From: Colin King <colin.king@canonical.com>
To: Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>,
Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH][next] trace: osnoise: Fix u64 less than zero comparison
Date: Tue, 29 Jun 2021 17:52:45 +0100 [thread overview]
Message-ID: <20210629165245.42157-1-colin.king@canonical.com> (raw)
From: Colin Ian King <colin.king@canonical.com>
The less than zero comparison of the u64 variable 'noise' is always
false because the variable is unsigned. Since the time_sub macro
can potentially return an -ve vale, make the variable a s64 to
fix the issue.
Addresses-Coverity: ("Unsigned compared against 0")
Fixes: bce29ac9ce0b ("trace: Add osnoise tracer")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
kernel/trace/trace_osnoise.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 38aa5e208ffd..02c984560ceb 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -1040,11 +1040,11 @@ static void osnoise_stop_tracing(void)
static int run_osnoise(void)
{
struct osnoise_variables *osn_var = this_cpu_osn_var();
- u64 noise = 0, sum_noise = 0, max_noise = 0;
+ u64 sum_noise = 0, max_noise = 0;
struct trace_array *tr = osnoise_trace;
u64 start, sample, last_sample;
u64 last_int_count, int_count;
- s64 total, last_total = 0;
+ s64 noise = 0, total, last_total = 0;
struct osnoise_sample s;
unsigned int threshold;
int hw_count = 0;
--
2.31.1
next reply other threads:[~2021-06-29 16:52 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-29 16:52 Colin King [this message]
2021-06-29 17:19 ` [PATCH][next] trace: osnoise: Fix u64 less than zero comparison Daniel Bristot de Oliveira
2021-06-29 17:21 ` Colin Ian King
2021-06-29 18:55 ` Dan Carpenter
2021-06-30 13:05 ` Steven Rostedt
2021-06-30 13:32 ` Daniel Bristot de Oliveira
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