From: Nathan Chancellor <[email protected]>
[ Upstream commit d7110a26e5905ec2fe3fc88bc6a538901accb72b ]
When building with Clang + -Wtautological-compare and
CONFIG_CPUMASK_OFFSTACK unset:
arch/x86/mm/mmio-mod.c:375:6: warning: comparison of array 'downed_cpus'
equal to a null pointer is always false [-Wtautological-pointer-compare]
if (downed_cpus == NULL &&
^~~~~~~~~~~ ~~~~
arch/x86/mm/mmio-mod.c:405:6: warning: comparison of array 'downed_cpus'
equal to a null pointer is always false [-Wtautological-pointer-compare]
if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
^~~~~~~~~~~ ~~~~
2 warnings generated.
Commit
f7e30f01a9e2 ("cpumask: Add helper cpumask_available()")
added cpumask_available() to fix warnings of this nature. Use that here
so that clang does not warn regardless of CONFIG_CPUMASK_OFFSTACK's
value.
Reported-by: Sedat Dilek <[email protected]>
Signed-off-by: Nathan Chancellor <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Acked-by: Steven Rostedt (VMware) <[email protected]>
Link: https://github.com/ClangBuiltLinux/linux/issues/982
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
---
arch/x86/mm/mmio-mod.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/mm/mmio-mod.c b/arch/x86/mm/mmio-mod.c
index 0057a7accfb1..5448ad4d0703 100644
--- a/arch/x86/mm/mmio-mod.c
+++ b/arch/x86/mm/mmio-mod.c
@@ -385,7 +385,7 @@ static void enter_uniprocessor(void)
int cpu;
int err;
- if (downed_cpus == NULL &&
+ if (!cpumask_available(downed_cpus) &&
!alloc_cpumask_var(&downed_cpus, GFP_KERNEL)) {
pr_notice("Failed to allocate mask\n");
goto out;
@@ -415,7 +415,7 @@ static void leave_uniprocessor(void)
int cpu;
int err;
- if (downed_cpus == NULL || cpumask_weight(downed_cpus) == 0)
+ if (!cpumask_available(downed_cpus) || cpumask_weight(downed_cpus) == 0)
return;
pr_notice("Re-enabling CPUs...\n");
for_each_cpu(cpu, downed_cpus) {
--
2.25.1
