Given a set of nodes and properties, find the regions of the device tree which describe those parts. A test is provided which builds a tree while tracking where the regions should be, then calls fdt_first/next_region() to make sure that it agrees. Further tests will come as part of fdtgrep. Signed-off-by: Simon Glass <sjg@xxxxxxxxxxxx> --- Changes in v3: - Add a feature to include all subnodes Changes in v2: - Move region code to separate fdt_region.c file - Fix info->count <= info->max_regions in fdt_add_region() merge case - Add new FDT_ERR_TOODEEP error type and use it - Change returned error from BADLAYOUT to BADSTRUCTURE - Return FDT_ERR_BADLAYOUT error if strings block is before structure block - Add note that changes in node/property order can cause false hash misses - Add more comments about the -1 return value from h_include - Drop FDT_IS_COMPAT and pass node offset to h_include function - Drop stale comment about names / wildcards - Move to a model with fdt_first_region()/fdt_next_region() - Add long comment explaining theory of operation libfdt/Makefile.libfdt | 3 +- libfdt/fdt_region.c | 457 +++++++++++++++++++++++++++++++++++++++++++++++++ libfdt/libfdt.h | 217 ++++++++++++++++++++++- tests/.gitignore | 1 + tests/Makefile.tests | 3 +- tests/region_tree.c | 352 +++++++++++++++++++++++++++++++++++++ tests/run_tests.sh | 5 + 7 files changed, 1035 insertions(+), 3 deletions(-) create mode 100644 libfdt/fdt_region.c create mode 100644 tests/region_tree.c diff --git a/libfdt/Makefile.libfdt b/libfdt/Makefile.libfdt index 91126c0..84769a4 100644 --- a/libfdt/Makefile.libfdt +++ b/libfdt/Makefile.libfdt @@ -6,5 +6,6 @@ LIBFDT_soname = libfdt.$(SHAREDLIB_EXT).1 LIBFDT_INCLUDES = fdt.h libfdt.h libfdt_env.h LIBFDT_VERSION = version.lds -LIBFDT_SRCS = fdt.c fdt_ro.c fdt_wip.c fdt_sw.c fdt_rw.c fdt_strerror.c fdt_empty_tree.c +LIBFDT_SRCS = fdt.c fdt_ro.c fdt_wip.c fdt_sw.c fdt_region.c +LIBFDT_SRCS += fdt_rw.c fdt_strerror.c fdt_empty_tree.c LIBFDT_OBJS = $(LIBFDT_SRCS:%.c=%.o) diff --git a/libfdt/fdt_region.c b/libfdt/fdt_region.c new file mode 100644 index 0000000..3bb550d --- /dev/null +++ b/libfdt/fdt_region.c @@ -0,0 +1,457 @@ +/* + * libfdt - Flat Device Tree manipulation + * Copyright (C) 2013 Google, Inc + * + * libfdt is dual licensed: you can use it either under the terms of + * the GPL, or the BSD license, at your option. + * + * a) This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this library; if not, write to the Free + * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, + * MA 02110-1301 USA + * + * Alternatively, + * + * b) Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * 1. Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * 2. Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND + * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, + * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, + * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "libfdt_env.h" + +#include <fdt.h> +#include <libfdt.h> + +#include "libfdt_internal.h" + +/** + * fdt_add_region() - Add a new region to our list + * + * The region is added if there is space, but in any case we increment the + * count. If permitted, and the new region overlaps the last one, we merge + * them. + * + * @info: State information + * @offset: Start offset of region + * @size: Size of region + */ +static int fdt_add_region(struct fdt_region_state *info, int offset, int size) +{ + struct fdt_region *reg = &info->region[info->count - 1]; + + if (info->can_merge && info->count && + info->count <= info->max_regions && + offset <= reg->offset + reg->size) { + reg->size = offset + size - reg->offset; + } else if (info->count++ < info->max_regions) { + reg++; + reg->offset = offset; + reg->size = size; + } else { + return -1; + } + + return 0; +} + +/** + * fdt_include_supernodes() - Include supernodes required by this node + * + * When we decided to include a node or property which is not at the top + * level, this function forces the inclusion of higher level nodes. For + * example, given this tree: + * + * / { + * testing { + * } + * } + * + * If we decide to include testing then we need the root node to have a valid + * tree. This function adds those regions. + * + * @info: State information + * @depth: Current stack depth + */ +static int