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| author | Alan Modra <amodra@gmail.com> | 2019-11-26 16:49:44 +1030 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2019-12-26 17:49:03 +1030 |
| commit | 8ce18f9cdf53c846e0486130a66ba55c96fc2b14 (patch) | |
| tree | 00869e348fe72b0b9165e3858861254b9489fc37 /ld/ChangeLog | |
| parent | 100b122fc125bdf1fe768a3331a0cd413c3d1261 (diff) | |
| download | binutils-8ce18f9cdf53c846e0486130a66ba55c96fc2b14.zip binutils-8ce18f9cdf53c846e0486130a66ba55c96fc2b14.tar.gz binutils-8ce18f9cdf53c846e0486130a66ba55c96fc2b14.tar.bz2 | |
Avoid ubsan bug complaining about &p->field
I reckon it's quite OK to write &p->field in C when p might be NULL,
and lots of old C programmers probably agree with me. However, ubsan
disagrees and so do some people I respect. I suspect C++ influence is
to blame for the ubsan behaviour. See
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92634. So far no one has
educated me as to why I'm wrong to claim that there isn't anything in
the C standard to say that p->field is always (*p).field. Note 79
doesn't quite do that because it doesn't cover null pointers. If
there was such an equivalence then you could claim &p->field has a
null pointer reference when p is NULL, even though no C compiler would
ever dereference p.
Anyway, to silence ubsan I'm going to apply the following though I
prefer to avoid casts when possible. And I'm using (void *)
deliberately because this is C, not C++!
* ldlang.c (lang_output_section_find_by_flags): Don't use &p->field
when p might be NULL.
* ldelf.c (output_rel_find, ldelf_place_orphan): Likewise.
(insert_os_after, lang_insert_orphan, lookup_name): Likewise.
(strip_excluded_output_sections, lang_clear_os_map): Likewise.
(lang_check, lang_for_each_input_file): Likewise.
(lang_reset_memory_regions, find_replacements_insert_point): Likewise.
(find_rescan_insertion, lang_propagate_lma_regions): Likewise.
(lang_record_phdrs): Likewise.
* emultempl/alphaelf.em (alpha_after_open): Likewise.
* emultempl/mmo.em (mmo_place_orphan): Likewise.
* emultempl/pe.em (gld_${EMULATION_NAME}_place_orphan): Likewise.
* emultempl/pep.em (gld_${EMULATION_NAME}_place_orphan): Likewise.
* emultempl/ppc32elf.em (ppc_after_check_relocs): Likewise.
* emultempl/spuelf.em (spu_before_allocation): Likewise.
(embedded_spu_file): Likewise.
Diffstat (limited to 'ld/ChangeLog')
| -rw-r--r-- | ld/ChangeLog | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/ld/ChangeLog b/ld/ChangeLog index cececa0..f29913e 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,22 @@ +2019-12-26 Alan Modra <amodra@gmail.com> + + * ldlang.c (lang_output_section_find_by_flags): Don't use &p->field + when p might be NULL. + * ldelf.c (output_rel_find, ldelf_place_orphan): Likewise. + (insert_os_after, lang_insert_orphan, lookup_name): Likewise. + (strip_excluded_output_sections, lang_clear_os_map): Likewise. + (lang_check, lang_for_each_input_file): Likewise. + (lang_reset_memory_regions, find_replacements_insert_point): Likewise. + (find_rescan_insertion, lang_propagate_lma_regions): Likewise. + (lang_record_phdrs): Likewise. + * emultempl/alphaelf.em (alpha_after_open): Likewise. + * emultempl/mmo.em (mmo_place_orphan): Likewise. + * emultempl/pe.em (gld_${EMULATION_NAME}_place_orphan): Likewise. + * emultempl/pep.em (gld_${EMULATION_NAME}_place_orphan): Likewise. + * emultempl/ppc32elf.em (ppc_after_check_relocs): Likewise. + * emultempl/spuelf.em (spu_before_allocation): Likewise. + (embedded_spu_file): Likewise. + 2019-12-19 Alan Modra <amodra@gmail.com> * testsuite/lib/ld-lib.exp (uses_genelf): Remove moxie. |