scripts/dtc: Update to upstream version v1.4.7-14-gc86da84d30e4

Major changes are I2C and SPI bus checks, YAML output format (for
future validation), some new libfdt functions, and more libfdt
validation of dtbs.

The YAML addition adds an optional dependency on libyaml. pkg-config is
used to test for it and pkg-config became a kconfig dependency in 4.18.

This adds the following commits from upstream:

c86da84d30e4 Add support for YAML encoded output
361b5e7d8067 Make type_marker_length helper public
bfbfab047e45 pylibfdt: Add a means to add and delete notes
9005f4108e7c pylibfdt: Allow delprop() to return errors
b94c056b137e Make valgrind optional
fd06c54d4711 tests: Better testing of dtc -I fs mode
c3f50c9a86d9 tests: Allow dtbs_equal_unordered to ignore mem reserves
0ac9fdee37c7 dtc: trivial '-I fs -O dts' test
0fd1c8c783f3 pylibfdt: fdt_get_mem_rsv returns 2 uint64_t values
04853cad18f4 pylibfdt: Don't incorrectly / unnecessarily override uint64_t typemap
9619c8619c37 Kill bogus TYPE_BLOB marker type
ac68ff92ae20 parser: add TYPE_STRING marker to path references
90a190eb04d9 checks: add SPI bus checks
53a1bd546905 checks: add I2C bus checks
88f18909db73 dtc: Bump version to v1.4.7
85bce8b2f06d tests: Correction to vg_prepare_blob()
57f7f9e7bc7c tests: Don't call memcmp() with NULL arguments
c12b2b0c20eb libfdt: fdt_address_cells() and fdt_size_cells()
3fe0eeda0b7f livetree: Set phandle properties type to uint32
853649acceba pylibfdt: Support the sequential-write interface
9b0e4fe26093 tests: Improve fdt_resize() tests
1087504bb3e8 libfdt: Add necessary header padding in fdt_create()
c72fa777e613 libfdt: Copy the struct region in fdt_resize()
32b9c6130762 Preserve datatype markers when emitting dts format
6dcb8ba408ec libfdt: Add helpers for accessing unaligned words
42607f21d43e tests: Fix incorrect check name 'prop_name_chars'
9d78c33bf8a1 tests: fix grep for checks error messages
b770f3d1c13f pylibfdt: Support setting the name of a node
2f0d07e678e0 pylibfdt: Add functions to set and get properties as strings
354d3dc55939 pylibfdt: Update the bytearray size with pack()
3c374d46acce pylibfdt: Allow reading integer values from properties
49d32ce40bb4 pylibfdt: Use an unsigned type for fdt32_t
481246a0c13a pylibfdt: Avoid accessing the internal _fdt member in tests
9aafa33d99ed pylibfdt: Add functions to update properties
5a598671fdbf pylibfdt: Support device-tree creation/expansion
483e170625e1 pylibfdt: Add support for reading the memory reserve map
29bb05aa4200 pylibfdt: Add support for the rest of the header functions
582a7159a5d0 pylibfdt: Add support for fdt_next_node()
f0f8c9169819 pylibfdt: Reorder functions to match libfdt.h
64a69d123935 pylibfdt: Return string instead of bytearray from getprop()
4d09a83420df fdtput: Add documentation
e617cbe1bd67 fdtget: Add documentation
180a93924014 Use <inttypes.h> format specifiers in a bunch of places we should
b9af3b396576 scripts/dtc: Fixed format mismatch in fprintf
4b8fcc3d015c libfdt: Add fdt_check_full() function
c14223fb2292 tests: Use valgrind client requests for better checking
5b67d2b955a3 tests: Better handling of valgrind errors saving blobs
e2556aaeb506 tests: Remove unused #define
fb9c6abddaa8 Use size_t for blob lengths in utilfdt_read*
0112fda03bf6 libfdt: Add fdt_header_size()
6473a21d8bfe Consolidate utilfdt_read_len() variants
d5db5382c5e5 libfdt: Safer access to memory reservations
719d582e98ec libfdt: Propagate name errors in fdt_getprop_by_offset()
70166d62a27f libfdt: Safer access to strings section
eb890c0f77dc libfdt: Make fdt_check_header() more thorough
899d6fad93f3 libfdt: Improve sequential write state checking
04b5b4062ccd libfdt: Clean up header checking functions
44d3efedc816 Preserve datatype information when parsing dts
f0be81bd8de0 Make Property a subclass of bytearray
24b1f3f064d4 pylibfdt: Add a method to access the device tree directly

Signed-off-by: Rob Herring <robh@kernel.org>

9 files changed, 441 insertions, 99 deletions

diff --git a/scripts/dtc/libfdt/fdt.c b/scripts/dtc/libfdt/fdt.c
index 7855a1787763..ae03b1112961 100644
--- a/scripts/dtc/libfdt/fdt.c
+++ b/scripts/dtc/libfdt/fdt.c
@@ -55,7 +55,12 @@
 
 #include "libfdt_internal.h"
 
