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2024-04-13ring-buffer: use READ_ONCE() to read cpu_buffer->commit_page in concurrent ↵linke li1-1/+1
environment [ Upstream commit f1e30cb6369251c03f63c564006f96a54197dcc4 ] In function ring_buffer_iter_empty(), cpu_buffer->commit_page is read while other threads may change it. It may cause the time_stamp that read in the next line come from a different page. Use READ_ONCE() to avoid having to reason about compiler optimizations now and in future. Link: https://lore.kernel.org/linux-trace-kernel/tencent_DFF7D3561A0686B5E8FC079150A02505180A@qq.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: linke li <lilinke99@qq.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-13panic: Flush kernel log buffer at the endJohn Ogness1-0/+8
[ Upstream commit d988d9a9b9d180bfd5c1d353b3b176cb90d6861b ] If the kernel crashes in a context where printk() calls always defer printing (such as in NMI or inside a printk_safe section) then the final panic messages will be deferred to irq_work. But if irq_work is not available, the messages will not get printed unless explicitly flushed. The result is that the final "end Kernel panic" banner does not get printed. Add one final flush after the last printk() call to make sure the final panic messages make it out as well. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20240207134103.1357162-14-john.ogness@linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10locking/rwsem: Disable preemption while trying for rwsem lockGokul krishna Krishnakumar1-2/+12
commit 48dfb5d2560d36fb16c7d430c229d1604ea7d185 upstream. Make the region inside the rwsem_write_trylock non preemptible. We observe RT task is hogging CPU when trying to acquire rwsem lock which was acquired by a kworker task but before the rwsem owner was set. Here is the scenario: 1. CFS task (affined to a particular CPU) takes rwsem lock. 2. CFS task gets preempted by a RT task before setting owner. 3. RT task (FIFO) is trying to acquire the lock, but spinning until RT throttling happens for the lock as the lock was taken by CFS task. This patch attempts to fix the above issue by disabling preemption until owner is set for the lock. While at it also fix the issues at the places where rwsem_{set,clear}_owner() are called. This also adds lockdep annotation of preemption disable in rwsem_{set,clear}_owner() on Peter Z. suggestion. Signed-off-by: Gokul krishna Krishnakumar <quic_gokukris@quicinc.com> Signed-off-by: Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Waiman Long <longman@redhat.com> Link: https://lore.kernel.org/r/1662661467-24203-1-git-send-email-quic_mojha@quicinc.com Cc: Aaro Koskinen <aaro.koskinen@iki.fi> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10bpf: Protect against int overflow for stack access sizeAndrei Matei1-0/+5
[ Upstream commit ecc6a2101840177e57c925c102d2d29f260d37c8 ] This patch re-introduces protection against the size of access to stack memory being negative; the access size can appear negative as a result of overflowing its signed int representation. This should not actually happen, as there are other protections along the way, but we should protect against it anyway. One code path was missing such protections (fixed in the previous patch in the series), causing out-of-bounds array accesses in check_stack_range_initialized(). This patch causes the verification of a program with such a non-sensical access size to fail. This check used to exist in a more indirect way, but was inadvertendly removed in a833a17aeac7. Fixes: a833a17aeac7 ("bpf: Fix verification of indirect var-off stack access") Reported-by: syzbot+33f4297b5f927648741a@syzkaller.appspotmail.com Reported-by: syzbot+aafd0513053a1cbf52ef@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/CAADnVQLORV5PT0iTAhRER+iLBTkByCYNBYyvBSgjN1T31K+gOw@mail.gmail.com/ Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Link: https://lore.kernel.org/r/20240327024245.318299-3-andreimatei1@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10perf/core: Fix reentry problem in perf_output_read_group()Yang Jihong1-0/+9
commit 6b959ba22d34ca793ffdb15b5715457c78e38b1a upstream. perf_output_read_group may respond to IPI request of other cores and invoke __perf_install_in_context function. As a result, hwc configuration is modified. causing inconsistency and unexpected consequences. Interrupts are not disabled when perf_output_read_group reads PMU counter. In this case, IPI request may be received from other cores. As a result, PMU configuration is modified and an error occurs when reading PMU counter: CPU0 CPU1 __se_sys_perf_event_open perf_install_in_context perf_output_read_group smp_call_function_single for_each_sibling_event(sub, leader) { generic_exec_single if ((sub != event) && remote_function (sub->state == PERF_EVENT_STATE_ACTIVE)) | <enter IPI handler: __perf_install_in_context> <----RAISE IPI-----+ __perf_install_in_context ctx_resched event_sched_out armpmu_del ... hwc->idx = -1; // event->hwc.idx is set to -1 ... <exit IPI> sub->pmu->read(sub); armpmu_read armv8pmu_read_counter armv8pmu_read_hw_counter int idx = event->hw.idx; // idx = -1 u64 val = armv8pmu_read_evcntr(idx); u32 counter = ARMV8_IDX_TO_COUNTER(idx); // invalid counter = 30 read_pmevcntrn(counter) // undefined instruction Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220902082918.179248-1-yangjihong1@huawei.com Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@igalia.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10fsnotify: make allow_dups a property of the groupAmir Goldstein1-2/+2
[ Upstream commit f3010343d9e119da35ee864b3a28993bb5c78ed7 ] Instead of passing the allow_dups argument to fsnotify_add_mark() as an argument, define the group flag FSNOTIFY_GROUP_DUPS to express the allow_dups behavior and set this behavior at group creation time for all calls of fsnotify_add_mark(). Rename the allow_dups argument to generic add_flags argument for future use. Link: https://lore.kernel.org/r/20220422120327.3459282-6-amir73il@gmail.com Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-04-10fsnotify: pass flags argument to fsnotify_alloc_group()Amir Goldstein3-3/+4
[ Upstream commit 867a448d587e7fa845bceaf4ee1c632448f2a9fa ] Add flags argument to fsnotify_alloc_group(), define and use the flag FSNOTIFY_GROUP_USER in inotify and fanotify instead of the helper fsnotify_alloc_user_group() to indicate user allocation. Although the flag FSNOTIFY_GROUP_USER is currently not used after group allocation, we store the flags argument in the group struct for future use of other group flags. Link: https://lore.kernel.org/r/20220422120327.3459282-5-amir73il@gmail.com Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-04-10NFSD: Remove svc_serv_ops::svo_moduleChuck Lever1-1/+1
[ Upstream commit f49169c97fceb21ad6a0aaf671c50b0f520f15a5 ] struct svc_serv_ops is about to be removed. Neil Brown says: > I suspect svo_module can go as well - I don't think the thread is > ever the thing that primarily keeps a module active. A random sample of kthread_create() callers shows sunrpc is the only one that manages module reference count in this way. Suggested-by: Neil Brown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-04-10exit: Rename module_put_and_exit to module_put_and_kthread_exitEric W. Biederman1-3/+3
[ Upstream commit ca3574bd653aba234a4b31955f2778947403be16 ] Update module_put_and_exit to call kthread_exit instead of do_exit. Change the name to reflect this change in functionality. All of the users of module_put_and_exit are causing the current kthread to exit so this change makes it clear what is happening. There is no functional change. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-04-10exit: Implement kthread_exitEric W. Biederman1-4/+19
[ Upstream commit bbda86e988d4c124e4cfa816291cbd583ae8bfb1 ] The way the per task_struct exit_code is used by kernel threads is not quite compatible how it is used by userspace applications. The low byte of the userspace exit_code value encodes the exit signal. While kthreads just use the value as an int holding ordinary kernel function exit status like -EPERM. Add kthread_exit to clearly separate the two kinds of uses. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Stable-dep-of: ca3574bd653a ("exit: Rename module_put_and_exit to module_put_and_kthread_exit") Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-04-10fsnotify: clarify contract for create event hooksAmir Goldstein2-4/+2
[ Upstream commit dabe729dddca550446e9cc118c96d1f91703345b ] Clarify argument names and contract for fsnotify_create() and fsnotify_mkdir() to reflect the anomaly of kernfs, which leaves dentries negavite after mkdir/create. Remove the WARN_ON(!inode) in audit code that were added by the Fixes commit under the wrong assumption that dentries cannot be negative after mkdir/create. Fixes: aa93bdc5500c ("fsnotify: use helpers to access data by data_type") Link: https://lore.kernel.org/linux-fsdevel/87mtp5yz0q.fsf@collabora.com/ Link: https://lore.kernel.org/r/20211025192746.66445-4-krisman@collabora.com Reviewed-by: Jan Kara <jack@suse.cz> Reported-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-04-10printk: Update @console_may_schedule in console_trylock_spinning()John Ogness1-0/+6
[ Upstream commit 8076972468584d4a21dab9aa50e388b3ea9ad8c7 ] console_trylock_spinning() may takeover the console lock from a schedulable context. Update @console_may_schedule to make sure it reflects a trylock acquire. Reported-by: Mukesh Ojha <quic_mojha@quicinc.com> Closes: https://lore.kernel.org/lkml/20240222090538.23017-1-quic_mojha@quicinc.com Fixes: dbdda842fe96 ("printk: Add console owner and waiter logic to load balance console writes") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Mukesh Ojha <quic_mojha@quicinc.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/875xybmo2z.fsf@jogness.linutronix.de Signed-off-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10dma-mapping: add dma_opt_mapping_size()John Garry1-0/+12
