(1) | cpus_write_unlock() [CPUHP_OFFLINE] | cpus_read_lock() | start_kthread(1) | cpus_read_unlock() | Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20240924094515.3561410-5-liwei391@huawei.com Fixes: ba998f7d ("trace/hwlat: Support hotplug operations") Signed-off-by:Wei Li <liwei391@huawei.com> Signed-off-by:
Steven Rostedt (Google) <rostedt@goodmis.org>
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Wei Li authored
There is another found exception that the "timerlat/1" thread was scheduled on CPU0, and lead to timer corruption finally: ``` ODEBUG: init active (active state 0) object: ffff888237c2e108 object type: hrtimer hint: timerlat_irq+0x0/0x220 WARNING: CPU: 0 PID: 426 at lib/debugobjects.c:518 debug_print_object+0x7d/0xb0 Modules linked in: CPU: 0 UID: 0 PID: 426 Comm: timerlat/1 Not tainted 6.11.0-rc7+ #45 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014 RIP: 0010:debug_print_object+0x7d/0xb0 ... Call Trace: <TASK> ? __warn+0x7c/0x110 ? debug_print_object+0x7d/0xb0 ? report_bug+0xf1/0x1d0 ? prb_read_valid+0x17/0x20 ? handle_bug+0x3f/0x70 ? exc_invalid_op+0x13/0x60 ? asm_exc_invalid_op+0x16/0x20 ? debug_print_object+0x7d/0xb0 ? debug_print_object+0x7d/0xb0 ? __pfx_timerlat_irq+0x10/0x10 __debug_object_init+0x110/0x150 hrtimer_init+0x1d/0x60 timerlat_main+0xab/0x2d0 ? __pfx_timerlat_main+0x10/0x10 kthread+0xb7/0xe0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2d/0x40 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> ``` After tracing the scheduling event, it was discovered that the migration of the "timerlat/1" thread was performed during thread creation. Further analysis confirmed that it is because the CPU online processing for osnoise is implemented through workers, which is asynchronous with the offline processing. When the worker was scheduled to create a thread, the CPU may has already been removed from the cpu_online_mask during the offline process, resulting in the inability to select the right CPU: T1 | T2 [CPUHP_ONLINE] | cpu_device_down() osnoise_hotplug_workfn() | | cpus_write_lock() | takedown_cpu(1) | cpus_write_unlock() [CPUHP_OFFLINE] | cpus_read_lock() | start_kthread(1) | cpus_read_unlock() | To fix this, skip online processing if the CPU is already offline. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20240924094515.3561410-4-liwei391@huawei.com Fixes: c8895e27 ("trace/osnoise: Support hotplug operations") Signed-off-by: -
Wei Li authored
stop_kthread() is the offline callback for "trace/osnoise:online", since commit 5bfbcd1e ("tracing/timerlat: Add interface_lock around clearing of kthread in stop_kthread()"), the following ABBA deadlock scenario is introduced: T1 | T2 [BP] | T3 [AP] osnoise_hotplug_workfn() | work_for_cpu_fn() | cpuhp_thread_fun() | _cpu_down() | osnoise_cpu_die() mutex_lock(&interface_lock) | | stop_kthread() | cpus_write_lock() | mutex_lock(&interface_lock) cpus_read_lock() | cpuhp_kick_ap() | As the interface_lock here in just for protecting the "kthread" field of the osn_var, use xchg() instead to fix this issue. Also use for_each_online_cpu() back in stop_per_cpu_kthreads() as it can take cpu_read_lock() again. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20240924094515.3561410-3-liwei391@huawei.com Fixes: 5bfbcd1e ("tracing/timerlat: Add interface_lock around clearing of kthread in stop_kthread()") Signed-off-by:
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Wei Li authored
osnoise_hotplug_workfn() is the asynchronous online callback for "trace/osnoise:online". It may be congested when a CPU goes online and offline repeatedly and is invoked for multiple times after a certain online. This will lead to kthread leak and timer corruption. Add a check in start_kthread() to prevent this situation. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20240924094515.3561410-2-liwei391@huawei.com Fixes: c8895e27 ("trace/osnoise: Support hotplug operations") Signed-off-by:
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Steven Rostedt authored
When the tp_printk kernel command line is used, the trace events go directly to printk(). It is still checked via the trace_check_vprintf() function to make sure the pointers of the trace event are legit. The addition of reading buffers from previous boots required adding a delta between the addresses of the previous boot and the current boot so that the pointers in the old buffer can still be used. But this required adding a trace_array pointer to acquire the delta offsets. The tp_printk code does not provide a trace_array (tr) pointer, so when the offsets were examined, a NULL pointer dereference happened and the kernel crashed. If the trace_array does not exist, just default the delta offsets to zero, as that also means the trace event is not being read from a previous boot. Link: https://lore.kernel.org/all/Zv3z5UsG_jsO9_Tb@aschofie-mobl2.lan/ Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20241003104925.4e1b1fd9@gandalf.local.home Fixes: 07714b4b ("tracing: Handle old buffer mappings for event strings and functions") Reported-by:
Alison Schofield <alison.schofield@intel.com> Tested-by:
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- Sep 27, 2024
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Al Viro authored
no_llseek had been defined to NULL two years ago, in commit 868941b1 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\<no_llseek\>/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- Sep 26, 2024
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Linus Torvalds authored
This reverts commit fb97d2eb. The logging was questionable to begin with, but it seems to actively deadlock on the task lock. "On second thought, let's not log core dump failures. 'Tis a silly place" because if you can't tell your core dump is truncated, maybe you should just fix your debugger instead of adding bugs to the kernel. Reported-by:
Vegard Nossum <vegard.nossum@oracle.com> Link: https://lore.kernel.org/all/d122ece6-3606-49de-ae4d-8da88846bef2@oracle.com/ Signed-off-by:
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- Sep 25, 2024
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Linus Torvalds authored
Currently the Rust support is gated on not having MODVERSIONS enabled, and as a result an "allmodconfig" build will disable Rust build tests. While MODVERSIONS configurations are worth build testing, the feature is not actually meaningful unless you run the result, and I'd rather get build coverage of Rust than MODVERSIONS. So let's disable MODVERSIONS for build testing until the Rust side clears up. Signed-off-by: -
Masami Hiramatsu (Google) authored
Support raw tracepoint events on future loaded (unloaded) modules. This allows user to create raw tracepoint events which can be used from module's __init functions. Note: since the kernel does not have any information about the tracepoints in the unloaded modules, fprobe events can not check whether the tracepoint exists nor extend the BTF based arguments. Link: https://lore.kernel.org/all/172397780593.286558.18360375226968537828.stgit@devnote2/ Suggested-by:
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by:
Masami Hiramatsu (Google) <mhiramat@kernel.org>
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Masami Hiramatsu (Google) authored
Support raw tracepoint event on module by fprobe events. Since it only uses for_each_kernel_tracepoint() to find a tracepoint, the tracepoints on modules are not handled. Thus if user specified a tracepoint on a module, it shows an error. This adds new for_each_module_tracepoint() API to tracepoint subsystem, and uses it to find tracepoints on modules. Link: https://lore.kernel.org/all/172397779651.286558.15903703620679186867.stgit@devnote2/ Reported-by:
don <zds100@gmail.com> Closes: https://lore.kernel.org/all/20240530215718.aeec973a1d0bf058d39cb1e3@kernel.org/ Signed-off-by:
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Masami Hiramatsu (Google) authored
Add for_each_tracepoint_in_module() function to iterate tracepoints in a module. This API is needed for handling tracepoints in a loading module from tracepoint_module_notifier callback function. This also update for_each_module_tracepoint() to pass the module to callback function so that it can find module easily. Link: https://lore.kernel.org/all/172397778740.286558.15781131277732977643.stgit@devnote2/ Signed-off-by:
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Masami Hiramatsu (Google) authored
Add for_each_module_tracepoint() for iterating over tracepoints on modules. This is similar to the for_each_kernel_tracepoint() but only for the tracepoints on modules (not including kernel built-in tracepoints). Link: https://lore.kernel.org/all/172397777800.286558.14554748203446214056.stgit@devnote2/ Signed-off-by:
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Andrii Nakryiko authored
trace_uprobe->nhit counter is not incremented atomically, so its value is questionable in when uprobe is hit on multiple CPUs simultaneously. Also, doing this shared counter increment across many CPUs causes heavy cache line bouncing, limiting uprobe/uretprobe performance scaling with number of CPUs. Solve both problems by making this a per-CPU counter. Link: https://lore.kernel.org/all/20240813203409.3985398-1-andrii@kernel.org/ Reviewed-by:
Oleg Nesterov <oleg@redhat.com> Signed-off-by:
Andrii Nakryiko <andrii@kernel.org> Signed-off-by:
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- Sep 23, 2024
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Andrea Righi authored
