diff options
Diffstat (limited to 'scripts/dtc/libfdt')
-rw-r--r-- | scripts/dtc/libfdt/fdt.c | 99 | ||||
-rw-r--r-- | scripts/dtc/libfdt/fdt_ro.c | 143 | ||||
-rw-r--r-- | scripts/dtc/libfdt/fdt_rw.c | 42 | ||||
-rw-r--r-- | scripts/dtc/libfdt/fdt_sw.c | 19 | ||||
-rw-r--r-- | scripts/dtc/libfdt/libfdt.h | 9 | ||||
-rw-r--r-- | scripts/dtc/libfdt/libfdt_internal.h | 122 |
6 files changed, 281 insertions, 153 deletions
diff --git a/scripts/dtc/libfdt/fdt.c b/scripts/dtc/libfdt/fdt.c index d6ce7c052dc8..c28fcc115771 100644 --- a/scripts/dtc/libfdt/fdt.c +++ b/scripts/dtc/libfdt/fdt.c @@ -19,15 +19,21 @@ int32_t fdt_ro_probe_(const void *fdt) { uint32_t totalsize = fdt_totalsize(fdt); + if (can_assume(VALID_DTB)) + return totalsize; + if (fdt_magic(fdt) == FDT_MAGIC) { /* Complete tree */ - if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION) - return -FDT_ERR_BADVERSION; - if (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION) - return -FDT_ERR_BADVERSION; + if (!can_assume(LATEST)) { + if (fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION) + return -FDT_ERR_BADVERSION; + if (fdt_last_comp_version(fdt) > + FDT_LAST_SUPPORTED_VERSION) + return -FDT_ERR_BADVERSION; + } } else if (fdt_magic(fdt) == FDT_SW_MAGIC) { /* Unfinished sequential-write blob */ - if (fdt_size_dt_struct(fdt) == 0) + if (!can_assume(VALID_INPUT) && fdt_size_dt_struct(fdt) == 0) return -FDT_ERR_BADSTATE; } else { return -FDT_ERR_BADMAGIC; @@ -70,44 +76,59 @@ size_t fdt_header_size_(uint32_t version) return FDT_V17_SIZE; } +size_t fdt_header_size(const void *fdt) +{ + return can_assume(LATEST) ? FDT_V17_SIZE : + fdt_header_size_(fdt_version(fdt)); +} + int fdt_check_header(const void *fdt) { size_t hdrsize; if (fdt_magic(fdt) != FDT_MAGIC) return -FDT_ERR_BADMAGIC; + if (!can_assume(LATEST)) { + 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; + } 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; + if (!can_assume(VALID_DTB)) { - /* Bounds check memrsv block */ - if (!check_off_(hdrsize, fdt_totalsize(fdt), fdt_off_mem_rsvmap(fdt))) - return -FDT_ERR_TRUNCATED; + if ((fdt_totalsize(fdt) < hdrsize) + || (fdt_totalsize(fdt) > INT_MAX)) + return -FDT_ERR_TRUNCATED; - /* Bounds check structure block */ - if (fdt_version(fdt) < 17) { + /* Bounds check memrsv block */ if (!check_off_(hdrsize, fdt_totalsize(fdt), - fdt_off_dt_struct(fdt))) + fdt_off_mem_rsvmap(fdt))) return -FDT_ERR_TRUNCATED; - } else { + } + + if (!can_assume(VALID_DTB)) { + /* Bounds check structure block */ + if (!can_assume(LATEST) && 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_struct(fdt), - fdt_size_dt_struct(fdt))) + fdt_off_dt_strings(fdt), + fdt_size_dt_strings(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; } @@ -115,12 +136,13 @@ const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len) { unsigned absoffset = offset + fdt_off_dt_struct(fdt); - if ((absoffset < offset) - || ((absoffset + len) < absoffset) - || (absoffset + len) > fdt_totalsize(fdt)) - return NULL; + if (!can_assume(VALID_INPUT)) + if ((absoffset < offset) + || ((absoffset + len) < absoffset) + || (absoffset + len) > fdt_totalsize(fdt)) + return NULL; - if (fdt_version(fdt) >= 0x11) + if (can_assume(LATEST) || fdt_version(fdt) >= 0x11) if (((offset + len) < offset) || ((offset + len) > fdt_size_dt_struct(fdt))) return NULL; @@ -137,7 +159,7 @@ uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset) *nextoffset = -FDT_ERR_TRUNCATED; tagp = fdt_offset_ptr(fdt, offset, FDT_TAGSIZE); - if (!tagp) + if (!can_assume(VALID_DTB) && !tagp) return FDT_END; /* premature end */ tag = fdt32_to_cpu(*tagp); offset += FDT_TAGSIZE; @@ -149,18 +171,19 @@ uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset) do { p = fdt_offset_ptr(fdt, offset++, 1); } while (p && (*p != '\0')); - if (!p) + if (!can_assume(VALID_DTB) && !p) return FDT_END; /* premature end */ break; case FDT_PROP: lenp = fdt_offset_ptr(fdt, offset, sizeof(*lenp)); - if (!lenp) + if (!can_assume(VALID_DTB) && !lenp) return FDT_END; /* premature end */ /* skip-name offset, length and value */ offset += sizeof(struct fdt_property) - FDT_TAGSIZE + fdt32_to_cpu(*lenp); - if (fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 && + if (!can_assume(LATEST) && + fdt_version(fdt) < 0x10 && fdt32_to_cpu(*lenp) >= 8 && ((offset - fdt32_to_cpu(*lenp)) % 8) != 0) offset += 4; break; @@ -183,6 +206,8 @@ uint32_t fdt_next_tag(const void *fdt, int startoffset, int *nextoffset) int fdt_check_node_offset_(const void *fdt, int offset) { + if (can_assume(VALID_INPUT)) + return offset; if ((offset < 0) || (offset % FDT_TAGSIZE) || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE)) return -FDT_ERR_BADOFFSET; diff --git a/scripts/dtc/libfdt/fdt_ro.c b/scripts/dtc/libfdt/fdt_ro.c index a5c2797cde65..e03570a56eb5 100644 --- a/scripts/dtc/libfdt/fdt_ro.c +++ b/scripts/dtc/libfdt/fdt_ro.c @@ -33,17 +33,26 @@ static int fdt_nodename_eq_(const void *fdt, int offset, const char *fdt_get_string(const void *fdt, int stroffset, int *lenp) { - int32_t totalsize = fdt_ro_probe_(fdt); - uint32_t absoffset = stroffset + fdt_off_dt_strings(fdt); + int32_t totalsize; + uint32_t absoffset; size_t len; int err; const char *s, *n; + if (can_assume(VALID_INPUT)) { + s = (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset; + + if (lenp) + *lenp = strlen(s); + return s; + } + totalsize = fdt_ro_probe_(fdt); err = totalsize; if (totalsize < 0) goto fail; err = -FDT_ERR_BADOFFSET; + absoffset = stroffset + fdt_off_dt_strings(fdt); if (absoffset >= totalsize) goto fail; len = totalsize - absoffset; @@ -51,7 +60,7 @@ const char *fdt_get_string(const void *fdt, int stroffset, int *lenp) if (fdt_magic(fdt) == FDT_MAGIC) { if (stroffset < 0) goto fail; - if (fdt_version(fdt) >= 17) { + if (can_assume(LATEST) || fdt_version(fdt) >= 17) { if (stroffset >= fdt_size_dt_strings(fdt)) goto fail; if ((fdt_size_dt_strings(fdt) - stroffset) < len) @@ -151,10 +160,13 @@ 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; + if (!can_assume(VALID_INPUT)) { + 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); } @@ -164,7 +176,7 @@ int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size) FDT_RO_PROBE(fdt); re = fdt_mem_rsv(fdt, n); - if (!re) + if (!can_assume(VALID_INPUT) && !re) return -FDT_ERR_BADOFFSET; *address = fdt64_ld(&re->address); @@ -295,7 +307,7 @@ const char *fdt_get_name(const void *fdt, int nodeoffset, int *len) nameptr = nh->name; - if (fdt_version(fdt) < 0x10) { + if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) { /* * For old FDT versions, match the naming conventions of V16: * give only the leaf name (after all /). The actual tree @@ -346,7 +358,8 @@ static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt, int err; const struct fdt_property *prop; - if ((err = fdt_check_prop_offset_(fdt, offset)) < 0) { + if (!can_assume(VALID_INPUT) && + (err = fdt_check_prop_offset_(fdt, offset)) < 0) { if (lenp) *lenp = err; return NULL; @@ -367,7 +380,7 @@ const struct fdt_property *fdt_get_property_by_offset(const void *fdt, /* Prior to version 16, properties may need realignment * and this API does not work. fdt_getprop_*() will, however. */ - if (fdt_version(fdt) < 0x10) { + if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) { if (lenp) *lenp = -FDT_ERR_BADVERSION; return NULL; @@ -388,7 +401,8 @@ static const struct fdt_property *fdt_get_property_namelen_(const void *fdt, (offset = fdt_next_property_offset(fdt, offset))) { const struct fdt_property *prop; - if (!(prop = fdt_get_property_by_offset_(fdt, offset, lenp))) { + prop = fdt_get_property_by_offset_(fdt, offset, lenp); + if (!can_assume(LIBFDT_FLAWLESS) && !prop) { offset = -FDT_ERR_INTERNAL; break; } @@ -413,7 +427,7 @@ const struct fdt_property *fdt_get_property_namelen(const void *fdt, { /* Prior to version 16, properties may need realignment * and this API does not work. fdt_getprop_*() will, however. */ - if (fdt_version(fdt) < 0x10) { + if (!can_assume(LATEST) && fdt_version(fdt) < 0x10) { if (lenp) *lenp = -FDT_ERR_BADVERSION; return NULL; @@ -444,8 +458,8 @@ const void *fdt_getprop_namelen(const void *fdt, int nodeoffset, return NULL; /* Handle realignment */ - if (fdt_version(fdt) < 0x10 && (poffset + sizeof(*prop)) % 8 && - fdt32_ld(&prop->len) >= 8) + if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 && + (poffset + sizeof(*prop)) % 8 && fdt32_ld(&prop->len) >= 8) return prop->data + 4; return prop->data; } @@ -461,19 +475,24 @@ const void *fdt_getprop_by_offset(const void *fdt, int offset, 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; + + if (!can_assume(VALID_INPUT)) { + name = fdt_get_string(fdt, fdt32_ld(&prop->nameoff), + &namelen); + if (!name) { + if (lenp) + *lenp = namelen; + return NULL; + } + *namep = name; + } else { + *namep = fdt_string(fdt, fdt32_ld(&prop->nameoff)); } - *namep = name; } /* Handle realignment */ - if (fdt_version(fdt) < 0x10 && (offset + sizeof(*prop)) % 8 && - fdt32_ld(&prop->len) >= 8) + if (!can_assume(LATEST) && fdt_version(fdt) < 0x10 && + (offset + sizeof(*prop)) % 8 && fdt32_ld(&prop->len) >= 8) return prop->data + 4; return prop->data; } @@ -598,10 +617,12 @@ int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset, } } - if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0)) - return -FDT_ERR_BADOFFSET; - else if (offset == -FDT_ERR_BADOFFSET) - return -FDT_ERR_BADSTRUCTURE; + if (!can_assume(VALID_INPUT)) { + if ((offset == -FDT_ERR_NOTFOUND) || (offset >= 0)) + return -FDT_ERR_BADOFFSET; + else if (offset == -FDT_ERR_BADOFFSET) + return -FDT_ERR_BADSTRUCTURE; + } return offset; /* error from fdt_next_node() */ } @@ -613,7 +634,8 @@ int fdt_node_depth(const void *fdt, int nodeoffset) err = fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, &nodedepth); if (err) - return (err < 0) ? err : -FDT_ERR_INTERNAL; + return (can_assume(LIBFDT_FLAWLESS) || err < 0) ? err : + -FDT_ERR_INTERNAL; return nodedepth; } @@ -833,66 +855,3 @@ 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 8795947c00dd..524b520c8486 100644 --- a/scripts/dtc/libfdt/fdt_rw.c +++ b/scripts/dtc/libfdt/fdt_rw.c @@ -24,14 +24,16 @@ static int fdt_blocks_misordered_(const void *fdt, static int fdt_rw_probe_(void *fdt) { + if (can_assume(VALID_DTB)) + return 0; FDT_RO_PROBE(fdt); - if (fdt_version(fdt) < 17) + if (!can_assume(LATEST) && fdt_version(fdt) < 17) return -FDT_ERR_BADVERSION; if (fdt_blocks_misordered_(fdt, sizeof(struct fdt_reserve_entry), fdt_size_dt_struct(fdt))) return -FDT_ERR_BADLAYOUT; - if (fdt_version(fdt) > 17) + if (!can_assume(LATEST) && fdt_version(fdt) > 17) fdt_set_version(fdt, 17); return 0; @@ -44,7 +46,7 @@ static int fdt_rw_probe_(void *fdt) return err_; \ } -static inline int fdt_data_size_(void *fdt) +static inline unsigned int fdt_data_size_(void *fdt) { return fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt); } @@ -52,15 +54,16 @@ static inline int fdt_data_size_(void *fdt) static int fdt_splice_(void *fdt, void *splicepoint, int oldlen, int newlen) { char *p = splicepoint; - char *end = (char *)fdt + fdt_data_size_(fdt); + unsigned int dsize = fdt_data_size_(fdt); + size_t soff = p - (char *)fdt; - if (((p + oldlen) < p) || ((p + oldlen) > end)) + if ((oldlen < 0) || (soff + oldlen < soff) || (soff + oldlen > dsize)) return -FDT_ERR_BADOFFSET; - if ((p < (char *)fdt) || ((end - oldlen + newlen) < (char *)fdt)) + if ((p < (char *)fdt) || (dsize + newlen < oldlen)) return -FDT_ERR_BADOFFSET; - if ((end - oldlen + newlen) > ((char *)fdt + fdt_totalsize(fdt))) + if (dsize - oldlen + newlen > fdt_totalsize(fdt)) return -FDT_ERR_NOSPACE; - memmove(p + newlen, p + oldlen, end - p - oldlen); + memmove(p + newlen, p + oldlen, ((char *)fdt + dsize) - (p + oldlen)); return 0; } @@ -112,6 +115,15 @@ static int fdt_splice_string_(void *fdt, int newlen) return 0; } +/** + * fdt_find_add_string_() - Find or allocate a string + * + * @fdt: pointer to the device tree to check/adjust + * @s: string to find/add + * @allocated: Set to 0 if the string was found, 1 if not found and so + * allocated. Ignored if can_assume(NO_ROLLBACK) + * @return offset of string in the string table (whether found or added) + */ static int fdt_find_add_string_(void *fdt, const char *s, int *allocated) { char *strtab = (char *)fdt + fdt_off_dt_strings(fdt); @@ -120,7 +132,8 @@ static int fdt_find_add_string_(void *fdt, const char *s, int *allocated) int len = strlen(s) + 1; int err; - *allocated = 0; + if (!can_assume(NO_ROLLBACK)) + *allocated = 0; p = fdt_find_string_(strtab, fdt_size_dt_strings(fdt), s); if (p) @@ -132,7 +145,8 @@ static int fdt_find_add_string_(void *fdt, const char *s, int *allocated) if (err) return err; - *allocated = 1; + if (!can_assume(NO_ROLLBACK)) + *allocated = 1; memcpy(new, s, len); return (new - strtab); @@ -206,7 +220,8 @@ static int fdt_add_property_(void *fdt, int nodeoffset, const char *name, err = fdt_splice_struct_(fdt, *prop, 0, proplen); if (err) { - if (allocated) + /* Delete the string if we failed to add it */ + if (!can_assume(NO_ROLLBACK) && allocated) fdt_del_last_string_(fdt, name); return err; } @@ -411,7 +426,7 @@ int fdt_open_into(const void *fdt, void *buf, int bufsize) mem_rsv_size = (fdt_num_mem_rsv(fdt)+1) * sizeof(struct fdt_reserve_entry); - if (fdt_version(fdt) >= 17) { + if (can_assume(LATEST) || fdt_version(fdt) >= 17) { struct_size = fdt_size_dt_struct(fdt); } else { struct_size = 0; @@ -421,7 +436,8 @@ int fdt_open_into(const void *fdt, void *buf, int bufsize) return struct_size; } - if (!fdt_blocks_misordered_(fdt, mem_rsv_size, struct_size)) { + if (can_assume(LIBFDT_ORDER) | + !fdt_blocks_misordered_(fdt, mem_rsv_size, struct_size)) { /* no