diff options
Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r-- | kernel/trace/trace.c | 53 |
1 files changed, 41 insertions, 12 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 672a749..b3ae845 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -649,7 +649,7 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) { - struct ring_buffer *buf = tr->buffer; + struct ring_buffer *buf; if (trace_stop_count) return; @@ -661,6 +661,7 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) } arch_spin_lock(&ftrace_max_lock); + buf = tr->buffer; tr->buffer = max_tr.buffer; max_tr.buffer = buf; @@ -2526,11 +2527,25 @@ static int set_tracer_option(struct tracer *trace, char *cmp, int neg) return -EINVAL; } -static void set_tracer_flags(unsigned int mask, int enabled) +/* Some tracers require overwrite to stay enabled */ +int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set) +{ + if (tracer->enabled && (mask & TRACE_ITER_OVERWRITE) && !set) + return -1; + + return 0; +} + +int set_tracer_flag(unsigned int mask, int enabled) { /* do nothing if flag is already set */ if (!!(trace_flags & mask) == !!enabled) - return; + return 0; + + /* Give the tracer a chance to approve the change */ + if (current_trace->flag_changed) + if (current_trace->flag_changed(current_trace, mask, !!enabled)) + return -EINVAL; if (enabled) trace_flags |= mask; @@ -2542,6 +2557,8 @@ static void set_tracer_flags(unsigned int mask, int enabled) if (mask == TRACE_ITER_OVERWRITE) ring_buffer_change_overwrite(global_trace.buffer, enabled); + + return 0; } static ssize_t @@ -2551,7 +2568,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf, char buf[64]; char *cmp; int neg = 0; - int ret; + int ret = -ENODEV; int i; if (cnt >= sizeof(buf)) @@ -2568,21 +2585,23 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf, cmp += 2; } + mutex_lock(&trace_types_lock); + for (i = 0; trace_options[i]; i++) { if (strcmp(cmp, trace_options[i]) == 0) { - set_tracer_flags(1 << i, !neg); + ret = set_tracer_flag(1 << i, !neg); break; } } /* If no option could be set, test the specific tracer options */ - if (!trace_options[i]) { - mutex_lock(&trace_types_lock); + if (!trace_options[i]) ret = set_tracer_option(current_trace, cmp, neg); - mutex_unlock(&trace_types_lock); - if (ret) - return ret; - } + + mutex_unlock(&trace_types_lock); + + if (ret < 0) + return ret; *ppos += cnt; @@ -2880,6 +2899,9 @@ static int tracing_set_tracer(const char *buf) goto out; trace_branch_disable(); + + current_trace->enabled = false; + if (current_trace && current_trace->reset) current_trace->reset(tr); if (current_trace && current_trace->use_max_tr) { @@ -2909,6 +2931,7 @@ static int tracing_set_tracer(const char *buf) goto out; } + current_trace->enabled = true; trace_branch_enable(tr); out: mutex_unlock(&trace_types_lock); @@ -4179,7 +4202,13 @@ trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, if (val != 0 && val != 1) return -EINVAL; - set_tracer_flags(1 << index, val); + + mutex_lock(&trace_types_lock); + ret = set_tracer_flag(1 << index, val); + mutex_unlock(&trace_types_lock); + + if (ret < 0) + return ret; *ppos += cnt; |