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[PATCH] ld: Add _bfd_elf_link_hide_sym_by_version
- From: "H.J. Lu" <hongjiu dot lu at intel dot com>
- To: binutils at sourceware dot org
- Date: Mon, 21 May 2018 08:06:06 -0700
- Subject: [PATCH] ld: Add _bfd_elf_link_hide_sym_by_version
- Reply-to: "H.J. Lu" <hjl dot tools at gmail dot com>
bfd_hide_sym_by_version can't be used to check if a versioned symbol is
hidden. This patch adds _bfd_elf_link_hide_sym_by_version to support
both versioned and unversioned symbols by extracting versioned symbol
check from _bfd_elf_link_assign_sym_version.
OK for master?
H.J.
---
bfd/
PR ld/23194
* elf-bfd.h (_bfd_elf_link_hide_sym_by_version): New.
* elflink.c (_bfd_elf_link_hide_versioned_symbol): New function.
Extracted from _bfd_elf_link_assign_sym_version.
(_bfd_elf_link_hide_sym_by_version): New function.
(_bfd_elf_link_assign_sym_version): Use
_bfd_elf_link_hide_versioned_symbol.
* elfxx-x86.c (_bfd_x86_elf_link_symbol_references_local): Call
_bfd_elf_link_hide_sym_by_version instead of
bfd_hide_sym_by_version. Don't check unversioned symbol.
ld/
PR ld/23194
* testsuite/ld-i386/pr23194.d: Expect only R_386_GLOB_DAT
against foobar.
* testsuite/ld-i386/pr23194.map: Add foobar.
* testsuite/ld-x86-64/pr23194.map: Likewise.
* testsuite/ld-i386/pr23194.s: Add a common foobar symbol.
* testsuite/ld-x86-64/pr23194.s: Likewise.
* testsuite/ld-x86-64/pr23194.d: Expect only R_X86_64_GLOB_DAT
against foobar.
---
bfd/elf-bfd.h | 3 +
bfd/elflink.c | 164 +++++++++++++++++++++--------
bfd/elfxx-x86.c | 11 +-
ld/testsuite/ld-i386/pr23194.d | 2 +-
ld/testsuite/ld-i386/pr23194.map | 1 +
ld/testsuite/ld-i386/pr23194.s | 3 +-
ld/testsuite/ld-x86-64/pr23194.d | 2 +-
ld/testsuite/ld-x86-64/pr23194.map | 1 +
ld/testsuite/ld-x86-64/pr23194.s | 3 +-
9 files changed, 134 insertions(+), 56 deletions(-)
diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
index 7b746900ba..ad958f3c86 100644
--- a/bfd/elf-bfd.h
+++ b/bfd/elf-bfd.h
@@ -2184,6 +2184,9 @@ extern const struct bfd_elf_special_section *_bfd_elf_get_special_section
extern const struct bfd_elf_special_section *_bfd_elf_get_sec_type_attr
(bfd *, asection *);
+extern bfd_boolean _bfd_elf_link_hide_sym_by_version
+ (struct bfd_link_info *, struct elf_link_hash_entry *);
+
/* If the target doesn't have reloc handling written yet: */
extern bfd_boolean _bfd_elf_no_info_to_howto
(bfd *, arelent *, Elf_Internal_Rela *);
diff --git a/bfd/elflink.c b/bfd/elflink.c
index ce3765e45b..734f8f88ad 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -2221,6 +2221,115 @@ _bfd_elf_link_find_version_dependencies (struct elf_link_hash_entry *h,
return TRUE;
}
+/* Return TRUE and set *HIDE to TRUE if the versioned symbol is
+ hidden. Set *T_P to NULL if there is no match. */
+
+static bfd_boolean
+_bfd_elf_link_hide_versioned_symbol (struct bfd_link_info *info,
+ struct elf_link_hash_entry *h,
+ const char *version_p,
+ struct bfd_elf_version_tree **t_p,
+ bfd_boolean *hide)
+{
+ struct bfd_elf_version_tree *t;
+
+ /* Look for the version. If we find it, it is no longer weak. */
+ for (t = info->version_info; t != NULL; t = t->next)
+ {
+ if (strcmp (t->name, version_p) == 0)
+ {
+ size_t len;
+ char *alc;
+ struct bfd_elf_version_expr *d;
+
+ len = version_p - h->root.root.string;
+ alc = (char *) bfd_malloc (len);
+ if (alc == NULL)
+ return FALSE;
+ memcpy (alc, h->root.root.string, len - 1);
+ alc[len - 1] = '\0';
+ if (alc[len - 2] == ELF_VER_CHR)
+ alc[len - 2] = '\0';
+
+ h->verinfo.vertree = t;
+ t->used = TRUE;
+ d = NULL;
+
+ if (t->globals.list != NULL)
+ d = (*t->match) (&t->globals, NULL, alc);