further work necessary */ err = fdt_move(fdt, buf, bufsize); if (err) diff --git a/scripts/dtc/libfdt/fdt_sw.c b/scripts/dtc/libfdt/fdt_sw.c index 76bea22f734f..26759d5dfb8c 100644 --- a/scripts/dtc/libfdt/fdt_sw.c +++ b/scripts/dtc/libfdt/fdt_sw.c @@ -12,10 +12,13 @@ static int fdt_sw_probe_(void *fdt) { - if (fdt_magic(fdt) == FDT_MAGIC) - return -FDT_ERR_BADSTATE; - else if (fdt_magic(fdt) != FDT_SW_MAGIC) - return -FDT_ERR_BADMAGIC; + if (!can_assume(VALID_INPUT)) { + if (fdt_magic(fdt) == FDT_MAGIC) + return -FDT_ERR_BADSTATE; + else if (fdt_magic(fdt) != FDT_SW_MAGIC) + return -FDT_ERR_BADMAGIC; + } + return 0; } @@ -38,7 +41,7 @@ static int fdt_sw_probe_memrsv_(void *fdt) if (err) return err; - if (fdt_off_dt_strings(fdt) != 0) + if (!can_assume(VALID_INPUT) && fdt_off_dt_strings(fdt) != 0) return -FDT_ERR_BADSTATE; return 0; } @@ -64,7 +67,8 @@ static int fdt_sw_probe_struct_(void *fdt) if (err) return err; - if (fdt_off_dt_strings(fdt) != fdt_totalsize(fdt)) + if (!can_assume(VALID_INPUT) && + fdt_off_dt_strings(fdt) != fdt_totalsize(fdt)) return -FDT_ERR_BADSTATE; return 0; } @@ -151,7 +155,8 @@ int fdt_resize(void *fdt, void *buf, int bufsize) headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt); tailsize = fdt_size_dt_strings(fdt); - if ((headsize + tailsize) > fdt_totalsize(fdt)) + if (!can_assume(VALID_DTB) && + headsize + tailsize > fdt_totalsize(fdt)) return -FDT_ERR_INTERNAL; if ((headsize + tailsize) > bufsize) diff --git a/scripts/dtc/libfdt/libfdt.h b/scripts/dtc/libfdt/libfdt.h index 8907b09b86cc..36fadcdea516 100644 --- a/scripts/dtc/libfdt/libfdt.h +++ b/scripts/dtc/libfdt/libfdt.h @@ -266,11 +266,12 @@ fdt_set_hdr_(size_dt_struct); * fdt_header_size - return the size of the tree's header * @fdt: pointer to a flattened device tree */ +size_t fdt_header_size(const void *fdt); + +/** + * fdt_header_size_ - internal function which takes a version number + */ 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 diff --git a/scripts/dtc/libfdt/libfdt_internal.h b/scripts/dtc/libfdt/libfdt_internal.h index 058c7358d441..d4e0bd49c037 100644 --- a/scripts/dtc/libfdt/libfdt_internal.h +++ b/scripts/dtc/libfdt/libfdt_internal.h @@ -48,4 +48,126 @@ static inline struct fdt_reserve_entry *fdt_mem_rsv_w_(void *fdt, int n) #define FDT_SW_MAGIC (~FDT_MAGIC) +/**********************************************************************/ +/* Checking controls */ +/**********************************************************************/ + +#ifndef FDT_ASSUME_MASK +#define FDT_ASSUME_MASK 0 +#endif + +/* + * Defines assumptions which can be enabled. Each of these can be enabled + * individually. For maximum safety, don't enable any assumptions! + * + * For minimal code size and no safety, use ASSUME_PERFECT at your own risk. + * You should have another method of validating the device tree, such as a + * signature or hash check before using libfdt. + * + * For situations where security is not a concern it may be safe to enable + * ASSUME_SANE. + */ +enum { + /* + * This does essentially no checks. Only the latest device-tree + * version is correctly handled. Inconsistencies or errors in the device + * tree may cause undefined behaviour or crashes. Invalid parameters + * passed to libfdt may do the same. + * + * If an error occurs when modifying the tree it may leave the tree in + * an intermediate (but valid) state. As an example, adding a property + * where there is insufficient space may result in the property name + * being added to the string table even though the property itself is + * not added to the struct section. + * + * Only use this if you have a fully validated device tree with + * the latest supported version and wish to minimise code size. + */ + ASSUME_PERFECT = 0xff, + + /* + * This assumes that the device tree is sane. i.e. header metadata + * and basic hierarchy are correct. + * + * With this assumption enabled, normal device trees produced by libfdt + * and the compiler should be handled safely. Malicious device trees and + * complete garbage may cause libfdt to behave badly or crash. Truncated + * device trees (e.g. those only partially loaded) can also cause + * problems. + * + * Note: Only checks that relate exclusively to the device tree itself + * (not the parameters passed to libfdt) are disabled by this + * assumption. This includes checking headers, tags and the like. + */ + ASSUME_VALID_DTB = 1 << 0, + + /* + * This builds on ASSUME_VALID_DTB and further assumes that libfdt + * functions are called with valid parameters, i.e. not trigger + * FDT_ERR_BADOFFSET or offsets that are out of bounds. It disables any + * extensive checking of parameters and the device tree, making various + * assumptions about correctness. + * + * It doesn't make sense to enable this assumption unless + * ASSUME_VALID_DTB is also enabled. + */ + ASSUME_VALID_INPUT = 1 << 1, + + /* + * This disables checks for device-tree version and removes all code + * which handles older versions. + * + * Only enable this if you know you have a device tree with the latest + * version. + */ + ASSUME_LATEST = 1 << 2, + + /* + * This assumes that it is OK for a failed addition to the device tree, + * due to lack of space or some other problem, to skip any rollback + * steps (such as dropping the property name from the string table). + * This is safe to enable in most circumstances, even though it may + * leave the tree in a sub-optimal state. + */ + ASSUME_NO_ROLLBACK = 1 << 3, + + /* + * This assumes that the device tree components appear in a 'convenient' + * order, i.e. the memory reservation block first, then the structure + * block and finally the string block. + * + * This order is not specified by the device-tree specification, + * but is expected by libfdt. The device-tree compiler always created + * device trees with this order. + * + * This assumption disables a check in fdt_open_into() and removes the + * ability to fix the problem there. This is safe if you know that the + * device tree is correctly ordered. See fdt_blocks_misordered_(). + */ + ASSUME_LIBFDT_ORDER = 1 << 4, + + /* + * This assumes that libfdt itself does not have any internal bugs. It + * drops certain checks that should never be needed unless libfdt has an + * undiscovered bug. + * + * This can generally be considered safe to enable. + */ + ASSUME_LIBFDT_FLAWLESS = 1 << 5, +}; + +/** + * can_assume_() - check if a particular assumption is enabled + * + * @mask: Mask to check (ASSUME_...) + * @return true if that assumption is enabled, else false + */ +static inline bool can_assume_(int mask) +{ + return FDT_ASSUME_MASK & mask; +} + +/** helper macros for checking assumptions */ +#define can_assume(_assume) can_assume_(ASSUME_ ## _assume) + #endif /* LIBFDT_INTERNAL_H */ |