diff -rupN binutils.orig/bfd/elfnn-riscv.c binutils-2.41/bfd/elfnn-riscv.c
--- binutils.orig/bfd/elfnn-riscv.c 2024-01-02 17:35:07.412218130 +0000
+++ binutils-2.41/bfd/elfnn-riscv.c 2024-01-02 17:36:52.274311071 +0000
@@ -1737,7 +1737,10 @@ perform_relocation (const reloc_howto_ty
{
if (howto->pc_relative)
value -= sec_addr (input_section) + rel->r_offset;
- value += rel->r_addend;
+
+ /* PR31179, ignore the non-zero addend of R_RISCV_SUB_ULEB128. */
+ if (ELFNN_R_TYPE (rel->r_info) != R_RISCV_SUB_ULEB128)
+ value += rel->r_addend;
switch (ELFNN_R_TYPE (rel->r_info))
{
@@ -1818,10 +1821,7 @@ perform_relocation (const reloc_howto_ty
value = ENCODE_CITYPE_LUI_IMM (RISCV_CONST_HIGH_PART (value));
break;
- /* SUB_ULEB128 must be applied after SET_ULEB128, so we only write the
- value back for SUB_ULEB128 should be enough. */
- case R_RISCV_SET_ULEB128:
- break;
+ /* R_RISCV_SET_ULEB128 won't go into here. */
case R_RISCV_SUB_ULEB128:
{
unsigned int len = 0;
@@ -2514,7 +2514,7 @@ riscv_elf_relocate_section (bfd *output_
else
{
msg = ("Mismatched R_RISCV_SET_ULEB128, it must be paired with"
- "and applied before R_RISCV_SUB_ULEB128");
+ " and applied before R_RISCV_SUB_ULEB128");
r = bfd_reloc_dangerous;
}
break;
@@ -2523,14 +2523,40 @@ riscv_elf_relocate_section (bfd *output_
if (uleb128_set_rel != NULL
&& uleb128_set_rel->r_offset == rel->r_offset)
{
- relocation = uleb128_set_vma - relocation;
+ relocation = uleb128_set_vma - relocation
+ + uleb128_set_rel->r_addend;
uleb128_set_vma = 0;
uleb128_set_rel = NULL;
+
+ /* PR31179, the addend of SUB_ULEB128 should be zero if using
+ .uleb128, but we make it non-zero by accident in assembler,
+ so just ignore it in perform_relocation, and make assembler
+ continue doing the right thing. Don't reset the addend of
+ SUB_ULEB128 to zero here since it will break the --emit-reloc,
+ even though the non-zero addend is unexpected.
+
+ We encourage people to rebuild their stuff to get the
+ non-zero addend of SUB_ULEB128, but that might need some
+ times, so report warnings to inform people need to rebuild
+ if --check-uleb128 is enabled. However, since the failed
+ .reloc cases for ADD/SET/SUB/ULEB128 are rarely to use, it
+ may acceptable that stop supproting them until people rebuld
+ their stuff, maybe half-year or one year later. I believe
+ this might be the least harmful option that we should go.
