From 7cf7fcc83ca9fb4c4b591b3142bcf12e6e8a2aa5 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Wed, 16 May 2018 11:33:48 +0930 Subject: [PATCH] PR22458, failure to choose a matching ELF target https://sourceware.org/ml/binutils/2013-05/msg00271.html was supposed to banish "file format is ambiguous" errors for ELF. It didn't, because the code supposedly detecting formats that implement match_priority didn't work. That was due to not placing all matching targets into the vector of matching targets. ELF objects should all match the generic ELF target (priority 2), plus one or more machine specific targets (priority 1), and perhaps a single machine specific target with OS/ABI set (priority 0, best match). So the armel object in the testcase actually matches elf32-littlearm, elf32-littlearm-symbian, and elf32-littlearm-vxworks (all priority 1), and elf32-little (priority 2). As the PR reported, elf32-little wasn't seen as matching. Fixing that part of the problem wasn't too difficult but matching the generic ELF target as well as the ARM ELF targets resulted in ARM testsuite failures. These proved to be the annoying reordering of stubs that occurs from time to time due to the stub names containing the section id. Matching another target causes more sections to be created in elf_object_p. If section ids change, stub names change, which results in different hashing and can therefore result in different hash table traversal and stub creation order. That particular problem is fixed by resetting section_id to the initial state before attempting each target match, and taking a snapshot of its value after a successful match. PR 22458 * format.c (struct bfd_preserve): Add section_id. (bfd_preserve_save, bfd_preserve_restore): Save and restore _bfd_section_id. (bfd_reinit): Set _bfd_section_id. (bfd_check_format_matches): Put all matches of any priority into matching_vector. Save initial section id and start each attempted match at that section id. * libbfd-in.h (_bfd_section_id): Declare. * section.c (_bfd_section_id): Rename from section_id and make global. Adjust uses. (bfd_get_next_section_id): Delete. * elf64-ppc.c (ppc64_elf_setup_section_lists): Replace use of bfd_get_section_id with _bfd_section_id. * libbfd.h: Regenerate. * bfd-in2.h: Regenerate. --- bfd/ChangeLog | 19 +++++++++++++++++++ bfd/bfd-in2.h | 2 -- bfd/elf64-ppc.c | 2 +- bfd/format.c | 24 +++++++++++++++--------- bfd/libbfd-in.h | 3 +++ bfd/libbfd.h | 3 +++ bfd/section.c | 23 +++-------------------- 7 files changed, 44 insertions(+), 32 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 655c0ada421..8ef34ef390d 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,22 @@ +2018-05-16 Alan Modra + + PR 22458 + * format.c (struct bfd_preserve): Add section_id. + (bfd_preserve_save, bfd_preserve_restore): Save and restore + _bfd_section_id. + (bfd_reinit): Set _bfd_section_id. + (bfd_check_format_matches): Put all matches of any priority into + matching_vector. Save initial section id and start each attempted + match at that section id. + * libbfd-in.h (_bfd_section_id): Declare. + * section.c (_bfd_section_id): Rename from section_id and make + global. Adjust uses. + (bfd_get_next_section_id): Delete. + * elf64-ppc.c (ppc64_elf_setup_section_lists): Replace use of + bfd_get_section_id with _bfd_section_id. + * libbfd.h: Regenerate. + * bfd-in2.h: Regenerate. + 2018-05-15 Christophe Guillon * coffcode.h (coff_bigobj_swap_aux_in): Make sure that all fields diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h index 48226860c71..5f7ecd35dba 100644 --- a/bfd/bfd-in2.h +++ b/bfd/bfd-in2.h @@ -1892,8 +1892,6 @@ asection *bfd_make_section_with_flags asection *bfd_make_section (bfd *, const char *name); -int bfd_get_next_section_id (void); - bfd_boolean bfd_set_section_flags (bfd *abfd, asection *sec, flagword flags); diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c index 09377d102ce..b1665589456 100644 --- a/bfd/elf64-ppc.c +++ b/bfd/elf64-ppc.c @@ -11760,7 +11760,7 @@ ppc64_elf_setup_section_lists (struct bfd_link_info *info) if (htab == NULL) return -1; - htab->sec_info_arr_size = bfd_get_next_section_id (); + htab->sec_info_arr_size = _bfd_section_id; amt = sizeof (*htab->sec_info) * (htab->sec_info_arr_size); htab->sec_info = bfd_zmalloc (amt); if (htab->sec_info == NULL) diff --git a/bfd/format.c b/bfd/format.c index 64d33f7f98f..c4afd97d082 100644 --- a/bfd/format.c +++ b/bfd/format.c @@ -103,6 +103,7 @@ struct bfd_preserve struct bfd_section *sections; struct bfd_section *section_last; unsigned int section_count; + unsigned int section_id; struct bfd_hash_table section_htab; const struct bfd_build_id *build_id; }; @@ -125,6 +126,7 @@ bfd_preserve_save (bfd *abfd, struct bfd_preserve *preserve) preserve->sections = abfd->sections; preserve->section_last = abfd->section_last; preserve->section_count = abfd->section_count; + preserve->section_id = _bfd_section_id; preserve->section_htab = abfd->section_htab; preserve->marker = bfd_alloc (abfd, 1); preserve->build_id = abfd->build_id; @@ -138,12 +140,13 @@ bfd_preserve_save (bfd *abfd, struct bfd_preserve *preserve) /* Clear out a subset of BFD state. */ static void -bfd_reinit (bfd *abfd) +bfd_reinit (bfd *abfd, unsigned int section_id) { abfd->tdata.any = NULL; abfd->arch_info = &bfd_default_arch_struct; abfd->flags &= BFD_FLAGS_SAVED; bfd_section_list_clear (abfd); + _bfd_section_id = section_id; } /* Restores bfd state saved by bfd_preserve_save. */ @@ -160,6 +163,7 @@ bfd_preserve_restore (bfd *abfd, struct bfd_preserve *preserve) abfd->sections = preserve->sections; abfd->section_last = preserve->section_last; abfd->section_count = preserve->section_count; + _bfd_section_id = preserve->section_id; abfd->build_id = preserve->build_id; /* bfd_release frees all memory more recently bfd_alloc'd than @@ -214,6 +218,7 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) const bfd_target *save_targ, *right_targ, *ar_right_targ, *match_targ; int match_count, best_count, best_match; int ar_match_index; + unsigned int initial_section_id = _bfd_section_id; struct bfd_preserve preserve; if (matching != NULL) @@ -287,14 +292,13 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) /* Don't check the default target twice. */ if (*target == &binary_vec - || (!abfd->target_defaulted && *target == save_targ) - || (*target)->match_priority > best_match) + || (!abfd->target_defaulted && *target == save_targ)) continue; /* If we already tried a match, the bfd is modified and may have sections attached, which will confuse the next _bfd_check_format call. */ - bfd_reinit (abfd); + bfd_reinit (abfd, initial_section_id); /* Change BFD's target temporarily. */ abfd->xvec = *target; @@ -329,9 +333,6 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) || (bfd_has_map (abfd) && bfd_get_error () != bfd_error_wrong_object_format)) { - /* This format checks out as ok! */ - right_targ = temp; - /* If this is the default target, accept it, even if other targets might match. People who want those other targets have to set the GNUTARGET variable. */ @@ -347,7 +348,12 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) best_match = match_priority; best_count = 0; } - best_count++; + if (match_priority <= best_match) + { + /* This format checks out as ok! */ + right_targ = temp; + best_count++; + } } else { @@ -446,7 +452,7 @@ bfd_check_format_matches (bfd *abfd, bfd_format format, char ***matching) state (except possibly for XVEC). */ if (match_targ != right_targ) { - bfd_reinit (abfd); + bfd_reinit (abfd, initial_section_id); if (bfd_seek (abfd, (file_ptr) 0, SEEK_SET) != 0) goto err_ret; match_targ = BFD_SEND_FMT (abfd, _bfd_check_format, (abfd)); diff --git a/bfd/libbfd-in.h b/bfd/libbfd-in.h index 0c80f4d5986..d8b445f8942 100644 --- a/bfd/libbfd-in.h +++ b/bfd/libbfd-in.h @@ -53,6 +53,9 @@ struct section_hash_entry asection section; }; +/* Unique section id. */ +extern unsigned int _bfd_section_id; + /* tdata for an archive. For an input archive, cache needs to be free()'d. For an output archive, symdefs do. */ diff --git a/bfd/libbfd.h b/bfd/libbfd.h index 66c2a5abc06..495ffb49f7e 100644 --- a/bfd/libbfd.h +++ b/bfd/libbfd.h @@ -58,6 +58,9 @@ struct section_hash_entry asection section; }; +/* Unique section id. */ +extern unsigned int _bfd_section_id; + /* tdata for an archive. For an input archive, cache needs to be free()'d. For an output archive, symdefs do. */ diff --git a/bfd/section.c b/bfd/section.c index 752f291cb10..7ee3f6915b6 100644 --- a/bfd/section.c +++ b/bfd/section.c @@ -820,21 +820,21 @@ _bfd_generic_new_section_hook (bfd *abfd, asection *newsect) return TRUE; } -static unsigned int section_id = 0x10; /* id 0 to 3 used by STD_SECTION. */ +unsigned int _bfd_section_id = 0x10; /* id 0 to 3 used by STD_SECTION. */ /* Initializes a new section. NEWSECT->NAME is already set. */ static asection * bfd_section_init (bfd *abfd, asection *newsect) { - newsect->id = section_id; + newsect->id = _bfd_section_id; newsect->index = abfd->section_count; newsect->owner = abfd; if (! BFD_SEND (abfd, _new_section_hook, (abfd, newsect))) return NULL; - section_id++; + _bfd_section_id++; abfd->section_count++; bfd_section_list_append (abfd, newsect); return newsect; @@ -1284,23 +1284,6 @@ bfd_make_section (bfd *abfd, const char *name) return bfd_make_section_with_flags (abfd, name, 0); } -/* -FUNCTION - bfd_get_next_section_id - -SYNOPSIS - int bfd_get_next_section_id (void); - -DESCRIPTION - Returns the id that the next section created will have. -*/ - -int -bfd_get_next_section_id (void) -{ - return section_id; -} - /* FUNCTION bfd_set_section_flags -- 2.30.2