From: H.J. Lu <hjl.tools@gmail.com>
Date: Sat, 16 Jan 2021 15:00:09 +0000 (-0800)
Subject: ld/elf/x86: Don't compare IFUNC address in the shared object
X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=75a933f39918ce4f4b9481234992895e022787ee;hp=68b007788a6cc5376708af42bc220f540e8c4b8a;p=deliverable%2Fbinutils-gdb.git

ld/elf/x86: Don't compare IFUNC address in the shared object

On x86, glibc 2.33 starts to issue a fatal error message when calling
IFUNC function defined in the unrelocated executable from a shared
library.

1. Update x86 ELF linker to always convert IFUNC function defined in
position-dependent executable (PDE) to the normal function.  GOT in PDE
will be updated by R_*_IRELATIVE at run-time.
2. Update PR ld/23169 tests not to compare function address of external
IFUNC function in the shared object to avoid calling the IFUNC function
defined in the unrelocated executable.
3. Remove pr23169e tests which call the IFUNC function defined in the
unrelocated position-independent executable from a shared library.

bfd/

	PR ld/23169
	* elfxx-x86.c (_bfd_x86_elf_link_fixup_ifunc_symbol): Don't
	check pointer_equality_needed.

ld/

	PR ld/23169
	* testsuite/ld-ifunc/ifunc.exp: Replace pr23169c.rd with
	pr23169a.rd for pr23169c and pr23169f.  Remove pr23169e tests.
	* testsuite/ld-ifunc/pr23169a.c (foo): Don't compare function
	address.
---

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index ac18a85067..dbb240ad61 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2021-01-16  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/23169
+	* elfxx-x86.c (_bfd_x86_elf_link_fixup_ifunc_symbol): Don't
+	check pointer_equality_needed.
+
 2021-01-15  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* elf-linker-x86.h (elf_linker_x86_params): Add
diff --git a/bfd/elfxx-x86.c b/bfd/elfxx-x86.c
index 8cda8d2d97..93ad38c5eb 100644
--- a/bfd/elfxx-x86.c
+++ b/bfd/elfxx-x86.c
@@ -1711,8 +1711,7 @@ _bfd_x86_elf_link_fixup_ifunc_symbol (struct bfd_link_info *info,
       && h->def_regular
       && h->dynindx != -1
       && h->plt.offset != (bfd_vma) -1
-      && h->type == STT_GNU_IFUNC
-      && h->pointer_equality_needed)
+      && h->type == STT_GNU_IFUNC)
     {
       asection *plt_s;
       bfd_vma plt_offset;
diff --git a/ld/ChangeLog b/ld/ChangeLog
index 6e53414890..8a20eba94a 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,11 @@
+2021-01-16  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/23169
+	* testsuite/ld-ifunc/ifunc.exp: Replace pr23169c.rd with
+	pr23169a.rd for pr23169c and pr23169f.  Remove pr23169e tests.
+	* testsuite/ld-ifunc/pr23169a.c (foo): Don't compare function
+	address.
+
 2021-01-15  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* NEWS: Mention -z report-relative-reloc.
diff --git a/ld/testsuite/ld-ifunc/ifunc.exp b/ld/testsuite/ld-ifunc/ifunc.exp
index 31666d0f29..9d3ace6521 100644
--- a/ld/testsuite/ld-ifunc/ifunc.exp
+++ b/ld/testsuite/ld-ifunc/ifunc.exp
@@ -640,7 +640,7 @@ run_cc_link_tests [list \
 	"$NOPIE_LDFLAGS -Wl,--no-as-needed tmpdir/libpr23169a.so" \
 	"-fPIE -O2 -g" \
 	{ pr23169b.c pr23169c.c } \
-	{{readelf {--dyn-syms} pr23169c.rd} \
+	{{readelf {--dyn-syms} pr23169a.rd} \
 	 {readelf {-r -W} pr23169b.rd}} \
 	"pr23169c" \
     ] \
@@ -653,21 +653,12 @@ run_cc_link_tests [list \
 	 {readelf {-r -W} pr23169b.rd}} \
 	"pr23169d" \
     ] \
-    [list \
-	"Build pr23169e" \
-	"-pie -Wl,--no-as-needed,-z,now tmpdir/libpr23169b.so" \
-	"-fPIE -O2 -g" \
-	{ pr23169b.c pr23169c.c } \
-	{{readelf {--dyn-syms} pr23169c.rd} \
-	 {readelf {-r -W} pr23169b.rd}} \
-	"pr23169e" \
-    ] \
     [list \
 	"Build pr23169f" \
 	"$NOPIE_LDFLAGS -Wl,--no-as-needed,-z,now tmpdir/libpr23169b.so" \
 	"-fPIE -O2 -g" \
 	{ pr23169b.c pr23169c.c } \
-	{{readelf {--dyn-syms} pr23169c.rd} \
+	{{readelf {--dyn-syms} pr23169a.rd} \
 	 {readelf {-r -W} pr23169b.rd}} \
 	"pr23169f" \
     ] \
@@ -774,15 +765,6 @@ run_ld_link_exec_tests [list \
 	"pass.out" \
 	"$NOPIE_CFLAGS -O2 -g" \
     ] \
-    [list \
-	"Run pr23169e" \
-	"-pie -Wl,--no-as-needed,-z,now tmpdir/libpr23169b.so" \
-	"" \
-	{ pr23169b.c pr23169c.c } \
-	"pr23169e" \
-	"pass.out" \
-	"-fPIE -O2 -g" \
-    ] \
     [list \
 	"Run pr23169f" \
 	"$NOPIE_LDFLAGS -Wl,--no-as-needed,-z,now tmpdir/libpr23169b.so" \
diff --git a/ld/testsuite/ld-ifunc/pr23169a.c b/ld/testsuite/ld-ifunc/pr23169a.c
index 02bf220890..8beed283bc 100644
--- a/ld/testsuite/ld-ifunc/pr23169a.c
+++ b/ld/testsuite/ld-ifunc/pr23169a.c
@@ -4,6 +4,6 @@ extern int func (void);
 void
 foo (void)
 {
-  if (func_p != &func || func_p () != 0xbadbeef)
+  if (func () != 0xbadbeef || func_p () != 0xbadbeef)
     __builtin_abort ();
 }