As discussed during the distro-centric session within the sched_ext Microconference at LPC 2024, introduce a sequence counter that is incremented every time a BPF scheduler is loaded. This feature can help distributions in diagnosing potential performance regressions by identifying systems where users are running (or have ran) custom BPF schedulers. Example: arighi@virtme-ng~> cat /sys/kernel/sched_ext/enable_seq 0 arighi@virtme-ng~> sudo scx_simple local=1 global=0 ^CEXIT: unregistered from user space arighi@virtme-ng~> cat /sys/kernel/sched_ext/enable_seq 1 In this way user-space tools (such as Ubuntu's apport and similar) are able to gather and include this information in bug reports. Cc: Giovanni Gherdovich <giovanni.gherdovich@suse.com> Cc: Kleber Sacilotto de Souza <kleber.souza@canonical.com> Cc: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> Cc: Phil Auld <pauld@redhat.com> Signed-off-by:
Andrea Righi <andrea.righi@linux.dev> Signed-off-by:
Tejun Heo <tj@kernel.org>
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Tejun Heo authored
a2f4b16e ("sched_ext: Build fix on !CONFIG_STACKTRACE[_SUPPORT]") tried fixing build when !CONFIG_STACKTRACE but didn't so fully. Also put stack_trace_print() and stack_trace_save() inside CONFIG_STACKTRACE to fix build when !CONFIG_STACKTRACE. Signed-off-by:
kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202409220642.fDW2OmWc-lkp@intel.com/
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Pat Somaru authored
Disable the rq empty path when scx is enabled. SCX must consult the BPF scheduler (via the dispatch path in balance) to determine if rq is empty. This fixes stalls when scx is enabled. Signed-off-by:
Pat Somaru <patso@likewhatevs.io> Fixes: 3dcac251 ("sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()") Signed-off-by:
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Yu Liao authored
When build with CONFIG_GROUP_SCHED_WEIGHT && !CONFIG_FAIR_GROUP_SCHED, the idle member is not defined: kernel/sched/ext.c:3701:16: error: 'struct task_group' has no member named 'idle' 3701 | if (!tg->idle) | ^~ Fix this by putting 'idle' under new CONFIG_GROUP_SCHED_WEIGHT. tj: Move idle field upward to avoid breaking up CONFIG_FAIR_GROUP_SCHED block. Fixes: e179e80c ("sched: Introduce CONFIG_GROUP_SCHED_WEIGHT") Reported-by:Yu Liao <liaoyu15@huawei.com> Signed-off-by:
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Yu Liao authored
Fix the following error when build with CONFIG_GROUP_SCHED_WEIGHT && !CONFIG_FAIR_GROUP_SCHED: kernel/sched/core.c:9634:15: error: implicit declaration of function 'sched_group_set_idle'; did you mean 'scx_group_set_idle'? [-Wimplicit-function-declaration] 9634 | ret = sched_group_set_idle(css_tg(css), idle); | ^~~~~~~~~~~~~~~~~~~~ | scx_group_set_idle Fixes: e179e80c ("sched: Introduce CONFIG_GROUP_SCHED_WEIGHT") Reported-by: -
Leon Romanovsky authored
While using the IOMMU DMA path, the dma_addressing_limited() function checks ops struct which doesn't exist in the IOMMU case. This causes to the kernel panic while loading ADMGPU driver. BUG: kernel NULL pointer dereference, address: 00000000000000a0 PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 10 UID: 0 PID: 611 Comm: (udev-worker) Tainted: G T 6.11.0-clang-07154-g726e2d0cf2bb #257 Tainted: [T]=RANDSTRUCT Hardware name: ASUS System Product Name/ROG STRIX Z690-G GAMING WIFI, BIOS 3701 07/03/2024 RIP: 0010:dma_addressing_limited+0x53/0xa0 Code: 8b 93 48 02 00 00 48 39 d1 49 89 d6 4c 0f 42 f1 48 85 d2 4c 0f 44 f1 f6 83 fc 02 00 00 40 75 0a 48 89 df e8 1f 09 00 00 eb 24 <4c> 8b 1c 25 a0 00 00 00 4d 85 db 74 17 48 89 df 41 ba 8b 84 2d 55 RSP: 0018:ffffa8d2c12cf740 EFLAGS: 00010202 RAX: 00000000ffffffff RBX: ffff8948820220c8 RCX: 000000ffffffffff RDX: 0000000000000000 RSI: ffffffffc124dc6d RDI: ffff8948820220c8 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff894883c3f040 R13: ffff89488dac8828 R14: 000000ffffffffff R15: ffff8948820220c8 FS: 00007fe6ba881900(0000) GS:ffff894fdf700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000a0 CR3: 0000000111984000 CR4: 0000000000f50ef0 PKRU: 55555554 Call Trace: <TASK> ? __die_body+0x65/0xc0 ? page_fault_oops+0x3b9/0x450 ? _prb_read_valid+0x212/0x390 ? do_user_addr_fault+0x608/0x680 ? exc_page_fault+0x4e/0xa0 ? asm_exc_page_fault+0x26/0x30 ? dma_addressing_limited+0x53/0xa0 amdgpu_ttm_init+0x56/0x4b0 [amdgpu] gmc_v8_0_sw_init+0x561/0x670 [amdgpu] amdgpu_device_ip_init+0xf5/0x570 [amdgpu] amdgpu_device_init+0x1a57/0x1ea0 [amdgpu] ? _raw_spin_unlock_irqrestore+0x1a/0x40 ? pci_conf1_read+0xc0/0xe0 ? pci_bus_read_config_word+0x52/0xa0 amdgpu_driver_load_kms+0x15/0xa0 [amdgpu] amdgpu_pci_probe+0x1b7/0x4c0 [amdgpu] pci_device_probe+0x1c5/0x260 really_probe+0x130/0x470 __driver_probe_device+0x77/0x150 driver_probe_device+0x19/0x120 __driver_attach+0xb1/0x1e0 ? __cfi___driver_attach+0x10/0x10 bus_for_each_dev+0x115/0x170 bus_add_driver+0x192/0x2d0 driver_register+0x5c/0xf0 ? __cfi_init_module+0x10/0x10 [amdgpu] do_one_initcall+0x128/0x380 ? idr_alloc_cyclic+0x139/0x1d0 ? security_kernfs_init_security+0x42/0x140 ? __kernfs_new_node+0x1be/0x250 ? sysvec_apic_timer_interrupt+0xb6/0xc0 ? asm_sysvec_apic_timer_interrupt+0x1a/0x20 ? _raw_spin_unlock+0x11/0x30 ? free_unref_page+0x283/0x650 ? kfree+0x274/0x3a0 ? kfree+0x274/0x3a0 ? kfree+0x274/0x3a0 ? load_module+0xf2e/0x1130 ? __kmalloc_cache_noprof+0x12a/0x2e0 do_init_module+0x7d/0x240 __se_sys_init_module+0x19e/0x220 do_syscall_64+0x8a/0x150 ? __irq_exit_rcu+0x5e/0x100 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fe6bb5980ee Code: 48 8b 0d 3d ed 12 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 af 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 0a ed 12 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd462219d8 EFLAGS: 00000206 ORIG_RAX: 00000000000000af RAX: ffffffffffffffda RBX: 0000556caf0d0670 RCX: 00007fe6bb5980ee RDX: 0000556caf0d3080 RSI: 0000000002893458 RDI: 00007fe6b3400010 RBP: 0000000000020000 R08: 0000000000020010 R09: 0000000000000080 R10: c26073c166186e00 R11: 0000000000000206 R12: 0000556caf0d3430 R13: 0000556caf0d0670 R14: 0000556caf0d3080 R15: 0000556caf0ce700 </TASK> Modules linked in: amdgpu(+) i915(+) drm_suballoc_helper intel_gtt drm_exec drm_buddy iTCO_wdt i2c_algo_bit intel_pmc_bxt drm_display_helper iTCO_vendor_support gpu_sched drm_ttm_helper cec ttm amdxcp video backlight pinctrl_alderlake nct6775 hwmon_vid nct6775_core coretemp CR2: 00000000000000a0 ---[ end trace 0000000000000000 ]--- RIP: 0010:dma_addressing_limited+0x53/0xa0 Code: 8b 93 48 02 00 00 48 39 d1 49 89 d6 4c 0f 42 f1 48 85 d2 4c 0f 44 f1 f6 83 fc 02 00 00 40 75 0a 48 89 df e8 1f 09 00 00 eb 24 <4c> 8b 1c 25 a0 00 00 00 4d 85 db 74 17 48 89 df 41 ba 8b 84 2d 55 RSP: 0018:ffffa8d2c12cf740 EFLAGS: 00010202 RAX: 00000000ffffffff RBX: ffff8948820220c8 RCX: 000000ffffffffff RDX: 0000000000000000 RSI: ffffffffc124dc6d RDI: ffff8948820220c8 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff894883c3f040 R13: ffff89488dac8828 R14: 000000ffffffffff R15: ffff8948820220c8 FS: 00007fe6ba881900(0000) GS:ffff894fdf700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000a0 CR3: 0000000111984000 CR4: 0000000000f50ef0 PKRU: 55555554 Fixes: b5c58b2f ("dma-mapping: direct calls for dma-iommu") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219292 Reported-by:
Niklāvs Koļesņikovs <pinkflames.linux@gmail.com> Signed-off-by:
Leon Romanovsky <leon@kernel.org> Signed-off-by:
Christoph Hellwig <hch@lst.de> Tested-by:
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- Sep 22, 2024
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Christoph Hellwig authored
Commit b5c58b2f ("dma-mapping: direct calls for dma-iommu") switched to use direct calls to dma-iommu, but missed the dma_vmap_noncontiguous, dma_vunmap_noncontiguous and dma_mmap_noncontiguous behavior keyed off the presence of the alloc_noncontiguous method. Fix this by removing the now unused alloc_noncontiguous and free_noncontiguous methods and moving the vmapping and mmaping of the noncontiguous allocations into the iommu code, as it is the only provider of actually noncontiguous allocations. Fixes: b5c58b2f ("dma-mapping: direct calls for dma-iommu") Reported-by:
Xi Ruoyao <xry111@xry111.site> Signed-off-by:
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Kan Liang authored
The below warning is triggered when building with arm multi_v7_defconfig. kernel/events/core.c: In function 'perf_event_setup_cpumask': kernel/events/core.c:14012:13: warning: the comparison will always evaluate as 'true' for the address of 'thread_sibling' will never be NULL [-Waddress] 14012 | if (!topology_sibling_cpumask(cpu)) { The perf_event_init_cpu() may be invoked at the early boot stage, while the topology_*_cpumask hasn't been initialized yet. The check is to specially handle the case, and initialize the perf_online_<domain>_masks on the boot CPU. X86 uses a per-cpu cpumask pointer, which could be NULL at the early boot stage. However, ARM uses a global variable, which never be NULL. Use perf_online_mask as an indicator instead. Only initialize the perf_online_<domain>_masks when perf_online_mask is empty. Fix a typo as well. Fixes: 4ba4f1af ("perf: Generic hotplug support for a PMU with a scope") Reported-by:Stephen Rothwell <sfr@canb.auug.org.au> Closes: https://lore.kernel.org/lkml/20240911153854.240bbc1f@canb.auug.org.au/ Reported-by:
Steven Price <steven.price@arm.com> Closes: https://lore.kernel.org/lkml/1835eb6d-3e05-47f3-9eae-507ce165c3bf@arm.com/ Signed-off-by:
Kan Liang <kan.liang@linux.intel.com> Tested-by:
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- Sep 20, 2024
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Jinjie Ruan authored
