| Message ID | 1392737253-10480-13-git-send-email-marc.zyngier@arm.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Feb 18, 2014 at 03:27:33PM +0000, Marc Zyngier wrote: > 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 <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
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)) {
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 <marc.zyngier@arm.com> --- arch/arm/kvm/mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)