From 5789f845fbf67d271e0f5ff154eb03319b551211 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Wed, 3 Mar 2021 12:14:55 +1030 Subject: [PATCH] --gc-sections with groups and start/stop syms The testcases added here show situations where synthesized start/stop symbols don't cause their associated input sections to be marked. Fixed with the elflink.c and ldlang.c changes. bfd/ PR 27500 * elflink.c (_bfd_elf_gc_mark_rsec): Do special start/stop processing not when start/stop symbol section is unmarked but on first time a start/stop symbol is processed. ld/ * ldlang.c (insert_undefined): Don't mark symbols here. (lang_mark_undefineds): Do so here instead, new function. (lang_process): Call lang_mark_undefineds. * testsuite/ld-gc/start3.d, * testsuite/ld-gc/start3.s: New test. * testsuite/ld-gc/start4.d, * testsuite/ld-gc/start4.s: New test. * testsuite/ld-gc/gc.exp: Run them. --- bfd/ChangeLog | 7 +++++++ bfd/elflink.c | 8 ++++++-- ld/ChangeLog | 12 ++++++++++++ ld/ldlang.c | 21 +++++++++++++++++++-- ld/testsuite/ld-gc/gc.exp | 2 ++ ld/testsuite/ld-gc/start3.d | 9 +++++++++ ld/testsuite/ld-gc/start3.s | 29 +++++++++++++++++++++++++++++ ld/testsuite/ld-gc/start4.d | 9 +++++++++ ld/testsuite/ld-gc/start4.s | 19 +++++++++++++++++++ 9 files changed, 112 insertions(+), 4 deletions(-) create mode 100644 ld/testsuite/ld-gc/start3.d create mode 100644 ld/testsuite/ld-gc/start3.s create mode 100644 ld/testsuite/ld-gc/start4.d create mode 100644 ld/testsuite/ld-gc/start4.s diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 0e518ceb34d..5e2571bf347 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,10 @@ +2021-03-03 Alan Modra + + PR 27500 + * elflink.c (_bfd_elf_gc_mark_rsec): Do special start/stop + processing not when start/stop symbol section is unmarked but + on first time a start/stop symbol is processed. + 2021-03-03 Alan Modra * reloc.c: Include x86_64.h rather than internal.h. diff --git a/bfd/elflink.c b/bfd/elflink.c index 74b54c2c0c0..e1278a5d95e 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -13422,6 +13422,8 @@ _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec, if (r_symndx >= cookie->locsymcount || ELF_ST_BIND (cookie->locsyms[r_symndx].st_info) != STB_LOCAL) { + bfd_boolean was_marked; + h = cookie->sym_hashes[r_symndx - cookie->extsymoff]; if (h == NULL) { @@ -13432,6 +13434,8 @@ _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec, while (h->root.type == bfd_link_hash_indirect || h->root.type == bfd_link_hash_warning) h = (struct elf_link_hash_entry *) h->root.u.i.link; + + was_marked = h->mark; h->mark = 1; /* Keep all aliases of the symbol too. If an object symbol needs to be copied into .dynbss then all of its aliases @@ -13444,7 +13448,7 @@ _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec, hw->mark = 1; } - if (h->start_stop && !h->root.ldscript_def) + if (!was_marked && h->start_stop && !h->root.ldscript_def) { if (info->start_stop_gc) return NULL; @@ -13455,7 +13459,7 @@ _bfd_elf_gc_mark_rsec (struct bfd_link_info *info, asection *sec, else if (start_stop != NULL) { asection *s = h->u2.start_stop_section; - *start_stop = !s->gc_mark; + *start_stop = TRUE; return s; } } diff --git a/ld/ChangeLog b/ld/ChangeLog index bf1d226b809..0f1da7fafab 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,15 @@ +2021-03-03 Alan Modra + + PR 27500 + * ldlang.c (insert_undefined): Don't mark symbols here. + (lang_mark_undefineds): Do so here instead, new function. + (lang_process): Call lang_mark_undefineds. + * testsuite/ld-gc/start3.d, + * testsuite/ld-gc/start3.s: New test. + * testsuite/ld-gc/start4.d, + * testsuite/ld-gc/start4.s: New