-int fdt_check_header(const void *fdt)
+/*
+ * Minimal sanity check for a read-only tree. fdt_ro_probe_() checks
+ * that the given buffer contains what appears to be a flattened
+ * device tree with sane information in its header.
+ */
+int fdt_ro_probe_(const void *fdt)
 {
         if (fdt_magic(fdt) == FDT_MAGIC) {
                 /* Complete tree */
@@ -74,6 +79,78 @@ int fdt_check_header(const void *fdt)
         return 0;
 }
 
+static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off)
+{
+        return (off >= hdrsize) && (off <= totalsize);
+}
+
+static int check_block_(uint32_t hdrsize, uint32_t totalsize,
+                        uint32_t base, uint32_t size)
+{
+        if (!check_off_(hdrsize, totalsize, base))
+                return 0; /* block start out of bounds */
+        if ((base + size) < base)
+                return 0; /* overflow */
+        if (!check_off_(hdrsize, totalsize, base + size))
+                return 0; /* block end out of bounds */
+        return 1;
+}
+
+size_t fdt_header_size_(uint32_t version)
+{
+        if (version <= 1)
+                return FDT_V1_SIZE;
+        else if (version <= 2)
+                return FDT_V2_SIZE;
+        else if (version <= 3)
+                return FDT_V3_SIZE;
+        else if (version <= 16)
+                return FDT_V16_SIZE;
+        else
+                return FDT_V17_SIZE;
+}
+
+int fdt_check_header(const void *fdt)
+{
+        size_t hdrsize;
+
+        if (fdt_magic(fdt) != FDT_MAGIC)
+                return -FDT_ERR_BADMAGIC;
+        hdrsize = fdt_header_size(fdt);
+        if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
+            || (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION))
+                return -FDT_ERR_BADVERSION;
+        if (fdt_version(fdt) < fdt_last_comp_version(fdt))
+                return -FDT_ERR_BADVERSION;
+
+        if ((fdt_totalsize(fdt) < hdrsize)
+            || (fdt_totalsize(fdt) > INT_MAX))
+                return -FDT_ERR_TRUNCATED;
+
+        /* Bounds check memrsv block */
+        if (!check_off_(hdrsize, fdt_totalsize(fdt), fdt_off_mem_rsvmap(fdt)))
+                return -FDT_ERR_TRUNCATED;
+
+        /* Bounds check structure block */
+        if (fdt_version(fdt) < 17) {
+                if (!check_off_(hdrsize, fdt_totalsize(fdt),
+                                fdt_off_dt_struct(fdt)))
+                        return -FDT_ERR_TRUNCATED;
+        } else {
+                if (!check_block_(hdrsize, fdt_totalsize(fdt),
+                                  fdt_off_dt_struct(fdt),
+                                  fdt_size_dt_struct(fdt)))
+                        return -FDT_ERR_TRUNCATED;
+        }
+
+        /* Bounds check strings block */
+        if (!check_block_(hdrsize, fdt_totalsize(fdt),
+                          fdt_off_dt_strings(fdt), fdt_size_dt_strings(fdt)))
+                return -FDT_ERR_TRUNCATED;
+
+        return 0;
+}
+
 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
 {
         unsigned absoffset = offset + fdt_off_dt_struct(fdt);
@@ -244,7 +321,7 @@ const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
 
 int fdt_move(const void *fdt, void *buf, int bufsize)
 {
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         if (fdt_totalsize(fdt) > bufsize)
                 return -FDT_ERR_NOSPACE;
diff --git a/scripts/dtc/libfdt/fdt_addresses.c b/scripts/dtc/libfdt/fdt_addresses.c
index eff4dbcc729d..49537b578d03 100644
--- a/scripts/dtc/libfdt/fdt_addresses.c
+++ b/scripts/dtc/libfdt/fdt_addresses.c
@@ -1,6 +1,7 @@
 /*
  * libfdt - Flat Device Tree manipulation
  * Copyright (C) 2014 David Gibson <david@gibson.dropbear.id.au>
+ * Copyright (C) 2018 embedded brains GmbH
  *
  * libfdt is dual licensed: you can use it either under the terms of
  * the GPL, or the BSD license, at your option.
@@ -55,42 +56,32 @@
 
 #include "libfdt_internal.h"
 
-int fdt_address_cells(const void *fdt, int nodeoffset)
+static int fdt_cells(const void *fdt, int nodeoffset, const char *name)
 {
-        const fdt32_t *ac;
+        const fdt32_t *c;
         int val;
         int len;
 
-        ac = fdt_getprop(fdt, nodeoffset, "#address-cells", &len);
-        if (!ac)
+        c = fdt_getprop(fdt, nodeoffset, name, &len);
+        if (!c)
                 return 2;
 
-        if (len != sizeof(*ac))
+        if (len != sizeof(*c))
                 return -FDT_ERR_BADNCELLS;
 
-        val = fdt32_to_cpu(*ac);
+        val = fdt32_to_cpu(*c);
         if ((val <= 0) || (val > FDT_MAX_NCELLS))
                 return -FDT_ERR_BADNCELLS;
 
         return val;
 }
 
-int fdt_size_cells(const void *fdt, int nodeoffset)
+int fdt_address_cells(const void *fdt, int nodeoffset)
 {
-        const fdt32_t *sc;
-        int val;
-        int len;
-
-        sc = fdt_getprop(fdt, nodeoffset, "#size-cells", &len);
-        if (!sc)
-                return 2;
-
-        if (len != sizeof(*sc))
-                return -FDT_ERR_BADNCELLS;
-
-        val = fdt32_to_cpu(*sc);
-        if ((val < 0) || (val > FDT_MAX_NCELLS))
-                return -FDT_ERR_BADNCELLS;
+        return fdt_cells(fdt, nodeoffset, "#address-cells");
+}
 