On RISCV64 Qemu machine with 512MB memory, cmdline "crashkernel=500M,high" will cause system stall as below: Zone ranges: DMA32 [mem 0x0000000080000000-0x000000009fffffff] Normal empty Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000080000000-0x000000008005ffff] node 0: [mem 0x0000000080060000-0x000000009fffffff] Initmem setup node 0 [mem 0x0000000080000000-0x000000009fffffff] (stall here) commit 5d99cadf1568 ("crash: fix x86_32 crash memory reserve dead loop bug") fix this on 32-bit architecture. However, the problem is not completely solved. If `CRASH_ADDR_LOW_MAX = CRASH_ADDR_HIGH_MAX` on 64-bit architecture, for example, when system memory is equal to CRASH_ADDR_LOW_MAX on RISCV64, the following infinite loop will also occur: -> reserve_crashkernel_generic() and high is true -> alloc at [CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX] fail -> alloc at [0, CRASH_ADDR_LOW_MAX] fail and repeatedly (because CRASH_ADDR_LOW_MAX = CRASH_ADDR_HIGH_MAX). As Catalin suggested, do not remove the ",high" reservation fallback to ",low" logic which will change arm64's kdump behavior, but fix it by skipping the above situation similar to commit d2f32f23190b ("crash: fix x86_32 crash memory reserve dead loop"). After this patch, it print: cannot allocate crashkernel (size:0x1f400000) Signed-off-by:Jinjie Ruan <ruanjinjie@huawei.com> Suggested-by:
Catalin Marinas <catalin.marinas@arm.com> Reviewed-by:
Baoquan He <bhe@redhat.com> Link: https://lore.kernel.org/r/20240812062017.2674441-1-ruanjinjie@huawei.com Signed-off-by:
Palmer Dabbelt <palmer@rivosinc.com>
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- Sep 17, 2024
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Oleg Nesterov authored
Now that xol_mapping has its own ->fault() method we no longer need xol_area->pages[1] == NULL, we need a single page. Link: https://lkml.kernel.org/r/20240911131437.GC3448@redhat.com Signed-off-by:
Andrew Morton <akpm@linux-foundation.org>
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Oleg Nesterov authored
Currently each xol_area has its own instance of vm_special_mapping, this is suboptimal and ugly. Kill xol_area->xol_mapping and add a single global instance of vm_special_mapping, the ->fault() method can use area->pages rather than xol_mapping->pages. As a side effect this fixes the problem introduced by the recent commit 223febc6 ("mm: add optional close() to struct vm_special_mapping"), if special_mapping_close() is called from the __mmput() paths, it will use vma->vm_private_data = &area->xol_mapping freed by uprobe_clear_state(). Link: https://lkml.kernel.org/r/20240911131407.GB3448@redhat.com Fixes: 223febc6 ("mm: add optional close() to struct vm_special_mapping") Signed-off-by:
Sven Schnelle <svens@linux.ibm.com> Closes: https://lore.kernel.org/all/yt9dy149vprr.fsf@linux.ibm.com/ Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by:
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Oleg Nesterov authored
This reverts commit 08e28de1. A malicious application can munmap() its "[uprobes]" vma and in this case xol_mapping.close == uprobe_clear_state() will free the memory which can be used by another thread, or the same thread when it hits the uprobe bp afterwards. Link: https://lkml.kernel.org/r/20240911131320.GA3448@redhat.com Signed-off-by:
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Huang Ying authored
Patch series "resource: Fix region_intersects() vs add_memory_driver_managed()", v3. The patchset fixes a bug of region_intersects() for systems with CXL memory. The details of the bug can be found in [1/3]. To avoid similar bugs in the future. A kunit test case for region_intersects() is added in [3/3]. [2/3] is a preparation patch for [3/3]. This patch (of 3): region_intersects() is important because it's used for /dev/mem permission checking. To avoid possible bug of region_intersects() in the future, a kunit test case for region_intersects() is added. Link: https://lkml.kernel.org/r/20240906030713.204292-1-ying.huang@intel.com Link: https://lkml.kernel.org/r/20240906030713.204292-4-ying.huang@intel.com Signed-off-by:
"Huang, Ying" <ying.huang@intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Jonathan Cameron <jonathan.cameron@huawei.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Baoquan He <bhe@redhat.com> Signed-off-by:
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Huang Ying authored
During developing a kunit test case for region_intersects(), some fake resources need to be inserted into iomem_resource. To do that, a resource hole needs to be found first in iomem_resource. However, alloc_free_mem_region() cannot work for iomem_resource now. Because the start address to check cannot be 0 to detect address wrapping 0 in gfr_continue(), while iomem_resource.start == 0. To make alloc_free_mem_region() works for iomem_resource, gfr_start() is changed to avoid to return 0 even if base->start == 0. We don't need to check 0 as start address. Link: https://lkml.kernel.org/r/20240906030713.204292-3-ying.huang@intel.com Signed-off-by:
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Huang Ying authored