+
+ /* See if there is anything to force this symbol to
+ local scope. */
+ if (d == NULL && t->locals.list != NULL)
+ {
+ d = (*t->match) (&t->locals, NULL, alc);
+ if (d != NULL
+ && h->dynindx != -1
+ && ! info->export_dynamic)
+ *hide = TRUE;
+ }
+
+ free (alc);
+ break;
+ }
+ }
+
+ *t_p = t;
+
+ return TRUE;
+}
+
+/* Return TRUE if the symbol H is hidden by version script. */
+
+bfd_boolean
+_bfd_elf_link_hide_sym_by_version (struct bfd_link_info *info,
+ struct elf_link_hash_entry *h)
+{
+ const char *p;
+ bfd_boolean hide = FALSE;
+ const struct elf_backend_data *bed
+ = get_elf_backend_data (info->output_bfd);
+
+ /* Version script only hides symbols defined in regular objects. */
+ if (!h->def_regular && !ELF_COMMON_DEF_P (h))
+ return TRUE;
+
+ p = strchr (h->root.root.string, ELF_VER_CHR);
+ if (p != NULL && h->verinfo.vertree == NULL)
+ {
+ struct bfd_elf_version_tree *t;
+
+ ++p;
+ if (*p == ELF_VER_CHR)
+ ++p;
+
+ if (*p != '\0'
+ && _bfd_elf_link_hide_versioned_symbol (info, h, p, &t, &hide)
+ && hide)
+ {
+ if (hide)
+ (*bed->elf_backend_hide_symbol) (info, h, TRUE);
+ return TRUE;
+ }
+ }
+
+ /* If we don't have a version for this symbol, see if we can find
+ something. */
+ if (h->verinfo.vertree == NULL && info->version_info != NULL)
+ {
+ h->verinfo.vertree
+ = bfd_find_version_for_sym (info->version_info,
+ h->root.root.string, &hide);
+ if (h->verinfo.vertree != NULL && hide)
+ {
+ (*bed->elf_backend_hide_symbol) (info, h, TRUE);
+ return TRUE;
+ }
+ }
+
+ return FALSE;
+}
+
/* Figure out appropriate versions for all the symbols. We may not
have the version number script until we have read all of the input
files, so until that point we don't know which symbols should be
@@ -2234,6 +2343,7 @@ _bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data)
const struct elf_backend_data *bed;
struct elf_info_failed eif;
char *p;
+ bfd_boolean hide;
sinfo = (struct elf_info_failed *) data;
info = sinfo->info;
@@ -2253,6 +2363,7 @@ _bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data)
if (!h->def_regular)
return TRUE;
+ hide = FALSE;
bed = get_elf_backend_data (info->output_bfd);
p = strchr (h->root.root.string, ELF_VER_CHR);
if (p != NULL && h->verinfo.vertree == NULL)
@@ -2267,50 +2378,15 @@ _bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data)
if (*p == '\0')
return TRUE;
- /* Look for the version. If we find it, it is no longer weak. */
- for (t = sinfo->info->version_info; t != NULL; t = t->next)
+ if (!_bfd_elf_link_hide_versioned_symbol (info, h, p, &t, &hide))
{
- if (strcmp (t->name, p) == 0)
- {
- size_t len;
- char *alc;
- struct bfd_elf_version_expr *d;
-
- len = p - h->root.root.string;
- alc = (char *) bfd_malloc (len);
- if (alc == NULL)
- {
- sinfo->failed = TRUE;
- return FALSE;
- }
- memcpy (alc, h->root.root.string, len - 1);
- alc[len - 1] = '\0';
- if (alc[len - 2] == ELF_VER_CHR)
- alc[len - 2] = '\0';
-
- h->verinfo.vertree = t;
- t->used = TRUE;
- d = NULL;
-
- if (t->globals.list != NULL)
- d = (*t->match) (&t->globals, NULL, alc);
-
- /* See if there is anything to force this symbol to
- local scope. */
- if (d == NULL && t->locals.list != NULL)
- {
- d = (*t->match) (&t->locals, NULL, alc);
- if (d != NULL
- && h->dynindx != -1
- && ! info->export_dynamic)
- (*bed->elf_backend_hide_symbol) (info, h, TRUE);
- }
-
- free (alc);
- break;
- }
+ sinfo->failed = TRUE;
+ return FALSE;
}
+ if (hide)
+ (*bed->elf_backend_hide_symbol) (info, h, TRUE);
+
/* If we are building an application, we need to create a
version node for this version. */
if (t == NULL && bfd_link_executable (info))
