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* Merge tag 'trace-v6.8-rc2' of ↵Linus Torvalds2024-02-032-4/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing and eventfs fixes from Steven Rostedt: - Fix the return code for ring_buffer_poll_wait() It was returing a -EINVAL instead of EPOLLERR. - Zero out the tracefs_inode so that all fields are initialized. The ti->private could have had stale data, but instead of just initializing it to NULL, clear out the entire structure when it is allocated. - Fix a crash in timerlat The hrtimer was initialized at read and not open, but is canceled at close. If the file was opened and never read the close will pass a NULL pointer to hrtime_cancel(). - Rewrite of eventfs. Linus wrote a patch series to remove the dentry references in the eventfs_inode and to use ref counting and more of proper VFS interfaces to make it work. - Add warning to put_ei() if ei is not set to free. That means something is about to free it when it shouldn't. - Restructure the eventfs_inode to make it more compact, and remove the unused llist field. - Remove the fsnotify*() funtions for when the inodes were being created in the lookup code. It doesn't make sense to notify about creation just because something is being looked up. - The inode hard link count was not accurate. It was being updated when a file was looked up. The inodes of directories were updating their parent inode hard link count every time the inode was created. That means if memory reclaim cleaned a stale directory inode and the inode was lookup up again, it would increment the parent inode again as well. Al Viro said to just have all eventfs directories have a hard link count of 1. That tells user space not to trust it. * tag 'trace-v6.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: eventfs: Keep all directory links at 1 eventfs: Remove fsnotify*() functions from lookup() eventfs: Restructure eventfs_inode structure to be more condensed eventfs: Warn if an eventfs_inode is freed without is_freed being set tracing/timerlat: Move hrtimer_init to timerlat_fd open() eventfs: Get rid of dentry pointers without refcounts eventfs: Clean up dentry ops and add revalidate function eventfs: Remove unused d_parent pointer field tracefs: dentry lookup crapectomy tracefs: Avoid using the ei->dentry pointer unnecessarily eventfs: Initialize the tracefs inode properly tracefs: Zero out the tracefs_inode when allocating it ring-buffer: Clean ring_buffer_poll_wait() error return
| * tracing/timerlat: Move hrtimer_init to timerlat_fd open()Daniel Bristot de Oliveira2024-02-011-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the timerlat's hrtimer is initialized at the first read of timerlat_fd, and destroyed at close(). It works, but it causes an error if the user program open() and close() the file without reading. Here's an example: # echo NO_OSNOISE_WORKLOAD > /sys/kernel/debug/tracing/osnoise/options # echo timerlat > /sys/kernel/debug/tracing/current_tracer # cat <<EOF > ./timerlat_load.py # !/usr/bin/env python3 timerlat_fd = open("/sys/kernel/tracing/osnoise/per_cpu/cpu0/timerlat_fd", 'r') timerlat_fd.close(); EOF # ./taskset -c 0 ./timerlat_load.py <BOOM> BUG: kernel NULL pointer dereference, address: 0000000000000010 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI CPU: 1 PID: 2673 Comm: python3 Not tainted 6.6.13-200.fc39.x86_64 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39 04/01/2014 RIP: 0010:hrtimer_active+0xd/0x50 Code: 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 1f 44 00 00 48 8b 57 30 <8b> 42 10 a8 01 74 09 f3 90 8b 42 10 a8 01 75 f7 80 7f 38 00 75 1d RSP: 0018:ffffb031009b7e10 EFLAGS: 00010286 RAX: 000000000002db00 RBX: ffff9118f786db08 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff9117a0e64400 RDI: ffff9118f786db08 RBP: ffff9118f786db80 R08: ffff9117a0ddd420 R09: ffff9117804d4f70 R10: 0000000000000000 R11: 0000000000000000 R12: ffff9118f786db08 R13: ffff91178fdd5e20 R14: ffff9117840978c0 R15: 0000000000000000 FS: 00007f2ffbab1740(0000) GS:ffff9118f7840000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000010 CR3: 00000001b402e000 CR4: 0000000000750ee0 PKRU: 55555554 Call Trace: <TASK> ? __die+0x23/0x70 ? page_fault_oops+0x171/0x4e0 ? srso_alias_return_thunk+0x5/0x7f ? avc_has_extended_perms+0x237/0x520 ? exc_page_fault+0x7f/0x180 ? asm_exc_page_fault+0x26/0x30 ? hrtimer_active+0xd/0x50 hrtimer_cancel+0x15/0x40 timerlat_fd_release+0x48/0xe0 __fput+0xf5/0x290 __x64_sys_close+0x3d/0x80 do_syscall_64+0x60/0x90 ? srso_alias_return_thunk+0x5/0x7f ? __x64_sys_ioctl+0x72/0xd0 ? srso_alias_return_thunk+0x5/0x7f ? syscall_exit_to_user_mode+0x2b/0x40 ? srso_alias_return_thunk+0x5/0x7f ? do_syscall_64+0x6c/0x90 ? srso_alias_return_thunk+0x5/0x7f ? exit_to_user_mode_prepare+0x142/0x1f0 ? srso_alias_return_thunk+0x5/0x7f ? syscall_exit_to_user_mode+0x2b/0x40 ? srso_alias_return_thunk+0x5/0x7f ? do_syscall_64+0x6c/0x90 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 RIP: 0033:0x7f2ffb321594 Code: 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 80 3d d5 cd 0d 00 00 74 13 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3c c3 0f 1f 00 55 48 89 e5 48 83 ec 10 89 7d RSP: 002b:00007ffe8d8eef18 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00007f2ffba4e668 RCX: 00007f2ffb321594 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007ffe8d8eef40 R08: 0000000000000000 R09: 0000000000000000 R10: 55c926e3167eae79 R11: 0000000000000202 R12: 0000000000000003 R13: 00007ffe8d8ef030 R14: 0000000000000000 R15: 00007f2ffba4e668 </TASK> CR2: 0000000000000010 ---[ end trace 0000000000000000 ]--- Move hrtimer_init to timerlat_fd open() to avoid this problem. Link: https://lore.kernel.org/linux-trace-kernel/7324dd3fc0035658c99b825204a66049389c56e3.1706798888.git.bristot@kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: stable@vger.kernel.org Fixes: e88ed227f639 ("tracing/timerlat: Add user-space interface") Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * ring-buffer: Clean ring_buffer_poll_wait() error returnVincent Donnefort2024-01-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The return type for ring_buffer_poll_wait() is __poll_t. This is behind the scenes an unsigned where we can set event bits. In case of a non-allocated CPU, we do return instead -EINVAL (0xffffffea). Lucky us, this ends up setting few error bits (EPOLLERR | EPOLLHUP | EPOLLNVAL), so user-space at least is aware something went wrong. Nonetheless, this is an incorrect code. Replace that -EINVAL with a proper EPOLLERR to clean that output. As this doesn't change the behaviour, there's no need to treat this change as a bug fix. Link: https://lore.kernel.org/linux-trace-kernel/20240131140955.3322792-1-vdonnefort@google.com Cc: stable@vger.kernel.org Fixes: 6721cb6002262 ("ring-buffer: Do not poll non allocated cpu buffers") Signed-off-by: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
* | Merge tag 'trace-v6.8-rc1-2' of ↵Linus Torvalds2024-01-301-2/+4
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: "Two small fixes for tracefs and eventfs: - Fix register_snapshot_trigger() on allocation error If the snapshot fails to allocate, the register_snapshot_trigger() can still return success. If the call to tracing_alloc_snapshot_instance() returned anything but 0, it returned 0, but it should have been returning the error code from that allocation function. - Remove leftover code from tracefs doing a dentry walk on remount. The update_gid() function was called by the tracefs code on remount to update the gid of eventfs, but that is no longer the case, but that code wasn't deleted. Nothing calls it. Remove it" * tag 'trace-v6.8-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracefs: remove stale 'update_gid' code tracing/trigger: Fix to return error if failed to alloc snapshot
