[PATCH] RISC-V: Fixed missed GOT relocation against a symbol that has a defined value
Nelson Chu
nelson@rivosinc.com
Thu Sep 4 08:44:12 GMT 2025
Committed, thanks.
Nelson
On Thu, Aug 14, 2025 at 12:01 PM Nelson Chu <nelson@rivosinc.com> wrote:
> SImilar to aarch64, commit eac4eb8ecb26
>
> There are two problems when GOT relocation against a symbol that has a
> defined
> value,
> 1. Pesudo la with pic and pseudo lga lost the relocations.
> 2. %got_pcrel_hi generates R_RISCV_GOT_HI20 with addend, which is wrong
> since
> commit 50331d64f108.
>
> The solution is to use deferred_expression for GOT relocation. Maybe other
> relocations also have same problem and need the deferred_expression, but
> we can
> add in the future patches.
> ---
> gas/config/tc-riscv.c | 85 +++++++++++++++------------
> gas/testsuite/gas/riscv/force_reloc.d | 47 +++++++++++++++
> gas/testsuite/gas/riscv/force_reloc.s | 22 +++++++
> 3 files changed, 117 insertions(+), 37 deletions(-)
> create mode 100644 gas/testsuite/gas/riscv/force_reloc.d
> create mode 100644 gas/testsuite/gas/riscv/force_reloc.s
>
> diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
> index 8a3356888d2..df60c206b82 100644
> --- a/gas/config/tc-riscv.c
> +++ b/gas/config/tc-riscv.c
> @@ -2518,13 +2518,16 @@ parse_relocation (char **str,
> bfd_reloc_code_real_type *reloc,
> }
>
> static void
> -my_getExpression (expressionS *ep, char *str)
> +my_getExpression (expressionS *ep, char *str, bool defer)
> {
> char *save_in;
>
> save_in = input_line_pointer;
> input_line_pointer = str;
> - expression (ep);
> + if (defer)
> + deferred_expression (ep);
> + else
> + expression (ep);
> expr_parse_end = input_line_pointer;
> input_line_pointer = save_in;
> }
> @@ -2543,6 +2546,7 @@ my_getSmallExpression (expressionS *ep,
> bfd_reloc_code_real_type *reloc,
> size_t reloc_index;
> unsigned crux_depth, str_depth;
> bool orig_probing = probing_insn_operands;
> + bool force_reloc = false;
> char *crux;
>
> /* Search for the start of the main expression.
> @@ -2582,7 +2586,10 @@ my_getSmallExpression (expressionS *ep,
> bfd_reloc_code_real_type *reloc,
> if (str_depth || reloc_index)
> probing_insn_operands = false;
>
> - my_getExpression (ep, crux);
> + if (*reloc == BFD_RELOC_RISCV_GOT_HI20)
> + force_reloc = true;
> +
> + my_getExpression (ep, crux, force_reloc);
> str = expr_parse_end;
>
> probing_insn_operands = orig_probing;
> @@ -2674,7 +2681,7 @@ my_getVsetvliExpression (expressionS *ep, char *str)
> }
> else
> {
> - my_getExpression (ep, str);
> + my_getExpression (ep, str, false/* defer */);
> str = expr_parse_end;
> }
> }
> @@ -2727,7 +2734,7 @@ my_getThVsetvliExpression (expressionS *ep, char
> *str)
> }
> else
> {
> - my_getExpression (ep, str);
> + my_getExpression (ep, str, false/* defer */);
> str = expr_parse_end;
> }
> }
> @@ -2851,6 +2858,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> error.missing_ext = NULL;
> /* Indicate we are assembling instruction with CSR. */
> bool insn_with_csr = false;
> + bool force_reloc = false;
>
> /* Parse the name of the instruction. Terminate the string if
> whitespace
> is found so that str_hash_find only sees the name part of the
> string. */
> @@ -3353,7 +3361,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case 'i': /* vector arith signed immediate */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if (imm_expr->X_add_number > 15
> || imm_expr->X_add_number < -16)
> @@ -3365,7 +3373,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case 'j': /* vector arith unsigned immediate */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if (imm_expr->X_add_number < 0
