Hello,
A call to d_find_alias() needs a corresponding call to dput() in order to avoid
resource leaks.
The first patch is a Coccinelle scripts that looks for missing calls to dput().
The other two patches add calls to dput() where needed.
WBR,
Cyril Roelandt.
Ensure that calls to d_find_alias() have a corresponding dput().
Signed-off-by: Cyril Roelandt <[email protected]>
---
scripts/coccinelle/api/d_find_alias.cocci | 80 +++++++++++++++++++++++++++++
1 file changed, 80 insertions(+)
create mode 100644 scripts/coccinelle/api/d_find_alias.cocci
diff --git a/scripts/coccinelle/api/d_find_alias.cocci b/scripts/coccinelle/api/d_find_alias.cocci
new file mode 100644
index 0000000..639eec7
--- /dev/null
+++ b/scripts/coccinelle/api/d_find_alias.cocci
@@ -0,0 +1,80 @@
+/// Make sure calls to d_find_alias() have a corresponding call to dput().
+//
+// Keywords: d_find_alias, dput
+//
+// Confidence: Moderate
+// URL: http://coccinelle.lip6.fr/
+// Options: -include_headers
+
+virtual context
+virtual org
+virtual patch
+virtual report
+
+@r exists@
+local idexpression struct dentry *dent;
+expression E, E1;
+statement S1, S2;
+position p1, p2;
+@@
+(
+ if (!(dent@p1 = d_find_alias(...))) S1
+|
+ dent@p1 = d_find_alias(...)
+)
+
+<...when != dput(dent)
+ when != if (...) { <+... dput(dent) ...+> }
+ when != true !dent || ...
+ when != dent = E
+ when != E = dent
+if (!dent || ...) S2
+...>
+(
+ return <+...dent...+>;
+|
+ return @p2 ...;
+|
+ dent@p2 = E1;
+|
+ E1 = dent;
+)
+
+@depends on context@
+local idexpression struct dentry *r.dent;
+position r.p1,r.p2;
+@@
+* dent@p1 = ...
+ ...
+(
+* return@p2 ...;
+|
+* dent@p2
+)
+
+
+@script:python depends on org@
+p1 << r.p1;
+p2 << r.p2;
+@@
+cocci.print_main("Missing call to dput()",p1)
+cocci.print_secs("",p2)
+
+@depends on patch@
+local idexpression struct dentry *r.dent;
+position r.p2;
+@@
+(
++ dput(dent);
+ return @p2 ...;
+|
++ dput(dent);
+ dent@p2 = ...;
+)
+
+@script:python depends on report@
+p1 << r.p1;
+p2 << r.p2;
+@@
+msg = "Missing call to dput() at line %s."
+coccilib.report.print_report(p1[0], msg % (p2[0].line))
--
1.7.10.4
Call to d_find_alias() needs a corresponding dput().
Signed-off-by: Cyril Roelandt <[email protected]>
---
drivers/iommu/tegra-smmu.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 4167863..4252d74 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -1052,6 +1052,7 @@ static int smmu_debugfs_stats_show(struct seq_file *s, void *v)
stats[i], val, offs);
}
seq_printf(s, "\n");
+ dput(dent);
return 0;
}
--
1.7.10.4
dput() was not called in the error path.
Signed-off-by: Cyril Roelandt <[email protected]>
---
fs/ceph/export.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/ceph/export.c b/fs/ceph/export.c
index 9349bb3..ca3ab3f 100644
--- a/fs/ceph/export.c
+++ b/fs/ceph/export.c
@@ -56,13 +56,15 @@ static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
struct ceph_nfs_confh *cfh = (void *)rawfh;
int connected_handle_length = sizeof(*cfh)/4;
int handle_length = sizeof(*fh)/4;
- struct dentry *dentry = d_find_alias(inode);
+ struct dentry *dentry;
struct dentry *parent;
/* don't re-export snaps */
if (ceph_snap(inode) != CEPH_NOSNAP)
return -EINVAL;
+ dentry = d_find_alias(inode);
+
/* if we found an alias, generate a connectable fh */
if (*max_len >= connected_handle_length && dentry) {
dout("encode_fh %p connectable\n", dentry);
--
1.7.10.4
Cyril Roelandt <[email protected]> wrote @ Sun, 11 Nov 2012 21:49:30 +0100:
> Call to d_find_alias() needs a corresponding dput().
>
> Signed-off-by: Cyril Roelandt <[email protected]>
> ---
Thanks. Looks ok for me. Acked-by Hiroshi Doyu <[email protected]>
On Sun, Nov 11, 2012 at 09:49:30PM +0100, Cyril Roelandt wrote:
> Call to d_find_alias() needs a corresponding dput().
>
> Signed-off-by: Cyril Roelandt <[email protected]>
Applied to iommu/fixes, thanks.
On 11/11/2012 02:49 PM, Cyril Roelandt wrote:
> dput() was not called in the error path.
>
> Signed-off-by: Cyril Roelandt <[email protected]>
This looks good, thanks a lot. I'll apply it.
Reviewed-by: Alex Elder <[email protected]>
> ---
> fs/ceph/export.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ceph/export.c b/fs/ceph/export.c
> index 9349bb3..ca3ab3f 100644
> --- a/fs/ceph/export.c
> +++ b/fs/ceph/export.c
> @@ -56,13 +56,15 @@ static int ceph_encode_fh(struct inode *inode, u32 *rawfh, int *max_len,
> struct ceph_nfs_confh *cfh = (void *)rawfh;
> int connected_handle_length = sizeof(*cfh)/4;
> int handle_length = sizeof(*fh)/4;
> - struct dentry *dentry = d_find_alias(inode);
> + struct dentry *dentry;
> struct dentry *parent;
>
> /* don't re-export snaps */
> if (ceph_snap(inode) != CEPH_NOSNAP)
> return -EINVAL;
>
> + dentry = d_find_alias(inode);
> +
> /* if we found an alias, generate a connectable fh */
> if (*max_len >= connected_handle_length && dentry) {
> dout("encode_fh %p connectable\n", dentry);
>