-        return val;
+int fdt_size_cells(const void *fdt, int nodeoffset)
+{
+        return fdt_cells(fdt, nodeoffset, "#size-cells");
 }
diff --git a/scripts/dtc/libfdt/fdt_overlay.c b/scripts/dtc/libfdt/fdt_overlay.c
index bf75388ec9a2..5fdab6c6371d 100644
--- a/scripts/dtc/libfdt/fdt_overlay.c
+++ b/scripts/dtc/libfdt/fdt_overlay.c
@@ -697,7 +697,7 @@ static int get_path_len(const void *fdt, int nodeoffset)
         int len = 0, namelen;
         const char *name;
 
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         for (;;) {
                 name = fdt_get_name(fdt, nodeoffset, &namelen);
@@ -866,8 +866,8 @@ int fdt_overlay_apply(void *fdt, void *fdto)
         uint32_t delta = fdt_get_max_phandle(fdt);
         int ret;
 
-        FDT_CHECK_HEADER(fdt);
-        FDT_CHECK_HEADER(fdto);
+        FDT_RO_PROBE(fdt);
+        FDT_RO_PROBE(fdto);
 
         ret = overlay_adjust_local_phandles(fdto, delta);
         if (ret)
diff --git a/scripts/dtc/libfdt/fdt_ro.c b/scripts/dtc/libfdt/fdt_ro.c
index dfb3236da388..eafc14282892 100644
--- a/scripts/dtc/libfdt/fdt_ro.c
+++ b/scripts/dtc/libfdt/fdt_ro.c
@@ -76,17 +76,72 @@ static int fdt_nodename_eq_(const void *fdt, int offset,
                 return 0;
 }
 
+const char *fdt_get_string(const void *fdt, int stroffset, int *lenp)
+{
+        uint32_t absoffset = stroffset + fdt_off_dt_strings(fdt);
+        size_t len;
+        int err;
+        const char *s, *n;
+
+        err = fdt_ro_probe_(fdt);
+        if (err != 0)
+                goto fail;
+
+        err = -FDT_ERR_BADOFFSET;
+        if (absoffset >= fdt_totalsize(fdt))
+                goto fail;
+        len = fdt_totalsize(fdt) - absoffset;
+
+        if (fdt_magic(fdt) == FDT_MAGIC) {
+                if (stroffset < 0)
+                        goto fail;
+                if (fdt_version(fdt) >= 17) {
+                        if (stroffset >= fdt_size_dt_strings(fdt))
+                                goto fail;
+                        if ((fdt_size_dt_strings(fdt) - stroffset) < len)
+                                len = fdt_size_dt_strings(fdt) - stroffset;
+                }
+        } else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
+                if ((stroffset >= 0)
+                    || (stroffset < -fdt_size_dt_strings(fdt)))
+                        goto fail;
+                if ((-stroffset) < len)
+                        len = -stroffset;
+        } else {
+                err = -FDT_ERR_INTERNAL;
+                goto fail;
+        }
+
+        s = (const char *)fdt + absoffset;
+        n = memchr(s, '\0', len);
+        if (!n) {
+                /* missing terminating NULL */
+                err = -FDT_ERR_TRUNCATED;
+                goto fail;
+        }
+
+        if (lenp)
+                *lenp = n - s;
+        return s;
+
+fail:
+        if (lenp)
+                *lenp = err;
+        return NULL;
+}
+
 const char *fdt_string(const void *fdt, int stroffset)
 {
-        return (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
+        return fdt_get_string(fdt, stroffset, NULL);
 }
 
 static int fdt_string_eq_(const void *fdt, int stroffset,
                           const char *s, int len)
 {
-        const char *p = fdt_string(fdt, stroffset);
+        int slen;
+        const char *p = fdt_get_string(fdt, stroffset, &slen);
 
-        return (strlen(p) == len) && (memcmp(p, s, len) == 0);
+        return p && (slen == len) && (memcmp(p, s, len) == 0);
 }
 
 uint32_t fdt_get_max_phandle(const void *fdt)
@@ -115,21 +170,42 @@ uint32_t fdt_get_max_phandle(const void *fdt)
         return 0;
 }
 
+static const struct fdt_reserve_entry *fdt_mem_rsv(const void *fdt, int n)
+{
+        int offset = n * sizeof(struct fdt_reserve_entry);
+        int absoffset = fdt_off_mem_rsvmap(fdt) + offset;
+
+        if (absoffset < fdt_off_mem_rsvmap(fdt))
+                return NULL;
+        if (absoffset > fdt_totalsize(fdt) - sizeof(struct fdt_reserve_entry))
+                return NULL;
+        return fdt_mem_rsv_(fdt, n);
+}
+
 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
 {
-        FDT_CHECK_HEADER(fdt);
-        *address = fdt64_to_cpu(fdt_mem_rsv_(fdt, n)->address);
-        *size = fdt64_to_cpu(fdt_mem_rsv_(fdt, n)->size);
+        const struct fdt_reserve_entry *re;
+
+        FDT_RO_PROBE(fdt);
+        re = fdt_mem_rsv(fdt, n);
+        if (!re)
+                return -FDT_ERR_BADOFFSET;
+
+        *address = fdt64_ld(&re->address);
+        *size = fdt64_ld(&re->size);
         return 0;
 }
 
 int fdt_num_mem_rsv(const void *fdt)
 {
-        int i = 0;
+        int i;
+        const struct fdt_reserve_entry *re;
 