+
+ Or maybe we should teach people that don't write the
+ .reloc R_RISCV_SUB* with non-zero constant, and report
+ warnings/errors in assembler. */
+ if (htab->params->check_uleb128
+ && rel->r_addend != 0)
+ _bfd_error_handler (_("%pB: warning: R_RISCV_SUB_ULEB128 with"
+ " non-zero addend, please rebuild by"
+ " Fedora 40 binutils or up"), input_bfd);
}
else
{
msg = ("Mismatched R_RISCV_SUB_ULEB128, it must be paired with"
- "and applied after R_RISCV_SET_ULEB128");
+ " and applied after R_RISCV_SET_ULEB128");
r = bfd_reloc_dangerous;
}
break;
@@ -5123,7 +5149,13 @@ _bfd_riscv_relax_section (bfd *abfd, ase
if (h != NULL && h->type == STT_GNU_IFUNC)
continue;
+ /* Maybe we should check UNDEFWEAK_NO_DYNAMIC_RELOC here? But that
+ will break the undefweak relaxation testcases, so just make sure
+ we won't do relaxations for linker_def symbols in short-term. */
if (h->root.type == bfd_link_hash_undefweak
+ /* The linker_def symbol like __ehdr_start that may be undefweak
+ for now, but will be guaranteed to be defined later. */
+ && !h->root.linker_def
&& (relax_func == _bfd_riscv_relax_lui
|| relax_func == _bfd_riscv_relax_pc))
{
diff -rupN binutils.orig/bfd/elfxx-riscv.h binutils-2.41/bfd/elfxx-riscv.h
--- binutils.orig/bfd/elfxx-riscv.h 2024-01-02 17:35:07.412218130 +0000
+++ binutils-2.41/bfd/elfxx-riscv.h 2024-01-02 17:35:24.252233056 +0000
@@ -31,6 +31,8 @@ struct riscv_elf_params
{
/* Whether to relax code sequences to GP-relative addressing. */
bool relax_gp;
+ /* Whether to check if SUB_ULEB128 relocation has non-zero addend. */
+ bool check_uleb128;
};
extern void riscv_elf32_set_options (struct bfd_link_info *,
diff -rupN binutils.orig/ld/NEWS binutils-2.41/ld/NEWS
--- binutils.orig/ld/NEWS 2024-01-02 17:35:08.012218662 +0000
+++ binutils-2.41/ld/NEWS 2024-01-02 17:35:56.139261318 +0000
@@ -1,5 +1,10 @@
-*- text -*-
+* On RISC-V, add ld target option --[no-]check-uleb128. Should rebuild the
+ objects by binutils 2.42 and up if enabling the option and get warnings,
+ since the non-zero addend of SUB_ULEB128 shouldn't be generated from .uleb128
+ directives.
+
* Added --warn-execstack-objects to warn about executable stacks only when an
input object file requests one. Also added --error-execstack and
--error-rxw-segments options to convert warnings about executable stacks and
diff -rupN binutils.orig/ld/emultempl/riscvelf.em binutils-2.41/ld/emultempl/riscvelf.em
--- binutils.orig/ld/emultempl/riscvelf.em 2024-01-02 17:35:07.699218385 +0000
+++ binutils-2.41/ld/emultempl/riscvelf.em 2024-01-02 17:35:24.252233056 +0000
@@ -25,7 +25,8 @@ fragment <<EOF
#include "elf/riscv.h"
#include "elfxx-riscv.h"
-static struct riscv_elf_params params = { .relax_gp = 1 };
+static struct riscv_elf_params params = { .relax_gp = 1,
+ .check_uleb128 = 0};
EOF
# Define some shell vars to insert bits of code into the standard elf
@@ -35,17 +36,23 @@ enum risccv_opt
{
OPTION_RELAX_GP = 321,
OPTION_NO_RELAX_GP,
+ OPTION_CHECK_ULEB128,
+ OPTION_NO_CHECK_ULEB128,
};
'
PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
{ "relax-gp", no_argument, NULL, OPTION_RELAX_GP },
{ "no-relax-gp", no_argument, NULL, OPTION_NO_RELAX_GP },
+ { "check-uleb128", no_argument, NULL, OPTION_CHECK_ULEB128 },
+ { "no-check-uleb128", no_argument, NULL, OPTION_NO_CHECK_ULEB128 },
'
PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
fprintf (file, _(" --relax-gp Perform GP relaxation\n"));
fprintf (file, _(" --no-relax-gp Don'\''t perform GP relaxation\n"));