On a system with CXL memory, the resource tree (/proc/iomem) related to CXL memory may look like something as follows. 490000000-50fffffff : CXL Window 0 490000000-50fffffff : region0 490000000-50fffffff : dax0.0 490000000-50fffffff : System RAM (kmem) Because drivers/dax/kmem.c calls add_memory_driver_managed() during onlining CXL memory, which makes "System RAM (kmem)" a descendant of "CXL Window X". This confuses region_intersects(), which expects all "System RAM" resources to be at the top level of iomem_resource. This can lead to bugs. For example, when the following command line is executed to write some memory in CXL memory range via /dev/mem, $ dd if=data of=/dev/mem bs=$((1 << 10)) seek=$((0x490000000 >> 10)) count=1 dd: error writing '/dev/mem': Bad address 1+0 records in 0+0 records out 0 bytes copied, 0.0283507 s, 0.0 kB/s the command fails as expected. However, the error code is wrong. It should be "Operation not permitted" instead of "Bad address". More seriously, the /dev/mem permission checking in devmem_is_allowed() passes incorrectly. Although the accessing is prevented later because ioremap() isn't allowed to map system RAM, it is a potential security issue. During command executing, the following warning is reported in the kernel log for calling ioremap() on system RAM. ioremap on RAM at 0x0000000490000000 - 0x0000000490000fff WARNING: CPU: 2 PID: 416 at arch/x86/mm/ioremap.c:216 __ioremap_caller.constprop.0+0x131/0x35d Call Trace: memremap+0xcb/0x184 xlate_dev_mem_ptr+0x25/0x2f write_mem+0x94/0xfb vfs_write+0x128/0x26d ksys_write+0xac/0xfe do_syscall_64+0x9a/0xfd entry_SYSCALL_64_after_hwframe+0x4b/0x53 The details of command execution process are as follows. In the above resource tree, "System RAM" is a descendant of "CXL Window 0" instead of a top level resource. So, region_intersects() will report no System RAM resources in the CXL memory region incorrectly, because it only checks the top level resources. Consequently, devmem_is_allowed() will return 1 (allow access via /dev/mem) for CXL memory region incorrectly. Fortunately, ioremap() doesn't allow to map System RAM and reject the access. So, region_intersects() needs to be fixed to work correctly with the resource tree with "System RAM" not at top level as above. To fix it, if we found a unmatched resource in the top level, we will continue to search matched resources in its descendant resources. So, we will not miss any matched resources in resource tree anymore. In the new implementation, an example resource tree |------------- "CXL Window 0" ------------| |-- "System RAM" --| will behave similar as the following fake resource tree for region_intersects(, IORESOURCE_SYSTEM_RAM, ), |-- "System RAM" --||-- "CXL Window 0a" --| Where "CXL Window 0a" is part of the original "CXL Window 0" that isn't covered by "System RAM". Link: https://lkml.kernel.org/r/20240906030713.204292-2-ying.huang@intel.com Fixes: c221c0b0 ("device-dax: "Hotplug" persistent memory for use like normal RAM") Signed-off-by:
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- Sep 13, 2024
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Hou Tao authored
Call the missed kfree() in btf_parse_struct_metas() when there is no special field in btf, otherwise will get the following kmemleak report: unreferenced object 0xffff888101033620 (size 8): comm "test_progs", pid 604, jiffies 4295127011 ...... backtrace (crc e77dc444): [<00000000186f90f3>] kmemleak_alloc+0x4b/0x80 [<00000000ac8e9c4d>] __kmalloc_cache_noprof+0x2a1/0x310 [<00000000d99d68d6>] btf_new_fd+0x72d/0xe90 [<00000000f010b7f8>] __sys_bpf+0xec3/0x2410 [<00000000e077ed6f>] __x64_sys_bpf+0x1f/0x30 [<00000000a12f9e55>] x64_sys_call+0x199/0x9f0 [<00000000f3029ea6>] do_syscall_64+0x3b/0xc0 [<000000005640913a>] entry_SYSCALL_64_after_hwframe+0x4b/0x53 Fixes: 7a851ecb ("bpf: Search for kptrs in prog BTF structs") Signed-off-by:Hou Tao <houtao1@huawei.com> Acked-by:
Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20240912012845.3458483-3-houtao@huaweicloud.com Signed-off-by:
Alexei Starovoitov <ast@kernel.org>
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Hou Tao authored
When security_bpf_map_create() in map_create() fails, map_create() will call btf_put() and ->map_free() callback to free the map. It doesn't free the btf_record of map value, so add the missed btf_record_free() when map creation fails. However btf_record_free() needs to be called after ->map_free() just like bpf_map_free_deferred() did, because ->map_free() may use the btf_record to free the special fields in preallocated map value. So factor out bpf_map_free() helper to free the map, btf_record, and btf orderly and use the helper in both map_create() and bpf_map_free_deferred(). Signed-off-by:
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Daniel Borkmann authored