-        while (fdt64_to_cpu(fdt_mem_rsv_(fdt, i)->size) != 0)
-                i++;
-        return i;
+        for (i = 0; (re = fdt_mem_rsv(fdt, i)) != NULL; i++) {
+                if (fdt64_ld(&re->size) == 0)
+                        return i;
+        }
+        return -FDT_ERR_TRUNCATED;
 }
 
 static int nextprop_(const void *fdt, int offset)
@@ -161,7 +237,7 @@ int fdt_subnode_offset_namelen(const void *fdt, int offset,
 {
         int depth;
 
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         for (depth = 0;
              (offset >= 0) && (depth >= 0);
@@ -187,7 +263,7 @@ int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
         const char *p = path;
         int offset = 0;
 
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         /* see if we have an alias */
         if (*path != '/') {
@@ -237,7 +313,7 @@ const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
         const char *nameptr;
         int err;
 
-        if (((err = fdt_check_header(fdt)) != 0)
+        if (((err = fdt_ro_probe_(fdt)) != 0)
             || ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0))
                         goto fail;
 
@@ -303,7 +379,7 @@ static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt,
         prop = fdt_offset_ptr_(fdt, offset);
 
         if (lenp)
-                *lenp = fdt32_to_cpu(prop->len);
+                *lenp = fdt32_ld(&prop->len);
 
         return prop;
 }
@@ -340,7 +416,7 @@ static const struct fdt_property *fdt_get_property_namelen_(const void *fdt,
                         offset = -FDT_ERR_INTERNAL;
                         break;
                 }
-                if (fdt_string_eq_(fdt, fdt32_to_cpu(prop->nameoff),
+                if (fdt_string_eq_(fdt, fdt32_ld(&prop->nameoff),
                                    name, namelen)) {
                         if (poffset)
                                 *poffset = offset;
@@ -393,7 +469,7 @@ const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
 
         /* Handle realignment */
         if (fdt_version(fdt) < 0x10 && (poffset + sizeof(*prop)) % 8 &&
-            fdt32_to_cpu(prop->len) >= 8)
+            fdt32_ld(&prop->len) >= 8)
                 return prop->data + 4;
         return prop->data;
 }
@@ -406,12 +482,22 @@ const void *fdt_getprop_by_offset(const void *fdt, int offset,
         prop = fdt_get_property_by_offset_(fdt, offset, lenp);
         if (!prop)
                 return NULL;
-        if (namep)
-                *namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
+        if (namep) {
+                const char *name;
+                int namelen;
+                name = fdt_get_string(fdt, fdt32_ld(&prop->nameoff),
+                                      &namelen);
+                if (!name) {
+                        if (lenp)
+                                *lenp = namelen;
+                        return NULL;
+                }
+                *namep = name;
+        }
 
         /* Handle realignment */
         if (fdt_version(fdt) < 0x10 && (offset + sizeof(*prop)) % 8 &&
-            fdt32_to_cpu(prop->len) >= 8)
+            fdt32_ld(&prop->len) >= 8)
                 return prop->data + 4;
         return prop->data;
 }
@@ -436,7 +522,7 @@ uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
                         return 0;
         }
 
-        return fdt32_to_cpu(*php);
+        return fdt32_ld(php);
 }
 
 const char *fdt_get_alias_namelen(const void *fdt,
@@ -462,7 +548,7 @@ int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
         int offset, depth, namelen;
         const char *name;
 
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         if (buflen < 2)
                 return -FDT_ERR_NOSPACE;
@@ -514,7 +600,7 @@ int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
         int offset, depth;
         int supernodeoffset = -FDT_ERR_INTERNAL;
 
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         if (supernodedepth < 0)
                 return -FDT_ERR_NOTFOUND;
@@ -573,7 +659,7 @@ int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
         const void *val;
         int len;
 
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         /* FIXME: The algorithm here is pretty horrible: we scan each
          * property of a node in fdt_getprop(), then if that didn't
@@ -599,7 +685,7 @@ int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
         if ((phandle == 0) || (phandle == -1))
                 return -FDT_ERR_BADPHANDLE;
 
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         /* FIXME: The algorithm here is pretty horrible: we
          * potentially scan each property of a node in
@@ -752,7 +838,7 @@ int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 {
         int offset, err;
 