| * tracing/trigger: Fix to return error if failed to alloc snapshotMasami Hiramatsu (Google)2024-01-261-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix register_snapshot_trigger() to return error code if it failed to allocate a snapshot instead of 0 (success). Unless that, it will register snapshot trigger without an error. Link: https://lore.kernel.org/linux-trace-kernel/170622977792.270660.2789298642759362200.stgit@devnote2 Fixes: 0bbe7f719985 ("tracing: Fix the race between registering 'snapshot' event trigger and triggering 'snapshot' operation") Cc: stable@vger.kernel.org Cc: Vincent Donnefort <vdonnefort@google.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
* | Merge tag 'mm-hotfixes-stable-2024-01-28-23-21' of ↵Linus Torvalds2024-01-301-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull misc fixes from Andrew Morton: "22 hotfixes. 11 are cc:stable and the remainder address post-6.7 issues or aren't considered appropriate for backporting" * tag 'mm-hotfixes-stable-2024-01-28-23-21' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (22 commits) mm: thp_get_unmapped_area must honour topdown preference mm: huge_memory: don't force huge page alignment on 32 bit userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb selftests/mm: ksm_tests should only MADV_HUGEPAGE valid memory scs: add CONFIG_MMU dependency for vfree_atomic() mm/memory: fix folio_set_dirty() vs. folio_mark_dirty() in zap_pte_range() mm/huge_memory: fix folio_set_dirty() vs. folio_mark_dirty() selftests/mm: Update va_high_addr_switch.sh to check CPU for la57 flag selftests: mm: fix map_hugetlb failure on 64K page size systems MAINTAINERS: supplement of zswap maintainers update stackdepot: make fast paths lock-less again stackdepot: add stats counters exported via debugfs mm, kmsan: fix infinite recursion due to RCU critical section mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again selftests/mm: switch to bash from sh MAINTAINERS: add man-pages git trees mm: memcontrol: don't throttle dying tasks on memory.high mm: mmap: map MAP_STACK to VM_NOHUGEPAGE uprobes: use pagesize-aligned virtual address when replacing pages selftests/mm: mremap_test: fix build warning ...
| * | uprobes: use pagesize-aligned virtual address when replacing pagesDavid Hildenbrand2024-01-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uprobes passes an unaligned page mapping address to folio_add_new_anon_rmap(), which ends up triggering a VM_BUG_ON() we recently extended in commit 372cbd4d5a066 ("mm: non-pmd-mappable, large folios for folio_add_new_anon_rmap()"). Arguably, this is uprobes code doing something wrong; however, for the time being it would have likely worked in rmap code because __folio_set_anon() would set folio->index to the same value. Looking at __replace_page(), we'd also pass slightly wrong values to mmu_notifier_range_init(), page_vma_mapped_walk(), flush_cache_page(), ptep_clear_flush() and set_pte_at_notify(). I suspect most of them are fine, but let's just mark the introducing commit as the one needed fixing. I don't think CC stable is warranted. We'll add more sanity checks in rmap code separately, to make sure that we always get properly aligned addresses. Link: https://lkml.kernel.org/r/20240115100731.91007-1-david@redhat.com Fixes: c517ee744b96 ("uprobes: __replace_page() should not use page_address_in_vma()") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Jiri Olsa <jolsa@kernel.org> Closes: https://lkml.kernel.org/r/ZaMR2EWN-HvlCfUl@krava Tested-by: Jiri Olsa <jolsa@kernel.org> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Shishkin Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Ian Rogers <irogers@google.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | | Merge tag 'locking_urgent_for_v6.8_rc2' of ↵Linus Torvalds2024-01-282-6/+20
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fix from Borislav Petkov: - Prevent an inconsistent futex operation leading to stale state exposure * tag 'locking_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Prevent the reuse of stale pi_state
| * | | futex: Prevent the reuse of stale pi_stateSebastian Andrzej Siewior2024-01-192-6/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jiri Slaby reported a futex state inconsistency resulting in -EINVAL during a lock operation for a PI futex. It requires that the a lock process is interrupted by a timeout or signal: T1 Owns the futex in user space. T2 Tries to acquire the futex in kernel (futex_lock_pi()). Allocates a pi_state and attaches itself to it. T2 Times out and removes its rt_waiter from the rt_mutex. Drops the rtmutex lock and tries to acquire the hash bucket lock to remove the futex_q. The lock is contended and T2 schedules out. T1 Unlocks the futex (futex_unlock_pi()). Finds a futex_q but no rt_waiter. Unlocks the futex (do_uncontended) and makes it available to user space. T3 Acquires the futex in user space. T4 Tries to acquire the futex in kernel (futex_lock_pi()). Finds the existing futex_q of T2 and tries to attach itself to the existing pi_state. This (attach_to_pi_state()) fails with -EINVAL because uval contains the TID of T3 but pi_state points to T1. It's incorrect to unlock the futex and make it available for user space to acquire as long as there is still an existing state attached to it in the kernel. T1 cannot hand over the futex to T2 because T2 already gave up and started to clean up and is blocked on the hash bucket lock, so T2's futex_q with the pi_state pointing to T1 is still queued. T2 observes the futex_q, but ignores it as there is no waiter on the corresponding rt_mutex and takes the uncontended path which allows the subsequent caller of futex_lock_pi() (T4) to observe that stale state. To prevent this the unlock path must dequeue all futex_q entries which point to the same pi_state when there is no waiter on the rt mutex. This requires obviously to make the dequeue conditional in the locking path to prevent a double dequeue. With that it's guaranteed that user space cannot observe an uncontended futex which has kernel state attached. Fixes: fbeb558b0dd0d ("futex/pi: Fix recursive rt_mutex waiter state") Reported-by: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20240118115451.0TkD_ZhB@linutronix.de Closes: https://lore.kernel.org/all/4611bcf2-44d0-4c34-9b84-17406f881003@kernel.org
* | | | Merge tag 'irq_urgent_for_v6.8_rc2' of ↵Linus Torvalds2024-01-281-1/+1
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fix from Borislav Petkov: - Initialize the resend node of each IRQ descriptor, not only the first one * tag 'irq_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Initialize resend_node hlist for all interrupt descriptors
| * | | | genirq: Initialize resend_node hlist for all interrupt descriptorsDawei Li2024-01-241-1/+1
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For a CONFIG_SPARSE_IRQ=n kernel, early_irq_init() is supposed to initialize all interrupt descriptors. It does except for irq_desc::resend_node, which ia only initialized for the first descriptor. Use the indexed decriptor and not the base pointer to address that. Fixes: bc06a9e08742 ("genirq: Use hlist for managing resend handlers") Signed-off-by: Dawei Li <dawei.li@shingroup.cn> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Marc Zyngier <maz@kernel.org> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240122085716.2999875-5-dawei.li@shingroup.cn
* | | | Merge tag 'timers_urgent_for_v6.8_rc2' of ↵Linus Torvalds2024-01-282-1/+29