fdt_include_supernodes(struct fdt_region_state *info, int depth) +{ + int base = fdt_off_dt_struct(info->fdt); + int start, stop_at; + int i; + + /* + * Work down the stack looking for supernodes that we didn't include. + * The algortihm here is actually pretty simple, since we know that + * no previous subnode had to include these nodes, or if it did, we + * marked them as included (on the stack) already. + */ + for (i = 0; i <= depth; i++) { + if (!info->stack[i].included) { + start = info->stack[i].offset; + + /* Add the FDT_BEGIN_NODE tag of this supernode */ + fdt_next_tag(info->fdt, start, &stop_at); + if (fdt_add_region(info, base + start, + stop_at - start)) + return -1; + + /* Remember that this supernode is now included */ + info->stack[i].included = 1; + info->can_merge = 1; + } + + /* Force (later) generation of the FDT_END_NODE tag */ + if (!info->stack[i].want) + info->stack[i].want = WANT_NODES_ONLY; + } + + return 0; +} + +enum { + FDT_DONE_NOTHING, + FDT_DONE_MEM_RSVMAP, + FDT_DONE_STRUCT, + FDT_DONE_END, + FDT_DONE_STRINGS, + FDT_DONE_ALL, +}; + +int fdt_first_region(const void *fdt, + int (*h_include)(void *priv, const void *fdt, int offset, + int type, const char *data, int size), + void *priv, struct fdt_region *region, + char *path, int path_len, int flags, + struct fdt_region_state *info) +{ + struct fdt_region_ptrs *p = &info->ptrs; + + /* Set up our state */ + info->fdt = fdt; + info->can_merge = 1; + info->max_regions = 1; + info->start = -1; + p->want = WANT_NOTHING; + p->end = path; + *p->end = '\0'; + p->nextoffset = 0; + p->depth = -1; + p->done = FDT_DONE_NOTHING; + + return fdt_next_region(fdt, h_include, priv, region, + path, path_len, flags, info); +} + +/* + * Theory of operation + * + * + * + +Note: in this description 'included' means that a node (or other part of +the tree) should be included in the region list, i.e. it will have a region +which covers its part of the tree. + +This function maintains some state from the last time it is called. It +checks the next part of the tree that it is supposed to look at +(p.nextoffset) to see if that should be included or not. When it finds +something to include, it sets info->start to its offset. This marks the +start of the region we want to include. + +Once info->start is set to the start (i.e. not -1), we continue scanning +until we find something that we don't want included. This will be the end +of a region. At this point we can close off the region and add it to the +list. So we do so, and reset info->start to -1. + +One complication here is that we want to merge regions. So when we come to +add another region later, we may in fact merge it with the previous one if +one ends where the other starts. + +The function fdt_add_region() will return -1 if it fails to add the region, +because we already have a region ready to be returned, and the new one +cannot be merged in with it. In this case, we must return the region we +found, and wait for another call to this function. When it comes, we will +repeat the processing of the tag and again try to add a region. This time it +will succeed. + +The current state of the pointers (stack, offset, etc.) is maintained in +a ptrs member. At the start of every loop iteration we make a copy of it. +The copy is then updated as the tag is processed. Only if we get to the end +of the loop iteration (and successfully call fdt_add_region() if we need +to) can we commit the changes we have made to these pointers. For example, +if we see an FDT_END_NODE tag we will decrement the depth value. But if we +need to add a region for this tag (let's say because the previous tag is +included and this FDT_END_NODE tag is not included) then we will only commit +the result if we were able to add the region. That allows us to retry again +next time. + +We keep track of a variable called 'want' which tells us what we want to +include when there is no specific information provided by the h_include +function for a particular property. This basically handles the inclusion of +properties which are pulled in by virtue of the node they are in. So if you +include a node, its properties are also included. In this case 'want' will +be WANT_NODES_AND_PROPS. The FDT_REG_DIRECT_SUBNODES feature also makes use +of 'want'. While we are inside the subnode, 