RISC-V: check offsets when linker relaxation is disabled

The assembler partially relied on the linker to check whether the
offset is valid.  However, some optimization logic (added later)
removes relocations relative to local symbols without checking offsets.

For instance, it caused following code to silently emit wrong jumps
(to the jump instruction "." itself) without relocations:

> .option norelax
> j .+0x200000   # J (or JAL) instruction cannot encode this offset.
> j .+1          # Jump to odd address is not valid.

This commit adds offset checks where necessary.

gas/ChangeLog:

	* config/tc-riscv.c (md_apply_fix): Check offsets when the
	relocation relative to a local symbol is being optimized out.
	* testsuite/gas/riscv/no-relax-branch-offset-fail.s: Failure
	case where the branch offset is invalid.
	* testsuite/gas/riscv/no-relax-branch-offset-fail.d: Ditto.
	* testsuite/gas/riscv/no-relax-branch-offset-fail.l: Ditto.
	* testsuite/gas/riscv/no-relax-branch-offset-ok.s: Border case.
	* testsuite/gas/riscv/no-relax-branch-offset-ok.d: Ditto.
	* testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.s: Failure
	case only on RV64 where the PC-relative offset exceed limits.
	* testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.d: Ditto.
	* testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.l: Ditto.
	* testsuite/gas/riscv/no-relax-pcrel-offset-fail-not-32.d: Test
	case for RV32 so that no errors occur.
	* testsuite/gas/riscv/no-relax-pcrel-offset-ok.s: Border case.
	* testsuite/gas/riscv/no-relax-pcrel-offset-ok.d: Ditto.

diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
index ca4030d6a9340d8738f53e48d88ec432ce7bc4e0..a35288e55cb1ca3b91db81049e0ff049786d7d09 100644 (file)
--- a/gas/config/tc-riscv.c
+++ b/gas/config/tc-riscv.c
@@ -4848,7 +4848,13 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
          bfd_vma delta = target - md_pcrel_from (fixP);
          bfd_putl32 (bfd_getl32 (buf) | ENCODE_JTYPE_IMM (delta), buf);
          if (!riscv_opts.relax && S_IS_LOCAL (fixP->fx_addsy))
-           fixP->fx_done = 1;
+           {
+             if (!VALID_JTYPE_IMM (delta))
+               as_bad_where (fixP->fx_file, fixP->fx_line,
+                             _("invalid J-type offset (%+lld)"),
+                             (long long) delta);
+             fixP->fx_done = 1;
+           }
        }
       break;
 
@@ -4860,7 +4866,13 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
          bfd_vma delta = target - md_pcrel_from (fixP);
          bfd_putl32 (bfd_getl32 (buf) | ENCODE_BTYPE_IMM (delta), buf);
          if (!riscv_opts.relax && S_IS_LOCAL (fixP->fx_addsy))
-           fixP->fx_done = 1;
+           {
+             if (!VALID_BTYPE_IMM (delta))
+               as_bad_where (fixP->fx_file, fixP->fx_line,
+                             _("invalid B-type offset (%+lld)"),
+                             (long long) delta);
+             fixP->fx_done = 1;
+           }
        }
       break;
 
@@ -4872,7 +4884,13 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
          bfd_vma delta = target - md_pcrel_from (fixP);
          bfd_putl16 (bfd_getl16 (buf) | ENCODE_CBTYPE_IMM (delta), buf);
          if (!riscv_opts.relax && S_IS_LOCAL (fixP->fx_addsy))
-           fixP->fx_done = 1;
+           {
+             if (!VALID_CBTYPE_IMM (delta))
+               as_bad_where (fixP->fx_file, fixP->fx_line,
+                             _("invalid CB-type offset (%+lld)"),
+                             (long long) delta);
+             fixP->fx_done = 1;
+           }
        }
       break;
 
