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authorNathan Fontenot <nfont@linux.vnet.ibm.com>2015-10-27 10:46:47 -0500
committerMichael Ellerman <mpe@ellerman.id.au>2015-10-28 12:08:18 +0900
commitf755ecfb8cec7b19dff84295309f2afb24a5afd1 (patch)
tree0786fec1e825368514b8db02c53ab31acb66505b /arch/powerpc
parent353169acf1858bb2dc3f91475dafabce547de14c (diff)
powerpc/pseries: Correct string length in pseries_of_derive_parent()
Commit a030e1e4bbd085bbcfd0a23f8d355fcd41f39bed make a change to use kstrndup() instead of kmalloc() + strlcpy() in the pseries_of_derive_parent() routine that introduces a subtle change in the parent path name generated. The kstrndup() routine will copy n characters followed by a terminating null, whereas strlcpy() will copy n-1 characters and add a terminating null. This slight difference results in having a parent path that includes the tailing '/' character, "/cpus/" vs. "/cpus". This then causes the subsequent call to of_find_node_by_path() to fail, and in the case of DLPAR add operations the DLPAR request fails. This patch decrements the pointer returned from kbasename() to point to the '/' character before the base name instead of the base name. This then adjusts the string length calculations to not include the trailing '/' in the parent path name. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/platforms/pseries/of_helpers.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/powerpc/platforms/pseries/of_helpers.c b/arch/powerpc/platforms/pseries/of_helpers.c
index 4417afef74d4..2798933c0e38 100644
--- a/arch/powerpc/platforms/pseries/of_helpers.c
+++ b/arch/powerpc/platforms/pseries/of_helpers.c
@@ -17,13 +17,16 @@ struct device_node *pseries_of_derive_parent(const char *path)
{
struct device_node *parent;
char *parent_path = "/";
- const char *tail = kbasename(path);
+ const char *tail;
+
+ /* We do not want the trailing '/' character */
+ tail = kbasename(path) - 1;
/* reject if path is "/" */
if (!strcmp(path, "/"))
return ERR_PTR(-EINVAL);
- if (tail > path + 1) {
+ if (tail > path) {
parent_path = kstrndup(path, tail - path, GFP_KERNEL);
if (!parent_path)
return ERR_PTR(-ENOMEM);