From: Wei Liu <wei.liu2@citrix.com>
To: Juergen Gross <jgross@suse.com>
Cc: wei.liu2@citrix.com, ian.jackson@eu.citrix.com, xen-devel@lists.xen.org
Subject: Re: [PATCH v2 2/5] xenstore: add explicit memory context parameter to get_parent()
Date: Tue, 19 Jul 2016 11:04:19 +0100 [thread overview]
Message-ID: <20160719100419.GJ13180@citrix.com> (raw)
In-Reply-To: <1468827089-9054-3-git-send-email-jgross@suse.com>
On Mon, Jul 18, 2016 at 09:31:26AM +0200, Juergen Gross wrote:
> Add a parameter to xenstored get_parent() function to explicitly
> specify the memory context to be used for allocations. This will make
> it easier to avoid memory leaks by using a context which is freed
> soon.
>
> When available use a temporary context when calling get_parent(),
> otherwise mimic the old behavior by calling get_parent() with the same
> argument for both parameters.
>
> Signed-off-by: Juergen Gross <jgross@suse.com>
> ---
> tools/xenstore/xenstored_core.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
> index 94c809c..9448ee8 100644
> --- a/tools/xenstore/xenstored_core.c
> +++ b/tools/xenstore/xenstored_core.c
> @@ -507,12 +507,12 @@ static enum xs_perm_type perm_for_conn(struct connection *conn,
> return perms[0].perms & mask;
> }
>
> -static char *get_parent(const char *node)
> +static char *get_parent(const void *mem, const char *node)
I would name mem ctx or context instead. And maybe document this
function a bit saying that memory allocation is done with the first
parameter.
With those cosmetic issues fixed:
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
> {
> char *slash = strrchr(node + 1, '/');
> if (!slash)
> - return talloc_strdup(node, "/");
> - return talloc_asprintf(node, "%.*s", (int)(slash - node), node);
> + return talloc_strdup(mem, "/");
> + return talloc_asprintf(mem, "%.*s", (int)(slash - node), node);
> }
>
> /* What do parents say? */
> @@ -521,7 +521,7 @@ static enum xs_perm_type ask_parents(struct connection *conn, const char *name)
> struct node *node;
>
> do {
> - name = get_parent(name);
> + name = get_parent(name, name);
> node = read_node(conn, name);
> if (node)
> break;
> @@ -816,7 +816,7 @@ static struct node *construct_node(struct connection *conn, const char *name)
> const char *base;
> unsigned int baselen;
> struct node *parent, *node;
> - char *children, *parentname = get_parent(name);
> + char *children, *parentname = get_parent(name, name);
>
> /* If parent doesn't exist, create it. */
> parent = read_node(conn, parentname);
> @@ -1036,7 +1036,7 @@ static int _rm(struct connection *conn, struct node *node, const char *name)
> /* Delete from parent first, then if we crash, the worst that can
> happen is the child will continue to take up space, but will
> otherwise be unreachable. */
> - struct node *parent = read_node(conn, get_parent(name));
> + struct node *parent = read_node(conn, get_parent(name, name));
> if (!parent) {
> send_error(conn, EINVAL);
> return 0;
> @@ -1073,7 +1073,7 @@ static void do_rm(struct connection *conn, struct buffered_data *in)
> if (!node) {
> /* Didn't exist already? Fine, if parent exists. */
> if (errno == ENOENT) {
> - node = read_node(conn, get_parent(name));
> + node = read_node(conn, get_parent(in, name));
> if (node) {
> send_ack(conn, XS_RM);
> return;
> --
> 2.6.6
>
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next prev parent reply other threads:[~2016-07-19 10:04 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-18 7:31 [PATCH v2 0/5] xenstore: fix memory leak of xenstored Juergen Gross
2016-07-18 7:31 ` [PATCH v2 1/5] xenstore: call each xenstored command function with temporary context Juergen Gross
2016-07-19 10:04 ` Wei Liu
2016-07-19 10:35 ` Ian Jackson
2016-07-18 7:31 ` [PATCH v2 2/5] xenstore: add explicit memory context parameter to get_parent() Juergen Gross
2016-07-19 10:04 ` Wei Liu [this message]
2016-07-19 10:37 ` Ian Jackson
2016-07-19 10:37 ` Ian Jackson
2016-07-18 7:31 ` [PATCH v2 3/5] xenstore: add explicit memory context parameter to read_node() Juergen Gross
2016-07-19 10:04 ` Wei Liu
2016-07-19 10:38 ` Ian Jackson
2016-07-18 7:31 ` [PATCH v2 4/5] xenstore: add explicit memory context parameter to get_node() Juergen Gross
2016-07-19 10:05 ` Wei Liu
2016-07-19 10:39 ` Ian Jackson
2016-07-18 7:31 ` [PATCH v2 5/5] xenstore: use temporary memory context for firing watches Juergen Gross
2016-07-19 10:23 ` Wei Liu
2016-07-19 10:40 ` Ian Jackson
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