'want' will be set to +WANT_NODES_ONLY, so that only the subnode's FDT_BEGIN_NODE and FDT_END_NODE +tags will be included, and properties will be skipped. If WANT_NOTHING is +selected, then we will just rely on what the h_include() function tells us. + +Using 'want' we work out 'include', which tells us whether this current tag +should be included or not. As you can imagine, if the value of 'include' +changes, that means we are on a boundary between nodes to include and nodes +to exclude. At this point we either close off a previous region and add it +to the list, or mark the start of a new region. + +Apart from the nodes, we have mem_rsvmap, the FDT_END tag and the string +list. Each of these dealt with as a whole (i.e. we create a region for each +if it is to be included). For mem_rsvmap we don't allow it to merge with +the first struct region. For the stringlist we don't allow it to merge with +the last struct region (which contains at minimum the FDT_END tag). +*/ +int fdt_next_region(const void *fdt, + int (*h_include)(void *priv, const void *fdt, int offset, + int type, const char *data, int size), + void *priv, struct fdt_region *region, + char *path, int path_len, int flags, + struct fdt_region_state *info) +{ + int base = fdt_off_dt_struct(fdt); + const char *str; + + info->region = region; + info->count = 0; + if (info->ptrs.done < FDT_DONE_MEM_RSVMAP && + (flags & FDT_REG_ADD_MEM_RSVMAP)) { + /* Add the memory reserve map into its own region */ + if (fdt_add_region(info, fdt_off_mem_rsvmap(fdt), + fdt_off_dt_struct(fdt) - fdt_off_mem_rsvmap(fdt))) + return 0; + info->can_merge = 0; /* Don't allow merging with this */ + info->ptrs.done = FDT_DONE_MEM_RSVMAP; + } + + /* + * Work through the tags one by one, deciding whether each needs to + * be included or not. We set the variable 'include' to indicate our + * decision. 'want' is used to track what we want to include - it + * allows us to pick up all the properties (and/or subnode tags) of + * a node. + */ + while (info->ptrs.done < FDT_DONE_STRUCT) { + const struct fdt_property *prop; + struct fdt_region_ptrs p; + const char *name; + int include = 0; + int stop_at = 0; + uint32_t tag; + int offset; + int val; + int len; + + /* + * Make a copy of our pointers. If we make it to the end of + * this block then we will commit them back to info->ptrs. + * Otherwise we can try again from the same starting state + * next time we are called. + */ + p = info->ptrs; + + /* + * Find the tag, and the offset of the next one. If we need to + * stop including tags, then by default we stop *after* + * including the current tag + */ + offset = p.nextoffset; + tag = fdt_next_tag(fdt, offset, &p.nextoffset); + stop_at = p.nextoffset; + + switch (tag) { + case FDT_PROP: + stop_at = offset; + prop = fdt_get_property_by_offset(fdt, offset, NULL); + str = fdt_string(fdt, fdt32_to_cpu(prop->nameoff)); + val = h_include(priv, fdt, offset, FDT_IS_PROP, str, + strlen(str) + 1); + if (val == -1) { + include = p.want >= WANT_NODES_AND_PROPS; + } else { + include = val; + /* + * Make sure we include the } for this block. + * It might be more correct to have this done + * by the call to fdt_include_supernodes() in + * the case where it adds the node we are + * currently in, but this is equivalent. + */ + if ((flags & FDT_REG_SUPERNODES) && val && + !p.want) + p.want = WANT_NODES_ONLY; + } + + /* Value grepping is not yet supported */ + break; + + case FDT_NOP: + include = p.want >= WANT_NODES_AND_PROPS; + stop_at = offset; + break; + + case FDT_BEGIN_NODE: + p.depth++; + if (p.depth == FDT_MAX_DEPTH) + return -FDT_ERR_TOODEEP; + name = fdt_get_name(fdt, offset, &len); + if (p.end - path + 2 + len >= path_len) + return -FDT_ERR_NOSPACE; + + /* Build the full path of this node */ + if (p.end != path + 1) + *p.end++ = '/'; + strcpy(p.end, name); + p.end += len; + info->stack[p.depth].want = p.want; + info->stack[p.depth].offset = offset; + + /* + * If we are not intending to include this node unless + * it matches, make sure we stop *before* its tag. + */ + if (p.want == WANT_NODES_ONLY || + !