From 2db912ba1a9e1c249cb4795f781fd4ea9fe9e7f2 Mon Sep 17 00:00:00 2001 From: Nick Alcock Date: Thu, 11 Jul 2019 16:21:26 +0100 Subject: libctf: add the object index and function index sections No code handles these yet, but our latest GCC patches are generating them, so we have to be ready for them or erroneously conclude that we have file corruption. (This simultaneously fixes a longstanding bug, concealed because nothing was generating anything in the object or function info sections, where the end of the section was being tested against the wrong thing: it would have walked over the entire contents of the variable section and treated them as part of the function info section. This had to change now anyway because the new sections have landed in between.) include/ * ctf.h: Add object index and function index sections. Describe them. Improve the description of the variable section and clarify the constraints on backward-pointing type nodes. (ctf_header): Add cth_objtidxoff, cth_funcidxoff. libctf/ * ctf-open.c (init_symtab): Check for overflow against the right section. (upgrade_header): Set cth_objtidxoff, cth_funcidxoff to zero-length. (upgrade_types_v1): Note that these sections are not checked. (flip_header): Endian-swap the header fields. (flip_ctf): Endian-swap the sections. (flip_objts): Update comment. (ctf_bufopen): Check header offsets and alignment for validity. --- libctf/ctf-open.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) (limited to 'libctf/ctf-open.c') diff --git a/libctf/ctf-open.c b/libctf/ctf-open.c index 51f9edc..c96bad7 100644 --- a/libctf/ctf-open.c +++ b/libctf/ctf-open.c @@ -278,7 +278,7 @@ init_symtab (ctf_file_t *fp, const ctf_header_t *hp, break; case STT_FUNC: - if (funcoff >= hp->cth_typeoff) + if (funcoff >= hp->cth_objtidxoff) { *xp = -1u; break; @@ -376,6 +376,8 @@ upgrade_header (ctf_header_t *hp) hp->cth_stroff = oldhp->cth_stroff; hp->cth_typeoff = oldhp->cth_typeoff; hp->cth_varoff = oldhp->cth_varoff; + hp->cth_funcidxoff = hp->cth_varoff; /* No index sections. */ + hp->cth_objtidxoff = hp->cth_funcidxoff; hp->cth_funcoff = oldhp->cth_funcoff; hp->cth_objtoff = oldhp->cth_objtoff; hp->cth_lbloff = oldhp->cth_lbloff; @@ -388,6 +390,9 @@ upgrade_header (ctf_header_t *hp) The upgrade is not done in-place: the ctf_base is moved. ctf_strptr() must not be called before reallocation is complete. + Sections not checked here due to nonexistence or nonpopulated state in older + formats: objtidx, funcidx. + Type kinds not checked here due to nonexistence in older formats: CTF_K_SLICE. */ static int @@ -967,6 +972,8 @@ flip_header (ctf_header_t *cth) swap_thing (cth->cth_cuname); swap_thing (cth->cth_objtoff); swap_thing (cth->cth_funcoff); + swap_thing (cth->cth_objtidxoff); + swap_thing (cth->cth_funcidxoff); swap_thing (cth->cth_varoff); swap_thing (cth->cth_typeoff); swap_thing (cth->cth_stroff); @@ -987,10 +994,10 @@ flip_lbls (void *start, size_t len) } } -/* Flip the endianness of the data-object or function sections, an array of - uint32_t. (The function section has more internal structure, but that - structure is an array of uint32_t, so can be treated as one big array for - byte-swapping.) */ +/* Flip the endianness of the data-object or function sections or their indexes, + all arrays of uint32_t. (The function section has more internal structure, + but that structure is an array of uint32_t, so can be treated as one big + array for byte-swapping.) */ static void flip_objts (void *start, size_t len) @@ -1176,7 +1183,9 @@ flip_ctf (ctf_header_t *cth, unsigned char *buf) { flip_lbls (buf + cth->cth_lbloff, cth->cth_objtoff - cth->cth_lbloff); flip_objts (buf + cth->cth_objtoff, cth->cth_funcoff - cth->cth_objtoff); - flip_objts (buf + cth->cth_funcoff, cth->cth_varoff - cth->cth_funcoff); + flip_objts (buf + cth->cth_funcoff, cth->cth_objtidxoff - cth->cth_funcoff); + flip_objts (buf + cth->cth_objtidxoff, cth->cth_funcidxoff - cth->cth_objtidxoff); + flip_objts (buf + cth->cth_funcidxoff, cth->cth_varoff - cth->cth_funcidxoff); flip_vars (buf + cth->cth_varoff, cth->cth_typeoff - cth->cth_varoff); return flip_types (buf + cth->cth_typeoff, cth->cth_stroff - cth->cth_typeoff); } @@ -1330,19 +1339,23 @@ ctf_bufopen (const ctf_sect_t *ctfsect, const ctf_sect_t *symsect, (unsigned long) fp->ctf_size); if (hp->cth_lbloff > fp->ctf_size || hp->cth_objtoff > fp->ctf_size - || hp->cth_funcoff > fp->ctf_size || hp->cth_typeoff > fp->ctf_size + || hp->cth_funcoff > fp->ctf_size || hp->cth_objtidxoff > fp->ctf_size + || hp->cth_funcidxoff > fp->ctf_size || hp->cth_typeoff > fp->ctf_size || hp->cth_stroff > fp->ctf_size) return (ctf_set_open_errno (errp, ECTF_CORRUPT)); if (hp->cth_lbloff > hp->cth_objtoff || hp->cth_objtoff > hp->cth_funcoff || hp->cth_funcoff > hp->cth_typeoff - || hp->cth_funcoff > hp->cth_varoff + || hp->cth_funcoff > hp->cth_objtidxoff + || hp->cth_objtidxoff > hp->cth_funcidxoff + || hp->cth_funcidxoff > hp->cth_varoff || hp->cth_varoff > hp->cth_typeoff || hp->cth_typeoff > hp->cth_stroff) return (ctf_set_open_errno (errp, ECTF_CORRUPT)); if ((hp->cth_lbloff & 3) || (hp->cth_objtoff & 2) - || (hp->cth_funcoff & 2) || (hp->cth_varoff & 3) + || (hp->cth_funcoff & 2) || (hp->cth_objtidxoff & 2) + || (hp->cth_funcidxoff & 2) || (hp->cth_varoff & 3) || (hp->cth_typeoff & 3)) return (ctf_set_open_errno (errp, ECTF_CORRUPT)); -- cgit v1.1