+ fprintf (file, _(" --check-uleb128 Check if SUB_ULEB128 has non-zero addend\n"));
+ fprintf (file, _(" --no-check-uleb128 Don'\''t check if SUB_ULEB128 has non-zero addend\n"));
'
PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
@@ -56,6 +63,14 @@ PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LI
case OPTION_NO_RELAX_GP:
params.relax_gp = 0;
break;
+
+ case OPTION_CHECK_ULEB128:
+ params.check_uleb128 = 1;
+ break;
+
+ case OPTION_NO_CHECK_ULEB128:
+ params.check_uleb128 = 0;
+ break;
'
fragment <<EOF
diff -rupN binutils.orig/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp binutils-2.41/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
--- binutils.orig/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp 2024-01-02 17:35:07.942218600 +0000
+++ binutils-2.41/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp 2024-01-02 17:35:24.252233056 +0000
@@ -173,6 +173,8 @@ if [istarget "riscv*-*-*"] {
run_dump_test "attr-phdr"
run_dump_test "relax-max-align-gp"
run_dump_test "uleb128"
+ run_dump_test "pr31179"
+ run_dump_test "pr31179-r"
run_ld_link_tests [list \
[list "Weak reference 32" "-T weakref.ld -m[riscv_choose_ilp32_emul]" "" \
"-march=rv32i -mabi=ilp32" {weakref32.s} \
diff -rupN binutils.orig/ld/testsuite/ld-riscv-elf/pr31179-r.d binutils-2.41/ld/testsuite/ld-riscv-elf/pr31179-r.d
--- binutils.orig/ld/testsuite/ld-riscv-elf/pr31179-r.d 1970-01-01 01:00:00.000000000 +0100
+++ binutils-2.41/ld/testsuite/ld-riscv-elf/pr31179-r.d 2024-01-02 17:35:24.252233056 +0000
@@ -0,0 +1,10 @@
+#source: pr31179.s
+#as:
+#readelf: -Wr
+
+Relocation section '.rela.text' at .*
+[ ]+Offset[ ]+Info[ ]+Type[ ]+.*
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_RISCV_SET_ULEB128[ ]+[0-9a-f]+[ ]+bar \+ 1
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_RISCV_SUB_ULEB128[ ]+[0-9a-f]+[ ]+foo \+ 0
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_RISCV_SET_ULEB128[ ]+[0-9a-f]+[ ]+bar \+ 1
+[0-9a-f]+[ ]+[0-9a-f]+[ ]+R_RISCV_SUB_ULEB128[ ]+[0-9a-f]+[ ]+foo \+ 1
diff -rupN binutils.orig/ld/testsuite/ld-riscv-elf/pr31179.d binutils-2.41/ld/testsuite/ld-riscv-elf/pr31179.d
--- binutils.orig/ld/testsuite/ld-riscv-elf/pr31179.d 1970-01-01 01:00:00.000000000 +0100
+++ binutils-2.41/ld/testsuite/ld-riscv-elf/pr31179.d 2024-01-02 17:35:24.252233056 +0000
@@ -0,0 +1,11 @@
+#source: pr31179.s
+#as:
+#ld: --check-uleb128
+#objdump: -sj .text
+#warning: .*R_RISCV_SUB_ULEB128 with non-zero addend, please rebuild by Fedora 40 binutils or up
+
+.*:[ ]+file format .*
+
+Contents of section .text:
+
+[ ]+[0-9a-f]+[ ]+00000303[ ]+.*
diff -rupN binutils.orig/ld/testsuite/ld-riscv-elf/pr31179.s binutils-2.41/ld/testsuite/ld-riscv-elf/pr31179.s
--- binutils.orig/ld/testsuite/ld-riscv-elf/pr31179.s 1970-01-01 01:00:00.000000000 +0100
+++ binutils-2.41/ld/testsuite/ld-riscv-elf/pr31179.s 2024-01-02 17:35:24.252233056 +0000
@@ -0,0 +1,13 @@
+.globl _start
+_start:
+
+foo:
+.2byte 0
+bar:
+
+.uleb128 bar - foo + 1
+
+reloc:
+.reloc reloc, R_RISCV_SET_ULEB128, bar + 1
+.reloc reloc, R_RISCV_SUB_ULEB128, foo + 1
+.byte 0x0
--- binutils.orig/gas/config/tc-riscv.c 2024-01-03 13:08:16.588286420 +0000
+++ binutils-2.41/gas/config/tc-riscv.c 2024-01-03 13:08:32.749297812 +0000
@@ -4949,6 +4949,7 @@ riscv_insert_uleb128_fixes (bfd *abfd AT
fix_new_exp (fragP, fragP->fr_fix, 0,
exp_dup, 0, BFD_RELOC_RISCV_SET_ULEB128);
exp_dup->X_add_symbol = exp->X_op_symbol;
+ exp_dup->X_add_number = 0; /* Set addend of SUB_ULEB128 to zero. */
fix_new_exp (fragP, fragP->fr_fix, 0,
exp_dup, 0, BFD_RELOC_RISCV_SUB_ULEB128);
}