[ Upstream commit a229cc14f3395311b899e5e582b71efa8dd01df0 ] Streaming DMA mapping involving an IOMMU may be much slower for larger total mapping size. This is because every IOMMU DMA mapping requires an IOVA to be allocated and freed. IOVA sizes above a certain limit are not cached, which can have a big impact on DMA mapping performance. Provide an API for device drivers to know this "optimal" limit, such that they may try to produce mapping which don't exceed it. Signed-off-by: John Garry <john.garry@huawei.com> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com> Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Stable-dep-of: afc5aa46ed56 ("iommu/dma: Force swiotlb_max_mapping_size on an untrusted device") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10swiotlb: Fix alignment checks when both allocation and DMA masks are presentWill Deacon1-2/+9
[ Upstream commit 51b30ecb73b481d5fac6ccf2ecb4a309c9ee3310 ] Nicolin reports that swiotlb buffer allocations fail for an NVME device behind an IOMMU using 64KiB pages. This is because we end up with a minimum allocation alignment of 64KiB (for the IOMMU to map the buffer safely) but a minimum DMA alignment mask corresponding to a 4KiB NVME page (i.e. preserving the 4KiB page offset from the original allocation). If the original address is not 4KiB-aligned, the allocation will fail because swiotlb_search_pool_area() erroneously compares these unmasked bits with the 64KiB-aligned candidate allocation. Tweak swiotlb_search_pool_area() so that the DMA alignment mask is reduced based on the required alignment of the allocation. Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers") Link: https://lore.kernel.org/r/cover.1707851466.git.nicolinc@nvidia.com Reported-by: Nicolin Chen <nicolinc@nvidia.com> Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10entry: Respect changes to system call number by trace_sys_enter()André Rösti1-1/+7
[ Upstream commit fb13b11d53875e28e7fbf0c26b288e4ea676aa9f ] When a probe is registered at the trace_sys_enter() tracepoint, and that probe changes the system call number, the old system call still gets executed. This worked correctly until commit b6ec41346103 ("core/entry: Report syscall correctly for trace and audit"), which removed the re-evaluation of the syscall number after the trace point. Restore the original semantics by re-evaluating the system call number after trace_sys_enter(). The performance impact of this re-evaluation is minimal because it only takes place when a trace point is active, and compared to the actual trace point overhead the read from a cache hot variable is negligible. Fixes: b6ec41346103 ("core/entry: Report syscall correctly for trace and audit") Signed-off-by: André Rösti <an.roesti@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240311211704.7262-1-an.roesti@gmail.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10tracing: Use .flush() call to wake up readersSteven Rostedt (Google)1-6/+15
commit e5d7c1916562f0e856eb3d6f569629fcd535fed2 upstream. The .release() function does not get called until all readers of a file descriptor are finished. If a thread is blocked on reading a file descriptor in ring_buffer_wait(), and another thread closes the file descriptor, it will not wake up the other thread as ring_buffer_wake_waiters() is called by .release(), and that will not get called until the .read() is finished. The issue originally showed up in trace-cmd, but the readers are actually other processes with their own file descriptors. So calling close() would wake up the other tasks because they are blocked on another descriptor then the one that was closed(). But there's other wake ups that solve that issue. When a thread is blocked on a read, it can still hang even when another thread closed its descriptor. This is what the .flush() callback is for. Have the .flush() wake up the readers. Link: https://lore.kernel.org/linux-trace-kernel/20240308202432.107909457@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linke li <lilinke99@qq.com> Cc: Rabin Vincent <rabin@rab.in> Fixes: f3ddb74ad0790 ("tracing: Wake up ring buffer waiters on closing of the file") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10ring-buffer: Use wait_event_interruptible() in ring_buffer_wait()Steven Rostedt (Google)1-48/+68
[ Upstream commit 7af9ded0c2caac0a95f33df5cb04706b0f502588 ] Convert ring_buffer_wait() over to wait_event_interruptible(). The default condition is to execute the wait loop inside __wait_event() just once. This does not change the ring_buffer_wait() prototype yet, but restructures the code so that it can take a "cond" and "data" parameter and will call wait_event_interruptible() with a helper function as the condition. The helper function (rb_wait_cond) takes the cond function and data parameters. It will first check if the buffer hit the watermark defined by the "full" parameter and then call the passed in condition parameter. If either are true, it returns true. If rb_wait_cond() does not return true, it will set the appropriate "waiters_pending" flag and returns false. Link: https://lore.kernel.org/linux-trace-kernel/CAHk-=wgsNgewHFxZAJiAQznwPMqEtQmi1waeS2O1v6L4c_Um5A@mail.gmail.com/ Link: https://lore.kernel.org/linux-trace-kernel/20240312121703.399598519@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linke li <lilinke99@qq.com> Cc: Rabin Vincent <rabin@rab.in> Fixes: f3ddb74ad0790 ("tracing: Wake up ring buffer waiters on closing of the file") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10ring-buffer: Fix full_waiters_pending in pollSteven Rostedt (Google)1-7/+20