(flags & (FDT_REG_DIRECT_SUBNODES | + FDT_REG_ALL_SUBNODES))) { + stop_at = offset; + p.want = WANT_NOTHING; + } + val = h_include(priv, fdt, offset, FDT_IS_NODE, path, + p.end - path + 1); + + /* Include this if requested */ + if (val) { + p.want = (flags & FDT_REG_ALL_SUBNODES) ? + WANT_ALL_NODES_AND_PROPS : + WANT_NODES_AND_PROPS; + } + + /* If not requested, decay our 'p.want' value */ + else if (p.want) { + if (p.want != WANT_ALL_NODES_AND_PROPS) + p.want--; + + /* Not including this tag, so stop now */ + } else { + stop_at = offset; + } + + /* + * Decide whether to include this tag, and update our + * stack with the state for this node + */ + include = p.want; + info->stack[p.depth].included = include; + break; + + case FDT_END_NODE: + include = p.want; + if (p.depth < 0) + return -FDT_ERR_BADSTRUCTURE; + + /* + * If we don't p.want this node, stop right away, unless + * we are including subnodes + */ + if (!p.want && !(flags & FDT_REG_DIRECT_SUBNODES)) + stop_at = offset; + p.want = info->stack[p.depth].want; + p.depth--; + while (p.end > path && *--p.end != '/') + ; + *p.end = '\0'; + break; + + case FDT_END: + /* We always include the end tag */ + include = 1; + p.done = FDT_DONE_STRUCT; + break; + } + + /* If this tag is to be included, mark it as region start */ + if (include && info->start == -1) { + /* Include any supernodes required by this one */ + if (flags & FDT_REG_SUPERNODES) { + if (fdt_include_supernodes(info, p.depth)) + return 0; + } + info->start = offset; + } + + /* + * If this tag is not to be included, finish up the current + * region. + */ + if (!include && info->start != -1) { + if (fdt_add_region(info, base + info->start, + stop_at - info->start)) + return 0; + info->start = -1; + info->can_merge = 1; + } + + /* If we have made it this far, we can commit our pointers */ + info->ptrs = p; + } + + /* Add a region for the END tag and a separate one for string table */ + if (info->ptrs.done < FDT_DONE_END) { + if (info->ptrs.nextoffset != fdt_size_dt_struct(fdt)) + return -FDT_ERR_BADSTRUCTURE; + + if (fdt_add_region(info, base + info->start, + info->ptrs.nextoffset - info->start)) + return 0; + info->ptrs.done++; + } + if (info->ptrs.done < FDT_DONE_STRINGS && + (flags & FDT_REG_ADD_STRING_TAB)) { + info->can_merge = 0; + if (fdt_off_dt_strings(fdt) < base + info->ptrs.nextoffset) + return -FDT_ERR_BADLAYOUT; + if (fdt_add_region(info, fdt_off_dt_strings(fdt), + fdt_size_dt_strings(fdt))) + return 0; + info->ptrs.done++; + } + + return info->count > 0 ? 0 : -FDT_ERR_NOTFOUND; +} diff --git a/libfdt/libfdt.h b/libfdt/libfdt.h index 02baa84..0a401bf 100644 --- a/libfdt/libfdt.h +++ b/libfdt/libfdt.h @@ -116,7 +116,12 @@ * Should never be returned, if it is, it indicates a bug in * libfdt itself. */ -#define FDT_ERR_MAX 13 +#define FDT_ERR_TOODEEP 14 + /* FDT_ERR_TOODEEP: The depth of a node has exceeded the internal + * libfdt limit. This can happen if you have more than + * FDT_MAX_DEPTH nested nodes. */ + +#define FDT_ERR_MAX 14 /**********************************************************************/ /* Low-level functions (you probably don't need these) */ @@ -1511,4 +1516,214 @@ int fdt_del_node(void *fdt, int nodeoffset); const char *fdt_strerror(int errval); +struct fdt_region { + int offset; + int size; +}; + +/* + * Flags for fdt_find_regions() + * + * Add a region for the string table (always the last region) + */ +#define FDT_REG_ADD_STRING_TAB (1 << 0) + +/* + * Add all supernodes of a matching node/property, useful for creating a + * valid subset tree + */ +#define FDT_REG_SUPERNODES (1 << 1) + +/* Add the FDT_BEGIN_NODE tags of subnodes, including their names */ +#define FDT_REG_DIRECT_SUBNODES (1 << 2) + +/* Add all subnodes of a matching node */ +#define FDT_REG_ALL_SUBNODES (1 << 3) + +/* Add a region for the mem_rsvmap table (always the first region) */ +#define FDT_REG_ADD_MEM_RSVMAP (1 << 4) + +/* Indicates what an fdt part is (node, property, value) */ +#define FDT_IS_NODE (1 << 0) +#define FDT_IS_PROP (1 << 1) +#define FDT_IS_VALUE (1 << 2) /* not supported */ +#define FDT_IS_COMPAT (1 << 3) /* used internally */ + +#define FDT_IS_ANY 15 + +/* We set a reasonable limit on the number of nested nodes */ +#define FDT_MAX_DEPTH 32 + +/* Decribes what we want to include from the current tag */ +enum want_t { + WANT_NOTHING, + WANT_NODES_ONLY, /* No proporties */ + WANT_NODES_AND_PROPS, /* Everything for one level */ + WANT_ALL_NODES_AND_PROPS /* Everything for all levels */ +}; + +/* Keeps track of the state at parent