[binutils-gdb] aarch64: Return an error on conditional branch to an undefined symbol
Siddhesh Poyarekar
siddhesh@sourceware.org
Thu Sep 10 16:14:50 GMT 2020
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=c7cd291722779c9d4703ed0010388fe394c644c8
commit c7cd291722779c9d4703ed0010388fe394c644c8
Author: Siddhesh Poyarekar <siddesh.poyarekar@arm.com>
Date: Tue Sep 1 14:25:52 2020 +0530
aarch64: Return an error on conditional branch to an undefined symbol
The fix in 7e05773767820b441b23a16628b55c98cb1aef46 introduced a PLT
for conditional jumps when the target symbol is undefined. This is
incorrect because conditional branch relocations are not allowed to
clobber IP0/IP1 and hence, should not result in a dynamic relocation.
Revert that change and in its place, issue an error when the target
symbol is undefined.
bfd/
2020-09-10 Siddhesh Poyarekar <siddesh.poyarekar@arm.com>
* elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Revert
changes in 7e05773767820b441b23a16628b55c98cb1aef46. Set
error for undefined symbol in BFD_RELOC_AARCH64_BRANCH19 and
BFD_RELOC_AARCH64_TSTBR14 relocations.
ld/
2020-09-10 Siddhesh Poyarekar <siddesh.poyarekar@arm.com>
* testsuite/ld-aarch64/emit-relocs-560.d: Expect error instead
of valid output.
Diff:
---
bfd/ChangeLog | 7 ++++++
bfd/elfnn-aarch64.c | 37 ++++++++++++++++---------------
ld/ChangeLog | 5 +++++
ld/testsuite/ld-aarch64/emit-relocs-560.d | 7 +-----
4 files changed, 32 insertions(+), 24 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index f26690145e3..19415d6b9f1 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,10 @@
+2020-09-10 Siddhesh Poyarekar <siddesh.poyarekar@arm.com>
+
+ * elfnn-aarch64.c (elfNN_aarch64_final_link_relocate): Revert
+ changes in 7e05773767820b441b23a16628b55c98cb1aef46. Set
+ error for undefined symbol in BFD_RELOC_AARCH64_BRANCH19 and
+ BFD_RELOC_AARCH64_TSTBR14 relocations.
+
2020-09-09 Nick Clifton <nickc@redhat.com>
* cofflink.c (coff_link_check_archive_element): Move the check for
diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c
index 5b4c189b593..a9924e7ec56 100644
--- a/bfd/elfnn-aarch64.c
+++ b/bfd/elfnn-aarch64.c
@@ -5447,7 +5447,6 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto,
bfd_vma orig_value = value;
bfd_boolean resolved_to_zero;
bfd_boolean abs_symbol_p;
- bfd_boolean via_plt_p;
globals = elf_aarch64_hash_table (info);
@@ -5469,8 +5468,6 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto,
: bfd_is_und_section (sym_sec));
abs_symbol_p = h != NULL && bfd_is_abs_symbol (&h->root);
- via_plt_p = (globals->root.splt != NULL && h != NULL
- && h->plt.offset != (bfd_vma) - 1);
/* Since STT_GNU_IFUNC symbol must go through PLT, we handle
it here if it is defined in a non-shared object. */
@@ -5806,23 +5803,12 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto,
value += signed_addend;
break;
- case BFD_RELOC_AARCH64_BRANCH19:
- case BFD_RELOC_AARCH64_TSTBR14:
- /* A conditional branch to an undefined weak symbol is converted to a
- branch to itself. */
- if (weak_undef_p && !via_plt_p)
- {
- value = _bfd_aarch64_elf_resolve_relocation (input_bfd, bfd_r_type,
- place, value,
- signed_addend,
- weak_undef_p);
- break;
- }
- /* Fall through. */
case BFD_RELOC_AARCH64_CALL26:
case BFD_RELOC_AARCH64_JUMP26:
{
asection *splt = globals->root.splt;
+ bfd_boolean via_plt_p =
+ splt != NULL && h != NULL && h->plt.offset != (bfd_vma) - 1;
/* A call to an undefined weak symbol is converted to a jump to
the next instruction unless a PLT entry will be created.
@@ -5903,6 +5889,23 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto,
bfd_set_error (bfd_error_bad_value);
return bfd_reloc_notsupported;
}
+ value = _bfd_aarch64_elf_resolve_relocation (input_bfd, bfd_r_type,
+ place, value,
+ signed_addend,
+ weak_undef_p);
+ break;
+
+ case BFD_RELOC_AARCH64_BRANCH19:
+ case BFD_RELOC_AARCH64_TSTBR14:
+ if (h && h->root.type == bfd_link_hash_undefined)
+ {
+ _bfd_error_handler
+ /* xgettext:c-format */
+ (_("%pB: conditional branch to undefined symbol `%s' "
+ "not allowed"), input_bfd, h->root.root.string);
+ bfd_set_error (bfd_error_bad_value);
+ return bfd_reloc_notsupported;
+ }
/* Fall through. */
case BFD_RELOC_AARCH64_16:
@@ -7968,8 +7971,6 @@ elfNN_aarch64_check_relocs (bfd *abfd, struct bfd_link_info *info,
break;
}
- case BFD_RELOC_AARCH64_BRANCH19:
- case BFD_RELOC_AARCH64_TSTBR14:
case BFD_RELOC_AARCH64_CALL26:
case BFD_RELOC_AARCH64_JUMP26:
/* If this is a local symbol then we resolve it
diff --git a/ld/ChangeLog b/ld/ChangeLog
index 3e8662868ae..3b9a4266972 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,8 @@
+2020-09-10 Siddhesh Poyarekar <siddesh.poyarekar@arm.com>
+
+ * testsuite/ld-aarch64/emit-relocs-560.d: Expect error instead
+ of valid output.
+
2020-09-10 H.J. Lu <hongjiu.lu@intel.com>
PR ld/26590
diff --git a/ld/testsuite/ld-aarch64/emit-relocs-560.d b/ld/testsuite/ld-aarch64/emit-relocs-560.d
index 153532457b4..8751b743bd4 100644
--- a/ld/testsuite/ld-aarch64/emit-relocs-560.d
+++ b/ld/testsuite/ld-aarch64/emit-relocs-560.d
@@ -1,8 +1,3 @@
#source: emit-relocs-560.s
#ld: -shared
-#readelf: -r
-
-Relocation section '.rela.plt' at offset 0x[0-9a-f]+ contains 2 entries:
- Offset Info Type Sym. Value Sym. Name \+ Addend
-[0-9a-f]+ 000100000402 R_AARCH64_JUMP_SL 0000000000000000 baz \+ 0
-[0-9a-f]+ 000200000402 R_AARCH64_JUMP_SL 0000000000000000 bar \+ 0
+#error: .*: conditional branch to undefined symbol `bar' not allowed
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