x86: Add GLIBC_ABI_GNU2_TLS version dependency

On Linux/x86, programs and shared libraries compiled with
-mtls-dialect=gnu2 may fail silently at run-time against glibc without
the GNU2 TLS run-time fixes for:

https://sourceware.org/bugzilla/show_bug.cgi?id=31501
https://sourceware.org/bugzilla/show_bug.cgi?id=31372

A version tag, GLIBC_ABI_GNU2_TLS, has been added to glibc to indicate
that glibc has the working GNU2 TLS run-time.  Add the --gnu2-tls-tag
option to i386/x86-64 ELF linker to add the GLIBC_ABI_GNU2_TLS version
dependency in output programs and shared libraries when linking against
glibc if input relocatable object files have R_386_TLS_DESC_CALL or
R_X86_64_TLSDESC_CALL relocation.  The output will fail to load and run
at run-time against glibc which doesn't define the GLIBC_ABI_GNU2_TLS
version.

Add the --enable-gnu2-tls-tag configure option to enable --gnu2-tls-tag
by default.  If unspecified, linker will add the GLIBC_ABI_GNU2_TLS
version dependency if input object files have R_386_TLS_DESC_CALL or
R_X86_64_TLSDESC_CALL relocation and libc.so defines the GLIBC_ABI_GNU2_TLS
version.

Update elf_link_add_glibc_verneed to properly add the GLIBC_2.36 version
dependency when -z mark-plt -z nopack-relative-relocs passed to x86-64
ELF linker.

bfd/

	PR ld/33130
	* elf-bfd.h (_bfd_elf_link_add_glibc_version_dependency): Add
	a pointer to bool argument.
	* elf-linker-x86.h (elf_linker_x86_params): Add
	gnu2_tls_version_tag.
	* elf32-i386.c (elf_i386_scan_relocs): Set has_tls_desc_call to
	1 for R_386_TLS_DESC_CALL.
	(elf_i386_add_glibc_version_dependency): New.  Undef before
	FreeBSD support.
	* elf64-x86-64.c (elf_x86_64_scan_relocs): Set has_tls_desc_call
	to 1 for R_X86_64_TLSDESC_CALL.
	(elf_x86_64_add_glibc_version_dependency): Add GLIBC_ABI_GNU2_TLS
	version dependency if GLIBC_ABI_GNU2_TLS dependency isn't disabled
	and has_tlsdesc_call isn't 0.
	(elf_backend_add_glibc_version_dependency): Undef before FreeBSD
	support and redefine for elf32-x86-64.
	* elflink.c (elf_link_add_glibc_verneed): Changed to return bool.
	Remove the pointer to elf_find_verdep_info argument.  Add a
	pointer to bool argument, auto_version. Return true if linked
	against glibc.  Otherwise return false.  If the version dependency
	is added, set *auto_version to true.  If *auto_version is true,
	add the version dependency only if libc.so defines the version.
	(_bfd_elf_link_add_glibc_version_dependency): Add a pointer to
	bool argument and pass it to elf_link_add_glibc_verneed.
	(_bfd_elf_link_add_dt_relr_dependency): Pass NULL to
	_bfd_elf_link_add_glibc_version_dependency.
	* elfxx-x86.h (elf_x86_link_hash_table): Add has_tls_desc_call.

ld/

	PR ld/33130
	* NEWS: Mention --gnu2-tls-tag, --no-gnu2-tls-tag and
	--enable-gnu2-tls-tag.
	* config.in: Regenerated.
	* configure: Likewise.
	* configure.ac: Add --enable-gnu2-tls-tag.
	* ld.texi: Document --gnu2-tls-tag/--no-gnu2-tls-tag.
	* ldlex.h (option_values): Add OPTION_GNU2_TLS_VERSION_TAG and
	OPTION_NO_GNU2_TLS_VERSION_TAG.
	* emulparams/elf32_x86_64.sh (EXTRA_EM_FILE): Changed to
	"elf-x86-64-glibc".
	* emulparams/elf_i386.sh (EXTRA_EM_FILE): Set to "elf-i386-glibc".
	* emulparams/elf_i386_fbsd.sh (EXTRA_EM_FILE): New.  Set to
	"elf-x86".
        * emulparams/elf_i386_haiku.sh (EXTRA_EM_FILE): Likewise.
	* emulparams/elf_x86_64.sh (EXTRA_EM_FILE): Likewise.
	* emulparams/elf_x86_64_fbsd.sh (EXTRA_EM_FILE): New.  Set to
	"elf-x86-64".
	* emulparams/elf_x86_64_haiku.sh (EXTRA_EM_FILE): Likewise.
	* (EXTRA_EM_FILE): Likewise.
	* (EXTRA_EM_FILE): Likewise.
        * emultempl/elf-i386-glibc.em: New file.
	* emultempl/elf-x86-64-glibc.em: Likewise.
	* emultempl/elf-x86-64.em: Likewise.
	* emultempl/elf-x86-glibc.em: Likewise.
	* emultempl/elf-x86.em (elf_x86_64_before_parse): Removed.
	(LDEMUL_BEFORE_PARSE): Likewise.
	(elf_x86_64_before_allocation): Likewise.
	(LDEMUL_BEFORE_ALLOCATION): Likewise.
	* emultempl/solaris2-x86-64.em: New file.
	* testsuite/ld-i386/gnu2-tls-1.s: Likewise.
	* testsuite/ld-i386/gnu2-tls-1a.rd: Likewise.
	* testsuite/ld-i386/gnu2-tls-1b.rd: Likewise.
	* testsuite/ld-x86-64/gnu2-tls-1.s: Likewise.
	* testsuite/ld-x86-64/gnu2-tls-1a.rd: Likewise.
	* testsuite/ld-x86-64/gnu2-tls-1b.rd: Likewise.
	* testsuite/ld-x86-64/mark-plt-2.rd: Likewise.
	* testsuite/ld-x86-64/mark-plt-2.s: Likewise.
	* testsuite/ld-i386/i386.exp: Run GLIBC_ABI_GNU2_TLS tests.
	* testsuite/ld-x86-64/x86-64.exp: Likewise.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>

10 files changed, 112 insertions, 1 deletions

diff --git a/ld/testsuite/ld-i386/gnu2-tls-1.s b/ld/testsuite/ld-i386/gnu2-tls-1.s
new file mode 100644
index 0000000..e3841c7
--- /dev/null
+++ b/ld/testsuite/ld-i386/gnu2-tls-1.s
@@ -0,0 +1,11 @@
+	.section	.text.startup,"ax",@progbits
+	.p2align 4
+	.globl	main
+	.type	main, @function
+main:
+	leal	ld@TLSDESC(%ebx), %eax
+	call	*ld@TLSCALL(%eax)
+	addl	%gs:0, %eax
+	ret
+	.size	main, .-main
+	.section	.note.GNU-stack,"",@progbits
diff --git a/ld/testsuite/ld-i386/gnu2-tls-1a.rd b/ld/testsuite/ld-i386/gnu2-tls-1a.rd
new file mode 100644
index 0000000..3eb926a
--- /dev/null
+++ b/ld/testsuite/ld-i386/gnu2-tls-1a.rd
@@ -0,0 +1,7 @@
+#...
+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_ABI_GNU2_TLS  Flags: none  Version: [0-9]+
+#pass
diff --git a/ld/testsuite/ld-i386/gnu2-tls-1b.rd b/ld/testsuite/ld-i386/gnu2-tls-1b.rd
new file mode 100644
index 0000000..33ef8ac
--- /dev/null
+++ b/ld/testsuite/ld-i386/gnu2-tls-1b.rd
@@ -0,0 +1,4 @@
+#failif
+#...
+  0x[a-f0-9]+:   Name: GLIBC_ABI_GNU2_TLS  Flags: none  Version: [0-9]+
+#...
diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp
index 8633a66..622c06e 100644
--- a/ld/testsuite/ld-i386/i386.exp
+++ b/ld/testsuite/ld-i386/i386.exp
@@ -1519,6 +1519,29 @@ run_ld_link_tests [list \
     ] \
 ]
 
+# The musl C library does not support --gnu2-tls-tag.
+if { ![istarget *-*-musl]
+     && [check_compiler_available] } {
+    run_cc_link_tests [list \
+	[list \
+	    "Build gnu2-tls-1a.so" \
+	    "-shared -Wl,--no-as-needed,--gnu2-tls-tag" \
+	    "-fPIC" \
+	    { gnu2-tls-1.s } \
+	    {{readelf {-W --version-info} gnu2-tls-1a.rd}} \
+	    "gnu2-tls-1a.so" \
+	] \
+	[list \
+	    "Build gnu2-tls-1b.so" \
+	    "-shared -Wl,--no-as-needed,--no-gnu2-tls-tag" \
+	    "-fPIC" \
+	    { gnu2-tls-1.s } \
+	    {{readelf {-W --version-info} gnu2-tls-1b.rd}} \
+	    "gnu2-tls-1b.so" \
+	] \
+    ]
+}
+
 # Linux only tests
 run_dump_test "pltgot-1"
 run_dump_test "pltgot-2"
diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-1.s b/ld/testsuite/ld-x86-64/gnu2-tls-1.s
new file mode 100644
index 0000000..eca788c
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gnu2-tls-1.s
@@ -0,0 +1,11 @@
+	.section	.text.startup,"ax",@progbits
+	.p2align 4
+	.globl	main
+	.type	main, @function
+main:
+	leaq	foo@TLSDESC(%rip), %rax
+	call	*foo@TLSCALL(%rax)
+	movl	%fs:(%rax), %eax
+	ret
+	.size	main, .-main
+	.section	.note.GNU-stack,"",@progbits
diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-1a.rd b/ld/testsuite/ld-x86-64/gnu2-tls-1a.rd
new file mode 100644
index 0000000..3eb926a
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gnu2-tls-1a.rd
@@ -0,0 +1,7 @@
+#...
+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_ABI_GNU2_TLS  Flags: none  Version: [0-9]+
+#pass
diff --git a/ld/testsuite/ld-x86-64/gnu2-tls-1b.rd b/ld/testsuite/ld-x86-64/gnu2-tls-1b.rd
new file mode 100644
index 0000000..33ef8ac
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/gnu2-tls-1b.rd
@@ -0,0 +1,4 @@
+#failif
+#...
+  0x[a-f0-9]+:   Name: GLIBC_ABI_GNU2_TLS  Flags: none  Version: [0-9]+
+#...
diff --git a/ld/testsuite/ld-x86-64/mark-plt-2.rd b/ld/testsuite/ld-x86-64/mark-plt-2.rd
new file mode 100644
index 0000000..b0ed702
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/mark-plt-2.rd
@@ -0,0 +1,7 @@
+#...
+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|GLIBC_ABI_DT_X86_64_PLT)  Flags: none  Version: [0-9]+
+#pass
diff --git a/ld/testsuite/ld-x86-64/mark-plt-2.s b/ld/testsuite/ld-x86-64/mark-plt-2.s
new file mode 100644
index 0000000..c816567
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/mark-plt-2.s
@@ -0,0 +1,13 @@
+	.text
+	.globl	foo
+	.type	foo, @function
+foo:
+	subq	$8, %rsp
+	leaq	xxx@TLSDESC(%rip), %rax
+	.nops 10
+	call	*xxx@TLSCALL(%rax)
+	movl	%fs:(%rax), %eax
+	addq	$8, %rsp
+	call	bar
+	ret
+	.section	.note.GNU-stack,"",@progbits
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index 9d97531..63cf1e4 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -2360,7 +2360,7 @@ run_dump_test "ibt-plt-3b-x32"
 run_dump_test "ibt-plt-3c-x32"
 run_dump_test "ibt-plt-3d-x32"
 
-# Skip -z mark-plt tests on MUSL.
+# Skip -z mark-plt and --gnu2-tls-tag tests on MUSL.
 if { [istarget "x86_64-*-musl*"]} {
     set ASFLAGS "$saved_ASFLAGS"
     return
@@ -2386,6 +2386,30 @@ if { [check_compiler_available] } {
 	     {readelf {-W --version-info} mark-plt-1b.rd}} \
 	    "mark-plt-1.so" \
 	] \
+	[list \
+	    "Build mark-plt-2.so" \
+	    "-shared -Wl,--no-as-needed,-z,mark-plt,-z,nopack-relative-relocs" \
+	    "-fPIC" \
+	    { mark-plt-2.s } \
+	    {{readelf {-W --version-info} mark-plt-2.rd}} \
+	    "mark-plt-2.so" \
+	] \
+	[list \
+	    "Build gnu2-tls-1a.so" \
+	    "-shared -Wl,--no-as-needed,--gnu2-tls-tag" \
+	    "-fPIC" \
+	    { gnu2-tls-1.s } \
+	    {{readelf {-W --version-info} gnu2-tls-1a.rd}} \
+	    "gnu2-tls-1a.so" \
+	] \
+	[list \
+	    "Build gnu2-tls-1b.so" \
+	    "-shared -Wl,--no-as-needed,--no-gnu2-tls-tag" \
+	    "-fPIC" \
+	    { gnu2-tls-1.s } \
+	    {{readelf {-W --version-info} gnu2-tls-1b.rd}} \
+	    "gnu2-tls-1b.so" \
+	] \
     ]
 }