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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-20 18:38:07 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-09-20 18:38:07 +0200 |
commit | c52f56a69d104d5294af3d652776d94b1ef6a175 (patch) | |
tree | 5c4014d8b4b05668dbfb98b90fce0c41e839987f /kernel | |
parent | Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/... (diff) | |
parent | tracing: Fix trace_pipe behavior for instance traces (diff) | |
download | linux-c52f56a69d104d5294af3d652776d94b1ef6a175.tar.xz linux-c52f56a69d104d5294af3d652776d94b1ef6a175.zip |
Merge tag 'trace-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This includes three minor fixes.
- Have writing to trace file clear the irqsoff (and friends) tracer
- trace_pipe behavior for instance buffers was different than top
buffer
- Show a message of why mmiotrace doesn't start from commandline"
* tag 'trace-v4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix trace_pipe behavior for instance traces
tracing: Ignore mmiotrace from kernel commandline
tracing: Erase irqsoff trace with empty write
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/trace/trace.c | 19 | ||||
-rw-r--r-- | kernel/trace/trace.h | 2 | ||||
-rw-r--r-- | kernel/trace/trace_mmiotrace.c | 1 |
3 files changed, 19 insertions, 3 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5360b7aec57a..752e5daf0896 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4020,11 +4020,17 @@ static int tracing_open(struct inode *inode, struct file *file) /* If this file was open for write, then erase contents */ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) { int cpu = tracing_get_cpu(inode); + struct trace_buffer *trace_buf = &tr->trace_buffer; + +#ifdef CONFIG_TRACER_MAX_TRACE + if (tr->current_trace->print_max) + trace_buf = &tr->max_buffer; +#endif if (cpu == RING_BUFFER_ALL_CPUS) - tracing_reset_online_cpus(&tr->trace_buffer); + tracing_reset_online_cpus(trace_buf); else - tracing_reset(&tr->trace_buffer, cpu); + tracing_reset(trace_buf, cpu); } if (file->f_mode & FMODE_READ) { @@ -5358,6 +5364,13 @@ static int tracing_set_tracer(struct trace_array *tr, const char *buf) if (t == tr->current_trace) goto out; + /* Some tracers won't work on kernel command line */ + if (system_state < SYSTEM_RUNNING && t->noboot) { + pr_warn("Tracer '%s' is not allowed on command line, ignored\n", + t->name); + goto out; + } + /* Some tracers are only allowed for the top level buffer */ if (!trace_ok_for_array(t, tr)) { ret = -EINVAL; @@ -5667,7 +5680,7 @@ static int tracing_wait_pipe(struct file *filp) * * iter->pos will be 0 if we haven't read anything. */ - if (!tracing_is_on() && iter->pos) + if (!tracer_tracing_is_on(iter->tr) && iter->pos) break; mutex_unlock(&iter->mutex); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index fb5d54d0d1b3..652c682707cd 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -444,6 +444,8 @@ struct tracer { #ifdef CONFIG_TRACER_MAX_TRACE bool use_max_tr; #endif + /* True if tracer cannot be enabled in kernel param */ + bool noboot; }; diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index cd7480d0a201..dca78fc48439 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -282,6 +282,7 @@ static struct tracer mmio_tracer __read_mostly = .close = mmio_close, .read = mmio_read, .print_line = mmio_print_line, + .noboot = true, }; __init static int init_mmio_trace(void) |