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| author | Simon Glass <sjg@chromium.org> | 2020-02-20 14:45:52 -0700 |
|---|---|---|
| committer | David Gibson <david@gibson.dropbear.id.au> | 2020-02-24 13:38:44 +1100 |
| commit | 57bc6327b80bc95bee9fc5f07d4fc83186a8f167 (patch) | |
| tree | 9da35900a63bed5ce4333a1424d6b4e96c445427 /libfdt/fdt.c | |
| parent | 464962489dcc563e354ff64c9e58856185f32728 (diff) | |
| download | dtc-57bc6327b80bc95bee9fc5f07d4fc83186a8f167.zip dtc-57bc6327b80bc95bee9fc5f07d4fc83186a8f167.tar.gz dtc-57bc6327b80bc95bee9fc5f07d4fc83186a8f167.tar.bz2 | |
libfdt: Add support for disabling dtb checks
Support ASSUME_VALID_DTB to disable some sanity checks
If we assume that the DTB itself is valid then we can skip some checks and
save code space. Add various conditions to handle this.
Signed-off-by: Simon Glass <sjg@chromium.org>
Message-Id: <20200220214557.176528-4-sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'libfdt/fdt.c')
| -rw-r--r-- | libfdt/fdt.c | 53 |
1 files changed, 31 insertions, 22 deletions
diff --git a/libfdt/fdt.c b/libfdt/fdt.c index 3e37a4b..d4daf60 100644 --- a/libfdt/fdt.c +++ b/libfdt/fdt.c @@ -19,6 +19,9 @@ 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) @@ -81,38 +84,44 @@ int fdt_check_header(const void *fdt) 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; + hdrsize = fdt_header_size(fdt); + if (!can_assume(VALID_DTB)) { - 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; + 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 (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; } @@ -142,7 +151,7 @@ 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; @@ -154,13 +163,13 @@ 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 |