[PATCH] ld: Add --warn-textrel and obsolete --warn-shared-textrel
H.J. Lu
hjl.tools@gmail.com
Mon May 25 13:51:26 GMT 2020
--warn-shared-textrel and -z text apply to both shared object and PIE.
But include/elf/common.h has
#define ET_EXEC 2 /* Executable file */
#define ET_DYN 3 /* Shared object file */
These predate PIE:
https://groups.google.com/forum/#!topic/generic-abi/mBKlSNldFW4
Updated comments to
#define ET_EXEC 2 /* Position-dependent executable file */
#define ET_DYN 3 /* Position-independent executable or
shared object file */
Add --warn-textrel and obsolete --warn-shared-textrel. Consolidate
--warn-textrel and -z text/notext/textoff implementation.
bfd/
PR ld/22909
* elflink.c (bfd_elf_final_link): Use bfd_link_textrel_check.
Check bfd_link_dll when issue a DT_TEXTREL warning.
* elfxx-x86.c (maybe_set_textrel): Likewise.
(_bfd_x86_elf_size_dynamic_sections): Likewise.
include/
PR ld/22909
* bfdlink.h (textrel_check_method): New enum.
(bfd_link_textrel_check): New.
(bfd_link_info): Replace warn_shared_textrel and error_textrel
with textrel_check.
* elf/common.h: Update comments for ET_EXEC and ET_DYN.
ld/
PR ld/22909
* NEWS: Mention --warn-textrel.
* ld.texi: Update -z text/notext/textoff. Add --warn-textrel.
Remove --warn-shared-textrel.
* ldlex.h (option_values): Rename OPTION_WARN_SHARED_TEXTREL to
OPTION_WARN_TEXTREL.
* lexsup.c (ld_options): Add --warn-textrel. Obsolete
--warn-shared-textrel.
(parse_args): Updated.
(elf_shlib_list_options): Check link_info.textrel_check.
* emultempl/elf.em: Updated.
* testsuite/ld-elf/pr19539.d: Replace -z notext with
--warn-textrel. Expect a warning.
* testsuite/ld-i386/warn1.d: Update expected warning.
---
bfd/elflink.c | 10 ++++++----
bfd/elfxx-x86.c | 6 ++----
include/bfdlink.h | 19 +++++++++++++-----
include/elf/common.h | 5 +++--
ld/NEWS | 3 +++
ld/emultempl/elf.em | 6 +++---
ld/ld.texi | 13 +++++++------
ld/ldlex.h | 2 +-
ld/lexsup.c | 36 +++++++++++++++++++++++++----------
ld/testsuite/ld-elf/pr19539.d | 3 ++-
ld/testsuite/ld-i386/warn1.d | 2 +-
11 files changed, 68 insertions(+), 37 deletions(-)
diff --git a/bfd/elflink.c b/bfd/elflink.c
index c157aea90d..f87927f0bd 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -12896,8 +12896,7 @@ bfd_elf_final_link (bfd *abfd, struct bfd_link_info *info)
goto error_return;
/* Check for DT_TEXTREL (late, in case the backend removes it). */
- if (((info->warn_shared_textrel && bfd_link_pic (info))
- || info->error_textrel)
+ if (bfd_link_textrel_check (info)
&& (o = bfd_get_linker_section (dynobj, ".dynamic")) != NULL)
{
bfd_byte *dyncon, *dynconend;
@@ -12912,12 +12911,15 @@ bfd_elf_final_link (bfd *abfd, struct bfd_link_info *info)
if (dyn.d_tag == DT_TEXTREL)
{
- if (info->error_textrel)
+ if (info->textrel_check == textrel_check_error)
info->callbacks->einfo
(_("%P%X: read-only segment has dynamic relocations\n"));
+ else if (bfd_link_dll (info))
+ info->callbacks->einfo
+ (_("%P: warning: creating DT_TEXTREL in a shared object\n"));
else
info->callbacks->einfo
- (_("%P: warning: creating a DT_TEXTREL in a shared object\n"));
+ (_("%P: warning: creating DT_TEXTREL in a PIE\n"));
break;
}
}
diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c
index 9679dca981..6cc47afd7e 100644
--- a/bfd/elfxx-x86.c
+++ b/bfd/elfxx-x86.c
@@ -575,8 +575,7 @@ maybe_set_textrel (struct elf_link_hash_entry *h, void *inf)
"in read-only section `%pA'\n"),
sec->owner, h->root.root.string, sec);
- if ((info->warn_shared_textrel && bfd_link_pic (info))
- || info->error_textrel)
+ if (bfd_link_textrel_check (info))
/* xgettext:c-format */
info->callbacks->einfo (_("%P: %pB: warning: relocation against `%s' "
"in read-only section `%pA'\n"),
@@ -1117,8 +1116,7 @@ _bfd_x86_elf_size_dynamic_sections (bfd *output_bfd,
&& (info->flags & DF_TEXTREL) == 0)
{
info->flags |= DF_TEXTREL;
- if ((info->warn_shared_textrel && bfd_link_pic (info))
- || info->error_textrel)
