[binutils-gdb] x86-64: Add GLIBC_ABI_DT_X86_64_PLT version dependency
H.J. Lu
hjl@sourceware.org
Wed Aug 20 21:31:21 GMT 2025
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=66e4999f343f85116cf2dda137cc0f31ac793ce6
commit 66e4999f343f85116cf2dda137cc0f31ac793ce6
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Sun Aug 17 10:09:25 2025 -0700
x86-64: Add GLIBC_ABI_DT_X86_64_PLT version dependency
On Linux/x86-64, programs and shared libraries created with -z mark-plt
have the GLIBC_2.36 version tag dependency since -z mark-plt uses the
r_addend field of the R_X86_64_JUMP_SLOT relocation to store the offset
of the indirect branch instruction. Glibc versions which don't have the
commit added to glibc 2.36:
commit f8587a61892cbafd98ce599131bf4f103466f084
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri May 20 19:21:48 2022 -0700
x86-64: Ignore r_addend for R_X86_64_GLOB_DAT/R_X86_64_JUMP_SLOT
won't ignore the r_addend value in the R_X86_64_JUMP_SLOT relocation. If
glibc versions defines GLIBC_ABI_DT_X86_64_PLT version tag with
commit 399384e0c8193e31aea014220ccfa24300ae5938
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Thu Aug 14 07:03:20 2025 -0700
x86-64: Add GLIBC_ABI_DT_X86_64_PLT [BZ #33212]
to indicate inclusion of the commit:
commit f8587a61892cbafd98ce599131bf4f103466f084
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri May 20 19:21:48 2022 -0700
x86-64: Ignore r_addend for R_X86_64_GLOB_DAT/R_X86_64_JUMP_SLOT
we can add GLIBC_ABI_DT_X86_64_PLT version tag dependency, instead of
GLIBC_2.36 version tag dependency.
PR ld/33213
* elf-bfd.h (_bfd_elf_link_add_glibc_version_dependency): Change
return type to bool.
* elf64-x86-64.c (elf_x86_64_add_glibc_version_dependency): Add
GLIBC_ABI_DT_X86_64_PLT version tag dependency, instead of,
GLIBC_2.36 version tag dependency, for -z mark-plt if libc.so
defines GLIBC_ABI_DT_X86_64_PLT version tag.
* elflink.c (_bfd_elf_link_add_glibc_version_dependency): Change
return type to bool. Return false if elf_link_add_glibc_verneed
returns false.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Diff:
---
bfd/elf-bfd.h | 2 +-
bfd/elf64-x86-64.c | 24 +++++++++++++++++++-----
bfd/elflink.c | 6 ++++--
ld/testsuite/ld-x86-64/mark-plt-1a.rd | 2 +-
4 files changed, 25 insertions(+), 9 deletions(-)
diff --git a/bfd/elf-bfd.h b/bfd/elf-bfd.h
index feb470fc477..de7cc410a99 100644
--- a/bfd/elf-bfd.h
+++ b/bfd/elf-bfd.h
@@ -2631,7 +2631,7 @@ extern bool _bfd_elf_link_output_relocs
(bfd *, asection *, Elf_Internal_Shdr *, Elf_Internal_Rela *,
struct elf_link_hash_entry **);
-extern void _bfd_elf_link_add_glibc_version_dependency
+extern bool _bfd_elf_link_add_glibc_version_dependency
(struct elf_find_verdep_info *, const char *const [], bool *);
extern void _bfd_elf_link_add_dt_relr_dependency
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 352dca65fdd..580975b6d67 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -6246,7 +6246,7 @@ static void
elf_x86_64_add_glibc_version_dependency
(struct elf_find_verdep_info *rinfo)
{
- unsigned int i = 0;
+ int i = 0, mark_plt = -1;
const char *version[4] = { NULL, NULL, NULL, NULL };
bool auto_version[4] = { false, false, false, false };
struct elf_x86_link_hash_table *htab;
@@ -6271,14 +6271,28 @@ elf_x86_64_add_glibc_version_dependency
}
if (htab->params->mark_plt)
{
- version[i] = "GLIBC_2.36";
+ mark_plt = i;
+ auto_version[i] = true;
+ version[i] = "GLIBC_ABI_DT_X86_64_PLT";
i++;
}
}
- if (i != 0)
- _bfd_elf_link_add_glibc_version_dependency (rinfo, version,
- auto_version);
+ if (i == 0
+ || !_bfd_elf_link_add_glibc_version_dependency (rinfo, version,
+ auto_version))
+ return;
+
+ if (mark_plt < 0 || auto_version[mark_plt])
+ return;
+
+ /* Add the GLIBC_2.36 version dependency if libc.so doesn't have
+ GLIBC_ABI_DT_X86_64_PLT. */
+ version[0] = "GLIBC_2.36";
+ auto_version[0] = false;
+ version[1] = NULL;
+ _bfd_elf_link_add_glibc_version_dependency (rinfo, version,
+ auto_version);
}
static const struct bfd_elf_special_section
diff --git a/bfd/elflink.c b/bfd/elflink.c
index d2c43f31bf5..53ec792852c 100644
--- a/bfd/elflink.c
+++ b/bfd/elflink.c
@@ -2399,7 +2399,7 @@ elf_link_add_glibc_verneed (struct elf_find_verdep_info *rinfo,
/* Add VERSION_DEP to the list of version dependencies when linked
against glibc. */
-void
+bool
_bfd_elf_link_add_glibc_version_dependency
(struct elf_find_verdep_info *rinfo,
const char *const version_dep[],
@@ -2412,11 +2412,13 @@ _bfd_elf_link_add_glibc_version_dependency
/* Return if not linked against glibc. */
if (!elf_link_add_glibc_verneed (rinfo, *version_dep,
&glibc_minor_base, auto_version))
- return;
+ return false;
version_dep++;
auto_version++;
}
while (*version_dep != NULL);
+
+ return true;
}
/* Add GLIBC_ABI_DT_RELR to the list of version dependencies when
diff --git a/ld/testsuite/ld-x86-64/mark-plt-1a.rd b/ld/testsuite/ld-x86-64/mark-plt-1a.rd
index 1234fbe038c..b0ed7024420 100644
--- a/ld/testsuite/ld-x86-64/mark-plt-1a.rd
+++ b/ld/testsuite/ld-x86-64/mark-plt-1a.rd
@@ -3,5 +3,5 @@ Version needs section '.gnu.version_r' contains 1 entry:
Addr: 0x[0-9a-f]+ +Offset: 0x[0-9a-f]+ +Link: +[0-9]+ +\(.dynstr\)
+0+: Version: 1 +File: libc\.so\.6(|\.1) +Cnt: +[0-9]+
#...
- 0x[a-f0-9]+: Name: GLIBC_2.36 Flags: none Version: [0-9]+
+ 0x[a-f0-9]+: Name: (GLIBC_2.36|GLIBC_ABI_DT_X86_64_PLT) Flags: none Version: [0-9]+
#pass
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