mirror of
https://github.com/linuxkit/linuxkit.git
synced 2025-11-04 08:25:51 +00:00
43 lines
1.6 KiB
Diff
43 lines
1.6 KiB
Diff
From c9c04b93f7a5c7efc87e6b5b4119e4c4502a2d64 Mon Sep 17 00:00:00 2001
|
|
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
|
|
Date: Thu, 18 Jan 2018 15:42:09 -0500
|
|
Subject: [PATCH 115/414] ring-buffer: Fix duplicate results in mapping context
|
|
to bits in recursive lock
|
|
|
|
In bringing back the context checks, the code checks first if its normal
|
|
(non-interrupt) context, and then for NMI then IRQ then softirq. The final
|
|
check is redundant. Since the if branch is only hit if the context is one of
|
|
NMI, IRQ, or SOFTIRQ, if it's not NMI or IRQ there's no reason to check if
|
|
it is SOFTIRQ. The current code returns the same result even if its not a
|
|
SOFTIRQ. Which is confusing.
|
|
|
|
pc & SOFTIRQ_OFFSET ? 2 : RB_CTX_SOFTIRQ
|
|
|
|
Is redundant as RB_CTX_SOFTIRQ *is* 2!
|
|
|
|
Fixes: a0e3a18f4baf ("ring-buffer: Bring back context level recursive checks")
|
|
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
|
|
(cherry picked from commit 0164e0d7e803af3ee1c63770978c728f8778ad01)
|
|
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
---
|
|
kernel/trace/ring_buffer.c | 3 +--
|
|
1 file changed, 1 insertion(+), 2 deletions(-)
|
|
|
|
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
|
|
index 3621164c234b..cad398ba3009 100644
|
|
--- a/kernel/trace/ring_buffer.c
|
|
+++ b/kernel/trace/ring_buffer.c
|
|
@@ -2633,8 +2633,7 @@ trace_recursive_lock(struct ring_buffer_per_cpu *cpu_buffer)
|
|
bit = RB_CTX_NORMAL;
|
|
else
|
|
bit = pc & NMI_MASK ? RB_CTX_NMI :
|
|
- pc & HARDIRQ_MASK ? RB_CTX_IRQ :
|
|
- pc & SOFTIRQ_OFFSET ? 2 : RB_CTX_SOFTIRQ;
|
|
+ pc & HARDIRQ_MASK ? RB_CTX_IRQ : RB_CTX_SOFTIRQ;
|
|
|
|
if (unlikely(val & (1 << bit)))
|
|
return 1;
|
|
--
|
|
2.17.0
|
|
|