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Borislav Petkov: - Preserve the number of idle calls and sleep entries across CPU hotplug events in order to be able to compute correct averages - Limit the duration of the clocksource watchdog checking interval as too long intervals lead to wrongly marking the TSC as unstable * tag 'timers_urgent_for_v6.8_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick/sched: Preserve number of idle sleeps across CPU hotplug events clocksource: Skip watchdog check for large watchdog intervals
| * | | | tick/sched: Preserve number of idle sleeps across CPU hotplug eventsTim Chen2024-01-251-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 71fee48f ("tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug") preserved total idle sleep time and iowait sleeptime across CPU hotplug events. Similar reasoning applies to the number of idle calls and idle sleeps to get the proper average of sleep time per idle invocation. Preserve those fields too. Fixes: 71fee48f ("tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug") Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240122233534.3094238-1-tim.c.chen@linux.intel.com
| * | | | clocksource: Skip watchdog check for large watchdog intervalsJiri Wiesner2024-01-251-1/+24
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There have been reports of the watchdog marking clocksources unstable on machines with 8 NUMA nodes: clocksource: timekeeping watchdog on CPU373: Marking clocksource 'tsc' as unstable because the skew is too large: clocksource: 'hpet' wd_nsec: 14523447520 clocksource: 'tsc' cs_nsec: 14524115132 The measured clocksource skew - the absolute difference between cs_nsec and wd_nsec - was 668 microseconds: cs_nsec - wd_nsec = 14524115132 - 14523447520 = 667612 The kernel used 200 microseconds for the uncertainty_margin of both the clocksource and watchdog, resulting in a threshold of 400 microseconds (the md variable). Both the cs_nsec and the wd_nsec value indicate that the readout interval was circa 14.5 seconds. The observed behaviour is that watchdog checks failed for large readout intervals on 8 NUMA node machines. This indicates that the size of the skew was directly proportinal to the length of the readout interval on those machines. The measured clocksource skew, 668 microseconds, was evaluated against a threshold (the md variable) that is suited for readout intervals of roughly WATCHDOG_INTERVAL, i.e. HZ >> 1, which is 0.5 second. The intention of 2e27e793e280 ("clocksource: Reduce clocksource-skew threshold") was to tighten the threshold for evaluating skew and set the lower bound for the uncertainty_margin of clocksources to twice WATCHDOG_MAX_SKEW. Later in c37e85c135ce ("clocksource: Loosen clocksource watchdog constraints"), the WATCHDOG_MAX_SKEW constant was increased to 125 microseconds to fit the limit of NTP, which is able to use a clocksource that suffers from up to 500 microseconds of skew per second. Both the TSC and the HPET use default uncertainty_margin. When the readout interval gets stretched the default uncertainty_margin is no longer a suitable lower bound for evaluating skew - it imposes a limit that is far stricter than the skew with which NTP can deal. The root causes of the skew being directly proportinal to the length of the readout interval are: * the inaccuracy of the shift/mult pairs of clocksources and the watchdog * the conversion to nanoseconds is imprecise for large readout intervals Prevent this by skipping the current watchdog check if the readout interval exceeds 2 * WATCHDOG_INTERVAL. Considering the maximum readout interval of 2 * WATCHDOG_INTERVAL, the current default uncertainty margin (of the TSC and HPET) corresponds to a limit on clocksource skew of 250 ppm (microseconds of skew per second). To keep the limit imposed by NTP (500 microseconds of skew per second) for all possible readout intervals, the margins would have to be scaled so that the threshold value is proportional to the length of the actual readout interval. As for why the readout interval may get stretched: Since the watchdog is executed in softirq context the expiration of the watchdog timer can get severely delayed on account of a ksoftirqd thread not getting to run in a timely manner. Surely, a system with such belated softirq execution is not working well and the scheduling issue should be looked into but the clocksource watchdog should be able to deal with it accordingly. Fixes: 2e27e793e280 ("clocksource: Reduce clocksource-skew threshold") Suggested-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Jiri Wiesner <jwiesner@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Feng Tang <feng.tang@intel.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240122172350.GA740@incl
* | | | Merge tag 'urgent-rcu.2024.01.24a' of https://github.com/neeraju/linuxLinus Torvalds2024-01-252-3/+34
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull RCU fix from Neeraj Upadhyay: "This fixes RCU grace period stalls, which are observed when an outgoing CPU's quiescent state reporting results in wakeup of one of the grace period kthreads, to complete the grace period. If those kthreads have SCHED_FIFO policy, the wake up can indirectly arm the RT bandwith timer to the local offline CPU. Earlier migration of the hrtimers from the CPU introduced in commit 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier") results in this timer getting ignored. If the RCU grace period kthreads are waiting for RT bandwidth to be available, they may never be actually scheduled, resulting in RCU stall warnings" * tag 'urgent-rcu.2024.01.24a' of https://github.com/neeraju/linux: rcu: Defer RCU kthreads wakeup when CPU is dying
| * | | | rcu: Defer RCU kthreads wakeup when CPU is dyingFrederic Weisbecker2024-01-242-3/+34
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the CPU goes idle for the last time during the CPU down hotplug process, RCU reports a final quiescent state for the current CPU. If this quiescent state propagates up to the top, some tasks may then be woken up to complete the grace period: the main grace period kthread and/or the expedited main workqueue (or kworker). If those kthreads have a SCHED_FIFO policy, the wake up can indirectly arm the RT bandwith timer to the local offline CPU. Since this happens after hrtimers have been migrated at CPUHP_AP_HRTIMERS_DYING stage, the timer gets ignored. Therefore if the RCU kthreads are waiting for RT bandwidth to be available, they may never be actually scheduled. This triggers TREE03 rcutorture hangs: rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 4-...!: (1 GPs behind) idle=9874/1/0x4000000000000000 softirq=0/0 fqs=20 rcuc=21071 jiffies(starved) rcu: (t=21035 jiffies g=938281 q=40787 ncpus=6) rcu: rcu_preempt kthread starved for 20964 jiffies! g938281 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:14896 pid:14 tgid:14 ppid:2 flags:0x00004000 Call Trace: <TASK> __schedule+0x2eb/0xa80 schedule+0x1f/0x90 schedule_timeout+0x163/0x270 ? __pfx_process_timeout+0x10/0x10 rcu_gp_fqs_loop+0x37c/0x5b0 ? __pfx_rcu_gp_kthread+0x10/0x10 rcu_gp_kthread+0x17c/0x200 kthread+0xde/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2b/0x40 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 </TASK> The situation can't be solved with just unpinning the timer. The hrtimer infrastructure and the nohz heuristics involved in finding the best remote target for an unpinned timer would then also need to handle enqueues from an offline CPU in the most horrendous way. So fix this on the RCU side instead and defer the wake up to an online CPU if it's too late for the local one. Reported-by: Paul E. McKenney <paulmck@kernel.org> Fixes: 5c0930ccaad5 ("hrtimers: Push pending hrtimers away from outgoing CPU earlier") Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.iitr10@gmail.com>
