On 6/29/21 6:52 PM, Colin King wrote: > From: Colin Ian King <colin.king@xxxxxxxxxxxxx> > > 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. Ops! concurrent bug fixing. Dan Carpenter reported the same bug (and another problem), and I was working in the patches... I saw yours after sending his ones: https://lore.kernel.org/lkml/acd7cd6e7d56b798a298c3bc8139a390b3c4ab52.1624986368.git.bristot@xxxxxxxxxx/ The patches do the same fix, but there it also: - Made also max_noise s64 (it is snapshot of noise). - Arranged the declarations in the inverted christmas tree. > Addresses-Coverity: ("Unsigned compared against 0") > Fixes: bce29ac9ce0b ("trace: Add osnoise tracer") > Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx> Steven, can we merge the flags? -- Daniel > --- > 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; >