For all non-tracing helpers which formerly had ARG_PTR_TO_{LONG,INT} as input arguments, zero the value for the case of an error as otherwise it could leak memory. For tracing, it is not needed given CAP_PERFMON can already read all kernel memory anyway hence bpf_get_func_arg() and bpf_get_func_ret() is skipped in here. Also, the MTU helpers mtu_len pointer value is being written but also read. Technically, the MEM_UNINIT should not be there in order to always force init. Removing MEM_UNINIT needs more verifier rework though: MEM_UNINIT right now implies two things actually: i) write into memory, ii) memory does not have to be initialized. If we lift MEM_UNINIT, it then becomes: i) read into memory, ii) memory must be initialized. This means that for bpf_*_check_mtu() we're readding the issue we're trying to fix, that is, it would then be able to write back into things like .rodata BPF maps. Follow-up work will rework the MEM_UNINIT semantics such that the intent can be better expressed. For now just clear the *mtu_len on error path which can be lifted later again. Fixes: 8a67f2de ("bpf: expose bpf_strtol and bpf_strtoul to all program types") Fixes: d7a4cb9b ("bpf: Introduce bpf_strtol and bpf_strtoul helpers") Signed-off-by:Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/e5edd241-59e7-5e39-0ee5-a51e31b6840a@iogearbox.net Link: https://lore.kernel.org/r/20240913191754.13290-5-daniel@iogearbox.net Signed-off-by:
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Daniel Borkmann authored
When checking malformed helper function signatures, also take other argument types into account aside from just ARG_PTR_TO_UNINIT_MEM. This concerns (formerly) ARG_PTR_TO_{INT,LONG} given uninitialized memory can be passed there, too. The func proto sanity check goes back to commit 435faee1 ("bpf, verifier: add ARG_PTR_TO_RAW_STACK type"), and its purpose was to detect wrong func protos which had more than just one MEM_UNINIT-tagged type as arguments. The reason more than one is currently not supported is as we mark stack slots with STACK_MISC in check_helper_call() in case of raw mode based on meta.access_size to allow uninitialized stack memory to be passed to helpers when they just write into the buffer. Probing for base type as well as MEM_UNINIT tagging ensures that other types do not get missed (as it used to be the case for ARG_PTR_TO_{INT,LONG}). Fixes: 57c3bb72 ("bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types") Reported-by:Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by:
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Daniel Borkmann authored
Lonial found an issue that despite user- and BPF-side frozen BPF map (like in case of .rodata), it was still possible to write into it from a BPF program side through specific helpers having ARG_PTR_TO_{LONG,INT} as arguments. In check_func_arg() when the argument is as mentioned, the meta->raw_mode is never set. Later, check_helper_mem_access(), under the case of PTR_TO_MAP_VALUE as register base type, it assumes BPF_READ for the subsequent call to check_map_access_type() and given the BPF map is read-only it succeeds. The helpers really need to be annotated as ARG_PTR_TO_{LONG,INT} | MEM_UNINIT when results are written into them as opposed to read out of them. The latter indicates that it's okay to pass a pointer to uninitialized memory as the memory is written to anyway. However, ARG_PTR_TO_{LONG,INT} is a special case of ARG_PTR_TO_FIXED_SIZE_MEM just with additional alignment requirement. So it is better to just get rid of the ARG_PTR_TO_{LONG,INT} special cases altogether and reuse the fixed size memory types. For this, add MEM_ALIGNED to additionally ensure alignment given these helpers write directly into the args via *<ptr> = val. The .arg*_size has been initialized reflecting the actual sizeof(*<ptr>). MEM_ALIGNED can only be used in combination with MEM_FIXED_SIZE annotated argument types, since in !MEM_FIXED_SIZE cases the verifier does not know the buffer size a priori and therefore cannot blindly write *<ptr> = val. Fixes: 57c3bb72 ("bpf: Introduce ARG_PTR_TO_{INT,LONG} arg types") Reported-by:Lonial Con <kongln9170@gmail.com> Signed-off-by:
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Daniel Borkmann authored
Both bpf_strtol() and bpf_strtoul() helpers passed a temporary "long long" respectively "unsigned long long" to __bpf_strtoll() / __bpf_strtoull(). Later, the result was checked for truncation via _res != ({unsigned,} long)_res as the destination buffer for the BPF helpers was of type {unsigned,} long which is 32bit on 32bit architectures. Given the latter was a bug in the helper signatures where the destination buffer got adjusted to {s,u}64, the truncation check can now be removed. Signed-off-by: -
Daniel Borkmann authored