* | | | Merge tag 'execve-v6.8-rc2' of ↵Linus Torvalds2024-01-241-0/+1
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull execve fixes from Kees Cook: - Fix error handling in begin_new_exec() (Bernd Edlinger) - MAINTAINERS: specifically mention ELF (Alexey Dobriyan) - Various cleanups related to earlier open() (Askar Safin, Kees Cook) * tag 'execve-v6.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: exec: Distinguish in_execve from in_exec exec: Fix error handling in begin_new_exec() exec: Add do_close_execat() helper exec: remove useless comment ELF, MAINTAINERS: specifically mention ELF
| * | | exec: Distinguish in_execve from in_execKees Cook2024-01-241-0/+1
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Just to help distinguish the fs->in_exec flag from the current->in_execve flag, add comments in check_unsafe_exec() and copy_fs() for more context. Also note that in_execve is only used by TOMOYO now. Cc: Kentaro Takeda <takedakn@nttdata.co.jp> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Kees Cook <keescook@chromium.org>
* / / tracing: Ensure visibility when inserting an element into tracing_mapPetr Pavlu2024-01-221-1/+6
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Running the following two commands in parallel on a multi-processor AArch64 machine can sporadically produce an unexpected warning about duplicate histogram entries: $ while true; do echo hist:key=id.syscall:val=hitcount > \ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist sleep 0.001 done $ stress-ng --sysbadaddr $(nproc) The warning looks as follows: [ 2911.172474] ------------[ cut here ]------------ [ 2911.173111] Duplicates detected: 1 [ 2911.173574] WARNING: CPU: 2 PID: 12247 at kernel/trace/tracing_map.c:983 tracing_map_sort_entries+0x3e0/0x408 [ 2911.174702] Modules linked in: iscsi_ibft(E) iscsi_boot_sysfs(E) rfkill(E) af_packet(E) nls_iso8859_1(E) nls_cp437(E) vfat(E) fat(E) ena(E) tiny_power_button(E) qemu_fw_cfg(E) button(E) fuse(E) efi_pstore(E) ip_tables(E) x_tables(E) xfs(E) libcrc32c(E) aes_ce_blk(E) aes_ce_cipher(E) crct10dif_ce(E) polyval_ce(E) polyval_generic(E) ghash_ce(E) gf128mul(E) sm4_ce_gcm(E) sm4_ce_ccm(E) sm4_ce(E) sm4_ce_cipher(E) sm4(E) sm3_ce(E) sm3(E) sha3_ce(E) sha512_ce(E) sha512_arm64(E) sha2_ce(E) sha256_arm64(E) nvme(E) sha1_ce(E) nvme_core(E) nvme_auth(E) t10_pi(E) sg(E) scsi_mod(E) scsi_common(E) efivarfs(E) [ 2911.174738] Unloaded tainted modules: cppc_cpufreq(E):1 [ 2911.180985] CPU: 2 PID: 12247 Comm: cat Kdump: loaded Tainted: G E 6.7.0-default #2 1b58bbb22c97e4399dc09f92d309344f69c44a01 [ 2911.182398] Hardware name: Amazon EC2 c7g.8xlarge/, BIOS 1.0 11/1/2018 [ 2911.183208] pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) [ 2911.184038] pc : tracing_map_sort_entries+0x3e0/0x408 [ 2911.184667] lr : tracing_map_sort_entries+0x3e0/0x408 [ 2911.185310] sp : ffff8000a1513900 [ 2911.185750] x29: ffff8000a1513900 x28: ffff0003f272fe80 x27: 0000000000000001 [ 2911.186600] x26: ffff0003f272fe80 x25: 0000000000000030 x24: 0000000000000008 [ 2911.187458] x23: ffff0003c5788000 x22: ffff0003c16710c8 x21: ffff80008017f180 [ 2911.188310] x20: ffff80008017f000 x19: ffff80008017f180 x18: ffffffffffffffff [ 2911.189160] x17: 0000000000000000 x16: 0000000000000000 x15: ffff8000a15134b8 [ 2911.190015] x14: 0000000000000000 x13: 205d373432323154 x12: 5b5d313131333731 [ 2911.190844] x11: 00000000fffeffff x10: 00000000fffeffff x9 : ffffd1b78274a13c [ 2911.191716] x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 000000000057ffa8 [ 2911.192554] x5 : ffff0012f6c24ec0 x4 : 0000000000000000 x3 : ffff2e5b72b5d000 [ 2911.193404] x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0003ff254480 [ 2911.194259] Call trace: [ 2911.194626] tracing_map_sort_entries+0x3e0/0x408 [ 2911.195220] hist_show+0x124/0x800 [ 2911.195692] seq_read_iter+0x1d4/0x4e8 [ 2911.196193] seq_read+0xe8/0x138 [ 2911.196638] vfs_read+0xc8/0x300 [ 2911.197078] ksys_read+0x70/0x108 [ 2911.197534] __arm64_sys_read+0x24/0x38 [ 2911.198046] invoke_syscall+0x78/0x108 [ 2911.198553] el0_svc_common.constprop.0+0xd0/0xf8 [ 2911.199157] do_el0_svc+0x28/0x40 [ 2911.199613] el0_svc+0x40/0x178 [ 2911.200048] el0t_64_sync_handler+0x13c/0x158 [ 2911.200621] el0t_64_sync+0x1a8/0x1b0 [ 2911.201115] ---[ end trace 0000000000000000 ]--- The problem appears to be caused by CPU reordering of writes issued from __tracing_map_insert(). The check for the presence of an element with a given key in this function is: val = READ_ONCE(entry->val); if (val && keys_match(key, val->key, map->key_size)) ... The write of a new entry is: elt = get_free_elt(map); memcpy(elt->key, key, map->key_size); entry->val = elt; The "memcpy(elt->key, key, map->key_size);" and "entry->val = elt;" stores may become visible in the reversed order on another CPU. This second CPU might then incorrectly determine that a new key doesn't match an already present val->key and subsequently insert a new element, resulting in a duplicate. Fix the problem by adding a write barrier between "memcpy(elt->key, key, map->key_size);" and "entry->val = elt;", and for good measure, also use WRITE_ONCE(entry->val, elt) for publishing the element. The sequence pairs with the mentioned "READ_ONCE(entry->val);" and the "val->key" check which has an address dependency. The barrier is placed on a path executed when adding an element for a new key. Subsequent updates targeting the same key remain unaffected. From the user's perspective, the issue was introduced by commit c193707dde77 ("tracing: Remove code which merges duplicates"), which followed commit cbf4100efb8f ("tracing: Add support to detect and avoid duplicates"). The previous code operated differently; it inherently expected potential races which result in duplicates but merged them later when they occurred. Link: https://lore.kernel.org/linux-trace-kernel/20240122150928.27725-1-petr.pavlu@suse.com Fixes: c193707dde77 ("tracing: Remove code which merges duplicates") Signed-off-by: Petr Pavlu <petr.pavlu@suse.com> Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
* | Merge tag 'timers-core-2024-01-21' of ↵Linus Torvalds2024-01-211-0/+5
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Updates for time and clocksources: - A fix for the idle and iowait time accounting vs CPU hotplug. The time is reset on CPU hotplug which makes the accumulated systemwide time jump backwards. - Assorted fixes and improvements for clocksource/event drivers" * tag 'timers-core-2024-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplug clocksource/drivers/ep93xx: Fix error handling during probe clocksource/drivers/cadence-ttc: Fix some kernel-doc warnings clocksource/drivers/timer-ti-dm: Fix make W=n kerneldoc warnings clocksource/timer-riscv: Add riscv_clock_shutdown callback dt-bindings: timer: Add StarFive JH8100 clint dt-bindings: timer: thead,c900-aclint-mtimer: separate mtime and mtimecmp regs