nodes */ +struct fdt_subnode_stack { + int offset; /* Offset of node */ + enum want_t want; /* The 'want' value here */ + int included; /* 1 if we included this node, 0 if not */ +}; + +struct fdt_region_ptrs { + int depth; /* Current tree depth */ + int done; /* What we have completed scanning */ + enum want_t want; /* What we are currently including */ + char *end; /* Pointer to end of full node path */ + int nextoffset; /* Next node offset to check */ +}; + +/* The state of our finding algortihm */ +struct fdt_region_state { + struct fdt_subnode_stack stack[FDT_MAX_DEPTH]; /* node stack */ + struct fdt_region *region; /* Contains list of regions found */ + int count; /* Numnber of regions found */ + const void *fdt; /* FDT blob */ + int max_regions; /* Maximum regions to find */ + int can_merge; /* 1 if we can merge with previous region */ + int start; /* Start position of current region */ + struct fdt_region_ptrs ptrs; /* Pointers for what we are up to */ +}; + +/** + * fdt_first_region() - find regions in device tree + * + * Given a nodes and properties to include and properties to exclude, find + * the regions of the device tree which describe those included parts. + * + * The use for this function is twofold. Firstly it provides a convenient + * way of performing a structure-aware grep of the tree. For example it is + * possible to grep for a node and get all the properties associated with + * that node. Trees can be subsetted easily, by specifying the nodes that + * are required, and then writing out the regions returned by this function. + * This is useful for small resource-constrained systems, such as boot + * loaders, which want to use an FDT but do not need to know about all of + * it. + * + * Secondly it makes it easy to hash parts of the tree and detect changes. + * The intent is to get a list of regions which will be invariant provided + * those parts are invariant. For example, if you request a list of regions + * for all nodes but exclude the property "data", then you will get the + * same region contents regardless of any change to "data" properties. + * + * This function can be used to produce a byte-stream to send to a hashing + * function to verify that critical parts of the FDT have not changed. + * Note that semantically null changes in order could still cause false + * hash misses. Such reordering might happen if the tree is regenerated + * from source, and nodes are reordered (the bytes-stream will be emitted + * in a different order and mnay hash functions will detect this). However + * if an existing tree is modified using libfdt functions, such as + * fdt_add_subnode() and fdt_setprop(), then this problem is avoided. + * + * The nodes/properties to include/exclude are defined by a function + * provided by the caller. This function is called for each node and + * property, and must return: + * + * 0 - to exclude this part + * 1 - to include this part + * -1 - for FDT_IS_PROP only: no information is available, so include + * if its containing node is included + * + * The last case is only used to deal with properties. Often a property is + * included if its containing node is included - this is the case where + * -1 is returned.. However if the property is specifically required to be + * included/excluded, then 0 or 1 can be returned. Note that including a + * property when the FDT_REG_SUPERNODES flag is given will force its + * containing node to be included since it is not valid to have a property + * that is not in a node. + * + * Using the information provided, the inclusion of a node can be controlled + * either by a node name or its compatible string, or any other property + * that the function can determine. + * + * As an example, including node "/" means to include the root node and all + * root properties. A flag provides a way of also including supernodes (of + * which there is none for the root node), and another flag includes + * immediate subnodes, so in this case we would get the FDT_BEGIN_NODE and + * FDT_END_NODE of all subnodes of /. + * + * The subnode feature helps in a hashing situation since it prevents the + * root node from changing at all. Any change to non-excluded properties, + * names of subnodes or number of subnodes would be detected. + * + * When used with FITs this provides the