@@ -2366,10 +2442,10 @@ _bfd_elf_link_assign_sym_version (struct elf_link_hash_entry *h, void *data)
/* If we don't have a version for this symbol, see if we can find
something. */
- if (h->verinfo.vertree == NULL && sinfo->info->version_info != NULL)
+ if (!hide
+ && h->verinfo.vertree == NULL
+ && sinfo->info->version_info != NULL)
{
- bfd_boolean hide;
-
h->verinfo.vertree
= bfd_find_version_for_sym (sinfo->info->version_info,
h->root.root.string, &hide);
diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c
index 29d92d288a..cb2487eacd 100644
--- a/bfd/elfxx-x86.c
+++ b/bfd/elfxx-x86.c
@@ -2038,21 +2038,16 @@ _bfd_x86_elf_link_symbol_references_local (struct bfd_link_info *info,
&& htab->interp == NULL)
|| info->dynamic_undefined_weak == 0))
|| ((h->def_regular || ELF_COMMON_DEF_P (h))
- && h->versioned == unversioned
&& info->version_info != NULL
- && bfd_hide_sym_by_version (info->version_info,
- h->root.root.string)))
+ && _bfd_elf_link_hide_sym_by_version (info, h)))
{
eh->local_ref = 2;
return TRUE;
}
/* Symbols created by HIDDEN and PROVIDE_HIDDEN assignments in linker
- script aren't forced local here yet. bfd_hide_sym_by_version
- can't be used to check if a versioned symbol is hidden. It has to
- be syncd with _bfd_elf_link_assign_sym_version to get the correct
- answer. */
- if (!h->root.ldscript_def && h->versioned == unversioned)
+ script aren't forced local here yet. */
+ if (!h->root.ldscript_def)
eh->local_ref = 1;
return FALSE;
diff --git a/ld/testsuite/ld-i386/pr23194.d b/ld/testsuite/ld-i386/pr23194.d
index b5e8c3330e..f6d2a03b5d 100644
--- a/ld/testsuite/ld-i386/pr23194.d
+++ b/ld/testsuite/ld-i386/pr23194.d
@@ -4,4 +4,4 @@
Relocation section '.rel.dyn' at offset 0x[0-9a-f]+ contains 1 entry:
Offset Info Type Sym. Value Symbol's Name
-[0-9a-f]+ +[0-9a-f]+ +R_386_RELATIVE +
+[0-9a-f]+ +[0-9a-f]+ +R_386_GLOB_DAT +[0-9a-f]+ +foobar@@FOO
diff --git a/ld/testsuite/ld-i386/pr23194.map b/ld/testsuite/ld-i386/pr23194.map
index 353c194af5..196dac9639 100644
--- a/ld/testsuite/ld-i386/pr23194.map
+++ b/ld/testsuite/ld-i386/pr23194.map
@@ -1,6 +1,7 @@
FOO {
global:
bar;
+ foobar;
local:
*;
};
diff --git a/ld/testsuite/ld-i386/pr23194.s b/ld/testsuite/ld-i386/pr23194.s
index 32693feb7f..a64bae16fe 100644
--- a/ld/testsuite/ld-i386/pr23194.s
+++ b/ld/testsuite/ld-i386/pr23194.s
@@ -3,10 +3,11 @@
.globl foo
.type foo, @function
foo:
- ret
+ movl foobar@GOT(%ebx), %eax
.size foo, .-foo
.globl bar
.type bar, @function
bar:
jmp *foo@GOT(%eax)
.size bar, .-bar
+ .comm foobar,30,4
diff --git a/ld/testsuite/ld-x86-64/pr23194.d b/ld/testsuite/ld-x86-64/pr23194.d
index 6b12060822..b907afbceb 100644
--- a/ld/testsuite/ld-x86-64/pr23194.d
+++ b/ld/testsuite/ld-x86-64/pr23194.d
@@ -4,4 +4,4 @@
Relocation section '.rela.dyn' at offset 0x[0-9a-f]+ contains 1 entry:
Offset Info Type Symbol's Value Symbol's Name \+ Addend
-[0-9a-f]+ +[0-9a-f]+ +R_X86_64_RELATIVE +[0-9a-f]+
+[0-9a-f]+ +[0-9a-f]+ +R_X86_64_GLOB_DAT +[0-9a-f]+ +foobar@@FOO \+ 0
diff --git a/ld/testsuite/ld-x86-64/pr23194.map b/ld/testsuite/ld-x86-64/pr23194.map
index 353c194af5..196dac9639 100644
--- a/ld/testsuite/ld-x86-64/pr23194.map
+++ b/ld/testsuite/ld-x86-64/pr23194.map
@@ -1,6 +1,7 @@
FOO {
global:
bar;
+ foobar;
local:
*;
};
diff --git a/ld/testsuite/ld-x86-64/pr23194.s b/ld/testsuite/ld-x86-64/pr23194.s
index 277c19d6dc..34517bc7e2 100644
--- a/ld/testsuite/ld-x86-64/pr23194.s
+++ b/ld/testsuite/ld-x86-64/pr23194.s
@@ -3,10 +3,11 @@
.globl foo
.type foo, @function
foo:
- ret
+ movq foobar@GOTPCREL(%rip), %rax
.size foo, .-foo
.globl bar
.type bar, @function
bar:
jmp *foo@GOTPCREL(%rip)
.size bar, .-bar
+ .comm foobar,30,4
--
2.17.0