| * | tick-sched: Fix idle and iowait sleeptime accounting vs CPU hotplugHeiko Carstens2024-01-191-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When offlining and onlining CPUs the overall reported idle and iowait times as reported by /proc/stat jump backward and forward: cpu 132 0 176 225249 47 6 6 21 0 0 cpu0 80 0 115 112575 33 3 4 18 0 0 cpu1 52 0 60 112673 13 3 1 2 0 0 cpu 133 0 177 226681 47 6 6 21 0 0 cpu0 80 0 116 113387 33 3 4 18 0 0 cpu 133 0 178 114431 33 6 6 21 0 0 <---- jump backward cpu0 80 0 116 114247 33 3 4 18 0 0 cpu1 52 0 61 183 0 3 1 2 0 0 <---- idle + iowait start with 0 cpu 133 0 178 228956 47 6 6 21 0 0 <---- jump forward cpu0 81 0 117 114929 33 3 4 18 0 0 Reason for this is that get_idle_time() in fs/proc/stat.c has different sources for both values depending on if a CPU is online or offline: - if a CPU is online the values may be taken from its per cpu tick_cpu_sched structure - if a CPU is offline the values are taken from its per cpu cpustat structure The problem is that the per cpu tick_cpu_sched structure is set to zero on CPU offline. See tick_cancel_sched_timer() in kernel/time/tick-sched.c. Therefore when a CPU is brought offline and online afterwards both its idle and iowait sleeptime will be zero, causing a jump backward in total system idle and iowait sleeptime. In a similar way if a CPU is then brought offline again the total idle and iowait sleeptimes will jump forward. It looks like this behavior was introduced with commit 4b0c0f294f60 ("tick: Cleanup NOHZ per cpu data on cpu down"). This was only noticed now on s390, since we switched to generic idle time reporting with commit be76ea614460 ("s390/idle: remove arch_cpu_idle_time() and corresponding code"). Fix this by preserving the values of idle_sleeptime and iowait_sleeptime members of the per-cpu tick_sched structure on CPU hotplug. Fixes: 4b0c0f294f60 ("tick: Cleanup NOHZ per cpu data on cpu down") Reported-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20240115163555.1004144-1-hca@linux.ibm.com
* | | Merge tag 'kgdb-6.8-rc1' of ↵Linus Torvalds2024-01-191-2/+0
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux Pull kgdb update from Daniel Thompson: "The entire changeset for kgdb this cycle is a single two-line change to remove some deadcode that, had it not been dead, would have called strncpy() in an unsafe manner. To be fair there were other modest clean ups were discussed this cycle but they are not finalized and will have to wait until next time" * tag 'kgdb-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux: kdb: Fix a potential buffer overflow in kdb_local()
| * | | kdb: Fix a potential buffer overflow in kdb_local()Christophe JAILLET2024-01-171-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When appending "[defcmd]" to 'kdb_prompt_str', the size of the string already in the buffer should be taken into account. An option could be to switch from strncat() to strlcat() which does the correct test to avoid such an overflow. However, this actually looks as dead code, because 'defcmd_in_progress' can't be true here. See a more detailed explanation at [1]. [1]: https://lore.kernel.org/all/CAD=FV=WSh7wKN7Yp-3wWiDgX4E3isQ8uh0LCzTmd1v9Cg9j+nQ@mail.gmail.com/ Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)") Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Douglas Anderson <dianders@chromium.org>
* | | | Merge tag 'net-6.8-rc1' of ↵Linus Torvalds2024-01-192-26/+209
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Including fixes from bpf and netfilter. Previous releases - regressions: - Revert "net: rtnetlink: Enslave device before bringing it up", breaks the case inverse to the one it was trying to fix - net: dsa: fix oob access in DSA's netdevice event handler dereference netdev_priv() before check its a DSA port - sched: track device in tcf_block_get/put_ext() only for clsact binder types - net: tls, fix WARNING in __sk_msg_free when record becomes full during splice and MORE hint set - sfp-bus: fix SFP mode detect from bitrate - drv: stmmac: prevent DSA tags from breaking COE Previous releases - always broken: - bpf: fix no forward progress in in bpf_iter_udp if output buffer is too small - bpf: reject variable offset alu on registers with a type of PTR_TO_FLOW_KEYS to prevent oob access - netfilter: tighten input validation - net: add more sanity check in virtio_net_hdr_to_skb() - rxrpc: fix use of Don't Fragment flag on RESPONSE packets, avoid infinite loop - amt: do not use the portion of skb->cb area which may get clobbered - mptcp: improve validation of the MPTCPOPT_MP_JOIN MCTCP option Misc: - spring cleanup of inactive maintainers" * tag 'net-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (88 commits) i40e: Include types.h to some headers ipv6: mcast: fix data-race in ipv6_mc_down / mld_ifc_work selftests: mlxsw: qos_pfc: Adjust the test to support 8 lanes selftests: mlxsw: qos_pfc: Remove wrong description mlxsw: spectrum_router: Register netdevice notifier before nexthop mlxsw: spectrum_acl_tcam: Fix stack corruption mlxsw: spectrum_acl_tcam: Fix NULL pointer dereference in error path mlxsw: spectrum_acl_erp: Fix error flow of pool allocation failure ethtool: netlink: Add missing ethnl_ops_begin/complete selftests: bonding: Add more missing config options selftests: netdevsim: add a config file libbpf: warn on unexpected __arg_ctx type when rewriting BTF selftests/bpf: add tests confirming type logic in kernel for __arg_ctx bpf: enforce types for __arg_ctx-tagged arguments in global subprogs bpf: extract bpf_ctx_convert_map logic and make it more reusable libbpf: feature-detect arg:ctx tag support in kernel ipvs: avoid stat macros calls from preemptible context netfilter: nf_tables: reject NFT_SET_CONCAT with not field length description netfilter: nf_tables: skip dead set elements in netlink dump netfilter: nf_tables: do not allow mismatch field size and set key length ...
| * | | | bpf: enforce types for __arg_ctx-tagged arguments in global subprogsAndrii Nakryiko2024-01-181-0/+160
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add enforcement of expected types for context arguments tagged with arg:ctx (__arg_ctx) tag. First, any program type will accept generic `void *` context type when combined with __arg_ctx tag. Besides accepting "canonical" struct names and `void *`, for a bunch of program types for which program context is actually a named struct, we allows a bunch of pragmatic exceptions to match real-world and expected usage: - for both kprobes and perf_event we allow `bpf_user_pt_regs_t *` as canonical context argument type, where `bpf_user_pt_regs_t` is a *typedef*, not a struct; - for kprobes, we also always accept `struct pt_regs *`, as that's what actually is passed as a context to any kprobe program; - for perf_event, we resolve typedefs (unless it's `bpf_user_pt_regs_t`) down to actual struct type and accept `struct pt_regs *`, or `struct user_pt_regs *`, or `struct user_regs_struct *`, depending on the actual struct type kernel architecture points `bpf_user_pt_regs_t` typedef to; otherwise, canonical `struct bpf_perf_event_data *` is expected; - for raw_tp/raw_tp.w programs, `u64/long *` are accepted, as that's what's expected with BPF_PROG() usage; otherwise, canonical `struct bpf_raw_tracepoint_args *` is expected; - tp_btf supports both `struct bpf_raw_tracepoint_args *` and `u64 *` formats, both are coded as expections as tp_btf is actually a TRACING program type, which has no canonical context type; - iterator programs accept `struct bpf_iter__xxx *` structs, currently with no further iterator-type specific enforcement; - fentry/fexit/fmod_ret/lsm/struct_ops all accept `u64 *`; - classic tracepoint programs, as well as syscall and freplace programs allow any user-provided type. In all other cases kernel will enforce exact match of struct name to expected canonical type. And if user-provided type doesn't match that expectation, verifier will emit helpful message with expected type name. Note a bit unnatural way the check is done after processing all the arguments. This is done to avoid conflict between bpf and bpf-next trees. Once trees converge, a small follow up patch will place a simple btf_validate_prog_ctx_type() check into a proper ARG_PTR_TO_CTX branch (which bpf-next tree patch refactored already), removing duplicated arg:ctx detection logic. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240118033143.3384355-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | bpf: extract bpf_ctx_convert_map logic and make it more reusableAndrii Nakryiko2024-01-181-26/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Refactor btf_get_prog_ctx_type() a bit to allow reuse of bpf_ctx_convert_map logic in more than one places. Simplify interface by returning btf_type instead of btf_member (field reference in BTF). To do the above we need to touch and start untangling btf_translate_to_vmlinux() implementation. We do the bare minimum to not regress anything for btf_translate_to_vmlinux(), but its implementation is very questionable for what it claims to be doing. Mapping kfunc argument types to kernel corresponding types conceptually is quite different from recognizing program context types. Fixing this is out of scope for this change though. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240118033143.3384355-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * | | | bpf: Reject variable offset alu on PTR_TO_FLOW_KEYSHao Sun2024-01-161-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For PTR_TO_FLOW_KEYS, check_flow_keys_access() only uses fixed off for validation. However, variable offset ptr alu is not prohibited for this ptr kind. So the variable offset is not checked. The following prog is accepted: func#0 @0 0: R1=ctx() R10=fp0 0: (bf) r6 = r1 ; R1=ctx() R6_w=ctx() 1: (79) r7 = *(u64 *)(r6 +144) ; R6_w=ctx() R7_w=flow_keys() 2: (b7) r8 = 1024 ; R8_w=1024 3: (37) r8 /= 1 ; R8_w=scalar() 4: (57) r8 &= 1024 ; R8_w=scalar(smin=smin32=0, smax=umax=smax32=umax32=1024,var_off=(0x0; 0x400)) 5: (0f) r7 += r8 mark_precise: frame0: last_idx 5 first_idx 0 subseq_idx -1 mark_precise: frame0: regs=r8 stack= before 4: (57) r8 &= 1024 mark_precise: frame0: regs=r8 stack= before 3: (37) r8 /= 1 mark_precise: frame0: regs=r8 stack= before 2: (b7) r8 = 1024 6: R7_w=flow_keys(smin=smin32=0,smax=umax=smax32=umax32=1024,var_off =(0x0; 0x400)) R8_w=scalar(smin=smin32=0,smax=umax=smax32=umax32=1024, var_off=(0x0; 0x400)) 6: (79) r0 = *(u64 *)(r7 +0) ; R0_w=scalar() 7: (95) exit This prog loads flow_keys to r7, and adds the variable offset r8 to r7, and finally causes out-of-bounds access: BUG: unable to handle page fault for address: ffffc90014c80038 [...] Call Trace: <TASK> bpf_dispatcher_nop_func include/linux/bpf.h:1231 [inline] __bpf_prog_run include/linux/filter.h:651 [inline] bpf_prog_run include/linux/filter.h:658 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:675 [inline] bpf_flow_dissect+0x15f/0x350 net/core/flow_dissector.c:991 bpf_prog_test_run_flow_dissector+0x39d/0x620 net/bpf/test_run.c:1359 bpf_prog_test_run kernel/bpf/syscall.c:4107 [inline] __sys_bpf+0xf8f/0x4560 kernel/bpf/syscall.c:5475 __do_sys_bpf kernel/bpf/syscall.c:5561 [inline] __se_sys_bpf kernel/bpf/syscall.c:5559 [inline] __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:5559 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x3f/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Fix this by rejecting ptr alu with variable offset on flow_keys. Applying the patch rejects the program with "R7 pointer arithmetic on flow_keys prohibited". Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") Signed-off-by: Hao Sun <sunhao.th@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20240115082028.9992-1-sunhao.th@gmail.com
* | | | | Merge tag 'dma-mapping-6.8-2024-01-18' of ↵Linus Torvalds2024-01-192-1/+5
|\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.infradead.org/users/hch/dma-mapping Pull dma-mapping fixes from Christoph Hellwig: - fix kerneldoc warnings (Randy Dunlap) - better bounds checking in swiotlb (ZhangPeng) * tag 'dma-mapping-6.8-2024-01-18' of git://git.infradead.org/users/hch/dma-mapping: dma-debug: fix kernel-doc warnings swiotlb: check alloc_size before the allocation of a new memory pool
| * | | | | dma-debug: fix kernel-doc warningsRandy Dunlap2024-01-151-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update the kernel-doc comments to catch up with the code changes and fix the kernel-doc warnings: debug.c:83: warning: Excess struct member 'stacktrace' description in 'dma_debug_entry' debug.c:83: warning: Function parameter or struct member 'stack_len' not described in 'dma_debug_entry' debug.c:83: warning: Function parameter or struct member 'stack_entries' not described in 'dma_debug_entry' Fixes: 746017ed8d4d ("dma/debug: Simplify stracktrace retrieval") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: iommu@lists.linux.dev Signed-off-by: Christoph Hellwig <hch@lst.de>
| * | | | | swiotlb: check alloc_size before the allocation of a new memory poolZhangPeng2024-01-091-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The allocation request for swiotlb contiguous memory greater than 128*2KB cannot be fulfilled because it exceeds the maximum contiguous memory limit. If the swiotlb memory we allocate is larger than 128*2KB, swiotlb_find_slots() will still schedule the allocation of a new memory pool, which will increase memory overhead. Fix it by adding a check with alloc_size no more than 128*2KB before scheduling the allocation of a new memory pool in swiotlb_find_slots(). Signed-off-by: ZhangPeng <zhangpeng362@huawei.com> Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
* | | | | | Merge tag 'iommu-updates-v6.8' of ↵Linus Torvalds2024-01-191-1/+1
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull iommu updates from Joerg Roedel: "Core changes: - Fix race conditions in device probe path - Retire IOMMU bus_ops - Support for passing custom allocators to page table drivers - Clean up Kconfig around IOMMU_SVA - Support for sharing SVA domains with all devices bound to a mm - Firmware data parsing cleanup - Tracing improvements for iommu-dma code - Some smaller fixes and cleanups ARM-SMMU drivers: - Device-tree binding updates: - Add additional compatible strings for Qualcomm SoCs - Document Adreno clocks for Qualcomm's SM8350 SoC - SMMUv2: - Implement support for the ->domain_alloc_paging() callback - Ensure Secure context is restored following suspend of Qualcomm SMMU implementation - SMMUv3: - Disable stalling mode for the "quiet" context descriptor - Minor refactoring and driver cleanups Intel VT-d driver: - Cleanup and refactoring AMD IOMMU driver: - Improve IO TLB invalidation logic - Small cleanups and improvements Rockchip IOMMU driver: - DT binding update to add Rockchip RK3588 Apple DART driver: - Apple M1 USB4/Thunderbolt DART support - Cleanups Virtio IOMMU driver: - Add support for iotlb_sync_map - Enable deferred IO TLB flushes" * tag 'iommu-updates-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (66 commits) iommu: Don't reserve 0-length IOVA region iommu/vt-d: Move inline helpers to header files iommu/vt-d: Remove unused vcmd interfaces iommu/vt-d: Remove unused parameter of intel_pasid_setup_pass_through() iommu/vt-d: Refactor device_to_iommu() to retrieve iommu directly iommu/sva: Fix memory leak in iommu_sva_bind_device() dt-bindings: iommu: rockchip: Add Rockchip RK3588 iommu/dma: Trace bounce buffer usage when mapping buffers iommu/arm-smmu: Convert to domain_alloc_paging() iommu/arm-smmu: Pass arm_smmu_domain to internal functions iommu/arm-smmu: Implement IOMMU_DOMAIN_BLOCKED iommu/arm-smmu: Convert to a global static identity domain iommu/arm-smmu: Reorganize arm_smmu_domain_add_master() iommu/arm-smmu-v3: Remove ARM_SMMU_DOMAIN_NESTED iommu/arm-smmu-v3: Master cannot be NULL in arm_smmu_write_strtab_ent() iommu/arm-smmu-v3: Add a type for the STE iommu/arm-smmu-v3: disable stall for quiet_cd iommu/qcom: restore IOMMU state if needed iommu/arm-smmu-qcom: Add QCM2290 MDSS compatible iommu/arm-smmu-qcom: Add missing GMU entry to match table ...
