re: ping: re:[PATCH 1/1] kernel code that do not handle NULL return of kmem_cache_zalloc

[zhouzhouyi]

From: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx>

the text of previous ping message maybe garbled sorry for the trouble

> I do a grep for kmem_cache_zalloc and kmem_cache_alloc
> in kernel tree, and find some code do not handle NULL
> return of kmem_cache_zalloc correctly


> Signed-off-by: Zhouyi Zhou <yizhouzhou@xxxxxxxxx>
---
 arch/powerpc/kvm/book3s_32_mmu_host.c |    5 +++++
 drivers/iommu/omap-iommu.c            |    3 ++-
 fs/jffs2/malloc.c                     |    4 ++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kvm/book3s_32_mmu_host.c b/arch/powerpc/kvm/book3s_32_mmu_host.c
index 3a0abd2..5fac89d 100644
--- a/arch/powerpc/kvm/book3s_32_mmu_host.c
+++ b/arch/powerpc/kvm/book3s_32_mmu_host.c
@@ -243,6 +243,11 @@ next_pteg:
 	/* Now tell our Shadow PTE code about the new page */
 
 	pte = kvmppc_mmu_hpte_cache_next(vcpu);
+	if (!pte) {
+		kvm_release_pfn_clean(hpaddr >> PAGE_SHIFT);
+		r = -EAGAIN;
+		goto out;
+	}
 
 	dprintk_mmu("KVM: %c%c Map 0x%llx: [%lx] 0x%llx (0x%llx) -> %lx\n",
 		    orig_pte->may_write ? 'w' : '-',
diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index bcd78a7..5155714 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -551,7 +551,8 @@ static u32 *iopte_alloc(struct omap_iommu *obj, u32 *iopgd, u32 da)
 		dev_vdbg(obj->dev, "%s: a new pte:%p\n", __func__, iopte);
 	} else {
 		/* We raced, free the reduniovant table */
-		iopte_free(iopte);
+		if (iopte)
+			iopte_free(iopte);
 	}
 
 pte_ready:
diff --git a/fs/jffs2/malloc.c b/fs/jffs2/malloc.c
index 4f47aa2..58e2336 100644
--- a/fs/jffs2/malloc.c
+++ b/fs/jffs2/malloc.c
@@ -287,6 +287,8 @@ struct jffs2_xattr_datum *jffs2_alloc_xattr_datum(void)
 {
 	struct jffs2_xattr_datum *xd;
 	xd = kmem_cache_zalloc(xattr_datum_cache, GFP_KERNEL);
+	if (!xd)
+		return NULL;
 	dbg_memalloc("%p\n", xd);
 
 	xd->class = RAWNODE_CLASS_XATTR_DATUM;
@@ -305,6 +307,8 @@ struct jffs2_xattr_ref *jffs2_alloc_xattr_ref(void)
 {
 	struct jffs2_xattr_ref *ref;
 	ref = kmem_cache_zalloc(xattr_ref_cache, GFP_KERNEL);
+	if (!ref)
+		return NULL;
 	dbg_memalloc("%p\n", ref);
 
 	ref->class = RAWNODE_CLASS_XATTR_REF;
-- 
1.7.10.4

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