From 5c87fb1d59b8414796016af7e5ea8c97675e1141 Mon Sep 17 00:00:00 2001 From: Alan Modra <amodra@gmail.com> Date: Mon, 6 Feb 2023 12:46:52 +1030 Subject: [PATCH] ppc32 and "LOAD segment with RWX permissions" When using a bss-plt we'll always trigger the RWX warning, which disturbs gcc test results. On the other hand, there may be reason to want the warning when gcc is configured with --enable-secureplt. So turning off the warning entirely for powerpc might not be the best solution. Instead, we'll turn off the warning whenever a bss-plt is generated, unless the user explicitly asked for the warning. bfd/ * elf32-ppc.c (ppc_elf_select_plt_layout): Set no_warn_rwx_segments on generating a bss plt, unless explicity enabled by the user. Also show the bss-plt warning when --warn-rwx-segments is given without --bss-plt. include/ * bfdlink.h (struct bfd_link_info): Add user_warn_rwx_segments. ld/ * lexsup.c (parse_args): Set user_warn_rwx_segments. * testsuite/ld-elf/elf.exp: Pass --secure-plt for powerpc to the rwx tests. (cherry picked from commit 84789002905d6db444ee76431705c86cbcde5616) --- bfd/elf32-ppc.c | 17 ++++++++++++----- include/bfdlink.h | 3 +++ ld/lexsup.c | 2 ++ ld/testsuite/ld-elf/elf.exp | 8 ++++++++ 4 files changed, 25 insertions(+), 5 deletions(-) diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c index a8234f27a8a4..833bc744563f 100644 --- a/bfd/elf32-ppc.c +++ b/bfd/elf32-ppc.c @@ -4020,12 +4020,19 @@ ppc_elf_select_plt_layout (bfd *output_bfd ATTRIBUTE_UNUSED, htab->plt_type = plt_type; } } - if (htab->plt_type == PLT_OLD && htab->params->plt_style == PLT_NEW) + if (htab->plt_type == PLT_OLD) { - if (htab->old_bfd != NULL) - _bfd_error_handler (_("bss-plt forced due to %pB"), htab->old_bfd); - else - _bfd_error_handler (_("bss-plt forced by profiling")); + if (!info->user_warn_rwx_segments) + info->no_warn_rwx_segments = 1; + if (htab->params->plt_style == PLT_NEW + || (htab->params->plt_style != PLT_OLD + && !info->no_warn_rwx_segments)) + { + if (htab->old_bfd != NULL) + _bfd_error_handler (_("bss-plt forced due to %pB"), htab->old_bfd); + else + _bfd_error_handler (_("bss-plt forced by profiling")); + } } BFD_ASSERT (htab->plt_type != PLT_VXWORKS); diff --git a/include/bfdlink.h b/include/bfdlink.h index 26c459c3815e..840790a298c3 100644 --- a/include/bfdlink.h +++ b/include/bfdlink.h @@ -501,6 +501,9 @@ struct bfd_link_info /* TRUE if warnings should not be generated for TLS segments with eXecute permission or LOAD segments with RWX permissions. */ unsigned int no_warn_rwx_segments: 1; + /* TRUE if the user gave either --warn-rwx-segments or + --no-warn-rwx-segments. */ + unsigned int user_warn_rwx_segments: 1; /* TRUE if the stack can be made executable because of the absence of a .note.GNU-stack section in an input file. Note - even if this field diff --git a/ld/lexsup.c b/ld/lexsup.c index c59603855729..a1c6140100de 100644 --- a/ld/lexsup.c +++ b/ld/lexsup.c @@ -936,9 +936,11 @@ parse_args (unsigned argc, char **argv) break; case OPTION_WARN_RWX_SEGMENTS: link_info.no_warn_rwx_segments = 0; + link_info.user_warn_rwx_segments = 1; break; case OPTION_NO_WARN_RWX_SEGMENTS: link_info.no_warn_rwx_segments = 1; + link_info.user_warn_rwx_segments = 1; break; case 'e': lang_add_entry (optarg, true); diff --git a/ld/testsuite/ld-elf/elf.exp b/ld/testsuite/ld-elf/elf.exp index a3a8994749d2..35235a08d8a9 100644 --- a/ld/testsuite/ld-elf/elf.exp +++ b/ld/testsuite/ld-elf/elf.exp @@ -238,6 +238,12 @@ if { [istarget *-*-*linux*] return $text } + set curr_ldflags $LDFLAGS + if { [istarget powerpc*-*-*] && ![istarget powerpc64*-*-*] } { + # Don't generate an executable .plt section + set LDFLAGS "$LDFLAGS --secure-plt" + } + # Since the warnings can be disabled by configure, ensure consistency # of the first test by forcing the flags. run_ld_link_tests [list \ @@ -285,6 +291,8 @@ if { [istarget *-*-*linux*] "rwx-segments-3.exe"] \ ] + set LDFLAGS $curr_ldflags + if { [target_defaults_to_execstack] } { run_ld_link_tests [list \ [list "PR ld/29072 (warn about absent .note.GNU-stack)" \ -- 2.39.2