@@ -4884,7 +4902,13 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
          bfd_vma delta = target - md_pcrel_from (fixP);
          bfd_putl16 (bfd_getl16 (buf) | ENCODE_CJTYPE_IMM (delta), buf);
          if (!riscv_opts.relax && S_IS_LOCAL (fixP->fx_addsy))
-           fixP->fx_done = 1;
+           {
+             if (!VALID_CJTYPE_IMM (delta))
+               as_bad_where (fixP->fx_file, fixP->fx_line,
+                             _("invalid CJ-type offset (%+lld)"),
+                             (long long) delta);
+             fixP->fx_done = 1;
+           }
        }
       break;
 
@@ -4919,7 +4943,14 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
                      | ENCODE_UTYPE_IMM (RISCV_CONST_HIGH_PART (value)),
                      buf);
          if (!riscv_opts.relax)
-           fixP->fx_done = 1;
+           {
+             if (xlen > 32
+                 && !VALID_UTYPE_IMM (RISCV_CONST_HIGH_PART (value)))
+               as_bad_where (fixP->fx_file, fixP->fx_line,
+                             _("invalid pcrel_hi offset (%+lld)"),
+                             (long long) value);
+             fixP->fx_done = 1;
+           }
        }
       relaxable = true;
       break;
@@ -4945,7 +4976,8 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
              bfd_putl32 (bfd_getl32 (buf) | ENCODE_STYPE_IMM (value), buf);
            else
              bfd_putl32 (bfd_getl32 (buf) | ENCODE_ITYPE_IMM (value), buf);
-           /* Relaxations should never be enabled by `.option relax'.  */
+           /* Relaxations should never be enabled by `.option relax'.
+              The offset is checked by corresponding %pcrel_hi entry.  */
            if (!riscv_opts.relax)
              fixP->fx_done = 1;
          }

diff --git a/gas/testsuite/gas/riscv/no-relax-branch-offset-fail.d b/gas/testsuite/gas/riscv/no-relax-branch-offset-fail.d
new file mode 100644 (file)
index 0000000..0e84771
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-branch-offset-fail.d
@@ -0,0 +1,2 @@
+#as: -march=rv32ic
+#error_output: no-relax-branch-offset-fail.l

diff --git a/gas/testsuite/gas/riscv/no-relax-branch-offset-fail.l b/gas/testsuite/gas/riscv/no-relax-branch-offset-fail.l
new file mode 100644 (file)
index 0000000..8f6b5c9
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-branch-offset-fail.l
@@ -0,0 +1,8 @@
+.*Assembler messages:
+.*:4: Error: invalid J-type offset \(\+1048576\)
+.*:5: Error: invalid J-type offset \(-1048578\)
+.*:8: Error: invalid J-type offset \(\+1048576\)
+.*:10: Error: invalid J-type offset \(-1048578\)
+.*:14: Error: invalid J-type offset \(\+1048576\)
+.*:17: Error: invalid J-type offset \(-1048578\)
+.*:20: Error: invalid CJ-type offset \(\+1\)

diff --git a/gas/testsuite/gas/riscv/no-relax-branch-offset-fail.s b/gas/testsuite/gas/riscv/no-relax-branch-offset-fail.s
new file mode 100644 (file)
index 0000000..98a0978
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-branch-offset-fail.s
@@ -0,0 +1,20 @@
+       .option norelax
+
+       # Relative to the current instruction.
+       j       .+0x0ffffe+2
+       j       .-0x100000-2
+
+       # Relative to local labels (make sure that all instructions except "c.j" occupy 4-bytes).
+       j       1f+0x0ffffe-4+2
+1:
+       j       2f-0x100000-4-2
+2:
+3:
+       lui     t0, 0x12345
+       j       3b+0x0ffffe+4+2
+4:
+       lui     t0, 0x2abcd
+       j       4b-0x100000+4-2
+
+       # Jump to odd address (violates instruction alignment).
+       c.j     .+1