[ Upstream commit 8145f1c35fa648da662078efab299c4467b85ad5 ] If a reader of the ring buffer is doing a poll, and waiting for the ring buffer to hit a specific watermark, there could be a case where it gets into an infinite ping-pong loop. The poll code has: rbwork->full_waiters_pending = true; if (!cpu_buffer->shortest_full || cpu_buffer->shortest_full > full) cpu_buffer->shortest_full = full; The writer will see full_waiters_pending and check if the ring buffer is filled over the percentage of the shortest_full value. If it is, it calls an irq_work to wake up all the waiters. But the code could get into a circular loop: CPU 0 CPU 1 ----- ----- [ Poll ] [ shortest_full = 0 ] rbwork->full_waiters_pending = true; if (rbwork->full_waiters_pending && [ buffer percent ] > shortest_full) { rbwork->wakeup_full = true; [ queue_irqwork ] cpu_buffer->shortest_full = full; [ IRQ work ] if (rbwork->wakeup_full) { cpu_buffer->shortest_full = 0; wakeup poll waiters; [woken] if ([ buffer percent ] > full) break; rbwork->full_waiters_pending = true; if (rbwork->full_waiters_pending && [ buffer percent ] > shortest_full) { rbwork->wakeup_full = true; [ queue_irqwork ] cpu_buffer->shortest_full = full; [ IRQ work ] if (rbwork->wakeup_full) { cpu_buffer->shortest_full = 0; wakeup poll waiters; [woken] [ Wash, rinse, repeat! ] In the poll, the shortest_full needs to be set before the full_pending_waiters, as once that is set, the writer will compare the current shortest_full (which is incorrect) to decide to call the irq_work, which will reset the shortest_full (expecting the readers to update it). Also move the setting of full_waiters_pending after the check if the ring buffer has the required percentage filled. There's no reason to tell the writer to wake up waiters if there are no waiters. Link: https://lore.kernel.org/linux-trace-kernel/20240312131952.630922155@goodmis.org Cc: stable@vger.kernel.org Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Fixes: 42fb0a1e84ff5 ("tracing/ring-buffer: Have polling block on watermark") Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10ring-buffer: Fix resetting of shortest_fullSteven Rostedt (Google)1-7/+23
[ Upstream commit 68282dd930ea38b068ce2c109d12405f40df3f93 ] The "shortest_full" variable is used to keep track of the waiter that is waiting for the smallest amount on the ring buffer before being woken up. When a tasks waits on the ring buffer, it passes in a "full" value that is a percentage. 0 means wake up on any data. 1-100 means wake up from 1% to 100% full buffer. As all waiters are on the same wait queue, the wake up happens for the waiter with the smallest percentage. The problem is that the smallest_full on the cpu_buffer that stores the smallest amount doesn't get reset when all the waiters are woken up. It does get reset when the ring buffer is reset (echo > /sys/kernel/tracing/trace). This means that tasks may be woken up more often then when they want to be. Instead, have the shortest_full field get reset just before waking up all the tasks. If the tasks wait again, they will update the shortest_full before sleeping. Also add locking around setting of shortest_full in the poll logic, and change "work" to "rbwork" to match the variable name for rb_irq_work structures that are used in other places. Link: https://lore.kernel.org/linux-trace-kernel/20240308202431.948914369@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linke li <lilinke99@qq.com> Cc: Rabin Vincent <rabin@rab.in> Fixes: 2c2b0a78b3739 ("ring-buffer: Add percentage of ring buffer full to wake up reader") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Stable-dep-of: 8145f1c35fa6 ("ring-buffer: Fix full_waiters_pending in poll") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10ring-buffer: Do not set shortest_full when full target is hitSteven Rostedt (Google)1-3/+4
[ Upstream commit 761d9473e27f0c8782895013a3e7b52a37c8bcfc ] The rb_watermark_hit() checks if the amount of data in the ring buffer is above the percentage level passed in by the "full" variable. If it is, it returns true. But it also sets the "shortest_full" field of the cpu_buffer that informs writers that it needs to call the irq_work if the amount of data on the ring buffer is above the requested amount. The rb_watermark_hit() always sets the shortest_full even if the amount in the ring buffer is what it wants. As it is not going to wait, because it has what it wants, there's no reason to set shortest_full. Link: https://lore.kernel.org/linux-trace-kernel/20240312115641.6aa8ba08@gandalf.local.home Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Fixes: 42fb0a1e84ff5 ("tracing/ring-buffer: Have polling block on watermark") Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10ring-buffer: Fix waking up ring buffer readersSteven Rostedt (Google)1-71/+68