ability to hash and sign parts of + * the FIT based on different configurations in the FIT. Then it is + * impossible to change anything about that configuration (include images + * attached to the configuration), but it may be possible to add new + * configurations, new images or new signatures within the existing + * framework. + * + * Adding new properties to a device tree may result in the string table + * being extended (if the new property names are different from those + * already added). This function can optionally include a region for + * the string table so that this can be part of the hash too. This is always + * the last region. + * + * The FDT also has a mem_rsvmap table which can also be included, and is + * always the first region if so. + * + * The device tree header is not included in the region list. Since the + * contents of the FDT are changing (shrinking, often), the caller will need + * to regenerate the header anyway. + * + * @fdt: Device tree to check + * @h_include: Function to call to determine whether to include a part or + * not: + * + * @priv: Private pointer as passed to fdt_find_regions() + * @fdt: Pointer to FDT blob + * @offset: Offset of this node / property + * @type: Type of this part, FDT_IS_... + * @data: Pointer to data (node name, property name, compatible + * string, value (not yet supported) + * @size: Size of data, or 0 if none + * @return 0 to exclude, 1 to include, -1 if no information is + * available + * @priv: Private pointer passed to h_include + * @region: Returns list of regions, sorted by offset + * @max_regions: Maximum length of region list + * @path: Pointer to a temporary string for the function to use for + * building path names + * @path_len: Length of path, must be large enough to hold the longest + * path in the tree + * @flags: Various flags that control the region algortihm, see + * FDT_REG_... + * @return number of regions in list. If this is >max_regions then the + * region array was exhausted. You should increase max_regions and try + * the call again. Only the first max_regions elements are available in the + * array. + * + * On error a -ve value is return, which can be: + * + * -FDT_ERR_BADSTRUCTURE (too deep or more END tags than BEGIN tags + * -FDT_ERR_BADLAYOUT + * -FDT_ERR_NOSPACE (path area is too small) + */ +int fdt_first_region(const void *fdt, + int (*h_include)(void *priv, const void *fdt, int offset, + int type, const char *data, int size), + void *priv, struct fdt_region *region, + char *path, int path_len, int flags, + struct fdt_region_state *info); + +/** fdt_next_region() - find next region + * + * See fdt_first_region() for full description. This function finds the + * next region according to the provided parameters, which must be the same + * as passed to fdt_first_region(). + * + * This function can additionally return -FDT_ERR_NOTFOUND when there are no + * more regions + */ +int fdt_next_region(const void *fdt, + int (*h_include)(void *priv, const void *fdt, int offset, + int type, const char *data, int size), + void *priv, struct fdt_region *region, + char *path, int path_len, int flags, + struct fdt_region_state *info); + #endif /* _LIBFDT_H */ diff --git a/tests/.gitignore b/tests/.gitignore index bb5e33a..4dc6466 100644 --- a/tests/.gitignore +++ b/tests/.gitignore @@ -41,6 +41,7 @@ tmp.* /phandle_format /propname_escapes /references +/region_tree /root_node /rw_tree1 /set_name diff --git a/tests/Makefile.tests b/tests/Makefile.tests index dafb618..636a242 100644 --- a/tests/Makefile.tests +++ b/tests/Makefile.tests @@ -21,7 +21,8 @@ LIB_TESTS_L = get_mem_rsv \ add_subnode_with_nops path_offset_aliases \ utilfdt_test \ integer-expressions \ - subnode_iterate + subnode_iterate \ + region_tree LIB_TESTS = $(LIB_TESTS_L:%=$(TESTS_PREFIX)%) LIBTREE_TESTS_L = truncated_property diff --git a/tests/region_tree.c b/tests/region_tree.c new file mode 100644 index 0000000..2ca8c98 --- /dev/null +++ b/tests/region_tree.c @@ -0,0 +1,352 @@ +/* + * hash_tree - Testcase for fdt_find_regions() + * + * Copyright (c) 2013, Google Inc. + * + * Copyright (C) 2006 David Gibson, IBM Corporation. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public License + * as published by the Free Software Foundation; either version 2.1 of + * the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <ctype.