The current implementation of fdt_get_path() has a couple of bugs, fixed by this patch.
First, contrary to its documentation, on success it returns the length of the node's path, rather than 0. The testcase is correspondingly wrong, and the patch fixes this as well.
Second, in some circumstances, it will return -FDT_ERR_BADOFFSET instead of -FDT_ERR_NOSPACE when given insufficient buffer space. Specifically this happens when there is insufficient space even to hold the path's second last component. This behaviour is corrected, and the testcase updated to check it.
Signed-off-by: David Gibson david@gibson.dropbear.id.au ---
This and the next patch are bugfixes from the dtc/libfdt project.
gvb
libfdt/fdt_ro.c | 23 +++++++++++------------ 1 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c index b09a6e9..f559eed 100644 --- a/libfdt/fdt_ro.c +++ b/libfdt/fdt_ro.c @@ -320,9 +320,6 @@ int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen) for (offset = 0, depth = 0; (offset >= 0) && (offset <= nodeoffset); offset = fdt_next_node(fdt, offset, &depth)) { - if (pdepth < depth) - continue; /* overflowed buffer */ - while (pdepth > depth) { do { p--; @@ -330,14 +327,16 @@ int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen) pdepth--; }
- name = fdt_get_name(fdt, offset, &namelen); - if (!name) - return namelen; - if ((p + namelen + 1) <= buflen) { - memcpy(buf + p, name, namelen); - p += namelen; - buf[p++] = '/'; - pdepth++; + if (pdepth >= depth) { + name = fdt_get_name(fdt, offset, &namelen); + if (!name) + return namelen; + if ((p + namelen + 1) <= buflen) { + memcpy(buf + p, name, namelen); + p += namelen; + buf[p++] = '/'; + pdepth++; + } }
if (offset == nodeoffset) { @@ -347,7 +346,7 @@ int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen) if (p > 1) /* special case so that root path is "/", not "" */ p--; buf[p] = '\0'; - return p; + return 0; } }