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authorSimona Vetter <simona.vetter@ffwll.ch>2026-03-11 11:09:21 +0100
committerSimona Vetter <simona.vetter@ffwll.ch>2026-03-11 11:18:31 +0100
commit58351f46de26bcc4403f9972f7aed430d15cbd03 (patch)
tree1fee527a7026a068b24ece9d4ef1d0ef82e6ca1a /kernel/trace/ring_buffer.c
parent5f0a63f81a027becb06a71406e0941c5d12e074d (diff)
parent1f318b96cc84d7c2ab792fcc0bfd42a7ca890681 (diff)
Merge v7.0-rc3 into drm-next
Requested by Maxime Ripard for drm-misc-next because renesas people need fb797a70108f ("drm: renesas: rz-du: mipi_dsi: Set DSI divider"). Signed-off-by: Simona Vetter <simona.vetter@ffwll.ch>
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r--kernel/trace/ring_buffer.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f16f053ef77d..17d0ea0cc3e6 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -7310,6 +7310,27 @@ int ring_buffer_map(struct trace_buffer *buffer, int cpu,
return err;
}
+/*
+ * This is called when a VMA is duplicated (e.g., on fork()) to increment
+ * the user_mapped counter without remapping pages.
+ */
+void ring_buffer_map_dup(struct trace_buffer *buffer, int cpu)
+{
+ struct ring_buffer_per_cpu *cpu_buffer;
+
+ if (WARN_ON(!cpumask_test_cpu(cpu, buffer->cpumask)))
+ return;
+
+ cpu_buffer = buffer->buffers[cpu];
+
+ guard(mutex)(&cpu_buffer->mapping_lock);
+
+ if (cpu_buffer->user_mapped)
+ __rb_inc_dec_mapped(cpu_buffer, true);
+ else
+ WARN(1, "Unexpected buffer stat, it should be mapped");
+}
+
int ring_buffer_unmap(struct trace_buffer *buffer, int cpu)
{
struct ring_buffer_per_cpu *cpu_buffer;