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| *-. \ \ \ \ \ Merge branches 'apple/dart', 'arm/rockchip', 'arm/smmu', 'virtio', ↵Joerg Roedel2024-01-031-1/+1
| |\ \ \ \ \ \ \ | | |_|_|_|/ / / | |/| | | | | | | | | | | | | | 'x86/vt-d', 'x86/amd' and 'core' into next
| | | * | | | | iommu: Change kconfig around IOMMU_SVAJason Gunthorpe2023-12-121-1/+1
| | |/ / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus suggested that the kconfig here is confusing: https://lore.kernel.org/all/CAHk-=wgUiAtiszwseM1p2fCJ+sC4XWQ+YN4TanFhUgvUqjr9Xw@mail.gmail.com/ Let's break it into three kconfigs controlling distinct things: - CONFIG_IOMMU_MM_DATA controls if the mm_struct has the additional fields for the IOMMU. Currently only PASID, but later patches store a struct iommu_mm_data * - CONFIG_ARCH_HAS_CPU_PASID controls if the arch needs the scheduling bit for keeping track of the ENQCMD instruction. x86 will select this if IOMMU_SVA is enabled - IOMMU_SVA controls if the IOMMU core compiles in the SVA support code for iommu driver use and the IOMMU exported API This way ARM will not enable CONFIG_ARCH_HAS_CPU_PASID Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20231027000525.1278806-2-tina.zhang@intel.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
* | | | | | | Merge tag 'trace-v6.8' of ↵Linus Torvalds2024-01-188-363/+777
|\ \ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing updates from Steven Rostedt: - Allow kernel trace instance creation to specify what events are created Inside the kernel, a subsystem may create a tracing instance that it can use to send events to user space. This sub-system may not care about the thousands of events that exist in eventfs. Allow the sub-system to specify what sub-systems of events it cares about, and only those events are exposed to this instance. - Allow the ring buffer to be broken up into bigger sub-buffers than just the architecture page size. A new tracefs file called "buffer_subbuf_size_kb" is created. The user can now specify a minimum size the sub-buffer may be in kilobytes. Note, that the implementation currently make the sub-buffer size a power of 2 pages (1, 2, 4, 8, 16, ...) but the user only writes in kilobyte size, and the sub-buffer will be updated to the next size that it will can accommodate it. If the user writes in 10, it will change the size to be 4 pages on x86 (16K), as that is the next available size that can hold 10K pages. - Update the debug output when a corrupt time is detected in the ring buffer. If the ring buffer detects inconsistent timestamps, there's a debug config options that will dump the contents of the meta data of the sub-buffer that is used for debugging. Add some more information to this dump that helps with debugging. - Add more timestamp debugging checks (only triggers when the config is enabled) - Increase the trace_seq iterator to 2 page sizes. - Allow strings written into tracefs_marker to be larger. Up to just under 2 page sizes (based on what trace_seq can hold). - Increase the trace_maker_raw write to be as big as a sub-buffer can hold. - Remove 32 bit time stamp logic, now that the rb_time_cmpxchg() has been removed. - More selftests were added. - Some code clean ups as well. * tag 'trace-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (29 commits) ring-buffer: Remove stale comment from ring_buffer_size() tracing histograms: Simplify parse_actions() function tracing/selftests: Remove exec permissions from trace_marker.tc test ring-buffer: Use subbuf_order for buffer page masking tracing: Update subbuffer with kilobytes not page order ringbuffer/selftest: Add basic selftest to test changing subbuf order ring-buffer: Add documentation on the buffer_subbuf_order file ring-buffer: Just update the subbuffers when changing their allocation order ring-buffer: Keep the same size when updating the order tracing: Stop the tracing while changing the ring buffer subbuf size tracing: Update snapshot order along with main buffer order ring-buffer: Make sure the spare sub buffer used for reads has same size ring-buffer: Do no swap cpu buffers if order is different ring-buffer: Clear pages on error in ring_buffer_subbuf_order_set() failure ring-buffer: Read and write to ring buffers with custom sub buffer size ring-buffer: Set new size of the ring buffer sub page ring-buffer: Add interface for configuring trace sub buffer size ring-buffer: Page size per ring buffer ring-buffer: Have ring_buffer_print_page_header() be able to access ring_buffer_iter ring-buffer: Check if absolute timestamp goes backwards ...
| * | | | | | | ring-buffer: Remove stale comment from ring_buffer_size()Steven Rostedt (Google)2024-01-101-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's been 11 years since the ring_buffer_size() function was updated to use the nr_pages from the buffer->buffers[cpu] structure instead of using the buffer->nr_pages that no longer exists. The comment in the code is more of what a change log should have and is pretty much useless for development. It's saying how things worked back in 2012 that bares no purpose on today's code. Remove it. Link: https://lore.kernel.org/linux-trace-kernel/84d3b41a72bd43dbb9d44921ef535c92@AcuMS.aculab.com/ Link: https://lore.kernel.org/linux-trace-kernel/20231220081028.7cd7e8e2@gandalf.local.home Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reported-by: David Laight <David.Laight@ACULAB.COM> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
| * | | | | | | tracing histograms: Simplify parse_actions() functionSteven Rostedt (Google)2024-01-081-25/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The parse_actions() function uses 'len = str_has_prefix()' to test which action is in the string being parsed. But then it goes and repeats the logic for each different action. This logic can be simplified and duplicate code can be removed as 'len' contains the length of the found prefix which should be used for all actions. Link: https://lore.kernel.org/all/20240107112044.6702cb66@gandalf.local.home/ Link: https://lore.kernel.org/linux-trace-kernel/20240107203258.37e26d2b@gandalf.local.home Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andy Shevchenko <andy@kernel.org> Cc: Tom Zanussi <zanussi@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Use subbuf_order for buffer page maskingSteven Rostedt (Google)2023-12-211-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The comparisons to PAGE_SIZE were all converted to use the buffer->subbuf_order, but the use of PAGE_MASK was missed. Convert all the PAGE_MASK usages over to: (PAGE_SIZE << cpu_buffer->buffer->subbuf_order) - 1 Link: https://lore.kernel.org/linux-trace-kernel/20231219173800.66eefb7a@gandalf.local.home 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: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Fixes: 139f84002145 ("ring-buffer: Page size per ring buffer") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | tracing: Update subbuffer with kilobytes not page orderSteven Rostedt (Google)2023-12-211-13/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using page order for deciding what the size of the ring buffer sub buffers are is exposing a bit too much of the implementation. Although the sub buffers are only allocated in orders of pages, allow the user to specify the minimum size of each sub-buffer via kilobytes like they can with the buffer size itself. If the user specifies 3 via: echo 3 > buffer_subbuf_size_kb Then the sub-buffer size will round up to 4kb (on a 4kb page size system). If they specify: echo 6 > buffer_subbuf_size_kb The sub-buffer size will become 8kb. and so on. Link: https://lore.kernel.org/linux-trace-kernel/20231219185631.809766769@goodmis.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: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Just update the subbuffers when changing their allocation orderSteven Rostedt (Google)2023-12-211-17/+71