[ Upstream commit b3594573681b53316ec0365332681a30463edfd6 ] A task can wait on a ring buffer for when it fills up to a specific watermark. The writer will check the minimum watermark that waiters are waiting for and if the ring buffer is past that, it will wake up all the waiters. The waiters are in a wait loop, and will first check if a signal is pending and then check if the ring buffer is at the desired level where it should break out of the loop. If a file that uses a ring buffer closes, and there's threads waiting on the ring buffer, it needs to wake up those threads. To do this, a "wait_index" was used. Before entering the wait loop, the waiter will read the wait_index. On wakeup, it will check if the wait_index is different than when it entered the loop, and will exit the loop if it is. The waker will only need to update the wait_index before waking up the waiters. This had a couple of bugs. One trivial one and one broken by design. The trivial bug was that the waiter checked the wait_index after the schedule() call. It had to be checked between the prepare_to_wait() and the schedule() which it was not. The main bug is that the first check to set the default wait_index will always be outside the prepare_to_wait() and the schedule(). That's because the ring_buffer_wait() doesn't have enough context to know if it should break out of the loop. The loop itself is not needed, because all the callers to the ring_buffer_wait() also has their own loop, as the callers have a better sense of what the context is to decide whether to break out of the loop or not. Just have the ring_buffer_wait() block once, and if it gets woken up, exit the function and let the callers decide what to do next. Link: https://lore.kernel.org/all/CAHk-=whs5MdtNjzFkTyaUy=vHi=qwWgPi0JgTe6OYUYMNSRZfg@mail.gmail.com/ Link: https://lore.kernel.org/linux-trace-kernel/20240308202431.792933613@goodmis.org Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linke li <lilinke99@qq.com> Cc: Rabin Vincent <rabin@rab.in> Fixes: e30f53aad2202 ("tracing: Do not busy wait in buffer splice") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Stable-dep-of: 761d9473e27f ("ring-buffer: Do not set shortest_full when full target is hit") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10serial: Lock console when calling into driver before registrationPeter Collingbourne1-3/+18
[ Upstream commit 801410b26a0e8b8a16f7915b2b55c9528b69ca87 ] During the handoff from earlycon to the real console driver, we have two separate drivers operating on the same device concurrently. In the case of the 8250 driver these concurrent accesses cause problems due to the driver's use of banked registers, controlled by LCR.DLAB. It is possible for the setup(), config_port(), pm() and set_mctrl() callbacks to set DLAB, which can cause the earlycon code that intends to access TX to instead access DLL, leading to missed output and corruption on the serial line due to unintended modifications to the baud rate. In particular, for setup() we have: univ8250_console_setup() -> serial8250_console_setup() -> uart_set_options() -> serial8250_set_termios() -> serial8250_do_set_termios() -> serial8250_do_set_divisor() For config_port() we have: serial8250_config_port() -> autoconfig() For pm() we have: serial8250_pm() -> serial8250_do_pm() -> serial8250_set_sleep() For set_mctrl() we have (for some devices): serial8250_set_mctrl() -> omap8250_set_mctrl() -> __omap8250_set_mctrl() To avoid such problems, let's make it so that the console is locked during pre-registration calls to these callbacks, which will prevent the earlycon driver from running concurrently. Remove the partial solution to this problem in the 8250 driver that locked the console only during autoconfig_irq(), as this would result in a deadlock with the new approach. The console continues to be locked during autoconfig_irq() because it can only be called through uart_configure_port(). Although this patch introduces more locking than strictly necessary (and in particular it also locks during the call to rs485_config() which is not affected by this issue as far as I can tell), it follows the principle that it is the responsibility of the generic console code to manage the earlycon handoff by ensuring that earlycon and real console driver code cannot run concurrently, and not the individual drivers. Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Link: https://linux-review.googlesource.com/id/I7cf8124dcebf8618e6b2ee543fa5b25532de55d8 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240304214350.501253-1-pcc@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10printk/console: Split out code that enables default consolePetr Mladek1-15/+23
[ Upstream commit ed758b30d541e9bf713cd58612a4414e57dc6d73 ] Put the code enabling a console by default into a separate function called try_enable_default_console(). Rename try_enable_new_console() to try_enable_preferred_console() to make the purpose of the different variants more clear. It is a code refactoring without any functional change. Signed-off-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Link: https://lore.kernel.org/r/20211122132649.12737-2-pmladek@suse.com Stable-dep-of: 801410b26a0e ("serial: Lock console when calling into driver before registration") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10PM: suspend: Set mem_sleep_current during kernel command line setupMaulik Shah1-0/+1
[ Upstream commit 9bc4ffd32ef8943f5c5a42c9637cfd04771d021b ] psci_init_system_suspend() invokes suspend_set_ops() very early during bootup even before kernel command line for mem_sleep_default is setup. This leads to kernel command line mem_sleep_default=s2idle not working as mem_sleep_current gets changed to deep via suspend_set_ops() and never changes back to s2idle. Set mem_sleep_current along with mem_sleep_default during kernel command line setup as default suspend mode. Fixes: faf7ec4a92c0 ("drivers: firmware: psci: add system suspend support") CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Maulik Shah <quic_mkshah@quicinc.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10bounds: support non-power-of-two CONFIG_NR_CPUSMatthew Wilcox (Oracle)1-1/+1
[ Upstream commit f2d5dcb48f7ba9e3ff249d58fc1fa963d374e66a ] ilog2() rounds down, so for example when PowerPC 85xx sets CONFIG_NR_CPUS to 24, we will only allocate 4 bits to store the number of CPUs instead of 5. Use bits_per() instead, which rounds up. Found by code inspection. The effect of this would probably be a misaccounting when doing NUMA balancing, so to a user, it would only be a performance penalty. The effects may be more wide-spread; it's hard to tell. Link: https://lkml.kernel.org/r/20231010145549.1244748-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Fixes: 90572890d202 ("mm: numa: Change page last {nid,pid} into {cpu,pid}") Reviewed-by: Rik van Riel <riel@surriel.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10timers: Rename del_timer_sync() to timer_delete_sync()Thomas Gleixner1-9/+9
[ Upstream commit 9b13df3fb64ee95e2397585404e442afee2c7d4f ] The timer related functions do not have a strict timer_ prefixed namespace which is really annoying. Rename del_timer_sync() to timer_delete_sync() and provide del_timer_sync() as a wrapper. Document that del_timer_sync() is not for new code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/r/20221123201624.954785441@linutronix.de Stable-dep-of: 0f7352557a35 ("wifi: brcmfmac: Fix use-after-free bug in brcmf_cfg80211_detach") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10timers: Use del_timer_sync() even on UPThomas Gleixner1-2/+0
[ Upstream commit 168f6b6ffbeec0b9333f3582e4cf637300858db5 ] del_timer_sync() is assumed to be pointless on uniprocessor systems and can be mapped to del_timer() because in theory del_timer() can never be invoked while the timer callback function is executed. This is not entirely true because del_timer() can be invoked from interrupt context and therefore hit in the middle of a running timer callback. Contrary to that del_timer_sync() is not allowed to be invoked from interrupt context unless the affected timer is marked with TIMER_IRQSAFE. del_timer_sync() has proper checks in place to detect such a situation. Give up on the UP optimization and make del_timer_sync() unconditionally available. Co-developed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/all/20220407161745.7d6754b3@gandalf.local.home Link: https://lore.kernel.org/all/20221110064101.429013735@goodmis.org Link: https://lore.kernel.org/r/20221123201624.888306160@linutronix.de Stable-dep-of: 0f7352557a35 ("wifi: brcmfmac: Fix use-after-free bug in brcmf_cfg80211_detach") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-04-10timers: Update kernel-doc for various functionsThomas Gleixner1-58/+90
[ Upstream commit 14f043f1340bf30bc60af127bff39f55889fef26 ] The kernel-doc of timer related functions is partially uncomprehensible word salad. Rewrite it to make it useful. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de> Link: https://lore.kernel.org/r/20221123201624.828703870@linutronix.de Stable-dep-of: 0f7352557a35 ("wifi: brcmfmac: Fix use-after-free bug in brcmf_cfg80211_detach") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26bpf: report RCU QS in cpumap kthreadYan Zhai1-0/+3
[ Upstream commit 00bf63122459e87193ee7f1bc6161c83a525569f ] When there are heavy load, cpumap kernel threads can be busy polling packets from redirect queues and block out RCU tasks from reaching quiescent states. It is insufficient to just call cond_resched() in such context. Periodically raise a consolidated RCU QS before cond_resched fixes the problem. Fixes: 6710e1126934 ("bpf: introduce new bpf cpu map type BPF_MAP_TYPE_CPUMAP") Reviewed-by: Jesper Dangaard Brouer <hawk@kernel.org> Signed-off-by: Yan Zhai <yan@cloudflare.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Jesper Dangaard Brouer <hawk@kernel.org> Link: https://lore.kernel.org/r/c17b9f1517e19d813da3ede5ed33ee18496bb5d8.1710877680.git.yan@cloudflare.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26modules: wait do_free_init correctlyChangbin Du1-2/+7
[ Upstream commit 8f8cd6c0a43ed637e620bbe45a8d0e0c2f4d5130 ] The synchronization here is to ensure the ordering of freeing of a module init so that it happens before W+X checking. It is worth noting it is not that the freeing was not happening, it is just that our sanity checkers raced against the permission checkers which assume init memory is already gone. Commit 1a7b7d922081 ("modules: Use vmalloc special flag") moved calling do_free_init() into a global workqueue instead of relying on it being called through call_rcu(..., do_free_init), which used to allowed us call do_free_init() asynchronously after the end of a subsequent grace period. The move to a global workqueue broke the gaurantees for code which needed to be sure the do_free_init() would complete with rcu_barrier(). To fix this callers which used to rely on rcu_barrier() must now instead use flush_work(&init_free_wq). Without this fix, we still could encounter false positive reports in W+X checking since the rcu_barrier() here can not ensure the ordering now. Even worse, the rcu_barrier() can introduce significant delay. Eric Chanudet reported that the rcu_barrier introduces ~0.1s delay on a PREEMPT_RT kernel. [ 0.291444] Freeing unused kernel memory: 5568K [ 0.402442] Run /sbin/init as init process With this fix, the above delay can be eliminated. Link: https://lkml.kernel.org/r/20240227023546.2490667-1-changbin.du@huawei.com Fixes: 1a7b7d922081 ("modules: Use vmalloc special flag") Signed-off-by: Changbin Du <changbin.du@huawei.com> Tested-by: Eric Chanudet <echanude@redhat.com> Acked-by: Luis Chamberlain <mcgrof@kernel.org> Cc: Xiaoyi Su <suxiaoyi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26module: Add support for default value for module async_probeSaravana Kannan1-1/+10
[ Upstream commit ae39e9ed964f8e450d0de410b5a757e19581dfc5 ] Add a module.async_probe kernel command line option that allows enabling async probing for all modules. When this command line option is used, there might still be some modules for which we want to explicitly force synchronous probing, so extend <modulename>.async_probe to take an optional bool input so that async probing can be disabled for a specific module. Signed-off-by: Saravana Kannan <saravanak@google.com> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Stable-dep-of: 8f8cd6c0a43e ("modules: wait do_free_init correctly") Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26bpf: Fix stackmap overflow check on 32-bit archesToke Høiland-Jørgensen1-3/+6
[ Upstream commit 7a4b21250bf79eef26543d35bd390448646c536b ] The stackmap code relies on roundup_pow_of_two() to compute the number of hash buckets, and contains an overflow check by checking if the resulting value is 0. However, on 32-bit arches, the roundup code itself can overflow by doing a 32-bit left-shift of an unsigned long value, which is undefined behaviour, so it is not guaranteed to truncate neatly. This was triggered by syzbot on the DEVMAP_HASH type, which contains the same check, copied from the hashtab code. The commit in the fixes tag actually attempted to fix this, but the fix did not account for the UB, so the fix only works on CPUs where an overflow does result in a neat truncation to zero, which is not guaranteed. Checking the value before rounding does not have this problem. Fixes: 6183f4d3a0a2 ("bpf: Check for integer overflow when using roundup_pow_of_two()") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Reviewed-by: Bui Quang Minh <minhquangbui99@gmail.com> Message-ID: <20240307120340.99577-4-toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26bpf: Fix hashtab overflow check on 32-bit archesToke Høiland-Jørgensen1-5/+9
[ Upstream commit 6787d916c2cf9850c97a0a3f73e08c43e7d973b1 ] The hashtab code relies on roundup_pow_of_two() to compute the number of hash buckets, and contains an overflow check by checking if the resulting value is 0. However, on 32-bit arches, the roundup code itself can overflow by doing a 32-bit left-shift of an unsigned long value, which is undefined behaviour, so it is not guaranteed to truncate neatly. This was triggered by syzbot on the DEVMAP_HASH type, which contains the same check, copied from the hashtab code. So apply the same fix to hashtab, by moving the overflow check to before the roundup. Fixes: daaf427c6ab3 ("bpf: fix arraymap NULL deref and missing overflow and zero size checks") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Message-ID: <20240307120340.99577-3-toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26bpf: Fix DEVMAP_HASH overflow check on 32-bit archesToke Høiland-Jørgensen1-5/+6
