[PATCH 2/6] stm class: adds a loop to extract the first valid STM device name

From: Chunyan Zhang
Date: Mon Feb 01 2016 - 03:20:12 EST


The node name of STM master management policy is a concatenation of an
STM device name to which this policy applies and following an arbitrary
string, these two strings are concatenated with a dot.

This patch adds a loop for extracting the STM device name when an
arbitrary number of dot(s) are found in this STM device name.

Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
---
drivers/hwtracing/stm/policy.c | 27 ++++++++++++++++-----------
1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/drivers/hwtracing/stm/policy.c b/drivers/hwtracing/stm/policy.c
index 11ab6d0..691686e 100644
--- a/drivers/hwtracing/stm/policy.c
+++ b/drivers/hwtracing/stm/policy.c
@@ -321,21 +321,26 @@ stp_policies_make(struct config_group *group, const char *name)
/*
* node must look like <device_name>.<policy_name>, where
* <device_name> is the name of an existing stm device and
- * <policy_name> is an arbitrary string
+ * <policy_name> is an arbitrary string, when an arbitrary
+ * number of dot(s) are found in the <device_name>, the
+ * first matched STM device name would be extracted.
*/
- p = strchr(devname, '.');
- if (!p) {
- kfree(devname);
- return ERR_PTR(-EINVAL);
- }
+ for (p = devname; ; p++) {
+ p = strchr(p, '.');
+ if (!p) {
+ kfree(devname);
+ return ERR_PTR(-EINVAL);
+ }

- *p++ = '\0';
+ *p = '\0';

- stm = stm_find_device(devname);
- kfree(devname);
+ stm = stm_find_device(devname);
+ if (stm)
+ break;
+ *p = '.';
+ };

- if (!stm)
- return ERR_PTR(-ENODEV);
+ kfree(devname);

mutex_lock(&stm->policy_mutex);
if (stm->policy) {
--
1.9.1