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ring_buffer_subbuf_order_set() was creating ring_buffer_per_cpu cpu_buffers with the new subbuffers with the updated order, and if they all successfully were created, then they the ring_buffer's per_cpu buffers would be freed and replaced by them. The problem is that the freed per_cpu buffers contains state that would be lost. Running the following commands: 1. # echo 3 > /sys/kernel/tracing/buffer_subbuf_order 2. # echo 0 > /sys/kernel/tracing/tracing_cpumask 3. # echo 1 > /sys/kernel/tracing/snapshot 4. # echo ff > /sys/kernel/tracing/tracing_cpumask 5. # echo test > /sys/kernel/tracing/trace_marker Would result in: -bash: echo: write error: Bad file descriptor That's because the state of the per_cpu buffers of the snapshot buffer is lost when the order is changed (the order of a freed snapshot buffer goes to 0 to save memory, and when the snapshot buffer is allocated again, it goes back to what the main buffer is). In operation 2, the snapshot buffers were set to "disable" (as all the ring buffers CPUs were disabled). In operation 3, the snapshot is allocated and a call to ring_buffer_subbuf_order_set() replaced the per_cpu buffers losing the "record_disable" count. When it was enabled again, the atomic_dec(&cpu_buffer->record_disable) was decrementing a zero, setting it to -1. Writing 1 into the snapshot would swap the snapshot buffer with the main buffer, so now the main buffer is "disabled", and nothing can write to the ring buffer anymore. Instead of creating new per_cpu buffers and losing the state of the old buffers, basically do what the resize does and just allocate new subbuf pages into the new_pages link list of the per_cpu buffer and if they all succeed, then replace the old sub buffers with the new ones. This keeps the per_cpu buffer descriptor in tact and by doing so, keeps its state. Link: https://lore.kernel.org/linux-trace-kernel/20231219185630.944104939@goodmis.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: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Keep the same size when updating the orderSteven Rostedt (Google)2023-12-211-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The function ring_buffer_subbuf_order_set() just updated the sub-buffers to the new size, but this also changes the size of the buffer in doing so. As the size is determined by nr_pages * subbuf_size. If the subbuf_size is increased without decreasing the nr_pages, this causes the total size of the buffer to increase. This broke the latency tracers as the snapshot needs to be the same size as the main buffer. The size of the snapshot buffer is only expanded when needed, and because the order is still the same, the size becomes out of sync with the main buffer, as the main buffer increased in size without the tracing system knowing. Calculate the nr_pages to allocate with the new subbuf_size to be buffer_size / new_subbuf_size. Link: https://lore.kernel.org/linux-trace-kernel/20231219185630.649397785@goodmis.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: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Fixes: f9b94daa542a ("ring-buffer: Set new size of the ring buffer sub page") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | tracing: Stop the tracing while changing the ring buffer subbuf sizeSteven Rostedt (Google)2023-12-211-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because the main buffer and the snapshot buffer need to be the same for some tracers, otherwise it will fail and disable all tracing, the tracers need to be stopped while updating the sub buffer sizes so that the tracers see the main and snapshot buffers with the same sub buffer size. Link: https://lore.kernel.org/linux-trace-kernel/20231219185630.353222794@goodmis.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: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Fixes: 2808e31ec12e ("ring-buffer: Add interface for configuring trace sub buffer size") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | tracing: Update snapshot order along with main buffer orderSteven Rostedt (Google)2023-12-211-2/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When updating the order of the sub buffers for the main buffer, make sure that if the snapshot buffer exists, that it gets its order updated as well. Link: https://lore.kernel.org/linux-trace-kernel/20231219185630.054668186@goodmis.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: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Make sure the spare sub buffer used for reads has same sizeSteven Rostedt (Google)2023-12-211-0/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the ring buffer specifies the size of its sub buffers, they all need to be the same size. When doing a read, a swap is done with a spare page. Make sure they are the same size before doing the swap, otherwise the read will fail. Link: https://lore.kernel.org/linux-trace-kernel/20231219185629.763664788@goodmis.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: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Do no swap cpu buffers if order is differentSteven Rostedt (Google)2023-12-211-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As all the subbuffer order (subbuffer sizes) must be the same throughout the ring buffer, check the order of the buffers that are doing a CPU buffer swap in ring_buffer_swap_cpu() to make sure they are the same. If the are not the same, then fail to do the swap, otherwise the ring buffer will think the CPU buffer has a specific subbuffer size when it does not. Link: https://lore.kernel.org/linux-trace-kernel/20231219185629.467894710@goodmis.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: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Clear pages on error in ring_buffer_subbuf_order_set() failureSteven Rostedt (Google)2023-12-211-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On failure to allocate ring buffer pages, the pointer to the CPU buffer pages is freed, but the pages that were allocated previously were not. Make sure they are freed too. Link: https://lore.kernel.org/linux-trace-kernel/20231219185629.179352802@goodmis.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: Tzvetomir Stoyanov <tz.stoyanov@gmail.com> Cc: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Fixes: f9b94daa542a ("tracing: Set new size of the ring buffer sub page") Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Read and write to ring buffers with custom sub buffer sizeTzvetomir Stoyanov (VMware)2023-12-203-38/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As the size of the ring sub buffer page can be changed dynamically, the logic that reads and writes to the buffer should be fixed to take that into account. Some internal ring buffer APIs are changed: ring_buffer_alloc_read_page() ring_buffer_free_read_page() ring_buffer_read_page() A new API is introduced: ring_buffer_read_page_data() Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-6-tz.stoyanov@gmail.com Link: https://lore.kernel.org/linux-trace-kernel/20231219185628.875145995@goodmis.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: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> [ Fixed kerneldoc on data_page parameter in ring_buffer_free_read_page() ] Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Set new size of the ring buffer sub pageTzvetomir Stoyanov (VMware)2023-12-201-7/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two approaches when changing the size of the ring buffer sub page: 1. Destroying all pages and allocating new pages with the new size. 2. Allocating new pages, copying the content of the old pages before destroying them. The first approach is easier, it is selected in the proposed implementation. Changing the ring buffer sub page size is supposed to not happen frequently. Usually, that size should be set only once, when the buffer is not in use yet and is supposed to be empty. Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-5-tz.stoyanov@gmail.com Link: https://lore.kernel.org/linux-trace-kernel/20231219185628.588995543@goodmis.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: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Add interface for configuring trace sub buffer sizeTzvetomir Stoyanov (VMware)2023-12-202-0/+121
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The trace ring buffer sub page size can be configured, per trace instance. A new ftrace file "buffer_subbuf_order" is added to get and set the size of the ring buffer sub page for current trace instance. The size must be an order of system page size, that's why the new interface works with system page order, instead of absolute page size: 0 means the ring buffer sub page is equal to 1 system page and so forth: 0 - 1 system page 1 - 2 system pages 2 - 4 system pages ... The ring buffer sub page size is limited between 1 and 128 system pages. The default value is 1 system page. New ring buffer APIs are introduced: ring_buffer_subbuf_order_set() ring_buffer_subbuf_order_get() ring_buffer_subbuf_size_get() Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-4-tz.stoyanov@gmail.com Link: https://lore.kernel.org/linux-trace-kernel/20231219185628.298324722@goodmis.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: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Page size per ring bufferTzvetomir Stoyanov (VMware)2023-12-204-45/+85
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the size of one sub buffer page is global for all buffers and it is hard coded to one system page. In order to introduce configurable ring buffer sub page size, the internal logic should be refactored to work with sub page size per ring buffer. Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-3-tz.stoyanov@gmail.com Link: https://lore.kernel.org/linux-trace-kernel/20231219185628.009147038@goodmis.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: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
| * | | | | | | ring-buffer: Have ring_buffer_print_page_header() be able to access ↵Tzvetomir Stoyanov (VMware)2023-12-201-30/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ring_buffer_iter In order to introduce sub-buffer size per ring buffer, some internal refactoring is needed. As ring_buffer_print_page_header() will depend on the trace_buffer structure, it is moved after the structure definition. Link: https://lore.kernel.org/linux-trace-devel/20211213094825.61876-2-tz.stoyanov@gmail.com Link: https://lore.kernel.org/linux-trace-kernel/20231219185627.723857541@goodmis.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: Vincent Donnefort <vdonnefort@google.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>