From d2c0190bd1126fe709e92171226df71254b11ccd Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 8 Apr 2020 13:53:23 -0700 Subject: [PATCH] x86/mmiotrace: Use cpumask_available() for cpumask_var_t variables [ 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 Signed-off-by: Nathan Chancellor Signed-off-by: Borislav Petkov Reviewed-by: Nick Desaulniers Acked-by: Steven Rostedt (VMware) Link: https://github.com/ClangBuiltLinux/linux/issues/982 Link: https://lkml.kernel.org/r/20200408205323.44490-1-natechancellor@gmail.com Signed-off-by: Sasha Levin --- 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 0057a7acc..5448ad4d0 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) {