From: Nathan Chancellor <natechancellor@gmail.com>
commit ef70eff9dea66f38f8c2c2dcc7fe4b7a2bbb4921 upstream.
When building with clang + -Wtautological-pointer-compare, these
instances pop up:
kernel/profile.c:339:6: warning: comparison of array 'prof_cpu_mask' not equal to a null pointer is always true [-Wtautological-pointer-compare]
if (prof_cpu_mask != NULL)
^~~~~~~~~~~~~ ~~~~
kernel/profile.c:376:6: warning: comparison of array 'prof_cpu_mask' not equal to a null pointer is always true [-Wtautological-pointer-compare]
if (prof_cpu_mask != NULL)
^~~~~~~~~~~~~ ~~~~
kernel/profile.c:406:26: warning: comparison of array 'prof_cpu_mask' not equal to a null pointer is always true [-Wtautological-pointer-compare]
if (!user_mode(regs) && prof_cpu_mask != NULL &&
^~~~~~~~~~~~~ ~~~~
3 warnings generated.
This can be addressed with the cpumask_available helper, introduced in
commit f7e30f01a9e2 ("cpumask: Add helper cpumask_available()") to fix
warnings like this while keeping the code the same.
Link: https://github.com/ClangBuiltLinux/linux/issues/747
Link: http://lkml.kernel.org/r/20191022191957.9554-1-natechancellor@gmail.com
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[ These warnings are also visible with recent GCC versions. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
kernel/profile.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/profile.c b/kernel/profile.c
index b5ce18b6f1b9..af3d5c34d051 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -344,7 +344,7 @@ static int profile_dead_cpu(unsigned int cpu)
struct page *page;
int i;
- if (prof_cpu_mask != NULL)
+ if (cpumask_available(prof_cpu_mask))
cpumask_clear_cpu(cpu, prof_cpu_mask);
for (i = 0; i < 2; i++) {
@@ -381,7 +381,7 @@ static int profile_prepare_cpu(unsigned int cpu)
static int profile_online_cpu(unsigned int cpu)
{
- if (prof_cpu_mask != NULL)
+ if (cpumask_available(prof_cpu_mask))
cpumask_set_cpu(cpu, prof_cpu_mask);
return 0;
@@ -411,7 +411,7 @@ void profile_tick(int type)
{
struct pt_regs *regs = get_irq_regs();
- if (!user_mode(regs) && prof_cpu_mask != NULL &&
+ if (!user_mode(regs) && cpumask_available(prof_cpu_mask) &&
cpumask_test_cpu(smp_processor_id(), prof_cpu_mask))
profile_hit(type, (void *)profile_pc(regs));
}
--
2.51.0