[committed, PATCH] PR ld/18808: aborting at bfd/elf64-x86-64.c:3791 in elf_x86_64_relocate_section

["H.J. Lu" <hongjiu dot lu at intel dot com>]

Skip IFUNC relocations in debug sections ignored by ld.so.

bfd/

	PR ld/18808
	* elf32-i386.c (elf_i386_relocate_section): Skip IFUNC
	relocations in debug sections.
	* elf64-x86-64.c (elf_x86_64_relocate_section): Likewise.

ld/testsuite/

	PR ld/18808
	* ld-ifunc/ifunc.exp: Add a test for PR ld/18808.
	* ld-ifunc/pr18808.out: New file.
	* ld-ifunc/pr18808a.c: Likewise.
	* ld-ifunc/pr18808b.c: Likewise.
---
 bfd/elf32-i386.c                  | 12 +++++++++--
 bfd/elf64-x86-64.c                | 12 +++++++++--
 ld/testsuite/ld-ifunc/ifunc.exp   | 27 +++++++++++++++++++++++
 ld/testsuite/ld-ifunc/pr18808.out |  1 +
 ld/testsuite/ld-ifunc/pr18808a.c  |  9 ++++++++
 ld/testsuite/ld-ifunc/pr18808b.c  | 24 +++++++++++++++++++++
 ld/testsuite/lib/ld-lib.exp       | 45 +++++++++++++++++++++++++++++++++++++++
 7 files changed, 126 insertions(+), 4 deletions(-)
 create mode 100644 ld/testsuite/ld-ifunc/pr18808.out
 create mode 100644 ld/testsuite/ld-ifunc/pr18808a.c
 create mode 100644 ld/testsuite/ld-ifunc/pr18808b.c

diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index 92e7f72..fb87421 100644
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -3503,8 +3503,16 @@ elf_i386_relocate_section (bfd *output_bfd,
 	  bfd_vma plt_index;
 	  const char *name;
 
-	  if ((input_section->flags & SEC_ALLOC) == 0
-	      || h->plt.offset == (bfd_vma) -1)
+	  if ((input_section->flags & SEC_ALLOC) == 0)
+	    {
+	      /* Dynamic relocs are not propagated for SEC_DEBUGGING
+		 sections because such sections are not SEC_ALLOC and
+		 thus ld.so will not process them.  */
+	      if ((input_section->flags & SEC_DEBUGGING) != 0)
+		break;
+	      abort ();
+	    }
+	  else if (h->plt.offset == (bfd_vma) -1)
 	    abort ();
 
 	  /* STT_GNU_IFUNC symbol must go through PLT.  */
diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index a4dfdc8..4b83032 100644
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -3786,8 +3786,16 @@ elf_x86_64_relocate_section (bfd *output_bfd,
 	  bfd_vma plt_index;
 	  const char *name;
 
-	  if ((input_section->flags & SEC_ALLOC) == 0
-	      || h->plt.offset == (bfd_vma) -1)
+	  if ((input_section->flags & SEC_ALLOC) == 0)
+	    {
+	      /* Dynamic relocs are not propagated for SEC_DEBUGGING
+		 sections because such sections are not SEC_ALLOC and
+		 thus ld.so will not process them.  */
+	      if ((input_section->flags & SEC_DEBUGGING) != 0)
+		break;
+	      abort ();
+	    }
+	  else if (h->plt.offset == (bfd_vma) -1)
 	    abort ();
 