+ if (bfd_link_textrel_check (info))
/* xgettext:c-format */
info->callbacks->einfo
(_("%P: %pB: warning: relocation "
diff --git a/include/bfdlink.h b/include/bfdlink.h
index ec97679e6f..34a0d2ec4e 100644
--- a/include/bfdlink.h
+++ b/include/bfdlink.h
@@ -273,6 +273,18 @@ enum report_method
RM_DIAGNOSE,
};
+/* How to handle DT_TEXTREL. */
+
+enum textrel_check_method
+{
+ textrel_check_none,
+ textrel_check_warning,
+ textrel_check_error
+};
+
+#define bfd_link_textrel_check(info) \
+ (info->textrel_check != textrel_check_none)
+
typedef enum {with_flags, without_flags} flag_type;
/* A section flag list. */
@@ -410,11 +422,8 @@ struct bfd_link_info
should be created. 1 for DWARF2 tables, 2 for compact tables. */
unsigned int eh_frame_hdr_type: 2;
- /* TRUE if we should warn when adding a DT_TEXTREL to a shared object. */
- unsigned int warn_shared_textrel: 1;
-
- /* TRUE if we should error when adding a DT_TEXTREL. */
- unsigned int error_textrel: 1;
+ /* What to do with DT_TEXTREL in output. */
+ ENUM_BITFIELD (textrel_check_method) textrel_check: 2;
/* TRUE if .hash section should be created. */
unsigned int emit_hash: 1;
diff --git a/include/elf/common.h b/include/elf/common.h
index 26e6fbc8e6..4d94c4fd5b 100644
--- a/include/elf/common.h
+++ b/include/elf/common.h
@@ -91,8 +91,9 @@
#define ET_NONE 0 /* No file type */
#define ET_REL 1 /* Relocatable file */
-#define ET_EXEC 2 /* Executable file */
-#define ET_DYN 3 /* Shared object file */
+#define ET_EXEC 2 /* Position-dependent executable file */
+#define ET_DYN 3 /* Position-independent executable or
+ shared object file */
#define ET_CORE 4 /* Core file */
#define ET_LOOS 0xFE00 /* Operating system-specific */
#define ET_HIOS 0xFEFF /* Operating system-specific */
diff --git a/ld/NEWS b/ld/NEWS
index 9f5bbe51cf..0aaa13d487 100644
--- a/ld/NEWS
+++ b/ld/NEWS
@@ -1,5 +1,8 @@
-*- text -*-
+* Add a command-line option for ELF linker, --warn-textrel, to warn that
+ DT_TEXTREL is set in a position-independent executable or shared object.
+
* Add command-line options --enable-non-contiguous-regions and
--enable-non-contiguous-regions-warnings.
diff --git a/ld/emultempl/elf.em b/ld/emultempl/elf.em
index 4fd6fdffe7..c4979eb953 100644
--- a/ld/emultempl/elf.em
+++ b/ld/emultempl/elf.em
@@ -803,11 +803,11 @@ fragment <<EOF
else if (strcmp (optarg, "nocommon") == 0)
link_info.elf_stt_common = no_elf_stt_common;
else if (strcmp (optarg, "text") == 0)
- link_info.error_textrel = TRUE;
+ link_info.textrel_check = textrel_check_error;
else if (strcmp (optarg, "notext") == 0)
- link_info.error_textrel = FALSE;
+ link_info.textrel_check = textrel_check_none;
else if (strcmp (optarg, "textoff") == 0)
- link_info.error_textrel = FALSE;
+ link_info.textrel_check = textrel_check_none;
EOF
fi
diff --git a/ld/ld.texi b/ld/ld.texi
index 4dc78e65fa..a7ec0d01b3 100644
--- a/ld/ld.texi
+++ b/ld/ld.texi
@@ -1358,9 +1358,9 @@ Specifying zero will override any default non-zero sized
@item text
@itemx notext
@itemx textoff
-Report an error if DT_TEXTREL is set, i.e., if the binary has dynamic
-relocations in read-only sections. Don't report an error if
-@samp{notext} or @samp{textoff}.
+Report an error if DT_TEXTREL is set, i.e., if the position-independent
+or shared object has dynamic relocations in read-only sections. Don't
+report an error if @samp{notext} or @samp{textoff}.
@item undefs
Do not report unresolved symbol references from regular object files,
@@ -2404,9 +2404,10 @@ The address will only be changed if it not explicitly specified; that
is, if the @code{SECTIONS} command does not specify a start address for
the section (@pxref{SECTIONS}).
-@kindex --warn-shared-textrel
-@item --warn-shared-textrel
-Warn if the linker adds a DT_TEXTREL to a shared object.
+@kindex --warn-textrel
+@item --warn-textrel
+Warn if the linker adds DT_TEXTREL to a position-independent executable
+or shared object.