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         /* FIXME: The algorithm here is pretty horrible: we scan each
          * property of a node in fdt_node_check_compatible(), then if
@@ -771,3 +857,66 @@ int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 
         return offset; /* error from fdt_next_node() */
 }
+
+int fdt_check_full(const void *fdt, size_t bufsize)
+{
+        int err;
+        int num_memrsv;
+        int offset, nextoffset = 0;
+        uint32_t tag;
+        unsigned depth = 0;
+        const void *prop;
+        const char *propname;
+
+        if (bufsize < FDT_V1_SIZE)
+                return -FDT_ERR_TRUNCATED;
+        err = fdt_check_header(fdt);
+        if (err != 0)
+                return err;
+        if (bufsize < fdt_totalsize(fdt))
+                return -FDT_ERR_TRUNCATED;
+
+        num_memrsv = fdt_num_mem_rsv(fdt);
+        if (num_memrsv < 0)
+                return num_memrsv;
+
+        while (1) {
+                offset = nextoffset;
+                tag = fdt_next_tag(fdt, offset, &nextoffset);
+
+                if (nextoffset < 0)
+                        return nextoffset;
+
+                switch (tag) {
+                case FDT_NOP:
+                        break;
+
+                case FDT_END:
+                        if (depth != 0)
+                                return -FDT_ERR_BADSTRUCTURE;
+                        return 0;
+
+                case FDT_BEGIN_NODE:
+                        depth++;
+                        if (depth > INT_MAX)
+                                return -FDT_ERR_BADSTRUCTURE;
+                        break;
+
+                case FDT_END_NODE:
+                        if (depth == 0)
+                                return -FDT_ERR_BADSTRUCTURE;
+                        depth--;
+                        break;
+
+                case FDT_PROP:
+                        prop = fdt_getprop_by_offset(fdt, offset, &propname,
+                                                     &err);
+                        if (!prop)
+                                return err;
+                        break;
+
+                default:
+                        return -FDT_ERR_INTERNAL;
+                }
+        }
+}
diff --git a/scripts/dtc/libfdt/fdt_rw.c b/scripts/dtc/libfdt/fdt_rw.c
index 9b829051e444..2e49855d7cf8 100644
--- a/scripts/dtc/libfdt/fdt_rw.c
+++ b/scripts/dtc/libfdt/fdt_rw.c
@@ -67,9 +67,9 @@ static int fdt_blocks_misordered_(const void *fdt,
                     (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
 }
 
-static int fdt_rw_check_header_(void *fdt)
+static int fdt_rw_probe_(void *fdt)
 {
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         if (fdt_version(fdt) < 17)
                 return -FDT_ERR_BADVERSION;
@@ -82,10 +82,10 @@ static int fdt_rw_check_header_(void *fdt)
         return 0;
 }
 
-#define FDT_RW_CHECK_HEADER(fdt) \
+#define FDT_RW_PROBE(fdt) \
         { \
                 int err_; \
-                if ((err_ = fdt_rw_check_header_(fdt)) != 0) \
+                if ((err_ = fdt_rw_probe_(fdt)) != 0) \
                         return err_; \
         }
 
@@ -176,7 +176,7 @@ int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
         struct fdt_reserve_entry *re;
         int err;
 
-        FDT_RW_CHECK_HEADER(fdt);
+        FDT_RW_PROBE(fdt);
 
         re = fdt_mem_rsv_w_(fdt, fdt_num_mem_rsv(fdt));
         err = fdt_splice_mem_rsv_(fdt, re, 0, 1);
@@ -192,7 +192,7 @@ int fdt_del_mem_rsv(void *fdt, int n)
 {
         struct fdt_reserve_entry *re = fdt_mem_rsv_w_(fdt, n);
 
-        FDT_RW_CHECK_HEADER(fdt);
+        FDT_RW_PROBE(fdt);
 
         if (n >= fdt_num_mem_rsv(fdt))
                 return -FDT_ERR_NOTFOUND;
@@ -252,7 +252,7 @@ int fdt_set_name(void *fdt, int nodeoffset, const char *name)
         int oldlen, newlen;
         int err;
 
-        FDT_RW_CHECK_HEADER(fdt);
+        FDT_RW_PROBE(fdt);
 
         namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
         if (!namep)
@@ -275,7 +275,7 @@ int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
         struct fdt_property *prop;
         int err;
 
-        FDT_RW_CHECK_HEADER(fdt);
+        FDT_RW_PROBE(fdt);
 
         err = fdt_resize_property_(fdt, nodeoffset, name, len, &prop);
         if (err == -FDT_ERR_NOTFOUND)
@@ -308,7 +308,7 @@ int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
         struct fdt_property *prop;
         int err, oldlen, newlen;
 
-        FDT_RW_CHECK_HEADER(fdt);
+        FDT_RW_PROBE(fdt);
 
         prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
         if (prop) {
@@ -334,7 +334,7 @@ int fdt_delprop(void *fdt, int nodeoffset, const char *name)
         struct fdt_property *prop;
         int len, proplen;
 
-        FDT_RW_CHECK_HEADER(fdt);
+        FDT_RW_PROBE(fdt);
 
         prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
         if (!prop)
@@ -354,7 +354,7 @@ int fdt_add_subnode_namelen(void *fdt, int parentoffset,
         uint32_t tag;
         fdt32_t *endtag;
 
-        FDT_RW_CHECK_HEADER(fdt);
+        FDT_RW_PROBE(fdt);
 
         offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
         if (offset >= 0)
@@ -394,7 +394,7 @@ int fdt_del_node(void *fdt, int nodeoffset)
 {
         int endoffset;
 