[ Upstream commit 281d464a34f540de166cee74b723e97ac2515ec3 ] The devmap code allocates a number hash buckets equal to the next power of two of the max_entries value provided when creating the map. When rounding up to the next power of two, the 32-bit variable storing the number of buckets can overflow, and the code checks for overflow by checking if the truncated 32-bit value is equal to 0. However, on 32-bit arches the rounding up itself can overflow mid-way through, because it ends up doing a left-shift of 32 bits on an unsigned long value. If the size of an unsigned long is four bytes, this is undefined behaviour, so there is no guarantee that we'll end up with a nice and tidy 0-value at the end. Syzbot managed to turn this into a crash on arm32 by creating a DEVMAP_HASH with max_entries > 0x80000000 and then trying to update it. Fix this by moving the overflow check to before the rounding up operation. Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index") Link: https://lore.kernel.org/r/000000000000ed666a0611af6818@google.com Reported-and-tested-by: syzbot+8cd36f6b65f3cafd400a@syzkaller.appspotmail.com Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Message-ID: <20240307120340.99577-2-toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26bpf: Mark bpf_spin_{lock,unlock}() helpers with notrace correctlyYonghong Song1-2/+2
[ Upstream commit 178c54666f9c4d2f49f2ea661d0c11b52f0ed190 ] Currently tracing is supposed not to allow for bpf_spin_{lock,unlock}() helper calls. This is to prevent deadlock for the following cases: - there is a prog (prog-A) calling bpf_spin_{lock,unlock}(). - there is a tracing program (prog-B), e.g., fentry, attached to bpf_spin_lock() and/or bpf_spin_unlock(). - prog-B calls bpf_spin_{lock,unlock}(). For such a case, when prog-A calls bpf_spin_{lock,unlock}(), a deadlock will happen. The related source codes are below in kernel/bpf/helpers.c: notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock) notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock) notrace is supposed to prevent fentry prog from attaching to bpf_spin_{lock,unlock}(). But actually this is not the case and fentry prog can successfully attached to bpf_spin_lock(). Siddharth Chintamaneni reported the issue in [1]. The following is the macro definition for above BPF_CALL_1: #define BPF_CALL_x(x, name, ...) \ static __always_inline \ u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ typedef u64 (*btf_##name)(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)); \ u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)); \ u64 name(__BPF_REG(x, __BPF_DECL_REGS, __BPF_N, __VA_ARGS__)) \ { \ return ((btf_##name)____##name)(__BPF_MAP(x,__BPF_CAST,__BPF_N,__VA_ARGS__));\ } \ static __always_inline \ u64 ____##name(__BPF_MAP(x, __BPF_DECL_ARGS, __BPF_V, __VA_ARGS__)) #define BPF_CALL_1(name, ...) BPF_CALL_x(1, name, __VA_ARGS__) The notrace attribute is actually applied to the static always_inline function ____bpf_spin_{lock,unlock}(). The actual callback function bpf_spin_{lock,unlock}() is not marked with notrace, hence allowing fentry prog to attach to two helpers, and this may cause the above mentioned deadlock. Siddharth Chintamaneni actually has a reproducer in [2]. To fix the issue, a new macro NOTRACE_BPF_CALL_1 is introduced which will add notrace attribute to the original function instead of the hidden always_inline function and this fixed the problem. [1] https://lore.kernel.org/bpf/CAE5sdEigPnoGrzN8WU7Tx-h-iFuMZgW06qp0KHWtpvoXxf1OAQ@mail.gmail.com/ [2] https://lore.kernel.org/bpf/CAE5sdEg6yUc_Jz50AnUXEEUh6O73yQ1Z6NV2srJnef0ZrQkZew@mail.gmail.com/ Fixes: d83525ca62cf ("bpf: introduce bpf_spin_lock") Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/bpf/20240207070102.335167-1-yonghong.song@linux.dev Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26sched/fair: Take the scheduling domain into account in select_idle_core()Keisuke Nishimura1-2/+2
[ Upstream commit 23d04d8c6b8ec339057264659b7834027f3e6a63 ] When picking a CPU on task wakeup, select_idle_core() has to take into account the scheduling domain where the function looks for the CPU. This is because the "isolcpus" kernel command line option can remove CPUs from the domain to isolate them from other SMT siblings. This change replaces the set of CPUs allowed to run the task from p->cpus_ptr by the intersection of p->cpus_ptr and sched_domain_span(sd) which is stored in the 'cpus' argument provided by select_idle_cpu(). Fixes: 9fe1f127b913 ("sched/fair: Merge select_idle_core/cpu()") Signed-off-by: Keisuke Nishimura <keisuke.nishimura@inria.fr> Signed-off-by: Julia Lawall <julia.lawall@inria.fr> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240110131707.437301-2-keisuke.nishimura@inria.fr Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-03-26timekeeping: Fix cross-timestamp interpolation for non-x86Peter Hilber1-4/+2
[ Upstream commit 14274d0bd31b4debf28284604589f596ad2e99f2 ] So far, get_device_system_crosststamp()