[binutils-gdb] RISC-V: Fixed missed GOT relocation against a symbol that has a defined value
Nelson Chu
nelsonc1225@sourceware.org
Thu Sep 4 08:42:55 GMT 2025
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cea397848b868c62993864dbef684877bceef1fc
commit cea397848b868c62993864dbef684877bceef1fc
Author: Nelson Chu <nelson@rivosinc.com>
Date: Thu Aug 14 12:01:38 2025 +0800
RISC-V: Fixed missed GOT relocation against a symbol that has a defined value
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.
Diff:
---
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(-)
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
More information about the Binutils-cvs
mailing list