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| author | Alan Modra <amodra@gmail.com> | 2021-03-01 08:22:49 +1030 |
|---|---|---|
| committer | Alan Modra <amodra@gmail.com> | 2021-03-01 17:28:03 +1030 |
| commit | 8ee10e86093150c70360d9e26b29e6d9b6398f33 (patch) | |
| tree | d9b022e21486a83064279ec452009a394b62a8b0 /bfd | |
| parent | 7824c1d22fcab8a68162634d4293f4a6666ca43e (diff) | |
| download | gdb-8ee10e86093150c70360d9e26b29e6d9b6398f33.zip gdb-8ee10e86093150c70360d9e26b29e6d9b6398f33.tar.gz gdb-8ee10e86093150c70360d9e26b29e6d9b6398f33.tar.bz2 | |
PR27451, -z start_stop_gc
When --gc-sections is in effect, a reference from a retained section
to __start_SECNAME or __stop_SECNAME causes all input sections named
SECNAME to also be retained, if SECNAME is representable as a C
identifier and either __start_SECNAME or __stop_SECNAME is synthesized
by the linker. Add an option to disable that feature, effectively
ignoring any relocation that references a synthesized linker defined
__start_ or __stop_ symbol.
PR 27451
include/
* bfdlink.h (struct bfd_link_info): Add start_stop_gc.
bfd/
* elflink.c (_bfd_elf_gc_mark_rsec): Ignore synthesized linker
defined start/stop symbols when start_stop_gc.
(bfd_elf_gc_mark_dynamic_ref_symbol): Likewise.
(bfd_elf_define_start_stop): Don't modify ldscript_def syms.
* linker.c (bfd_generic_define_start_stop): Likewise.
ld/
* emultempl/elf.em: Handle -z start-stop-gc and -z nostart-stop-gc.
* lexsup.c (elf_static_list_options): Display help for them. Move
help for -z stack-size to here from elf_shlib_list_options. Add
help for -z start-stop-visibility and -z undefs.
* ld.texi: Document -z start-stop-gc and -z nostart-stop-gc.
* NEWS: Mention -z start-stop-gc.
* testsuite/ld-gc/start2.s,
* testsuite/ld-gc/start2.d: New test.
* testsuite/ld-gc/gc.exp: Run it.
Diffstat (limited to 'bfd')
| -rw-r--r-- | bfd/ChangeLog | 9 | ||||
| -rw-r--r-- | bfd/elflink.c | 11 | ||||
| -rw-r--r-- | bfd/linker.c | 1 |
3 files changed, 19 insertions, 2 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 2fef817..818f580 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,12 @@ +2021-03-01 Alan Modra <amodra@gmail.com> + Fangrui Song <maskray@google.com> + + * elflink.c (_bfd_elf_gc_mark_rsec): Ignore synthesized linker + defined start/stop symbols when start_stop_gc. + (bfd_elf_gc_mark_dynamic_ref_symbol): Likewise. + (bfd_elf_define_start_stop): Don't modify ldscript_def syms. + * linker.c (bfd_generic_define_start_stop): Likewise. + 2021-02-25 Alan Modra <amodra@gmail.com> PR 27441 diff --git a/bfd/elflink.c b/bfd/elflink.c index 7b74f26..74b54c2 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -13444,12 +13444,15 @@ _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec, hw->mark = 1; } - if (start_stop != NULL) + if (h->start_stop && !h->root.ldscript_def) { + if (info->start_stop_gc) + return NULL; + /* To work around a glibc bug, mark XXX input sections when there is a reference to __start_XXX or __stop_XXX symbols. */ - if (h->start_stop) + else if (start_stop != NULL) { asection *s = h->u2.start_stop_section; *start_stop = !s->gc_mark; @@ -13912,6 +13915,9 @@ bfd_elf_gc_mark_dynamic_ref_symbol (struct elf_link_hash_entry *h, void *inf) if ((h->root.type == bfd_link_hash_defined || h->root.type == bfd_link_hash_defweak) + && (!h->start_stop + || h->root.ldscript_def + || !info->start_stop_gc) && ((h->ref_dynamic && !h->forced_local) || ((h->def_regular || ELF_COMMON_DEF_P (h)) && ELF_ST_VISIBILITY (h->other) != STV_INTERNAL @@ -14984,6 +14990,7 @@ bfd_elf_define_start_stop (struct bfd_link_info *info, FALSE, FALSE, TRUE); /* NB: Common symbols will be turned into definition later. */ if (h != NULL + && !h->root.ldscript_def && (h->root.type == bfd_link_hash_undefined || h->root.type == bfd_link_hash_undefweak || ((h->ref_regular || h->def_dynamic) diff --git a/bfd/linker.c b/bfd/linker.c index 1fb5787..7e0415c 100644 --- a/bfd/linker.c +++ b/bfd/linker.c @@ -3188,6 +3188,7 @@ bfd_generic_define_start_stop (struct bfd_link_info *info, h = bfd_link_hash_lookup (info->hash, symbol, FALSE, FALSE, TRUE); if (h != NULL + && !h->ldscript_def && (h->type == bfd_link_hash_undefined || h->type == bfd_link_hash_undefweak)) { |