[binutils-gdb] arm: Define elf_backend_extern_protected_data to 0 [PR 18705]

[Fangrui Song]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=af9bf9cb4703909caf6e66a9f746bdd66a74f633

commit af9bf9cb4703909caf6e66a9f746bdd66a74f633
Author: Fangrui Song <i@maskray.me>
Date:   Sat Jun 25 10:27:49 2022 -0700

    arm: Define elf_backend_extern_protected_data to 0 [PR 18705]
    
    Similar to commit 4fb55bf6a9606eb7b626c30a9f4e71d6c2d4fbb2 for aarch64.
    
    Commit b68a20d6675f1360ea4db50a9835c073675b9889 changed ld to produce
    R_ARM_GLOB_DAT but that defeated the purpose of protected visibility
    as an optimization.  Restore the previous behavior (which matches
    ld.lld) by defining elf_backend_extern_protected_data to 0.

Diff:
---
 bfd/elf32-arm.c                      | 2 +-
 ld/testsuite/ld-arm/protected-data.d | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/bfd/elf32-arm.c b/bfd/elf32-arm.c
index 60f89ec6117..0852b38ae4c 100644
--- a/bfd/elf32-arm.c
+++ b/bfd/elf32-arm.c
@@ -20315,7 +20315,7 @@ elf32_arm_backend_symbol_processing (bfd *abfd, asymbol *sym)
 #define elf_backend_dtrel_excludes_plt 1
 
 #define elf_backend_got_header_size	12
-#define elf_backend_extern_protected_data 1
+#define elf_backend_extern_protected_data 0
 
 #undef	elf_backend_obj_attrs_vendor
 #define elf_backend_obj_attrs_vendor		"aeabi"
diff --git a/ld/testsuite/ld-arm/protected-data.d b/ld/testsuite/ld-arm/protected-data.d
index 3f266dea1b4..7dffe9ab958 100644
--- a/ld/testsuite/ld-arm/protected-data.d
+++ b/ld/testsuite/ld-arm/protected-data.d
@@ -2,4 +2,4 @@
 #ld: -shared
 #readelf: -r -W
 #...
-.* R_ARM_GLOB_DAT .* var.*
+.* R_ARM_RELATIVE .*