libfdt: Several cleanups to parameter checking

This patch makes a couple of small cleanups to parameter checking of
libfdt functions.

	- In several functions which take a node offset, we use an
idiom involving fdt_next_tag() first to check that we have indeed been
given a node offset.  This patch adds a helper function
_fdt_check_node_offset() to encapsulate this usage of fdt_next_tag().

	- In fdt_rw.c in several places we have the expanded version
of the RW_CHECK_HEADER() macro for no particular reason.  This patch
replaces those instances with an invocation of the macro; that's what
it's for.

	- In fdt_sw.c we rename the check_header_sw() function to
sw_check_header() to match the analgous function in fdt_rw.c, and we
provide an SW_CHECK_HEADER() wrapper macro as RW_CHECK_HEADER()
functions in fdt_rw.c

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

diff --git a/libfdt/fdt.c b/libfdt/fdt.c
index cfa1989d8e544c53cb87f67d4a953b545cf2bf3e..cb08ba0a94630cc20b90955423be04886c4546c6 100644 (file)
--- a/libfdt/fdt.c
+++ b/libfdt/fdt.c
@@ -133,16 +133,23 @@ uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset)
        return tag;
 }
 
+int _fdt_check_node_offset(const void *fdt, int offset)
+{
+       if ((offset < 0) || (offset % FDT_TAGSIZE)
+           || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
+               return -FDT_ERR_BADOFFSET;
+
+       return offset;
+}
+
 int fdt_next_node(const void *fdt, int offset, int *depth)
 {
        int nextoffset = 0;
        uint32_t tag;
 
-       if (offset >= 0) {
-               tag = fdt_next_tag(fdt, offset, &nextoffset);
-               if (tag != FDT_BEGIN_NODE)
-                       return -FDT_ERR_BADOFFSET;
-       }
+       if (offset >= 0)
+               if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
+                       return nextoffset;
 
        do {
                offset = nextoffset;

diff --git a/libfdt/fdt_ro.c b/libfdt/fdt_ro.c
index 11d80d2fa249d8a6085888e48b44130d6f7ca531..69af7bb843ae4e36ce4a3f89fb1190a52c27d254 100644 (file)
--- a/libfdt/fdt_ro.c
+++ b/libfdt/fdt_ro.c
@@ -161,16 +161,12 @@ int fdt_path_offset(const void *fdt, const char *path)
 
 const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
 {
-       const struct fdt_node_header *nh;
+       const struct fdt_node_header *nh = _fdt_offset_ptr(fdt, nodeoffset);
        int err;
 
-       if ((err = fdt_check_header(fdt)) != 0)
-               goto fail;
-
-       err = -FDT_ERR_BADOFFSET;
-       nh = fdt_offset_ptr(fdt, nodeoffset, sizeof(*nh));
-       if (!nh || (fdt32_to_cpu(nh->tag) != FDT_BEGIN_NODE))
-               goto fail;
+       if (((err = fdt_check_header(fdt)) != 0)
+           || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
+                       goto fail;
 
        if (len)
                *len = strlen(nh->name);
@@ -193,17 +189,11 @@ const struct fdt_property *fdt_get_property(const void *fdt,
        int offset, nextoffset;
        int err;
 
-       if ((err = fdt_check_header(fdt)) != 0)
-               goto fail;
-
-       err = -FDT_ERR_BADOFFSET;
-       if (nodeoffset % FDT_TAGSIZE)
-               goto fail;
-
-       tag = fdt_next_tag(fdt, nodeoffset, &nextoffset);
-       if (tag != FDT_BEGIN_NODE)
-               goto fail;
+       if (((err = fdt_check_header(fdt)) != 0)
+           || ((err = _fdt_check_node_offset(fdt, nodeoffset)) < 0))
+                       goto fail;
 
+       nextoffset = err;
        do {
                offset = nextoffset;
 

diff --git a/libfdt/fdt_rw.c b/libfdt/fdt_rw.c
index 8609fa7d76f521c631ac3aaace7f6a5ea8a6dac6..95a5c2c62bee3888d7d13daf726b7f435d378c2a 100644 (file)
--- a/libfdt/fdt_rw.c
+++ b/libfdt/fdt_rw.c
@@ -176,8 +176,7 @@ int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
        struct fdt_reserve_entry *re;
        int err;
 
-       if ((err = rw_check_header(fdt)))
-               return err;
+       RW_CHECK_HEADER(fdt);
 
        re = _fdt_mem_rsv_w(fdt, fdt_num_mem_rsv(fdt));
        err = _blob_splice_mem_rsv(fdt, re, 0, 1);
@@ -194,8 +193,8 @@ int fdt_del_mem_rsv(void *fdt, int n)
        struct fdt_reserve_entry *re = _fdt_mem_rsv_w(fdt, n);
        int err;
 
-       if ((err = rw_check_header(fdt)))
-               return err;
+       RW_CHECK_HEADER(fdt);
+
        if (n >= fdt_num_mem_rsv(fdt))
                return -FDT_ERR_NOTFOUND;
 
@@ -227,15 +226,13 @@ static int _resize_property(void *fdt, int nodeoffset, const char *name, int len
 static int _add_property(void *fdt, int nodeoffset, const char *name, int len,
                         struct fdt_property **prop)
 {
-       uint32_t tag;
        int proplen;
        int nextoffset;
        int namestroff;
        int err;
 