> || imm_expr->X_add_number >= 32)
> @@ -3377,7 +3385,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case 'k': /* vector arith signed immediate, minus 1 */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if (imm_expr->X_add_number > 16
> || imm_expr->X_add_number < -15)
> @@ -3389,7 +3397,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case 'l': /* 6-bit vector arith unsigned immediate */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if (imm_expr->X_add_number < 0
> || imm_expr->X_add_number >= 64)
> @@ -3453,7 +3461,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> break;
>
> case '<': /* Shift amount, 0 - 31. */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, false);
> if ((unsigned long) imm_expr->X_add_number > 31)
> as_bad (_("improper shift amount (%"PRIu64")"),
> @@ -3464,7 +3472,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case '>': /* Shift amount, 0 - (XLEN-1). */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, false);
> if ((unsigned long) imm_expr->X_add_number >= xlen)
> as_bad (_("improper shift amount (%"PRIu64")"),
> @@ -3475,7 +3483,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case 'Z': /* CSRRxI immediate. */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, false);
> if ((unsigned long) imm_expr->X_add_number > 31)
> as_bad (_("improper CSRxI immediate (%"PRIu64")"),
> @@ -3492,7 +3500,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> INSERT_OPERAND (CSR, *ip, regno);
> else
> {
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, true);
> if ((unsigned long) imm_expr->X_add_number > 0xfff)
> as_bad (_("improper CSR address (%"PRIu64")"),
> @@ -3591,7 +3599,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> break;
>
> case 'I':
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> if (imm_expr->X_op != O_big
> && imm_expr->X_op != O_constant)
> break;
> @@ -3600,7 +3608,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case 'A':
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> normalize_constant_expr (imm_expr);
> /* The 'A' format specifier must be a symbol. */
> if (imm_expr->X_op != O_symbol)
> @@ -3610,7 +3618,10 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case 'B':
> - my_getExpression (imm_expr, asarg);
> + if (ip->insn_mo->mask == M_LGA
> + || (riscv_opts.pic && ip->insn_mo->mask == M_LA))
> + force_reloc = true;
> + my_getExpression (imm_expr, asarg, force_reloc);
> normalize_constant_expr (imm_expr);
> /* The 'B' format specifier must be a symbol or a constant.
> */
> if (imm_expr->X_op != O_symbol && imm_expr->X_op !=
> O_constant)
> @@ -3662,7 +3673,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> case 'p': /* PC-relative offset. */
> branch:
> *imm_reloc = BFD_RELOC_12_PCREL;
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> asarg = expr_parse_end;
> continue;
>
> @@ -3685,13 +3696,13 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
>
> case 'a': /* 20-bit PC-relative offset. */
> jump:
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> asarg = expr_parse_end;
> *imm_reloc = BFD_RELOC_RISCV_JMP;
> continue;
>
> case 'c':
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> asarg = expr_parse_end;
> if (strcmp (asarg, "@plt") == 0)
> asarg += 4;
> @@ -3792,7 +3803,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> break;
>
> case 'y': /* bs immediate */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if ((unsigned long)imm_expr->X_add_number > 3)
> as_bad(_("Improper bs immediate (%lu)"),
> @@ -3803,7 +3814,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case 'Y': /* rnum immediate */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if ((unsigned long)imm_expr->X_add_number > 10)
