Patchwork [3/6] arch/powerpc/kvm/e500_tlb.c: fix error return code

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Submitter Julia Lawall
Date Aug. 5, 2012, 9:52 a.m.
Message ID <1344160356-387-4-git-send-email-Julia.Lawall@lip6.fr>
Download mbox | patch
Permalink /patch/175178/
State Changes Requested
Headers show

Comments

Julia Lawall - Aug. 5, 2012, 9:52 a.m.
From: Julia Lawall <julia@diku.dk>

Convert a 0 error return code to a negative one, as returned elsewhere in the
function.

A new label is also added to avoid freeing things that are known to not yet
be allocated.

A simplified version of the semantic match that finds the first problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier ret;
expression e,e1,e2,e3,e4,x;
@@

(
if (\(ret != 0\|ret < 0\) || ...) { ... return ...; }
|
ret = 0
)
... when != ret = e1
*x = \(kmalloc\|kzalloc\|kcalloc\|devm_kzalloc\|ioremap\|ioremap_nocache\|devm_ioremap\|devm_ioremap_nocache\)(...);
... when != x = e2
    when != ret = e3
*if (x == NULL || ...)
{
  ... when != ret = e4
*  return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 arch/powerpc/kvm/e500_tlb.c |   19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)
Alexander Graf - Oct. 2, 2012, 11:04 a.m.
On 05.08.2012, at 11:52, Julia Lawall wrote:

> From: Julia Lawall <julia@diku.dk>
> 
> Convert a 0 error return code to a negative one, as returned elsewhere in the
> function.
> 
> A new label is also added to avoid freeing things that are known to not yet
> be allocated.
> 
> A simplified version of the semantic match that finds the first problem is as
> follows: (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @@
> identifier ret;
> expression e,e1,e2,e3,e4,x;
> @@
> 
> (
> if (\(ret != 0\|ret < 0\) || ...) { ... return ...; }
> |
> ret = 0
> )
> ... when != ret = e1
> *x = \(kmalloc\|kzalloc\|kcalloc\|devm_kzalloc\|ioremap\|ioremap_nocache\|devm_ioremap\|devm_ioremap_nocache\)(...);
> ... when != x = e2
>    when != ret = e3
> *if (x == NULL || ...)
> {
>  ... when != ret = e4
> *  return ret;
> }
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>

Thanks, applied to kvm-ppc-next.


Alex

Patch

diff --git a/arch/powerpc/kvm/e500_tlb.c b/arch/powerpc/kvm/e500_tlb.c
index c8f6c58..85fcdf7 100644
--- a/arch/powerpc/kvm/e500_tlb.c
+++ b/arch/powerpc/kvm/e500_tlb.c
@@ -1176,21 +1176,27 @@  int kvm_vcpu_ioctl_config_tlb(struct kvm_vcpu *vcpu,
 	}
 
 	virt = vmap(pages, num_pages, VM_MAP, PAGE_KERNEL);
-	if (!virt)
+	if (!virt) {
+		ret = -ENOMEM;
 		goto err_put_page;
+	}
 
 	privs[0] = kzalloc(sizeof(struct tlbe_priv) * params.tlb_sizes[0],
 			   GFP_KERNEL);
 	privs[1] = kzalloc(sizeof(struct tlbe_priv) * params.tlb_sizes[1],
 			   GFP_KERNEL);
 
-	if (!privs[0] || !privs[1])
-		goto err_put_page;
+	if (!privs[0] || !privs[1]) {
+		ret = -ENOMEM;
+		goto err_privs;
+	}
 
 	g2h_bitmap = kzalloc(sizeof(u64) * params.tlb_sizes[1],
 	                     GFP_KERNEL);
-	if (!g2h_bitmap)
-		goto err_put_page;
+	if (!g2h_bitmap) {
+		ret = -ENOMEM;
+		goto err_privs;
+	}
 
 	free_gtlb(vcpu_e500);
 
@@ -1230,10 +1236,11 @@  int kvm_vcpu_ioctl_config_tlb(struct kvm_vcpu *vcpu,
 	kvmppc_recalc_tlb1map_range(vcpu_e500);
 	return 0;
 
-err_put_page:
+err_privs:
 	kfree(privs[0]);
 	kfree(privs[1]);
 
+err_put_page:
 	for (i = 0; i < num_pages; i++)
 		put_page(pages[i]);