Messages in this thread Patch in this message | | | From | Nathan Chancellor <> | Subject | [PATCH] x86: mmiotrace: Use cpumask_available for cpumask_var_t variables | Date | Wed, 8 Apr 2020 13:53:23 -0700 |
| |
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.
Link: https://github.com/ClangBuiltLinux/linux/issues/982 Reported-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> --- 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 109325d77b3e..43fd19b3f118 100644 --- a/arch/x86/mm/mmio-mod.c +++ b/arch/x86/mm/mmio-mod.c @@ -372,7 +372,7 @@ 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; @@ -402,7 +402,7 @@ 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) { base-commit: ae46d2aa6a7fbe8ca0946f24b061b6ccdc6c3f25 -- 2.26.0
| |