> as_bad(_("Improper rnum immediate (%lu)"),
> @@ -3833,7 +3844,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> pseudo S-type but lower 5-bits zero. */
> if (riscv_handle_implicit_zero_offset (imm_expr,
> asarg))
> continue;
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, false);
> if (((unsigned) (imm_expr->X_add_number) & 0x1fU)
> || imm_expr->X_add_number >= RISCV_IMM_REACH / 2
> @@ -4025,7 +4036,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> s = strtol (oparg + 1, (char **)&oparg, 10);
> oparg--;
>
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, false);
> if (!sign)
> {
> @@ -4053,7 +4064,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> switch (*++oparg)
> {
> case '2':
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> asarg = expr_parse_end;
> if (imm_expr->X_add_number<0
> @@ -4063,7 +4074,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> |= ENCODE_CV_IS2_UIMM5
> (imm_expr->X_add_number);
> continue;
> case '3':
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> asarg = expr_parse_end;
> if (imm_expr->X_add_number < 0
> @@ -4073,7 +4084,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> |= ENCODE_CV_IS3_UIMM5
> (imm_expr->X_add_number);
> continue;
> case '4':
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> asarg = expr_parse_end;
> if (imm_expr->X_add_number < -16
> @@ -4083,7 +4094,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> |= ENCODE_CV_IS2_UIMM5
> (imm_expr->X_add_number);
> continue;
> case '5':
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> asarg = expr_parse_end;
> if (imm_expr->X_add_number < -32
> @@ -4093,7 +4104,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> |= ENCODE_CV_SIMD_IMM6
> (imm_expr->X_add_number);
> continue;
> case '6':
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> asarg = expr_parse_end;
> if (imm_expr->X_add_number < 0
> @@ -4103,7 +4114,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> |= ENCODE_CV_BITMANIP_UIMM5
> (imm_expr->X_add_number);
> continue;
> case '7':
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> asarg = expr_parse_end;
> if (imm_expr->X_add_number < 0
> @@ -4113,7 +4124,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> |= ENCODE_CV_BITMANIP_UIMM2
> (imm_expr->X_add_number);
> continue;
> case '8':
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> asarg = expr_parse_end;
> ++oparg;
> @@ -4194,7 +4205,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> switch (*++oparg)
> {
> case '@': /* hint 0 - 31. */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if ((unsigned long)imm_expr->X_add_number > 31)
> as_bad(_("Improper hint amount (%lu)"),
> @@ -4205,7 +4216,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case '#': /* immediate 0 - 511. */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if ((unsigned long)imm_expr->X_add_number > 511)
> as_bad(_("Improper immediate amount (%lu)"),
> @@ -4216,7 +4227,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case '$': /* LDP offset 0 to (1<<7)-8. */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if ((unsigned long)imm_expr->X_add_number >= (1 << 7)
> || ((unsigned long)imm_expr->X_add_number & 0x7)
> != 0)
> @@ -4229,7 +4240,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case '%': /* LWP offset 0 to (1<<7)-4. */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if ((unsigned long)imm_expr->X_add_number >= (1 << 7)
> || ((unsigned long)imm_expr->X_add_number & 0x3)
> != 0)
> @@ -4242,7 +4253,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case '^': /* SDP offset 0 to (1<<7)-8. */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if ((unsigned long)imm_expr->X_add_number >= (1 << 7)