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <libfdt_env.h> +#include <fdt.h> +#include <libfdt.h> + +#include "tests.h" +#include "testdata.h" + +#define SPACE 65536 + +#define CHECK(code) \ + { \ + err = (code); \ + if (err) \ + FAIL(#code ": %s", fdt_strerror(err)); \ + } + +/* + * Regions we expect to see returned from fdt_find_regions(). We build up a + * list of these as we make the tree, then check the results of + * fdt_find_regions() once we are done. + */ +static struct fdt_region expect[20]; + +/* Number of expected regions */ +int expect_count; + +/* Mark the start of a new region */ +static void start(void *fdt) +{ + expect[expect_count].offset = fdt_size_dt_struct(fdt); + verbose_printf("[%d: %x ", expect_count, + fdt_off_dt_struct(fdt) + expect[expect_count].offset); +} + +/* Mark the end of a region */ +static void stop(void *fdt) +{ + expect[expect_count].size = fdt_size_dt_struct(fdt) - + expect[expect_count].offset; + expect[expect_count].offset += fdt_off_dt_struct(fdt); + verbose_printf("%x]\n", expect[expect_count].offset + + expect[expect_count].size); + expect_count++; +} + +/** + * build_tree() - Build a tree + * + * @fdt: Pointer to place to put tree, assumed to be large enough + * @flags: Flags to control the tree creation (FDT_REG_...) + * @space: Amount of space to create for later tree additions + * + * This creates a tree modelled on a U-Boot FIT image, with various nodes + * and properties which are useful for testing the hashing features of + * fdt_find_regions(). + * + * See h_include() below for a list of the nodes we later search for. + */ +static void build_tree(void *fdt, int flags, int space) +{ + int direct_subnodes = flags & FDT_REG_DIRECT_SUBNODES; + int all_subnodes = flags & FDT_REG_ALL_SUBNODES; + int supernodes = flags & FDT_REG_SUPERNODES; + int either = !all_subnodes && (direct_subnodes || supernodes); + int err; + + CHECK(fdt_create(fdt, SPACE)); + + CHECK(fdt_add_reservemap_entry(fdt, TEST_ADDR_1, TEST_SIZE_1)); + CHECK(fdt_add_reservemap_entry(fdt, TEST_ADDR_2, TEST_SIZE_2)); + CHECK(fdt_finish_reservemap(fdt)); + + /* + * This is the start of a new region because in the fdt_xxx_region() + * call, we pass "/" as one of the nodes to find. + */ + start(fdt); /* region 0 */ + CHECK(fdt_begin_node(fdt, "")); + CHECK(fdt_property_string(fdt, "description", "kernel image")); + CHECK(fdt_property_u32(fdt, "#address-cells", 1)); + + /* /images */ + if (!either && !all_subnodes) + stop(fdt); + CHECK(fdt_begin_node(fdt, "images")); + if (either) + stop(fdt); + CHECK(fdt_property_u32(fdt, "image-prop", 1)); + + /* /images/kernel@1 */ + if (!all_subnodes) + start(fdt); /* region 1 */ + CHECK(fdt_begin_node(fdt, "kernel@1")); + CHECK(fdt_property_string(fdt, "description", "exynos kernel")); + stop(fdt); + CHECK(fdt_property_string(fdt, "data", "this is the kernel image")); + start(fdt); /* region 2 */ + + /* /images/kernel/hash@1 */ + CHECK(fdt_begin_node(fdt, "hash@1")); + CHECK(fdt_property_string(fdt, "algo", "sha1")); + CHECK(fdt_end_node(fdt)); + + /* /images/kernel/hash@2 */ + if (!direct_subnodes) + stop(fdt); + CHECK(fdt_begin_node(fdt, "hash@2")); + if (direct_subnodes) + stop(fdt); + CHECK(fdt_property_string(fdt, "algo", "sha1")); + if (direct_subnodes) + start(fdt); /* region 3 */ + CHECK(fdt_end_node(fdt)); + if (!direct_subnodes) + start(fdt); /* region 3 */ + + CHECK(fdt_end_node(fdt)); + + /* /images/fdt@1 */ + CHECK(fdt_begin_node(fdt, "fdt@1")); + CHECK(fdt_property_string(fdt, "description", "snow FDT")); + if (!all_subnodes) + stop(fdt); + CHECK(fdt_property_string(fdt, "data", "FDT data")); + if (!all_subnodes) + start(fdt); /* region 4 */ + + /* /images/kernel/hash@1 */ + CHECK(fdt_begin_node(fdt, "hash@1")); + CHECK(fdt_property_string(fdt, "algo", "sha1")); + CHECK(fdt_end_node(fdt)); + + CHECK(fdt_end_node(fdt)); + + if (!either && !all_subnodes) + stop(fdt); + CHECK(fdt_end_node(fdt)); + + /* /configurations */ + CHECK(fdt_begin_node(fdt, "configurations")); + if (either) + stop(fdt); + CHECK(fdt_property_string(fdt, "default", "conf@1")); + + /* /configurations/conf@1 */ + if (!all_subnodes) + start(fdt); /* region 6 */ + CHECK(fdt_begin_node(fdt, "conf@1")); + CHECK(fdt_property_string(fdt, "kernel", "kernel@1")); + CHECK(fdt_property_string(fdt, "fdt", "fdt@1")); + CHECK(fdt_end_node(fdt)); + if (!all_subnodes) + stop(fdt); + + /* /configurations/conf@2 */ + CHECK(fdt_begin_node(fdt, "conf@2")); + CHECK(fdt_property_string(fdt, "kernel", "kernel@1")); + CHECK(fdt_property_string(fdt, "fdt", "fdt@2")); + CHECK(fdt_end_node(fdt)); + + if (either) + start(fdt); /* region 7 */ + CHECK(fdt_end_node(fdt)); + if (!either && !all_subnodes) + start(fdt); /* region 7 */ + + CHECK(fdt_end_node(fdt)); + + CHECK(fdt_finish(fdt)); + stop(fdt); + + /* Add in the strings */ + if (flags & FDT_REG_ADD_STRING_TAB) { + expect[expect_count].offset = fdt_off_dt_strings(fdt); + expect[expect_count].size = fdt_size_dt_strings(fdt); + expect_count++; + } + + /* Make a bit of space */ + if (space) + CHECK(fdt_open_into(fdt, fdt, fdt_totalsize(fdt) + space)); + + verbose_printf("Completed tree, totalsize = %d\n", fdt_totalsize(fdt)); +} + +/** + * strlist_contains() - Returns 1 if a string is contained in a list + * + * @list: List of strings + * @count: Number of strings in list + * @str: String to search for + */ +static int strlist_contains(const char * const list[], int count, + const char *str) +{ + int i; + + for (i = 0; i < count; i++) + if (!strcmp(list[i], str)) + return 1; + + return 0; +} + +/** + * h_include() - Our include handler for fdt_find_regions() + * + * This is very simple - we have a list of nodes we are looking for, and + * one property that we want to exclude. + */ +static int h_include(void *priv, const void *fdt, int offset, int type, + const char *data, int size) +{ + const char * const inc[] = { + "/", + "/images/kernel@1", + "/images/fdt@1", + "/configurations/conf@1", + "/images/kernel@1/hash@1", + "/images/fdt@1/hash@1", + }; + + switch (type) { + case FDT_IS_NODE: + return strlist_contains(inc, 6, data); + case FDT_IS_PROP: + return !strcmp(data, "data") ? 0 : -1; + } + + return 0; +} + +/** + * check_regions() - Check that the regions are as we expect + * + * Call fdt_find_regions() and check that the results are as we expect them, + * matching the list of expected regions we created at the same time as + * the tree. + * + * @fdt: Pointer to device tree to check + * @flags: Flags value (FDT_REG_...) + * @return 0 if ok, -1 on failure + */ +static int check_regions(const void *fdt, int flags) +{ + struct fdt_region_state state; + struct fdt_region reg; + int err, ret = 0; + char path[1024]; + int count; + int i; + + ret = fdt_first_region(fdt, h_include, NULL, ®, + path, sizeof(path), flags, &state); + if (ret < 0) + CHECK(ret); + + verbose_printf("Regions: %d\n", count); + for (i = 0; ; i++) { + struct fdt_region *exp = &expect[i]; + + verbose_printf("%d: %-10x %-10x\n", i, reg.offset, + reg.offset + reg.size); + if (memcmp(exp, ®, sizeof(reg))) { + ret = -1; + verbose_printf("exp: %-10x %-10x\n", exp->offset, + exp->offset + exp->size); + } + + ret = fdt_next_region(fdt, h_include, NULL, ®, + path, sizeof(path), flags, &state); + if (ret < 0) { + if (ret == -FDT_ERR_NOTFOUND) + ret = 0; + CHECK(ret); + i++; + break; + } + } + verbose_printf("expect_count = %d, i=%d\n", expect_count, i); + if (expect_count != i) + FAIL(); + + return ret; +} + +int main(int argc, char *argv[]) +{ + const char *fname = NULL; + int flags = 0; + int space = 0; + void *fdt; + + test_init(argc, argv); + if (argc < 2) { + verbose_printf("Usage: %s <flag value> [<space>]" + " [<output_fname.dtb>]", argv[0]); + FAIL(); + } + flags = atoi(argv[1]); + if (argc >= 3) + space = atoi(argv[2]); + if (argc >= 4) + fname = argv[3]; + + /* + * Allocate space for the tree and build it, creating a list of + * expected regions. + */ + fdt = xmalloc(SPACE); + build_tree(fdt, flags, space); + + /* Write the tree out if required */ + if (fname) + save_blob(fname, fdt); + + /* Check the regions are what we expect */ + if (check_regions(fdt, flags)) + FAIL(); + else + PASS(); + + return 0; +} diff --git a/tests/run_tests.sh b/tests/run_tests.sh index c0a136b..8757c11 100755 --- a/tests/run_tests.sh +++ b/tests/run_tests.sh @@ -249,6 +249,11 @@ libfdt_tests () { # Specific bug tests run_test add_subnode_with_nops + + # Tests for fdt_find_regions() + for flags in $(seq 0 15); do + run_test region_tree ${flags} + done } dtc_tests () { -- 1.8.4.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html