diff --git a/gas/testsuite/gas/riscv/no-relax-branch-offset-ok.d b/gas/testsuite/gas/riscv/no-relax-branch-offset-ok.d
new file mode 100644 (file)
index 0000000..6ef31e2
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-branch-offset-ok.d
@@ -0,0 +1,17 @@
+#as: -march=rv32ic
+#objdump: -dr
+
+.*:     file format .*
+
+
+Disassembly of section \.text:
+
+0+ <\.text>:
+[      ]+0:[   ]+7ffff06f[     ]+j[    ][0-9a-f]+.*
+[      ]+4:[   ]+8000006f[     ]+j[    ][0-9a-f]+.*
+[      ]+8:[   ]+7ffff06f[     ]+j[    ][0-9a-f]+.*
+[      ]+c:[   ]+8000006f[     ]+j[    ][0-9a-f]+.*
+[      ]+10:[  ]+123452b7[     ]+lui[  ]t0,0x12345
+[      ]+14:[  ]+7ffff06f[     ]+j[    ][0-9a-f]+.*
+[      ]+18:[  ]+2abcd2b7[     ]+lui[  ]t0,0x2abcd
+[      ]+1c:[  ]+8000006f[     ]+j[    ][0-9a-f]+.*

diff --git a/gas/testsuite/gas/riscv/no-relax-branch-offset-ok.s b/gas/testsuite/gas/riscv/no-relax-branch-offset-ok.s
new file mode 100644 (file)
index 0000000..4711c90
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-branch-offset-ok.s
@@ -0,0 +1,17 @@
+       .option norelax
+
+       # Relative to the current instruction.
+       j       .+0x0ffffe
+       j       .-0x100000
+
+       # Relative to local labels (make sure that all instructions occupy 4-bytes).
+       j       1f+0x0ffffe-4
+1:
+       j       2f-0x100000-4
+2:
+3:
+       lui     t0, 0x12345
+       j       3b+0x0ffffe+4
+4:
+       lui     t0, 0x2abcd
+       j       4b-0x100000+4

diff --git a/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.d b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.d
new file mode 100644 (file)
index 0000000..79d59de
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.d
@@ -0,0 +1,2 @@
+#as: -march=rv64i
+#error_output: no-relax-pcrel-offset-fail-64.l

diff --git a/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.l b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.l
new file mode 100644 (file)
index 0000000..bcc0925
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.l
@@ -0,0 +1,7 @@
+.*Assembler messages:
+.*:8: Error: invalid pcrel_hi offset \(\+2147481600\)
+.*:11: Error: invalid pcrel_hi offset \(-2147485697\)
+.*:17: Error: invalid pcrel_hi offset \(\+2147481600\)
+.*:21: Error: invalid pcrel_hi offset \(-2147485697\)
+.*:26: Error: invalid pcrel_hi offset \(\+2147481600\)
+.*:30: Error: invalid pcrel_hi offset \(-2147485697\)

diff --git a/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.s b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.s
new file mode 100644 (file)
index 0000000..d01ffe9
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-64.s
@@ -0,0 +1,31 @@
+       .option norelax
+
+       ## Fail on RV64, wrap without errors on RV32.
+
+       # Relative to the current instruction.
+
+1:
+       auipc   a0, %pcrel_hi(.+0x7ffff7ff+1)
+       addi    a0, a0, %pcrel_lo(1b)
+2:
+       auipc   a0, %pcrel_hi(.-0x80000800-1)
+       addi    a0, a0, %pcrel_lo(2b)
+
+       # Relative to local labels (all instructions occupy 4-bytes).
+
+3:
+       auipc   a0, %pcrel_hi(4f+0x7ffff7ff-4+1)
+4:
+       addi    a0, a0, %pcrel_lo(3b)
+5:
+       auipc   a0, %pcrel_hi(6f-0x80000800-4-1)
+6:
+       addi    a0, a0, %pcrel_lo(5b)
+
+7:
+       auipc   a0, %pcrel_hi(6b+0x7ffff7ff+4+1)
+8:
+       addi    a0, a0, %pcrel_lo(7b)
+9:
+       auipc   a0, %pcrel_hi(8b-0x80000800+4-1)
+       addi    a0, a0, %pcrel_lo(9b)