> || ((unsigned long)imm_expr->X_add_number & 0x7)
> != 0)
> @@ -4257,7 +4268,7 @@ riscv_ip (char *str, struct riscv_cl_insn *ip,
> expressionS *imm_expr,
> continue;
>
> case '&': /* SWP offset 0 to (1<<7)-4. */
> - my_getExpression (imm_expr, asarg);
> + my_getExpression (imm_expr, asarg, force_reloc);
> check_absolute_expr (ip, imm_expr, FALSE);
> if ((unsigned long)imm_expr->X_add_number >= (1 << 7)
> || ((unsigned long)imm_expr->X_add_number & 0x3)
> != 0)
> @@ -4613,7 +4624,7 @@ bool riscv_parse_name (const char *name, struct
> expressionS *ep,
> if (!probing_insn_operands)
> return false;
>
> - gas_assert (mode == expr_normal);
> + gas_assert (mode == expr_normal || expr_defer_p (mode));
>
> regno = reg_lookup_internal (name, RCLASS_GPR);
> if (regno == -1u)
> diff --git a/gas/testsuite/gas/riscv/force_reloc.d
> b/gas/testsuite/gas/riscv/force_reloc.d
> new file mode 100644
> index 00000000000..df37a60d203
> --- /dev/null
> +++ b/gas/testsuite/gas/riscv/force_reloc.d
> @@ -0,0 +1,47 @@
> +#as:
> +#objdump: -dr -Mnumeric,no-aliases
> +
> +.*:[ ]+file format .*
> +
> +
> +Disassembly of section .text:
> +
> +0+ <_start>:
> +[ ]+0:[ ]+[0-9a-f]+[ ]+auipc[ ]+x1,0x0
> +[ ]+0:[ ]+R_RISCV_GOT_HI20[ ]+sym_abs_before
> +[ ]+0:[ ]+R_RISCV_RELAX.*
> +[ ]+4:[ ]+[0-9a-f]+[ ]+(lw|ld)[ ]+x1,0\(x1\) # 0 .*
> +[ ]+4:[ ]+R_RISCV_PCREL_LO12_I[ ]+.L0.*
> +[ ]+4:[ ]+R_RISCV_RELAX.*
> +[ ]+8:[ ]+[0-9a-f]+[ ]+auipc[ ]+x2,0x0
> +[ ]+8:[ ]+R_RISCV_GOT_HI20[ ]+sym_abs_before
> +[ ]+8:[ ]+R_RISCV_RELAX.*
> +[ ]+c:[ ]+[0-9a-f]+[ ]+(lw|ld)[ ]+x2,0\(x2\) # 8 .*
> +[ ]+c:[ ]+R_RISCV_PCREL_LO12_I[ ]+.L0.*
> +[ ]+c:[ ]+R_RISCV_RELAX.*
> +
> +0+10 <.L1>:
> +[ ]+10:[ ]+[0-9a-f]+[ ]+auipc[ ]+x3,0x0
> +[ ]+10:[ ]+R_RISCV_GOT_HI20[ ]+sym_abs_before
> +[ ]+14:[ ]+[0-9a-f]+[ ]+addi[ ]+x3,x3,0 # 10 .*
> +[ ]+14:[ ]+R_RISCV_PCREL_LO12_I[ ]+.L1.*
> +[ ]+14:[ ]+R_RISCV_RELAX.*
> +[ ]+18:[ ]+[0-9a-f]+[ ]+auipc[ ]+x4,0x0
> +[ ]+18:[ ]+R_RISCV_GOT_HI20[ ]+sym_abs_after
> +[ ]+18:[ ]+R_RISCV_RELAX.*
> +[ ]+1c:[ ]+[0-9a-f]+[ ]+(lw|ld)[ ]+x4,0\(x4\) # 18 .*
> +[ ]+1c:[ ]+R_RISCV_PCREL_LO12_I[ ]+.L0.*
> +[ ]+1c:[ ]+R_RISCV_RELAX.*
> +[ ]+20:[ ]+[0-9a-f]+[ ]+auipc[ ]+x5,0x0
> +[ ]+20:[ ]+R_RISCV_GOT_HI20[ ]+sym_abs_after
> +[ ]+20:[ ]+R_RISCV_RELAX.*
> +[ ]+24:[ ]+[0-9a-f]+[ ]+(lw|ld)[ ]+x5,0\(x5\) # 20 .*
> +[ ]+24:[ ]+R_RISCV_PCREL_LO12_I[ ]+.L0.*
> +[ ]+24:[ ]+R_RISCV_RELAX.*
> +
> +0+28 <.L2>:
> +[ ]+28:[ ]+[0-9a-f]+[ ]+auipc[ ]+x6,0x0
> +[ ]+28:[ ]+R_RISCV_GOT_HI20[ ]+sym_abs_after
> +[ ]+2c:[ ]+[0-9a-f]+[ ]+addi[ ]+x6,x6,0 # 28 .*
> +[ ]+2c:[ ]+R_RISCV_PCREL_LO12_I[ ]+.L2.*
> +[ ]+2c:[ ]+R_RISCV_RELAX.*
> diff --git a/gas/testsuite/gas/riscv/force_reloc.s
> b/gas/testsuite/gas/riscv/force_reloc.s
> new file mode 100644
> index 00000000000..787c419c182
> --- /dev/null
> +++ b/gas/testsuite/gas/riscv/force_reloc.s
> @@ -0,0 +1,22 @@
> +.option pic
> +.option norvc
> +
> +.global sym_abs_before
> +.set sym_abs_before, 42
> +
> +.text
> +.global _start
> +_start:
> +# Need defer expression
> +la x1, sym_abs_before
> +lga x2, sym_abs_before
> +.L1: auipc x3, %got_pcrel_hi (sym_abs_before)
> + addi x3, x3, %pcrel_lo (.L1)
> +# This is fine
> +la x4, sym_abs_after
> +lga x5, sym_abs_after
> +.L2: auipc x6, %got_pcrel_hi (sym_abs_after)
> + addi x6, x6, %pcrel_lo (.L2)
> +
> +.global sym_abs_after
> +.set sym_abs_after, 42
> --
> 2.39.5 (Apple Git-154)
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://sourceware.org/pipermail/binutils/attachments/20250904/f0a51bba/attachment-0001.htm>
More information about the Binutils
mailing list