 	  /* STT_GNU_IFUNC symbol must go through PLT.  */
diff --git a/ld/testsuite/ld-ifunc/ifunc.exp b/ld/testsuite/ld-ifunc/ifunc.exp
index e08261b..498cb2d 100644
--- a/ld/testsuite/ld-ifunc/ifunc.exp
+++ b/ld/testsuite/ld-ifunc/ifunc.exp
@@ -457,3 +457,30 @@ run_ld_link_exec_tests [] [list \
 	"-fpic" \
     ] \
 ]
+
+# Run-time tests which require working ifunc attribute support.
+if { ![check_ifunc_attribute_available] } {
+    return
+}
+
+run_cc_link_tests [list \
+    [list \
+	"Build libpr18808.so" \
+	"-shared" \
+	"-fPIC -O2 -g" \
+	{ pr18808b.c } \
+	{} \
+	"libpr18808.so" \
+    ] \
+]
+
+run_ld_link_exec_tests [] [list \
+    [list \
+	"Run pr18808" \
+	"tmpdir/libpr18808.so" \
+	"" \
+	{ pr18808a.c } \
+	"pr18808" \
+	"pr18808.out" \
+    ] \
+]
diff --git a/ld/testsuite/ld-ifunc/pr18808.out b/ld/testsuite/ld-ifunc/pr18808.out
new file mode 100644
index 0000000..d86bac9
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/pr18808.out
@@ -0,0 +1 @@
+OK
diff --git a/ld/testsuite/ld-ifunc/pr18808a.c b/ld/testsuite/ld-ifunc/pr18808a.c
new file mode 100644
index 0000000..35228ae
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/pr18808a.c
@@ -0,0 +1,9 @@
+#include <stdio.h>
+
+void bar(void);
+int main(void)
+{
+  bar();
+  printf("OK\n");
+  return 0;
+}
diff --git a/ld/testsuite/ld-ifunc/pr18808b.c b/ld/testsuite/ld-ifunc/pr18808b.c
new file mode 100644
index 0000000..6f0db5a
--- /dev/null
+++ b/ld/testsuite/ld-ifunc/pr18808b.c
@@ -0,0 +1,24 @@
+int foo (int x) __attribute__ ((ifunc ("resolve_foo")));
+extern void abort (void);
+
+static int foo_impl(int x)
+{
+  return x;
+}
+
+int bar()
+{
+  int (*f)(int) = foo;
+
+  if (foo (5) != 5)
+    abort ();
+
+  if (f(42) != 42)
+    abort ();
+}
+
+
+void *resolve_foo (void)
+{
+  return (void *) foo_impl;
+}
diff --git a/ld/testsuite/lib/ld-lib.exp b/ld/testsuite/lib/ld-lib.exp
index 6904499..364c6fa 100644
--- a/ld/testsuite/lib/ld-lib.exp
+++ b/ld/testsuite/lib/ld-lib.exp
@@ -1960,6 +1960,51 @@ proc check_ifunc_available { } {
     return $ifunc_available_saved
 }
 
+# Returns true if ifunc attribute works.
+
+proc check_ifunc_attribute_available { } {
+    global ifunc_attribute_available_saved
+    global CC
+
+    if {![info exists ifunc_attribute_available_saved]} {
+        if { [which $CC] == 0 } {
+	    set ifunc_attribute_available_saved 0
+	    return 0
+	}
+	# Check if gcc supports -flto -fuse-linker-plugin
+	set flags ""
+	if [board_info [target_info name] exists cflags] {
+	    append flags " [board_info [target_info name] cflags]"
+	}
+	if [board_info [target_info name] exists ldflags] {
+	    append flags " [board_info [target_info name] ldflags]"
+	}
+
+	set basename "tmpdir/ifunc[pid]"
+	set src ${basename}.c
+	set output ${basename}.out
+	set f [open $src "w"]
+	puts $f "extern int library_func2 (void) __attribute__ ((ifunc (\"foo\")));"
+	puts $f "int main (void)"
+	puts $f "{"
+	puts $f "  if (library_func2 () != 2) __builtin_abort ();"
+	puts $f "  return 0; "
+	puts $f "}"
+	puts $f "static int library_func1 (void) {return 2; }"
+	puts $f "void *foo (void) { return library_func1; }"
+	close $f
+	remote_download host $src
+	set ifunc_attribute_available_saved [run_host_cmd_yesno "$CC" "$flags $src -o $output"]
+	if { $ifunc_attribute_available_saved == 1 } {
+	  set ifunc_attribute_available_saved [run_host_cmd_yesno "$output" ""]
+	}
+	remote_file host delete $src
+	remote_file host delete $output
+	file delete $src
+    }
+    return $ifunc_attribute_available_saved
+}
+
 # Provide virtual target "cfi" for targets supporting CFI.
 
 rename "istarget" "istarget_ld"
-- 
2.4.3