[Crosstoolchain-logs] [device-tree-compiler] 300/357: libfdt: Fix bugs in fdt_get_path()

[Hector Oron]

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zumbi pushed a commit to branch upstream/1.3.x
in repository device-tree-compiler.

commit 8daae14b742a48078c77fca3ccb24cd376232bc1
Author: David Gibson <david at gibson.dropbear.id.au>
Date:   Fri Aug 29 14:19:13 2008 +1000

    libfdt: Fix bugs in fdt_get_path()
    
    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 at gibson.dropbear.id.au>
---
 libfdt/fdt_ro.c  | 23 +++++++++++------------
 tests/get_path.c | 10 +++++++---
 2 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
index 2f3ff48..1d1e35e 100644
--- a/libfdt/fdt_ro.c
+++ b/libfdt/fdt_ro.c
@@ -316,9 +316,6 @@ 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--;
@@ -326,14 +323,16 @@ 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) {
@@ -343,7 +342,7 @@ 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;
 		}
 	}
 
diff --git a/tests/get_path.c b/tests/get_path.c
index b9c0f60..1e05f7c 100644
--- a/tests/get_path.c
+++ b/tests/get_path.c
@@ -43,6 +43,8 @@ static void check_path_buf(void *fdt, const char *path, int pathlen, int buflen)
 	memset(buf, POISON, sizeof(buf)); /* poison the buffer */
 
 	len = fdt_get_path(fdt, offset, buf, buflen);
+	verbose_printf("get_path() %s -> %d -> %s\n", path, offset, buf);
+
 	if (buflen <= pathlen) {
 		if (len != -FDT_ERR_NOSPACE)
 			FAIL("fdt_get_path([%d bytes]) returns %d with "
@@ -51,9 +53,9 @@ static void check_path_buf(void *fdt, const char *path, int pathlen, int buflen)
 		if (len < 0)
 			FAIL("fdt_get_path([%d bytes]): %s", buflen,
 			     fdt_strerror(len));
-		if (len != pathlen)
-			FAIL("fdt_get_path([%d bytes]) reports length %d "
-			     "instead of %d", buflen, len, pathlen);
+		if (len != 0)
+			FAIL("fdt_get_path([%d bytes]) returns %d "
+			     "instead of 0", buflen, len);
 		if (strcmp(buf, path) != 0)
 			FAIL("fdt_get_path([%d bytes]) returns \"%s\" "
 			     "instead of \"%s\"", buflen, buf, path);
@@ -70,6 +72,8 @@ static void check_path(void *fdt, const char *path)
 	check_path_buf(fdt, path, pathlen, 1024);
 	check_path_buf(fdt, path, pathlen, pathlen+1);
 	check_path_buf(fdt, path, pathlen, pathlen);
+	check_path_buf(fdt, path, pathlen, 0);
+	check_path_buf(fdt, path, pathlen, 2);
 }
 
 int main(int argc, char *argv[])

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