-       tag = fdt_next_tag(fdt, nodeoffset, &nextoffset);
-       if (tag != FDT_BEGIN_NODE)
-               return -FDT_ERR_BADOFFSET;
+       if ((nextoffset = _fdt_check_node_offset(fdt, nodeoffset)) < 0)
+               return nextoffset;
 
        namestroff = _find_add_string(fdt, name);
        if (namestroff < 0)
@@ -260,8 +257,7 @@ int fdt_set_name(void *fdt, int nodeoffset, const char *name)
        int oldlen, newlen;
        int err;
 
-       if ((err = rw_check_header(fdt)))
-               return err;
+       RW_CHECK_HEADER(fdt);
 
        namep = (char *)fdt_get_name(fdt, nodeoffset, &oldlen);
        if (!namep)
@@ -284,8 +280,7 @@ int fdt_setprop(void *fdt, int nodeoffset, const char *name,
        struct fdt_property *prop;
        int err;
 
-       if ((err = rw_check_header(fdt)))
-               return err;
+       RW_CHECK_HEADER(fdt);
 
        err = _resize_property(fdt, nodeoffset, name, len, &prop);
        if (err == -FDT_ERR_NOTFOUND)
@@ -456,11 +451,8 @@ int fdt_open_into(const void *fdt, void *buf, int bufsize)
 int fdt_pack(void *fdt)
 {
        int mem_rsv_size;
-       int err;
 
-       err = rw_check_header(fdt);
-       if (err)
-               return err;
+       RW_CHECK_HEADER(fdt);
 
        mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
                * sizeof(struct fdt_reserve_entry);

diff --git a/libfdt/fdt_sw.c b/libfdt/fdt_sw.c
index dda2de34b2e0a968463cf808b669b37e226620df..df0987606e3f90ee743847dd340c6b78de00f14a 100644 (file)
--- a/libfdt/fdt_sw.c
+++ b/libfdt/fdt_sw.c
@@ -55,13 +55,21 @@
 
 #include "libfdt_internal.h"
 
-static int check_header_sw(void *fdt)
+static int sw_check_header(void *fdt)
 {
        if (fdt_magic(fdt) != SW_MAGIC)
                return -FDT_ERR_BADMAGIC;
+       /* FIXME: should check more details about the header state */
        return 0;
 }
 
+#define SW_CHECK_HEADER(fdt) \
+       { \
+               int err; \
+               if ((err = sw_check_header(fdt)) != 0) \
+                       return err; \
+       }
+
 static void *grab_space(void *fdt, int len)
 {
        int offset = fdt_size_dt_struct(fdt);
@@ -102,11 +110,10 @@ int fdt_create(void *buf, int bufsize)
 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
 {
        struct fdt_reserve_entry *re;
-       int err = check_header_sw(fdt);
        int offset;
 
-       if (err)
-               return err;
+       SW_CHECK_HEADER(fdt);
+
        if (fdt_size_dt_struct(fdt))
                return -FDT_ERR_BADSTATE;
 
@@ -131,11 +138,9 @@ int fdt_finish_reservemap(void *fdt)
 int fdt_begin_node(void *fdt, const char *name)
 {
        struct fdt_node_header *nh;
-       int err = check_header_sw(fdt);
        int namelen = strlen(name) + 1;
 
-       if (err)
-               return err;
+       SW_CHECK_HEADER(fdt);
 
        nh = grab_space(fdt, sizeof(*nh) + ALIGN(namelen, FDT_TAGSIZE));
        if (! nh)
@@ -149,10 +154,8 @@ int fdt_begin_node(void *fdt, const char *name)
 int fdt_end_node(void *fdt)
 {
        uint32_t *en;
-       int err = check_header_sw(fdt);
 
-       if (err)
-               return err;
+       SW_CHECK_HEADER(fdt);
 
        en = grab_space(fdt, FDT_TAGSIZE);
        if (! en)
@@ -188,11 +191,9 @@ static int find_add_string(void *fdt, const char *s)
 int fdt_property(void *fdt, const char *name, const void *val, int len)
 {
        struct fdt_property *prop;
-       int err = check_header_sw(fdt);
        int nameoff;
 
-       if (err)
-               return err;
+       SW_CHECK_HEADER(fdt);
 
        nameoff = find_add_string(fdt, name);
        if (nameoff == 0)
@@ -211,15 +212,13 @@ int fdt_property(void *fdt, const char *name, const void *val, int len)
 
 int fdt_finish(void *fdt)
 {
-       int err = check_header_sw(fdt);
        char *p = (char *)fdt;
        uint32_t *end;
        int oldstroffset, newstroffset;
        uint32_t tag;
        int offset, nextoffset;
 
-       if (err)
-               return err;
+       SW_CHECK_HEADER(fdt);
 
        /* Add terminator */
        end = grab_space(fdt, sizeof(*end));

diff --git a/libfdt/libfdt_internal.h b/libfdt/libfdt_internal.h
index 52e1b8d810b08b69e08b88c34b3208b5869f2189..f72e70dbe647ac3be205440ca37ea655b22a8a21 100644 (file)
--- a/libfdt/libfdt_internal.h
+++ b/libfdt/libfdt_internal.h
@@ -66,6 +66,7 @@
        }
 
 uint32_t _fdt_next_tag(const void *fdt, int startoffset, int *nextoffset);
+int _fdt_check_node_offset(const void *fdt, int offset);
 const char *_fdt_find_string(const char *strtab, int tabsize, const char *s);
 int _fdt_node_end_offset(void *fdt, int nodeoffset);