The bpf_strtol() and bpf_strtoul() helpers are currently broken on 32bit: The argument type ARG_PTR_TO_LONG is BPF-side "long", not kernel-side "long" and therefore always considered fixed 64bit no matter if 64 or 32bit underlying architecture. This contract breaks in case of the two mentioned helpers since their BPF_CALL definition for the helpers was added with {unsigned,}long *res. Meaning, the transition from BPF-side "long" (BPF program) to kernel-side "long" (BPF helper) breaks here. Both helpers call __bpf_strtoll() with "long long" correctly, but later assigning the result into 32-bit "*(long *)" on 32bit architectures. From a BPF program point of view, this means upper bits will be seen as uninitialised. Therefore, fix both BPF_CALL signatures to {s,u}64 types to fix this situation. Now, changing also uapi/bpf.h helper documentation which generates bpf_helper_defs.h for BPF programs is tricky: Changing signatures there to __{s,u}64 would trigger compiler warnings (incompatible pointer types passing 'long *' to parameter of type '__s64 *' (aka 'long long *')) for existing BPF programs. Leaving the signatures as-is would be fine as from BPF program point of view it is still BPF-side "long" and thus equivalent to __{s,u}64 on 64 or 32bit underlying architectures. Note that bpf_strtol() and bpf_strtoul() are the only helpers with this issue. Fixes: d7a4cb9b ("bpf: Introduce bpf_strtol and bpf_strtoul helpers") Reported-by: -
Yonghong Song authored
Zac Ecob reported a problem where a bpf program may cause kernel crash due to the following error: Oops: divide error: 0000 [#1] PREEMPT SMP KASAN PTI The failure is due to the below signed divide: LLONG_MIN/-1 where LLONG_MIN equals to -9,223,372,036,854,775,808. LLONG_MIN/-1 is supposed to give a positive number 9,223,372,036,854,775,808, but it is impossible since for 64-bit system, the maximum positive number is 9,223,372,036,854,775,807. On x86_64, LLONG_MIN/-1 will cause a kernel exception. On arm64, the result for LLONG_MIN/-1 is LLONG_MIN. Further investigation found all the following sdiv/smod cases may trigger an exception when bpf program is running on x86_64 platform: - LLONG_MIN/-1 for 64bit operation - INT_MIN/-1 for 32bit operation - LLONG_MIN%-1 for 64bit operation - INT_MIN%-1 for 32bit operation where -1 can be an immediate or in a register. On arm64, there are no exceptions: - LLONG_MIN/-1 = LLONG_MIN - INT_MIN/-1 = INT_MIN - LLONG_MIN%-1 = 0 - INT_MIN%-1 = 0 where -1 can be an immediate or in a register. Insn patching is needed to handle the above cases and the patched codes produced results aligned with above arm64 result. The below are pseudo codes to handle sdiv/smod exceptions including both divisor -1 and divisor 0 and the divisor is stored in a register. sdiv: tmp = rX tmp += 1 /* [-1, 0] -> [0, 1] if tmp >(unsigned) 1 goto L2 if tmp == 0 goto L1 rY = 0 L1: rY = -rY; goto L3 L2: rY /= rX L3: smod: tmp = rX tmp += 1 /* [-1, 0] -> [0, 1] if tmp >(unsigned) 1 goto L1 if tmp == 1 (is64 ? goto L2 : goto L3) rY = 0; goto L2 L1: rY %= rX L2: goto L4 // only when !is64 L3: wY = wY // only when !is64 L4: [1] https://lore.kernel.org/bpf/tPJLTEh7S_DxFEqAI2Ji5MBSoZVg7_G-Py2iaZpAaWtM961fFTWtsnlzwvTbzBzaUzwQAoNATXKUlt0LZOFgnDcIyKCswAnAGdUF3LBrhGQ=@protonmail.com/ Reported-by:Zac Ecob <zacecob@protonmail.com> Signed-off-by:
Yonghong Song <yonghong.song@linux.dev> Acked-by:
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Vincent Donnefort authored
commit ac3b4328 ("module: replace module_layout with module_memory") introduced a set of memory regions for the module layout sharing the same attributes. However, it didn't update the kmemleak scanned areas which intended to limit kmemleak scan to sections containing writable data. This means sections such as .text and .rodata are scanned by kmemleak. Refine the scanned areas for modules by limiting it to MOD_TEXT and MOD_INIT_TEXT mod_mem regions. CC: Song Liu <song@kernel.org> Reviewed-by:
Vincent Donnefort <vdonnefort@google.com> Signed-off-by:
Luis Chamberlain <mcgrof@kernel.org>
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Chunhui Li authored
When insmod a kernel module, if fails in add_notes_attrs or add_sysfs_attrs such as memory allocation fail, mod_sysfs_setup will still return success, but we can't access user interface on android device. Patch for make mod_sysfs_setup can check the error of add_notes_attrs and add_sysfs_attrs [mcgrof: the section stuff comes from linux history.git [0]] Fixes: 3f7b0672086b ("Module section offsets in /sys/module") [0] Fixes: 6d760133 ("Add /sys/module/name/notes") Acked-by:Petr Pavlu <petr.pavlu@suse.com> Reported-by:
Xion Wang <xion.wang@mediatek.com> Signed-off-by:
Chunhui Li <chunhui.li@mediatek.com> Signed-off-by:
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Al Viro authored
Keep file reference through the entire thing, don't bother with grabbing struct path reference and while we are at it, don't confuse the hell out of readers by random mix of path.dentry->d_sb and path.mnt->mnt_sb uses - these two are equal, so just put one of those into a local variable and use that. Reviewed-by:
Christian Brauner <brauner@kernel.org> Acked-by:
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- Sep 12, 2024
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Christoph Hellwig authored
dma_supported has become too much spaghetti for my taste. Reflow it to remove the duplicate use_dma_iommu condition and make the main path more obvious. Signed-off-by:
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