From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Tue, 18 Feb 2014 15:27:33 +0000 Subject: [PATCH v4 12/12] ARM: KVM: fix warning in mmu.c In-Reply-To: <1392737253-10480-1-git-send-email-marc.zyngier@arm.com> References: <1392737253-10480-1-git-send-email-marc.zyngier@arm.com> Message-ID: <1392737253-10480-13-git-send-email-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Compiling with THP enabled leads to the following warning: arch/arm/kvm/mmu.c: In function ?unmap_range?: arch/arm/kvm/mmu.c:177:39: warning: ?pte? may be used uninitialized in this function [-Wmaybe-uninitialized] if (kvm_pmd_huge(*pmd) || page_empty(pte)) { ^ Code inspection reveals that these two cases are mutually exclusive, so GCC is a bit overzealous here. Silence it anyway by initializing pte to NULL and testing it later on. Signed-off-by: Marc Zyngier --- arch/arm/kvm/mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 209f20f..5e56cbc 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -144,6 +144,7 @@ static void unmap_range(struct kvm *kvm, pgd_t *pgdp, while (addr < end) { pgd = pgdp + pgd_index(addr); pud = pud_offset(pgd, addr); + pte = NULL; if (pud_none(*pud)) { addr = kvm_pud_addr_end(addr, end); continue; @@ -174,7 +175,7 @@ static void unmap_range(struct kvm *kvm, pgd_t *pgdp, /* * If the pmd entry is to be cleared, walk back up the ladder */ - if (kvm_pmd_huge(*pmd) || page_empty(pte)) { + if (kvm_pmd_huge(*pmd) || (pte && page_empty(pte))) { clear_pmd_entry(kvm, pmd, addr); next = kvm_pmd_addr_end(addr, end); if (page_empty(pmd) && !page_empty(pud)) { -- 1.8.3.4