This is a note to let you know that I've just added the patch titled tracing: Fix complicated dependency of CONFIG_TRACER_MAX_TRACE to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tracing-fix-complicated-dependency-of-config_tracer_max_trace.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e25e43a4e5d8cb2323553d8b6a7ba08d2ebab21f Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx> Date: Tue, 6 Dec 2022 23:18:01 +0900 Subject: tracing: Fix complicated dependency of CONFIG_TRACER_MAX_TRACE From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> commit e25e43a4e5d8cb2323553d8b6a7ba08d2ebab21f upstream. Both CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER partially enables the CONFIG_TRACER_MAX_TRACE code, but that is complicated and has introduced a bug; It declares tracing_max_lat_fops data structure outside of #ifdefs, but since it is defined only when CONFIG_TRACER_MAX_TRACE=y or CONFIG_HWLAT_TRACER=y, if only CONFIG_OSNOISE_TRACER=y, that declaration comes to a definition(!). To fix this issue, and do not repeat the similar problem, makes CONFIG_OSNOISE_TRACER and CONFIG_HWLAT_TRACER enables the CONFIG_TRACER_MAX_TRACE always. It has there benefits; - Fix the tracing_max_lat_fops bug - Simplify the #ifdefs - CONFIG_TRACER_MAX_TRACE code is fully enabled, or not. Link: https://lore.kernel.org/linux-trace-kernel/167033628155.4111793.12185405690820208159.stgit@devnote3 Fixes: 424b650f35c7 ("tracing: Fix missing osnoise tracer on max_latency") Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Reported-by: David Howells <dhowells@xxxxxxxxxx> Reported-by: kernel test robot <lkp@xxxxxxxxx> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> Link: https://lore.kernel.org/all/166992525941.1716618.13740663757583361463.stgit@xxxxxxxxxxxxxxxxxxxxxx/ (original thread and v1) Link: https://lore.kernel.org/all/202212052253.VuhZ2ulJ-lkp@xxxxxxxxx/T/#u (v1 error report) Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/Kconfig | 2 ++ kernel/trace/trace.c | 23 +++++++++++++---------- kernel/trace/trace.h | 8 +++----- 3 files changed, 18 insertions(+), 15 deletions(-) --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -375,6 +375,7 @@ config SCHED_TRACER config HWLAT_TRACER bool "Tracer to detect hardware latencies (like SMIs)" select GENERIC_TRACER + select TRACER_MAX_TRACE help This tracer, when enabled will create one or more kernel threads, depending on what the cpumask file is set to, which each thread @@ -410,6 +411,7 @@ config HWLAT_TRACER config OSNOISE_TRACER bool "OS Noise tracer" select GENERIC_TRACER + select TRACER_MAX_TRACE help In the context of high-performance computing (HPC), the Operating System Noise (osnoise) refers to the interference experienced by an --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1421,6 +1421,7 @@ int tracing_snapshot_cond_disable(struct return false; } EXPORT_SYMBOL_GPL(tracing_snapshot_cond_disable); +#define free_snapshot(tr) do { } while (0) #endif /* CONFIG_TRACER_SNAPSHOT */ void tracer_tracing_off(struct trace_array *tr) @@ -1692,6 +1693,8 @@ static ssize_t trace_seq_to_buffer(struc } unsigned long __read_mostly tracing_thresh; + +#ifdef CONFIG_TRACER_MAX_TRACE static const struct file_operations tracing_max_lat_fops; #ifdef LATENCY_FS_NOTIFY @@ -1748,18 +1751,14 @@ void latency_fsnotify(struct trace_array irq_work_queue(&tr->fsnotify_irqwork); } -#elif defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) \ - || defined(CONFIG_OSNOISE_TRACER) +#else /* !LATENCY_FS_NOTIFY */ #define trace_create_maxlat_file(tr, d_tracer) \ trace_create_file("tracing_max_latency", TRACE_MODE_WRITE, \ d_tracer, &tr->max_latency, &tracing_max_lat_fops) -#else -#define trace_create_maxlat_file(tr, d_tracer) do { } while (0) #endif -#ifdef CONFIG_TRACER_MAX_TRACE /* * Copy the new maximum trace into the separate maximum-trace * structure. (this way the maximum trace is permanently saved, @@ -1834,14 +1833,15 @@ update_max_tr(struct trace_array *tr, st ring_buffer_record_off(tr->max_buffer.buffer); #ifdef CONFIG_TRACER_SNAPSHOT - if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data)) - goto out_unlock; + if (tr->cond_snapshot && !tr->cond_snapshot->update(tr, cond_data)) { + arch_spin_unlock(&tr->max_lock); + return; + } #endif swap(tr->array_buffer.buffer, tr->max_buffer.buffer); __update_max_tr(tr, tsk, cpu); - out_unlock: arch_spin_unlock(&tr->max_lock); } @@ -1888,6 +1888,7 @@ update_max_tr_single(struct trace_array __update_max_tr(tr, tsk, cpu); arch_spin_unlock(&tr->max_lock); } + #endif /* CONFIG_TRACER_MAX_TRACE */ static int wait_on_pipe(struct trace_iterator *iter, int full) @@ -6572,7 +6573,7 @@ out: return ret; } -#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) +#ifdef CONFIG_TRACER_MAX_TRACE static ssize_t tracing_max_lat_read(struct file *filp, char __user *ubuf, @@ -7587,7 +7588,7 @@ static const struct file_operations trac .llseek = generic_file_llseek, }; -#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) +#ifdef CONFIG_TRACER_MAX_TRACE static const struct file_operations tracing_max_lat_fops = { .open = tracing_open_generic, .read = tracing_max_lat_read, @@ -9601,7 +9602,9 @@ init_tracer_tracefs(struct trace_array * create_trace_options_dir(tr); +#ifdef CONFIG_TRACER_MAX_TRACE trace_create_maxlat_file(tr, d_tracer); +#endif if (ftrace_create_function_files(tr, d_tracer)) MEM_FAIL(1, "Could not allocate function filter files"); --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -308,8 +308,7 @@ struct trace_array { struct array_buffer max_buffer; bool allocated_snapshot; #endif -#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) \ - || defined(CONFIG_OSNOISE_TRACER) +#ifdef CONFIG_TRACER_MAX_TRACE unsigned long max_latency; #ifdef CONFIG_FSNOTIFY struct dentry *d_max_latency; @@ -688,12 +687,11 @@ void update_max_tr(struct trace_array *t void *cond_data); void update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu); -#endif /* CONFIG_TRACER_MAX_TRACE */ -#if (defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) \ - || defined(CONFIG_OSNOISE_TRACER)) && defined(CONFIG_FSNOTIFY) +#ifdef CONFIG_FSNOTIFY #define LATENCY_FS_NOTIFY #endif +#endif /* CONFIG_TRACER_MAX_TRACE */ #ifdef LATENCY_FS_NOTIFY void latency_fsnotify(struct trace_array *tr); Patches currently in stable-queue which might be from mhiramat@xxxxxxxxxx are queue-6.1/tracing-fix-race-where-eprobes-can-be-called-before-the-event.patch queue-6.1/x86-kprobes-fix-optprobe-optimization-check-with-config_rethunk.patch queue-6.1/tracing-fix-issue-of-missing-one-synthetic-field.patch queue-6.1/arm64-prohibit-instrumentation-on-arch_stack_walk.patch queue-6.1/tracing-hist-fix-wrong-return-value-in-parse_action_params.patch queue-6.1/tracing-probes-handle-system-names-with-hyphens.patch queue-6.1/tracing-hist-fix-out-of-bound-write-on-action_data.var_ref_idx.patch queue-6.1/x86-kprobes-fix-kprobes-instruction-boudary-check-with-config_rethunk.patch queue-6.1/tracing-fix-complicated-dependency-of-config_tracer_max_trace.patch queue-6.1/tracing-fix-infinite-loop-in-tracing_read_pipe-on-overflowed-print_trace_line.patch queue-6.1/ftrace-x86-add-back-ftrace_expected-for-ftrace-bug-reports.patch