5.15-stable patches

added patches:
	tracing-avoid-possible-softlockup-in-tracing_iter_reset.patch

diff --git a/queue-5.15/series b/queue-5.15/series
index 93d8022e6ed8a459dd4750b8f300503589c2e010..71d418fc45d1295d299401bdd91fe73914775d01 100644 (file)
--- a/queue-5.15/series
+++ b/queue-5.15/series
@@ -82,3 +82,4 @@ clk-qcom-clk-alpha-pll-fix-the-trion-pll-postdiv-set-rate-api.patch
 clk-qcom-clk-alpha-pll-fix-zonda-set_rate-failure-when-pll-is-disabled.patch
 clk-qcom-clk-alpha-pll-update-set_rate-for-zonda-pll.patch
 can-mcp251x-fix-deadlock-if-an-interrupt-occurs-during-mcp251x_open.patch
+tracing-avoid-possible-softlockup-in-tracing_iter_reset.patch

diff --git a/queue-5.15/tracing-avoid-possible-softlockup-in-tracing_iter_reset.patch b/queue-5.15/tracing-avoid-possible-softlockup-in-tracing_iter_reset.patch
new file mode 100644 (file)
index 0000000..82a1d3a
--- /dev/null
+++ b/queue-5.15/tracing-avoid-possible-softlockup-in-tracing_iter_reset.patch
@@ -0,0 +1,40 @@
+From 49aa8a1f4d6800721c7971ed383078257f12e8f9 Mon Sep 17 00:00:00 2001
+From: Zheng Yejian <zhengyejian@huaweicloud.com>
+Date: Tue, 27 Aug 2024 20:46:54 +0800
+Subject: tracing: Avoid possible softlockup in tracing_iter_reset()
+
+From: Zheng Yejian <zhengyejian@huaweicloud.com>
+
+commit 49aa8a1f4d6800721c7971ed383078257f12e8f9 upstream.
+
+In __tracing_open(), when max latency tracers took place on the cpu,
+the time start of its buffer would be updated, then event entries with
+timestamps being earlier than start of the buffer would be skipped
+(see tracing_iter_reset()).
+
+Softlockup will occur if the kernel is non-preemptible and too many
+entries were skipped in the loop that reset every cpu buffer, so add
+cond_resched() to avoid it.
+
+Cc: stable@vger.kernel.org
+Fixes: 2f26ebd549b9a ("tracing: use timestamp to determine start of latency traces")
+Link: https://lore.kernel.org/20240827124654.3817443-1-zhengyejian@huaweicloud.com
+Suggested-by: Steven Rostedt <rostedt@goodmis.org>
+Signed-off-by: Zheng Yejian <zhengyejian@huaweicloud.com>
+Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ kernel/trace/trace.c |    2 ++
+ 1 file changed, 2 insertions(+)
+
+--- a/kernel/trace/trace.c
++++ b/kernel/trace/trace.c
+@@ -4068,6 +4068,8 @@ void tracing_iter_reset(struct trace_ite
+                       break;
+               entries++;
+               ring_buffer_iter_advance(buf_iter);
++              /* This could be a big loop */
++              cond_resched();
+       }
+ 
+       per_cpu_ptr(iter->array_buffer->data, cpu)->skipped_entries = entries;