From f460772291f8171988b2b60141a45706123d0c69 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Sun, 30 Dec 2018 14:05:13 +1100 Subject: [PATCH] KVM: PPC: Book3S HV: radix: Fix uninitialized var build error Old GCCs (4.6.3 at least), aren't able to follow the logic in __kvmhv_copy_tofrom_guest_radix() and warn that old_pid is used uninitialized: arch/powerpc/kvm/book3s_64_mmu_radix.c:75:3: error: 'old_pid' may be used uninitialized in this function The logic is OK, we only use old_pid if quadrant == 1, and in that case it has definitely be initialised, eg: if (quadrant == 1) { old_pid = mfspr(SPRN_PID); ... if (quadrant == 1 && pid != old_pid) mtspr(SPRN_PID, old_pid); Annotate it to fix the error. Signed-off-by: Michael Ellerman --- arch/powerpc/kvm/book3s_64_mmu_radix.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index fb88167a402a..1b821c6efdef 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -33,8 +33,8 @@ unsigned long __kvmhv_copy_tofrom_guest_radix(int lpid, int pid, gva_t eaddr, void *to, void *from, unsigned long n) { + int uninitialized_var(old_pid), old_lpid; unsigned long quadrant, ret = n; - int old_pid, old_lpid; bool is_load = !!to; /* Can't access quadrants 1 or 2 in non-HV mode, call the HV to do it */