diff options
author | Roland McGrath <roland@redhat.com> | 2008-12-03 03:41:58 +0000 |
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committer | Roland McGrath <roland@redhat.com> | 2008-12-03 03:41:58 +0000 |
commit | a845f68bf43f90e0670ed6b33154f2aff98ad46b (patch) | |
tree | 3bc6809479ef0de95b106f0f8616ca8cb0c02cc2 /libdwfl/dwfl_getmodules.c | |
parent | a4c9d281616090c46ffc4fc3234d64e915008e1a (diff) | |
download | elfutils-a845f68bf43f90e0670ed6b33154f2aff98ad46b.tar.gz |
src/
2008-12-02 Roland McGrath <roland@redhat.com>
* readelf.c (count_dwflmod, process_file): Don't presume encoding of
nonzero OFFSET argument to dwfl_getmodules.
Diffstat (limited to 'libdwfl/dwfl_getmodules.c')
-rw-r--r-- | libdwfl/dwfl_getmodules.c | 62 |
1 files changed, 34 insertions, 28 deletions
diff --git a/libdwfl/dwfl_getmodules.c b/libdwfl/dwfl_getmodules.c index f205b899..7c6ab971 100644 --- a/libdwfl/dwfl_getmodules.c +++ b/libdwfl/dwfl_getmodules.c @@ -59,49 +59,55 @@ dwfl_getmodules (Dwfl *dwfl, if (dwfl == NULL) return -1; + /* We iterate through the linked list when it's all we have. + But continuing from an offset is slow that way. So when + DWFL->lookup_module is populated, we can instead keep our + place by jumping directly into the array. Since the actions + of a callback could cause it to get populated, we must + choose the style of place-holder when we return an offset, + and we encode the choice in the low bits of that value. */ + Dwfl_Module *m = dwfl->modulelist; - if (unlikely (dwfl->lookup_module == NULL)) + if ((offset & 3) == 1) { + offset >>= 2; for (ptrdiff_t pos = 0; pos < offset; ++pos) if (m == NULL) return -1; else m = m->next; - while (m != NULL) - { - ++offset; - if ((*callback) (MODCB_ARGS (m), arg) != DWARF_CB_OK) - return offset; - m = m->next; - } } - else + else if (((offset & 3) == 2) && likely (dwfl->lookup_module != NULL)) { - if (offset > 0) - { - if ((size_t) offset - 1 == dwfl->lookup_elts) - return 0; + offset >>= 2; - if (unlikely ((size_t) offset - 1 > dwfl->lookup_elts)) - return -1; + if ((size_t) offset - 1 == dwfl->lookup_elts) + return 0; - m = dwfl->lookup_module[offset - 1]; - if (unlikely (m == NULL)) - return -1; - } + if (unlikely ((size_t) offset - 1 > dwfl->lookup_elts)) + return -1; - while (m != NULL) - { - int ok = (*callback) (MODCB_ARGS (m), arg); - m = m->next; - if (ok != DWARF_CB_OK) - return (m == NULL - ? (ptrdiff_t) dwfl->lookup_elts + 1 - : m->segment + 1); - } + m = dwfl->lookup_module[offset - 1]; + if (unlikely (m == NULL)) + return -1; + } + else if (offset != 0) + { + __libdwfl_seterrno (DWFL_E_BADSTROFF); + return -1; } + while (m != NULL) + { + int ok = (*callback) (MODCB_ARGS (m), arg); + ++offset; + m = m->next; + if (ok != DWARF_CB_OK) + return ((dwfl->lookup_module == NULL) ? ((offset << 2) | 1) + : (((m == NULL ? (ptrdiff_t) dwfl->lookup_elts + 1 + : m->segment + 1) << 2) | 2)); + } return 0; } INTDEF (dwfl_getmodules) |