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-rw-r--r--kernel/trace/trace.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8696ce6bf2f6..465d56febc5b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -7659,10 +7659,21 @@ __init static int tracer_alloc_buffers(void)
raw_spin_lock_init(&global_trace.start_lock);
+ /*
+ * The prepare callbacks allocates some memory for the ring buffer. We
+ * don't free the buffer if the if the CPU goes down. If we were to free
+ * the buffer, then the user would lose any trace that was in the
+ * buffer. The memory will be removed once the "instance" is removed.
+ */
+ ret = cpuhp_setup_state_multi(CPUHP_TRACE_RB_PREPARE,
+ "trace/RB:preapre", trace_rb_cpu_prepare,
+ NULL);
+ if (ret < 0)
+ goto out_free_cpumask;
/* Used for event triggers */
temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE);
if (!temp_buffer)
- goto out_free_cpumask;
+ goto out_rm_hp_state;
if (trace_create_savedcmd() < 0)
goto out_free_temp_buffer;
@@ -7723,6 +7734,8 @@ out_free_savedcmd:
free_saved_cmdlines_buffer(savedcmd);
out_free_temp_buffer:
ring_buffer_free(temp_buffer);
+out_rm_hp_state:
+ cpuhp_remove_multi_state(CPUHP_TRACE_RB_PREPARE);
out_free_cpumask:
free_cpumask_var(global_trace.tracing_cpumask);
out_free_buffer_mask: