IFUNC: Update IFUNC resolver check with DT_TEXTREL

Add ifunc_resolvers to elf_link_hash_table and use it for both x86 and
ppc64.  Before glibc commit b5c45e837, DT_TEXTREL is incompatible with
IFUNC resolvers.  Set ifunc_resolvers if there are IFUNC resolvers and
issue a warning for IFUNC resolvers with DT_TEXTREL.

bfd/

	PR ld/18801
	* elf-bfd.h (elf_link_hash_table): Add ifunc_resolvers.
	(_bfd_elf_allocate_ifunc_dyn_relocs): Remove the
	bfd_boolean * argument.  Set ifunc_resolvers if there are IFUNC
	resolvers.
	* elf-ifunc.c (_bfd_elf_allocate_ifunc_dyn_relocs): Updated.
	Set ifunc_resolvers if there are FUNC resolvers.
	* elf64-ppc.c (ppc_link_hash_table): Remove local_ifunc_resolver.
	(build_global_entry_stubs_and_plt): Replace local_ifunc_resolver
	with elf.ifunc_resolvers.
	(write_plt_relocs_for_local_syms): Likewise.
	(ppc64_elf_relocate_section): Likewise.
	(ppc64_elf_finish_dynamic_sections): Likewise.
	* elfnn-aarch64.c (elfNN_aarch64_allocate_ifunc_dynrelocs):
	Updated.
	* elfxx-x86.c (elf_x86_allocate_dynrelocs): Likewise.
	(_bfd_x86_elf_size_dynamic_sections): Check elf.ifunc_resolvers
	instead of readonly_dynrelocs_against_ifunc.
	* elfxx-x86.h (elf_x86_link_hash_table): Remove
	readonly_dynrelocs_against_ifunc.

ld/

	PR ld/18801
	* testsuite/ld-i386/i386.exp: Run ifunc-textrel-1a,
	ifunc-textrel-1b, ifunc-textrel-2a and ifunc-textrel-2b.
	* testsuite/ld-x86-64/x86-64.exp: Likewise.
	* testsuite/ld-i386/ifunc-textrel-1a.d: Likewise.
	* testsuite/ld-i386/ifunc-textrel-1b.d: Likewise.
	* testsuite/ld-i386/ifunc-textrel-2a.d: Likewise.
	* testsuite/ld-i386/ifunc-textrel-2b.d: Likewise.
	* testsuite/ld-x86-64/ifunc-textrel-1.s: Likewise.
	* testsuite/ld-x86-64/ifunc-textrel-1a.d: Likewise.
	* testsuite/ld-x86-64/ifunc-textrel-1b.d: Likewise.
	* testsuite/ld-x86-64/ifunc-textrel-2.s: Likewise.
	* testsuite/ld-x86-64/ifunc-textrel-2a.d: Likewise.
	* testsuite/ld-x86-64/ifunc-textrel-2b.d: Likewise.
	* testsuite/ld-i386/pr18801a.d: Expect warning for IFUNC
	resolvers.
	* testsuite/ld-i386/pr18801b.d: Likewise.
	* estsuite/ld-x86-64/pr18801a.d: Likewise.
	* estsuite/ld-x86-64/pr18801b.d: Likewise.

17 files changed, 138 insertions, 4 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index b0336b7..ba4151e 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,25 @@
+2020-06-09  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/18801
+	* testsuite/ld-i386/i386.exp: Run ifunc-textrel-1a,
+	ifunc-textrel-1b, ifunc-textrel-2a and ifunc-textrel-2b.
+	* testsuite/ld-x86-64/x86-64.exp: Likewise.
+	* testsuite/ld-i386/ifunc-textrel-1a.d: Likewise.
+	* testsuite/ld-i386/ifunc-textrel-1b.d: Likewise.
+	* testsuite/ld-i386/ifunc-textrel-2a.d: Likewise.
+	* testsuite/ld-i386/ifunc-textrel-2b.d: Likewise.
+	* testsuite/ld-x86-64/ifunc-textrel-1.s: Likewise.
+	* testsuite/ld-x86-64/ifunc-textrel-1a.d: Likewise.
+	* testsuite/ld-x86-64/ifunc-textrel-1b.d: Likewise.
+	* testsuite/ld-x86-64/ifunc-textrel-2.s: Likewise.
+	* testsuite/ld-x86-64/ifunc-textrel-2a.d: Likewise.
+	* testsuite/ld-x86-64/ifunc-textrel-2b.d: Likewise.
+	* testsuite/ld-i386/pr18801a.d: Expect warning for IFUNC
+	resolvers.
+	* testsuite/ld-i386/pr18801b.d: Likewise.
+	* estsuite/ld-x86-64/pr18801a.d: Likewise.
+	* estsuite/ld-x86-64/pr18801b.d: Likewise.
+
 2020-06-09  Alan Modra  <amodra@gmail.com>
 
 	PR 26065
diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp
index e1bbcdd..891ebce 100644
--- a/ld/testsuite/ld-i386/i386.exp
+++ b/ld/testsuite/ld-i386/i386.exp
@@ -519,6 +519,10 @@ run_dump_test "pr17935-1"
 run_dump_test "pr17935-2"
 run_dump_test "pr18801a"
 run_dump_test "pr18801b"
+run_dump_test "ifunc-textrel-1a"
+run_dump_test "ifunc-textrel-1b"
+run_dump_test "ifunc-textrel-2a"
+run_dump_test "ifunc-textrel-2b"
 run_dump_test "pr18815"
 run_dump_test "pr19939a"
 run_dump_test "pr19939b"
diff --git a/ld/testsuite/ld-i386/ifunc-textrel-1a.d b/ld/testsuite/ld-i386/ifunc-textrel-1a.d
new file mode 100644
index 0000000..15f545d
--- /dev/null
+++ b/ld/testsuite/ld-i386/ifunc-textrel-1a.d
@@ -0,0 +1,4 @@
+#source: ../ld-x86-64/ifunc-textrel-1.s
+#as: --32
+#ld: -m elf_i386 -pie
+#warning: GNU indirect functions with DT_TEXTREL may result in a segfault at runtime; recompile with -fPIE
diff --git a/ld/testsuite/ld-i386/ifunc-textrel-1b.d b/ld/testsuite/ld-i386/ifunc-textrel-1b.d
new file mode 100644
index 0000000..6e4a67c
--- /dev/null
+++ b/ld/testsuite/ld-i386/ifunc-textrel-1b.d
@@ -0,0 +1,4 @@
+#source: ../ld-x86-64/ifunc-textrel-1.s
+#as: --32
+#ld: -m elf_i386 -shared
+#warning: GNU indirect functions with DT_TEXTREL may result in a segfault at runtime; recompile with -fPIC
diff --git a/ld/testsuite/ld-i386/ifunc-textrel-2a.d b/ld/testsuite/ld-i386/ifunc-textrel-2a.d
new file mode 100644
index 0000000..7195912
--- /dev/null
+++ b/ld/testsuite/ld-i386/ifunc-textrel-2a.d
@@ -0,0 +1,8 @@
+#source: ../ld-x86-64/ifunc-textrel-2.s
+#as: --32
+#ld: -m elf_i386 -pie -z notext
+#readelf: -r --wide
+
+#failif
+[0-9a-f]+ +[0-9a-f]+ +R_386_IRELATIVE +
+#..
diff --git a/ld/testsuite/ld-i386/ifunc-textrel-2b.d b/ld/testsuite/ld-i386/ifunc-textrel-2b.d
new file mode 100644
index 0000000..7d51e68
--- /dev/null
+++ b/ld/testsuite/ld-i386/ifunc-textrel-2b.d
@@ -0,0 +1,8 @@
+#source: ../ld-x86-64/ifunc-textrel-2.s
+#as: --32
+#ld: -m elf_i386 -shared -z notext
+#readelf: -r --wide
+
+#failif
+[0-9a-f]+ +[0-9a-f]+ +R_386_IRELATIVE +
+#..
diff --git a/ld/testsuite/ld-i386/pr18801a.d b/ld/testsuite/ld-i386/pr18801a.d
index f8dc3f1..73cb5d1 100644
--- a/ld/testsuite/ld-i386/pr18801a.d
+++ b/ld/testsuite/ld-i386/pr18801a.d
@@ -1,4 +1,4 @@
 #source: pr18801.s
 #as: --32
 #ld: -m elf_i386 -pie
-#error: read-only segment has dynamic IFUNC relocations; recompile with -fPIE
+#warning: GNU indirect functions with DT_TEXTREL may result in a segfault at runtime; recompile with -fPIE
diff --git a/ld/testsuite/ld-i386/pr18801b.d b/ld/testsuite/ld-i386/pr18801b.d
index f1d5c8d..0bf7fb7 100644
--- a/ld/testsuite/ld-i386/pr18801b.d
+++ b/ld/testsuite/ld-i386/pr18801b.d
@@ -1,4 +1,4 @@
 #source: pr18801.s
 #as: --32
 #ld: -m elf_i386 -shared
-#error: read-only segment has dynamic IFUNC relocations; recompile with -fPIC
+#warning: GNU indirect functions with DT_TEXTREL may result in a segfault at runtime; recompile with -fPIC
diff --git a/ld/testsuite/ld-x86-64/ifunc-textrel-1.s b/ld/testsuite/ld-x86-64/ifunc-textrel-1.s
new file mode 100644
index 0000000..373e15f
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/ifunc-textrel-1.s
@@ -0,0 +1,28 @@
+	.text
+	.type   selector, %function
+foo:
+	movl	$0, %eax
+	ret
+selector:
+.ifdef __x86_64__
+	leaq	foo(%rip), %rax
+.else
+	leal	foo@GOTOFF(%eax), %eax
+.endif
+	ret
+	.type   selector, %gnu_indirect_function
+	.globl	_start
+_start:
+.ifdef __x86_64__
+	movabs	ptr, %rax
+	call	*%rax
+.else
+	mov	ptr, %eax
+	call	*%eax
+.endif
+	ret
+	.data
+	.type	ptr, @object
+ptr:
+	.dc.a	selector
+	.section	.note.GNU-stack,"",@progbits
diff --git a/ld/testsuite/ld-x86-64/ifunc-textrel-1a.d b/ld/testsuite/ld-x86-64/ifunc-textrel-1a.d
new file mode 100644
index 0000000..64a1e70
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/ifunc-textrel-1a.d
@@ -0,0 +1,4 @@
+#source: ifunc-textrel-1.s
+#as: --64 -defsym __x86_64__=1
+#ld: -m elf_x86_64 -pie
+#warning: GNU indirect functions with DT_TEXTREL may result in a segfault at runtime; recompile with -fPIE
diff --git a/ld/testsuite/ld-x86-64/ifunc-textrel-1b.d b/ld/testsuite/ld-x86-64/ifunc-textrel-1b.d
new file mode 100644
index 0000000..aeb31fd
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/ifunc-textrel-1b.d
@@ -0,0 +1,4 @@
+#source: ifunc-textrel-1.s
+#as: --64 -defsym __x86_64__=1
+#ld: -m elf_x86_64 -shared
+#warning: GNU indirect functions with DT_TEXTREL may result in a segfault at runtime; recompile with -fPIC
diff --git a/ld/testsuite/ld-x86-64/ifunc-textrel-2.s b/ld/testsuite/ld-x86-64/ifunc-textrel-2.s
new file mode 100644
index 0000000..5c8f271
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/ifunc-textrel-2.s
@@ -0,0 +1,28 @@
+	.text
+	.type   selector, %function
+foo:
+	movl	$0, %eax
+	ret
+selector:
+.ifdef __x86_64__
+	leaq	foo(%rip), %rax
+.else
+	leal	foo@GOTOFF(%eax), %eax
+.endif
+	ret
+	.type   selector, %gnu_indirect_function
+	.globl	_start
+_start:
+.ifdef __x86_64__
+	movabs	ptr, %rax
+	call	*%rax
+.else
+	mov	ptr, %eax
+	call	*%eax
+.endif
+	ret
+	.data
+	.type	ptr, @object
+ptr:
+	.dc.a	foo
+	.section	.note.GNU-stack,"",@progbits
diff --git a/ld/testsuite/ld-x86-64/ifunc-textrel-2a.d b/ld/testsuite/ld-x86-64/ifunc-textrel-2a.d
new file mode 100644
index 0000000..7bef52e
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/ifunc-textrel-2a.d
@@ -0,0 +1,8 @@
+#source: ifunc-textrel-2.s
+#as: --64 -defsym __x86_64__=1
+#ld: -m elf_x86_64 -pie -z notext
+#readelf: -r --wide
+
+#failif
+[0-9a-f]+ +[0-9a-f]+ +R_X86_64_IRELATIVE +[0-9a-f]+
+#..
diff --git a/ld/testsuite/ld-x86-64/ifunc-textrel-2b.d b/ld/testsuite/ld-x86-64/ifunc-textrel-2b.d
new file mode 100644
index 0000000..629ecc8
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/ifunc-textrel-2b.d
@@ -0,0 +1,8 @@
+#source: ifunc-textrel-2.s
+#as: --64 -defsym __x86_64__=1
+#ld: -m elf_x86_64 -shared -z notext
+#readelf: -r --wide
+
+#failif
+[0-9a-f]+ +[0-9a-f]+ +R_X86_64_IRELATIVE +[0-9a-f]+
+#..
diff --git a/ld/testsuite/ld-x86-64/pr18801a.d b/ld/testsuite/ld-x86-64/pr18801a.d
index b527f04..2b4159d 100644
--- a/ld/testsuite/ld-x86-64/pr18801a.d
+++ b/ld/testsuite/ld-x86-64/pr18801a.d
@@ -1,4 +1,4 @@
 #source: pr18801.s
 #as: --64
 #ld: -melf_x86_64 -pie
-#error: read-only segment has dynamic IFUNC relocations; recompile with -fPIE
+#warning: GNU indirect functions with DT_TEXTREL may result in a segfault at runtime; recompile with -fPIE
diff --git a/ld/testsuite/ld-x86-64/pr18801b.d b/ld/testsuite/ld-x86-64/pr18801b.d
index 7cdb2cd..34dab1a 100644
--- a/ld/testsuite/ld-x86-64/pr18801b.d
+++ b/ld/testsuite/ld-x86-64/pr18801b.d
@@ -1,4 +1,4 @@
 #source: pr18801.s
 #as: --64
 #ld: -melf_x86_64 -shared
-#error: read-only segment has dynamic IFUNC relocations; recompile with -fPIC
+#warning: GNU indirect functions with DT_TEXTREL may result in a segfault at runtime; recompile with -fPIC
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index fd8fd34..69548f2 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -581,6 +581,10 @@ run_dump_test "pr18160"
 run_dump_test "pr18176"
 run_dump_test "pr18801a"
 run_dump_test "pr18801b"
+run_dump_test "ifunc-textrel-1a"
+run_dump_test "ifunc-textrel-1b"
+run_dump_test "ifunc-textrel-2a"
+run_dump_test "ifunc-textrel-2b"
 run_dump_test "pr18815"
 run_dump_test "pr19013"
 run_dump_test "pr19013-x32"