@kindex --warn-alternate-em
@item --warn-alternate-em
diff --git a/ld/ldlex.h b/ld/ldlex.h
index 22b928d2d9..318ac7a789 100644
--- a/ld/ldlex.h
+++ b/ld/ldlex.h
@@ -130,7 +130,7 @@ enum option_values
OPTION_UNRESOLVED_SYMBOLS,
OPTION_WARN_UNRESOLVED_SYMBOLS,
OPTION_ERROR_UNRESOLVED_SYMBOLS,
- OPTION_WARN_SHARED_TEXTREL,
+ OPTION_WARN_TEXTREL,
OPTION_WARN_ALTERNATE_EM,
OPTION_REDUCE_MEMORY_OVERHEADS,
#ifdef ENABLE_PLUGINS
diff --git a/ld/lexsup.c b/ld/lexsup.c
index 04db2f129f..3733a7c893 100644
--- a/ld/lexsup.c
+++ b/ld/lexsup.c
@@ -516,9 +516,11 @@ static const struct ld_option ld_options[] =
{ {"warn-section-align", no_argument, NULL, OPTION_WARN_SECTION_ALIGN},
'\0', NULL, N_("Warn if start of section changes due to alignment"),
TWO_DASHES },
- { {"warn-shared-textrel", no_argument, NULL, OPTION_WARN_SHARED_TEXTREL},
- '\0', NULL, N_("Warn if shared object has DT_TEXTREL"),
+ { {"warn-textrel", no_argument, NULL, OPTION_WARN_TEXTREL},
+ '\0', NULL, N_("Warn if outpout has DT_TEXTREL"),
TWO_DASHES },
+ { {"warn-shared-textrel", no_argument, NULL, OPTION_WARN_TEXTREL},
+ '\0', NULL, NULL, NO_HELP },
{ {"warn-alternate-em", no_argument, NULL, OPTION_WARN_ALTERNATE_EM},
'\0', NULL, N_("Warn if an object has alternate ELF machine code"),
TWO_DASHES },
@@ -1438,8 +1440,8 @@ parse_args (unsigned argc, char **argv)
case OPTION_WARN_SECTION_ALIGN:
config.warn_section_align = TRUE;
break;
- case OPTION_WARN_SHARED_TEXTREL:
- link_info.warn_shared_textrel = TRUE;
+ case OPTION_WARN_TEXTREL:
+ link_info.textrel_check = textrel_check_warning;
break;
case OPTION_WARN_ALTERNATE_EM:
link_info.warn_alternate_em = TRUE;
@@ -1846,12 +1848,26 @@ elf_shlib_list_options (FILE *file)
-z nocommon Generate common symbols with STT_OBJECT type\n"));
fprintf (file, _("\
-z stack-size=SIZE Set size of stack segment\n"));
- fprintf (file, _("\
- -z text Treat DT_TEXTREL in shared object as error\n"));
- fprintf (file, _("\
- -z notext Don't treat DT_TEXTREL in shared object as error\n"));
- fprintf (file, _("\
- -z textoff Don't treat DT_TEXTREL in shared object as error\n"));
+ if (link_info.textrel_check == textrel_check_error)
+ fprintf (file, _("\
+ -z text Treat DT_TEXTREL in output as error (default)\n"));
+ else
+ fprintf (file, _("\
+ -z text Treat DT_TEXTREL in output as error\n"));
+ if (link_info.textrel_check == textrel_check_none)
+ {
+ fprintf (file, _("\
+ -z notext Don't treat DT_TEXTREL in output as error (default)\n"));
+ fprintf (file, _("\
+ -z textoff Don't treat DT_TEXTREL in output as error (default)\n"));
+ }
+ else
+ {
+ fprintf (file, _("\
+ -z notext Don't treat DT_TEXTREL in output as error\n"));
+ fprintf (file, _("\
+ -z textoff Don't treat DT_TEXTREL in output as error\n"));
+ }
}
static void
diff --git a/ld/testsuite/ld-elf/pr19539.d b/ld/testsuite/ld-elf/pr19539.d
index 56e6502ca6..211d3e1639 100644
--- a/ld/testsuite/ld-elf/pr19539.d
+++ b/ld/testsuite/ld-elf/pr19539.d
@@ -1,7 +1,8 @@
#source: start.s
#source: pr19539.s
-#ld: -pie -T pr19539.t -z notext
+#ld: -pie -T pr19539.t --warn-textrel
#readelf : --dyn-syms --wide
+#warning: .*: creating DT_TEXTREL in a PIE
#target: *-*-linux* *-*-gnu* *-*-solaris* arm*-*-uclinuxfdpiceabi
#xfail: cris*-*-* ![check_pie_support]
diff --git a/ld/testsuite/ld-i386/warn1.d b/ld/testsuite/ld-i386/warn1.d
index 3c78f31efd..c00fdb36dc 100644
--- a/ld/testsuite/ld-i386/warn1.d
+++ b/ld/testsuite/ld-i386/warn1.d
@@ -1,4 +1,4 @@
#name: --warn-shared-textrel --fatal-warnings
#as: --32
#ld: -shared -melf_i386 --warn-shared-textrel --fatal-warnings
-#error: .*warning: creating a DT_TEXTREL in a shared object
+#error: .*warning: creating DT_TEXTREL in a shared object
--
2.26.2
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