test. + * testsuite/ld-gc/gc.exp: Run them. + 2021-03-03 Alan Modra * testsuite/ld-gc/gc.exp: Define UNDERSCORE in ASFLAGS. diff --git a/ld/ldlang.c b/ld/ldlang.c index a77e8fabeff..684e1d23a21 100644 --- a/ld/ldlang.c +++ b/ld/ldlang.c @@ -3986,8 +3986,6 @@ insert_undefined (const char *name) h->type = bfd_link_hash_undefined; h->u.undef.abfd = NULL; h->non_ir_ref_regular = TRUE; - if (is_elf_hash_table (link_info.hash)) - ((struct elf_link_hash_entry *) h)->mark = 1; bfd_link_add_undef (link_info.hash, h); } } @@ -4005,6 +4003,23 @@ lang_place_undefineds (void) insert_undefined (ptr->name); } +/* Mark -u symbols against garbage collection. */ + +static void +lang_mark_undefineds (void) +{ + ldlang_undef_chain_list_type *ptr; + + if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour) + for (ptr = ldlang_undef_chain_list_head; ptr != NULL; ptr = ptr->next) + { + struct elf_link_hash_entry *h = (struct elf_link_hash_entry *) + bfd_link_hash_lookup (link_info.hash, ptr->name, FALSE, FALSE, TRUE); + if (h != NULL) + h->mark = 1; + } +} + /* Structure used to build the list of symbols that the user has required be defined. */ @@ -8116,6 +8131,8 @@ lang_process (void) /* Remove unreferenced sections if asked to. */ lang_gc_sections (); + lang_mark_undefineds (); + /* Check relocations. */ lang_check_relocs (); diff --git a/ld/testsuite/ld-gc/gc.exp b/ld/testsuite/ld-gc/gc.exp index ba528d000bf..cd5c6f7c4ea 100644 --- a/ld/testsuite/ld-gc/gc.exp +++ b/ld/testsuite/ld-gc/gc.exp @@ -101,6 +101,8 @@ if { [is_elf_format] } then { run_dump_test "stop" run_dump_test "start" run_dump_test "start2" + run_dump_test "start3" + run_dump_test "start4" } if { [is_elf_format] && [check_shared_lib_support] } then { diff --git a/ld/testsuite/ld-gc/start3.d b/ld/testsuite/ld-gc/start3.d new file mode 100644 index 00000000000..a57dab187ea --- /dev/null +++ b/ld/testsuite/ld-gc/start3.d @@ -0,0 +1,9 @@ +#name: --gc-sections with groups and start/stop syms +#ld: --gc-sections -e _start +#nm: -n +#notarget: [is_generic] +#xfail: bfin-*-*linux* frv-*-*linux* lm32-*-*linux* + +#... +[0-9a-f]+ T +bar +#... diff --git a/ld/testsuite/ld-gc/start3.s b/ld/testsuite/ld-gc/start3.s new file mode 100644 index 00000000000..0e720ba3fb0 --- /dev/null +++ b/ld/testsuite/ld-gc/start3.s @@ -0,0 +1,29 @@ + .text + .global _start +_start: + .dc.a foo + .ifdef UNDERSCORE + .dc.a ___start_xx, ___stop_xx + .else + .dc.a __start_xx, __stop_xx + .endif + + .section .text,"axG",%progbits,foo_group + .global foo +foo: + .dc.a 0 + + .section xx,"aG",%progbits,foo_group + .global foo_xx +foo_xx: + .dc.a 1 + + .section .text,"axG",%progbits,bar_group + .global bar +bar: + .dc.a 2 + + .section xx,"aG",%progbits,bar_group + .global bar_xx +bar_xx: + .dc.a 3 diff --git a/ld/testsuite/ld-gc/start4.d b/ld/testsuite/ld-gc/start4.d new file mode 100644 index 00000000000..ae77aa9bf73 --- /dev/null +++ b/ld/testsuite/ld-gc/start4.d @@ -0,0 +1,9 @@ +#name: --gc-sections with other syms and start/stop syms +#ld: --gc-sections -e _start +#nm: -n +#target: [supports_gnu_unique] +#xfail: bfin-*-*linux* frv-*-*linux* lm32-*-*linux* + +#... +[0-9a-f]+ R +bar_xx +#... diff --git a/ld/testsuite/ld-gc/start4.s b/ld/testsuite/ld-gc/start4.s new file mode 100644 index 00000000000..1aa94454e05 --- /dev/null +++ b/ld/testsuite/ld-gc/start4.s @@ -0,0 +1,19 @@ + .text + .global _start +_start: + .dc.a foo_xx + .ifdef UNDERSCORE + .dc.a ___start_xx, ___stop_xx + .else + .dc.a __start_xx, __stop_xx + .endif + + .section xx,"a",%progbits,unique,0 + .global foo_xx +foo_xx: + .dc.a 1 + + .section xx,"a",%progbits,unique,1 + .global bar_xx +bar_xx: + .dc.a 3 -- 2.30.2