-        FDT_RW_CHECK_HEADER(fdt);
+        FDT_RW_PROBE(fdt);
 
         endoffset = fdt_node_end_offset_(fdt, nodeoffset);
         if (endoffset < 0)
@@ -435,7 +435,7 @@ int fdt_open_into(const void *fdt, void *buf, int bufsize)
         const char *fdtend = fdtstart + fdt_totalsize(fdt);
         char *tmp;
 
-        FDT_CHECK_HEADER(fdt);
+        FDT_RO_PROBE(fdt);
 
         mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
                 * sizeof(struct fdt_reserve_entry);
@@ -494,7 +494,7 @@ int fdt_pack(void *fdt)
 {
         int mem_rsv_size;
 
-        FDT_RW_CHECK_HEADER(fdt);
+        FDT_RW_PROBE(fdt);
 
         mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
                 * sizeof(struct fdt_reserve_entry);
diff --git a/scripts/dtc/libfdt/fdt_sw.c b/scripts/dtc/libfdt/fdt_sw.c
index 6d33cc29d022..9fa4a94d83c3 100644
--- a/scripts/dtc/libfdt/fdt_sw.c
+++ b/scripts/dtc/libfdt/fdt_sw.c
@@ -55,21 +55,77 @@
 
 #include "libfdt_internal.h"
 
-static int fdt_sw_check_header_(void *fdt)
+static int fdt_sw_probe_(void *fdt)
 {
-        if (fdt_magic(fdt) != FDT_SW_MAGIC)
+        if (fdt_magic(fdt) == FDT_MAGIC)
+                return -FDT_ERR_BADSTATE;
+        else if (fdt_magic(fdt) != FDT_SW_MAGIC)
                 return -FDT_ERR_BADMAGIC;
-        /* FIXME: should check more details about the header state */
         return 0;
 }
 
-#define FDT_SW_CHECK_HEADER(fdt) \
+#define FDT_SW_PROBE(fdt) \
+        { \
+                int err; \
+                if ((err = fdt_sw_probe_(fdt)) != 0) \
+                        return err; \
+        }
+
+/* 'memrsv' state:      Initial state after fdt_create()
+ *
+ * Allowed functions:
+ *      fdt_add_reservmap_entry()
+ *      fdt_finish_reservemap()         [moves to 'struct' state]
+ */
+static int fdt_sw_probe_memrsv_(void *fdt)
+{
+        int err = fdt_sw_probe_(fdt);
+        if (err)
+                return err;
+
+        if (fdt_off_dt_strings(fdt) != 0)
+                return -FDT_ERR_BADSTATE;
+        return 0;
+}
+
+#define FDT_SW_PROBE_MEMRSV(fdt) \
+        { \
+                int err; \
+                if ((err = fdt_sw_probe_memrsv_(fdt)) != 0) \
+                        return err; \
+        }
+
+/* 'struct' state:      Enter this state after fdt_finish_reservemap()
+ *
+ * Allowed functions:
+ *      fdt_begin_node()
+ *      fdt_end_node()
+ *      fdt_property*()
+ *      fdt_finish()                    [moves to 'complete' state]
+ */
+static int fdt_sw_probe_struct_(void *fdt)
+{
+        int err = fdt_sw_probe_(fdt);
+        if (err)
+                return err;
+
+        if (fdt_off_dt_strings(fdt) != fdt_totalsize(fdt))
+                return -FDT_ERR_BADSTATE;
+        return 0;
+}
+
+#define FDT_SW_PROBE_STRUCT(fdt) \
         { \
                 int err; \
-                if ((err = fdt_sw_check_header_(fdt)) != 0) \
+                if ((err = fdt_sw_probe_struct_(fdt)) != 0) \
                         return err; \
         }
 
+/* 'complete' state:    Enter this state after fdt_finish()
+ *
+ * Allowed functions: none
+ */
+
 static void *fdt_grab_space_(void *fdt, size_t len)
 {
         int offset = fdt_size_dt_struct(fdt);
@@ -87,9 +143,11 @@ static void *fdt_grab_space_(void *fdt, size_t len)
 
 int fdt_create(void *buf, int bufsize)
 {
+        const size_t hdrsize = FDT_ALIGN(sizeof(struct fdt_header),
+                                         sizeof(struct fdt_reserve_entry));
         void *fdt = buf;
 
-        if (bufsize < sizeof(struct fdt_header))
+        if (bufsize < hdrsize)
                 return -FDT_ERR_NOSPACE;
 
         memset(buf, 0, bufsize);
@@ -99,10 +157,9 @@ int fdt_create(void *buf, int bufsize)
         fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
         fdt_set_totalsize(fdt,  bufsize);
 
-        fdt_set_off_mem_rsvmap(fdt, FDT_ALIGN(sizeof(struct fdt_header),
-                                              sizeof(struct fdt_reserve_entry)));
+        fdt_set_off_mem_rsvmap(fdt, hdrsize);
         fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
-        fdt_set_off_dt_strings(fdt, bufsize);
+        fdt_set_off_dt_strings(fdt, 0);
 
         return 0;
 }
@@ -112,11 +169,14 @@ int fdt_resize(void *fdt, void *buf, int bufsize)
         size_t headsize, tailsize;
         char *oldtail, *newtail;
 
