diff options
Diffstat (limited to 'ld')
| -rw-r--r-- | ld/ChangeLog | 13 | ||||
| -rw-r--r-- | ld/NEWS | 3 | ||||
| -rw-r--r-- | ld/emultempl/elf.em | 4 | ||||
| -rw-r--r-- | ld/ld.texi | 17 | ||||
| -rw-r--r-- | ld/ldmain.c | 1 | ||||
| -rw-r--r-- | ld/lexsup.c | 13 | ||||
| -rw-r--r-- | ld/testsuite/ld-gc/gc.exp | 1 | ||||
| -rw-r--r-- | ld/testsuite/ld-gc/start2.d | 10 | ||||
| -rw-r--r-- | ld/testsuite/ld-gc/start2.s | 7 |
9 files changed, 67 insertions, 2 deletions
diff --git a/ld/ChangeLog b/ld/ChangeLog index 2347f9a..d72d69a 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,4 +1,17 @@ 2021-03-01 Alan Modra <amodra@gmail.com> + Fangrui Song <maskray@google.com> + + * 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. + +2021-03-01 Alan Modra <amodra@gmail.com> * ldlang.c (undef_start_stop): For ELF make undefined start/stop symbols undefweak if that was how they were referenced. Undo @@ -5,6 +5,9 @@ * Add -z report-relative-reloc to x86 ELF linker to report dynamic relative relocations. +* Add -z start-stop-gc to disable special treatment of __start_*/__stop_* + references when --gc-sections. + Changes in 2.36: * Add libdep plugin, for linking dependencies of static libraries that diff --git a/ld/emultempl/elf.em b/ld/emultempl/elf.em index 5e59f38..cea89e5 100644 --- a/ld/emultempl/elf.em +++ b/ld/emultempl/elf.em @@ -760,6 +760,10 @@ fragment <<EOF { link_info.flags_1 |= DF_1_GLOBAUDIT; } + else if (CONST_STRNEQ (optarg, "start-stop-gc")) + link_info.start_stop_gc = TRUE; + else if (CONST_STRNEQ (optarg, "nostart-stop-gc")) + link_info.start_stop_gc = FALSE; else if (CONST_STRNEQ (optarg, "start-stop-visibility=")) { if (strcmp (optarg, "start-stop-visibility=default") == 0) @@ -1453,6 +1453,23 @@ Specify a stack size for an ELF @code{PT_GNU_STACK} segment. Specifying zero will override any default non-zero sized @code{PT_GNU_STACK} segment creation. +@item start-stop-gc +@itemx nostart-stop-gc +@cindex start-stop-gc +When @samp{--gc-sections} is in effect, a reference from a retained +section to @code{__start_SECNAME} or @code{__stop_SECNAME} causes all +input sections named @code{SECNAME} to also be retained, if +@code{SECNAME} is representable as a C identifier and either +@code{__start_SECNAME} or @code{__stop_SECNAME} is synthesized by the +linker. @samp{-z start-stop-gc} disables this effect, allowing +sections to be garbage collected as if the special synthesized symbols +were not defined. @samp{-z start-stop-gc} has no effect on a +definition of @code{__start_SECNAME} or @code{__stop_SECNAME} in an +object file or linker script. Such a definition will prevent the +linker providing a synthesized @code{__start_SECNAME} or +@code{__stop_SECNAME} respectively, and therefore the special +treatment by garbage collection for those references. + @item start-stop-visibility=@var{value} @cindex visibility @cindex ELF symbol visibility diff --git a/ld/ldmain.c b/ld/ldmain.c index 5c88ee7..7a3c02a 100644 --- a/ld/ldmain.c +++ b/ld/ldmain.c @@ -357,6 +357,7 @@ main (int argc, char **argv) #ifdef DEFAULT_NEW_DTAGS link_info.new_dtags = DEFAULT_NEW_DTAGS; #endif + link_info.start_stop_gc = FALSE; link_info.start_stop_visibility = STV_PROTECTED; ldfile_add_arch (""); diff --git a/ld/lexsup.c b/ld/lexsup.c index f005a58..36492ab 100644 --- a/ld/lexsup.c +++ b/ld/lexsup.c @@ -2070,8 +2070,6 @@ elf_shlib_list_options (FILE *file) -z common Generate common symbols with STT_COMMON type\n")); fprintf (file, _("\ -z nocommon Generate common symbols with STT_OBJECT type\n")); - fprintf (file, _("\ - -z stack-size=SIZE Set size of stack segment\n")); if (link_info.textrel_check == textrel_check_error) fprintf (file, _("\ -z text Treat DT_TEXTREL in output as error (default)\n")); @@ -2116,8 +2114,12 @@ elf_static_list_options (FILE *file) fprintf (file, _("\ -z defs Report unresolved symbols in object files\n")); fprintf (file, _("\ + -z undefs Ignore unresolved symbols in object files\n")); + fprintf (file, _("\ -z muldefs Allow multiple definitions\n")); fprintf (file, _("\ + -z stack-size=SIZE Set size of stack segment\n")); + fprintf (file, _("\ -z execstack Mark executable as requiring executable stack\n")); fprintf (file, _("\ -z noexecstack Mark executable as not requiring executable stack\n")); @@ -2127,6 +2129,13 @@ elf_static_list_options (FILE *file) -z nounique-symbol Keep duplicated local symbol names (default)\n")); fprintf (file, _("\ -z globalaudit Mark executable requiring global auditing\n")); + fprintf (file, _("\ + -z start-stop-gc Enable garbage collection on __start/__stop\n")); + fprintf (file, _("\ + -z nostart-stop-gc Don't garbage collect __start/__stop (default)\n")); + fprintf (file, _("\ + -z start-stop-visibility=V Set visibility of built-in __start/__stop symbols\n\ + to DEFAULT, PROTECTED, HIDDEN or INTERNAL\n")); } static void diff --git a/ld/testsuite/ld-gc/gc.exp b/ld/testsuite/ld-gc/gc.exp index b3245bb..ad3bc2e 100644 --- a/ld/testsuite/ld-gc/gc.exp +++ b/ld/testsuite/ld-gc/gc.exp @@ -89,6 +89,7 @@ test_gc "Check --gc-section/-r/-u" "gcrel" $ld "-r --gc-sections -u used_func" run_dump_test "noent" run_dump_test "abi-note" run_dump_test "start" +run_dump_test "start2" run_dump_test "stop" run_dump_test "pr19167" if { [is_elf_format] } then { diff --git a/ld/testsuite/ld-gc/start2.d b/ld/testsuite/ld-gc/start2.d new file mode 100644 index 0000000..480dc74 --- /dev/null +++ b/ld/testsuite/ld-gc/start2.d @@ -0,0 +1,10 @@ +#name: --gc-sections with -z start-stop-gc +#ld: --gc-sections -e _start -z start-stop-gc +#nm: -n +#target: *-*-linux* *-*-gnu* arm*-*-uclinuxfdpiceabi +#xfail: bfin-*-*linux* frv-*-* + +#failif +#... +[0-9a-f]+ D +__start__foo +#... diff --git a/ld/testsuite/ld-gc/start2.s b/ld/testsuite/ld-gc/start2.s new file mode 100644 index 0000000..b0084a1 --- /dev/null +++ b/ld/testsuite/ld-gc/start2.s @@ -0,0 +1,7 @@ +.globl _start +_start: + .weak __start__foo + .dc.a __start__foo + .section _foo,"aw",%progbits +foo: + .long 1 |