linux/kernel/trace
Petr Pavlu 09661f75e7 ring-buffer: Fix reader locking when changing the sub buffer order
The function ring_buffer_subbuf_order_set() updates each
ring_buffer_per_cpu and installs new sub buffers that match the requested
page order. This operation may be invoked concurrently with readers that
rely on some of the modified data, such as the head bit (RB_PAGE_HEAD), or
the ring_buffer_per_cpu.pages and reader_page pointers. However, no
exclusive access is acquired by ring_buffer_subbuf_order_set(). Modifying
the mentioned data while a reader also operates on them can then result in
incorrect memory access and various crashes.

Fix the problem by taking the reader_lock when updating a specific
ring_buffer_per_cpu in ring_buffer_subbuf_order_set().

Link: https://lore.kernel.org/linux-trace-kernel/20240715145141.5528-1-petr.pavlu@suse.com/
Link: https://lore.kernel.org/linux-trace-kernel/20241010195849.2f77cc3f@gandalf.local.home/
Link: https://lore.kernel.org/linux-trace-kernel/20241011112850.17212b25@gandalf.local.home/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/20241015112440.26987-1-petr.pavlu@suse.com
Fixes: 8e7b58c27b ("ring-buffer: Just update the subbuffers when changing their allocation order")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-15 11:18:51 -04:00
..
rv [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
Kconfig
Makefile
blktrace.c
bpf_trace.c bpf-next-6.12 2024-09-21 09:27:50 -07:00
bpf_trace.h
error_report-traces.c
fgraph.c tracing: fgraph: Fix to add new fgraph_ops to array after ftrace_startup_subops() 2024-08-21 13:49:59 -04:00
fprobe.c
ftrace.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
ftrace_internal.h
kprobe_event_gen_test.c
pid_list.c
pid_list.h
power-traces.c
preemptirq_delay_test.c minmax: make generic MIN() and MAX() macros available everywhere 2024-07-28 15:49:18 -07:00
rethook.c
ring_buffer.c ring-buffer: Fix reader locking when changing the sub buffer order 2024-10-15 11:18:51 -04:00
ring_buffer_benchmark.c
rpm-traces.c
synth_event_gen_test.c
trace.c ring-buffer: Fix refcount setting of boot mapped buffers 2024-10-14 14:30:59 -04:00
trace.h tracing: Add option to set an instance to be the trace_printk destination 2024-08-26 13:54:08 -04:00
trace_benchmark.c
trace_benchmark.h
trace_boot.c
trace_branch.c
trace_btf.c
trace_btf.h
trace_clock.c
trace_dynevent.c
trace_dynevent.h
trace_entries.h
trace_eprobe.c
trace_event_perf.c
trace_events.c tracing: Use refcount for trace_event_file reference counter 2024-08-07 18:12:46 -04:00
trace_events_filter.c
trace_events_filter_test.h
trace_events_hist.c tracing: Have format file honor EVENT_FILE_FL_FREED 2024-08-07 18:12:46 -04:00
trace_events_inject.c tracing: Have format file honor EVENT_FILE_FL_FREED 2024-08-07 18:12:46 -04:00
trace_events_synth.c
trace_events_trigger.c tracing: Have format file honor EVENT_FILE_FL_FREED 2024-08-07 18:12:46 -04:00
trace_events_user.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
trace_export.c
trace_fprobe.c tracing/fprobe: Support raw tracepoints on future loaded modules 2024-09-25 23:23:44 +09:00
trace_functions.c
trace_functions_graph.c tracing/fgraph: Have fgraph handle previous boot function addresses 2024-08-15 08:35:48 -04:00
trace_hwlat.c tracing/hwlat: Fix a race during cpuhp processing 2024-10-03 16:43:23 -04:00
trace_irqsoff.c
trace_kdb.c
trace_kprobe.c
trace_kprobe_selftest.c
trace_kprobe_selftest.h
trace_mmiotrace.c
trace_nop.c
trace_osnoise.c tracing/timerlat: Fix a race during cpuhp processing 2024-10-03 16:43:22 -04:00
trace_output.c tracing: Have trace_printk not use binary prints if boot buffer 2024-08-26 13:54:08 -04:00
trace_output.h
trace_preemptirq.c
trace_printk.c
trace_probe.c
trace_probe.h
trace_probe_kernel.h
trace_probe_tmpl.h
trace_recursion_record.c
trace_sched_switch.c
trace_sched_wakeup.c sched/rt: Rename realtime_{prio, task}() to rt_or_dl_{prio, task}() 2024-08-07 18:32:38 +02:00
trace_selftest.c tracing: Fix memory leak in fgraph storage selftest 2024-08-21 15:10:33 -04:00
trace_selftest_dynamic.c
trace_seq.c
trace_stack.c sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
trace_stat.c
trace_stat.h
trace_synth.h
trace_syscalls.c bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing 2024-09-11 13:27:27 -07:00
trace_uprobe.c Probes updates for v6.12: 2024-09-26 08:55:36 -07:00
tracing_map.c tracing: Fix overflow in get_free_elt() 2024-08-07 20:23:12 -04:00
tracing_map.h