-        FDT_SW_CHECK_HEADER(fdt);
+        FDT_SW_PROBE(fdt);
 
-        headsize = fdt_off_dt_struct(fdt);
+        headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
         tailsize = fdt_size_dt_strings(fdt);
 
+        if ((headsize + tailsize) > fdt_totalsize(fdt))
+                return -FDT_ERR_INTERNAL;
+
         if ((headsize + tailsize) > bufsize)
                 return -FDT_ERR_NOSPACE;
 
@@ -133,8 +193,9 @@ int fdt_resize(void *fdt, void *buf, int bufsize)
                 memmove(buf, fdt, headsize);
         }
 
-        fdt_set_off_dt_strings(buf, bufsize);
         fdt_set_totalsize(buf, bufsize);
+        if (fdt_off_dt_strings(buf))
+                fdt_set_off_dt_strings(buf, bufsize);
 
         return 0;
 }
@@ -144,10 +205,7 @@ int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
         struct fdt_reserve_entry *re;
         int offset;
 
-        FDT_SW_CHECK_HEADER(fdt);
-
-        if (fdt_size_dt_struct(fdt))
-                return -FDT_ERR_BADSTATE;
+        FDT_SW_PROBE_MEMRSV(fdt);
 
         offset = fdt_off_dt_struct(fdt);
         if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
@@ -164,16 +222,23 @@ int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
 
 int fdt_finish_reservemap(void *fdt)
 {
-        return fdt_add_reservemap_entry(fdt, 0, 0);
+        int err = fdt_add_reservemap_entry(fdt, 0, 0);
+
+        if (err)
+                return err;
+
+        fdt_set_off_dt_strings(fdt, fdt_totalsize(fdt));
+        return 0;
 }
 
 int fdt_begin_node(void *fdt, const char *name)
 {
         struct fdt_node_header *nh;
-        int namelen = strlen(name) + 1;
+        int namelen;
 
-        FDT_SW_CHECK_HEADER(fdt);
+        FDT_SW_PROBE_STRUCT(fdt);
 
+        namelen = strlen(name) + 1;
         nh = fdt_grab_space_(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
         if (! nh)
                 return -FDT_ERR_NOSPACE;
@@ -187,7 +252,7 @@ int fdt_end_node(void *fdt)
 {
         fdt32_t *en;
 
-        FDT_SW_CHECK_HEADER(fdt);
+        FDT_SW_PROBE_STRUCT(fdt);
 
         en = fdt_grab_space_(fdt, FDT_TAGSIZE);
         if (! en)
@@ -225,7 +290,7 @@ int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp)
         struct fdt_property *prop;
         int nameoff;
 
-        FDT_SW_CHECK_HEADER(fdt);
+        FDT_SW_PROBE_STRUCT(fdt);
 
         nameoff = fdt_find_add_string_(fdt, name);
         if (nameoff == 0)
@@ -262,7 +327,7 @@ int fdt_finish(void *fdt)
         uint32_t tag;
         int offset, nextoffset;
 
-        FDT_SW_CHECK_HEADER(fdt);
+        FDT_SW_PROBE_STRUCT(fdt);
 
         /* Add terminator */
         end = fdt_grab_space_(fdt, sizeof(*end));
diff --git a/scripts/dtc/libfdt/libfdt.h b/scripts/dtc/libfdt/libfdt.h
index 1e27780e1185..2bd151dd355f 100644
--- a/scripts/dtc/libfdt/libfdt.h
+++ b/scripts/dtc/libfdt/libfdt.h
@@ -90,8 +90,9 @@
 
 /* Error codes: codes for bad device tree blobs */
 #define FDT_ERR_TRUNCATED       8
-        /* FDT_ERR_TRUNCATED: Structure block of the given device tree
-         * ends without an FDT_END tag. */
+        /* FDT_ERR_TRUNCATED: FDT or a sub-block is improperly
+         * terminated (overflows, goes outside allowed bounds, or
+         * isn't properly terminated).  */
 #define FDT_ERR_BADMAGIC        9
         /* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
          * device tree at all - it is missing the flattened device
@@ -153,6 +154,29 @@ static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
 
 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
 
+/*
+ * Alignment helpers:
+ *     These helpers access words from a device tree blob.  They're
+ *     built to work even with unaligned pointers on platforms (ike
+ *     ARM) that don't like unaligned loads and stores
+ */
+
+static inline uint32_t fdt32_ld(const fdt32_t *p)
+{
+        fdt32_t v;
+
+        memcpy(&v, p, sizeof(v));
+        return fdt32_to_cpu(v);
+}
+
+static inline uint64_t fdt64_ld(const fdt64_t *p)
+{
+        fdt64_t v;
+
+        memcpy(&v, p, sizeof(v));
+        return fdt64_to_cpu(v);
+}
+
 /**********************************************************************/
 /* Traversal functions                                                */
 /**********************************************************************/
@@ -213,7 +237,7 @@ int fdt_next_subnode(const void *fdt, int offset);
 /* General functions                                                  */
 /**********************************************************************/
 #define fdt_get_header(fdt, field) \
-        (fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
+        (fdt32_ld(&((const struct fdt_header *)(fdt))->field))
 #define fdt_magic(fdt)                  (fdt_get_header(fdt, magic))
 #define fdt_totalsize(fdt)              (fdt_get_header(fdt, totalsize))
 #define fdt_off_dt_struct(fdt)          (fdt_get_header(fdt, off_dt_struct))
@@ -244,18 +268,31 @@ fdt_set_hdr_(size_dt_struct);
 #undef fdt_set_hdr_
 
