[PATCH] tracing: fix "softirq" flag detection

From	Pavankumar Kondeti <pkondeti@codeaurora.org>
Newsgroups	linux.kernel
Subject	[PATCH] tracing: fix "softirq" flag detection
Date	2016-12-07 04:40 +0100
Message-ID	<sLBfj-2Ht-21@gated-at.bofh.it> (permalink)
Organization	linux.* mail to news gateway

Show all headers | View raw

The 's' flag is supposed to indicate that a softirq is running. This
can be detected by testing the preempt_count with SOFTIRQ_OFFSET.

The current code tests the preempt_count with SOFTIRQ_MASK, which
would be true even when softirqs are disabled but not serving a
softirq.

Change-Id: I084531ce806e0f7d42a38be0a7ad45977c43d158
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
---
 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index ae68222..1d0f1a1 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1685,7 +1685,7 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags,
 		TRACE_FLAG_IRQS_NOSUPPORT |
 #endif
 		((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) |
-		((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) |
+		((pc & SOFTIRQ_OFFSET) ? TRACE_FLAG_SOFTIRQ : 0) |
 		(tif_need_resched() ? TRACE_FLAG_NEED_RESCHED : 0) |
 		(test_preempt_need_resched() ? TRACE_FLAG_PREEMPT_RESCHED : 0);
 }
-- 
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

Back to linux.kernel | Previous | Next | Find similar | Unroll thread

Thread

[PATCH] tracing: fix "softirq" flag detection Pavankumar Kondeti <pkondeti@codeaurora.org> - 2016-12-07 04:40 +0100

csiph-web