 /**
- * fdt_check_header - sanity check a device tree or possible device tree
+ * fdt_header_size - return the size of the tree's header
+ * @fdt: pointer to a flattened device tree
+ */
+size_t fdt_header_size_(uint32_t version);
+static inline size_t fdt_header_size(const void *fdt)
+{
+        return fdt_header_size_(fdt_version(fdt));
+}
+
+/**
+ * fdt_check_header - sanity check a device tree header
+
  * @fdt: pointer to data which might be a flattened device tree
  *
  * fdt_check_header() checks that the given buffer contains what
- * appears to be a flattened device tree with sane information in its
- * header.
+ * appears to be a flattened device tree, and that the header contains
+ * valid information (to the extent that can be determined from the
+ * header alone).
  *
  * returns:
  *     0, if the buffer appears to contain a valid device tree
  *     -FDT_ERR_BADMAGIC,
  *     -FDT_ERR_BADVERSION,
- *     -FDT_ERR_BADSTATE, standard meanings, as above
+ *     -FDT_ERR_BADSTATE,
+ *     -FDT_ERR_TRUNCATED, standard meanings, as above
  */
 int fdt_check_header(const void *fdt);
 
@@ -284,6 +321,24 @@ int fdt_move(const void *fdt, void *buf, int bufsize);
 /* Read-only functions                                                */
 /**********************************************************************/
 
+int fdt_check_full(const void *fdt, size_t bufsize);
+
+/**
+ * fdt_get_string - retrieve a string from the strings block of a device tree
+ * @fdt: pointer to the device tree blob
+ * @stroffset: offset of the string within the strings block (native endian)
+ * @lenp: optional pointer to return the string's length
+ *
+ * fdt_get_string() retrieves a pointer to a single string from the
+ * strings block of the device tree blob at fdt, and optionally also
+ * returns the string's length in *lenp.
+ *
+ * returns:
+ *     a pointer to the string, on success
+ *     NULL, if stroffset is out of bounds, or doesn't point to a valid string
+ */
+const char *fdt_get_string(const void *fdt, int stroffset, int *lenp);
+
 /**
  * fdt_string - retrieve a string from the strings block of a device tree
  * @fdt: pointer to the device tree blob
@@ -294,7 +349,7 @@ int fdt_move(const void *fdt, void *buf, int bufsize);
  *
  * returns:
  *     a pointer to the string, on success
- *     NULL, if stroffset is out of bounds
+ *     NULL, if stroffset is out of bounds, or doesn't point to a valid string
  */
 const char *fdt_string(const void *fdt, int stroffset);
 
@@ -1090,7 +1145,7 @@ int fdt_address_cells(const void *fdt, int nodeoffset);
  *
  * returns:
  *      0 <= n < FDT_MAX_NCELLS, on success
- *      2, if the node has no #address-cells property
+ *      2, if the node has no #size-cells property
  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
  *              #size-cells property
  *      -FDT_ERR_BADMAGIC,
@@ -1313,10 +1368,13 @@ static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
         fdt64_t tmp = cpu_to_fdt64(val);
         return fdt_property(fdt, name, &tmp, sizeof(tmp));
 }
+
+#ifndef SWIG /* Not available in Python */
 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
 {
         return fdt_property_u32(fdt, name, val);
 }
+#endif
 
 /**
  * fdt_property_placeholder - add a new property and return a ptr to its value
diff --git a/scripts/dtc/libfdt/libfdt_env.h b/scripts/dtc/libfdt/libfdt_env.h
index bd2474628775..eb2053845c9c 100644
--- a/scripts/dtc/libfdt/libfdt_env.h
+++ b/scripts/dtc/libfdt/libfdt_env.h
@@ -56,6 +56,7 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
+#include <limits.h>
 
 #ifdef __CHECKER__
 #define FDT_FORCE __attribute__((force))
diff --git a/scripts/dtc/libfdt/libfdt_internal.h b/scripts/dtc/libfdt/libfdt_internal.h
index 7681e192295b..4109f890ae60 100644
--- a/scripts/dtc/libfdt/libfdt_internal.h
+++ b/scripts/dtc/libfdt/libfdt_internal.h
@@ -55,10 +55,11 @@
 #define FDT_ALIGN(x, a)         (((x) + (a) - 1) & ~((a) - 1))
 #define FDT_TAGALIGN(x)         (FDT_ALIGN((x), FDT_TAGSIZE))
 
-#define FDT_CHECK_HEADER(fdt) \
+int fdt_ro_probe_(const void *fdt);
+#define FDT_RO_PROBE(fdt)                       \
         { \
                 int err_; \
-                if ((err_ = fdt_check_header(fdt)) != 0) \
+                if ((err_ = fdt_ro_probe_(fdt)) != 0)   \
                         return err_; \
         }