diff --git a/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-not-32.d b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-not-32.d
new file mode 100644 (file)
index 0000000..0d7cb7c
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-fail-not-32.d
@@ -0,0 +1,22 @@
+#as: -march=rv32i
+#source: no-relax-pcrel-offset-fail-64.s
+#objdump: -dr
+
+.*:     file format .*
+
+
+Disassembly of section \.text:
+
+0+ <\.text>:
+[      ]+0:[   ]+80000517[     ]+auipc[        ]a0,0x80000
+[      ]+4:[   ]+80050513[     ]+addi[         ]a0,a0,-2048([^0-9].*)?
+[      ]+8:[   ]+7ffff517[     ]+auipc[        ]a0,0x7ffff
+[      ]+c:[   ]+7ff50513[     ]+addi[         ]a0,a0,2047([^0-9].*)?
+[      ]+10:[  ]+80000517[     ]+auipc[        ]a0,0x80000
+[      ]+14:[  ]+80050513[     ]+addi[         ]a0,a0,-2048([^0-9].*)?
+[      ]+18:[  ]+7ffff517[     ]+auipc[        ]a0,0x7ffff
+[      ]+1c:[  ]+7ff50513[     ]+addi[         ]a0,a0,2047([^0-9].*)?
+[      ]+20:[  ]+80000517[     ]+auipc[        ]a0,0x80000
+[      ]+24:[  ]+80050513[     ]+addi[         ]a0,a0,-2048([^0-9].*)?
+[      ]+28:[  ]+7ffff517[     ]+auipc[        ]a0,0x7ffff
+[      ]+2c:[  ]+7ff50513[     ]+addi[         ]a0,a0,2047([^0-9].*)?

diff --git a/gas/testsuite/gas/riscv/no-relax-pcrel-offset-ok.d b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-ok.d
new file mode 100644 (file)
index 0000000..e585032
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-ok.d
@@ -0,0 +1,21 @@
+#as: -march=rv64i
+#objdump: -dr
+
+.*:     file format .*
+
+
+Disassembly of section \.text:
+
+0+ <\.text>:
+[      ]+0:[   ]+7ffff517[     ]+auipc[        ]a0,0x7ffff
+[      ]+4:[   ]+7ff50513[     ]+addi[         ]a0,a0,2047([^0-9].*)?
+[      ]+8:[   ]+80000517[     ]+auipc[        ]a0,0x80000
+[      ]+c:[   ]+80050513[     ]+addi[         ]a0,a0,-2048([^0-9].*)?
+[      ]+10:[  ]+7ffff517[     ]+auipc[        ]a0,0x7ffff
+[      ]+14:[  ]+7ff50513[     ]+addi[         ]a0,a0,2047([^0-9].*)?
+[      ]+18:[  ]+80000517[     ]+auipc[        ]a0,0x80000
+[      ]+1c:[  ]+80050513[     ]+addi[         ]a0,a0,-2048([^0-9].*)?
+[      ]+20:[  ]+7ffff517[     ]+auipc[        ]a0,0x7ffff
+[      ]+24:[  ]+7ff50513[     ]+addi[         ]a0,a0,2047([^0-9].*)?
+[      ]+28:[  ]+80000517[     ]+auipc[        ]a0,0x80000
+[      ]+2c:[  ]+80050513[     ]+addi[         ]a0,a0,-2048([^0-9].*)?

diff --git a/gas/testsuite/gas/riscv/no-relax-pcrel-offset-ok.s b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-ok.s
new file mode 100644 (file)
index 0000000..ededcca
--- /dev/null
+++ b/gas/testsuite/gas/riscv/no-relax-pcrel-offset-ok.s
@@ -0,0 +1,29 @@
+       .option norelax
+
+       # Relative to the current instruction.
+
+1:
+       auipc   a0, %pcrel_hi(.+0x7ffff7ff)
+       addi    a0, a0, %pcrel_lo(1b)
+2:
+       auipc   a0, %pcrel_hi(.-0x80000800)
+       addi    a0, a0, %pcrel_lo(2b)
+
+       # Relative to local labels (all instructions occupy 4-bytes).
+
+3:
+       auipc   a0, %pcrel_hi(4f+0x7ffff7ff-4)
+4:
+       addi    a0, a0, %pcrel_lo(3b)
+5:
+       auipc   a0, %pcrel_hi(6f-0x80000800-4)
+6:
+       addi    a0, a0, %pcrel_lo(5b)
+
+7:
+       auipc   a0, %pcrel_hi(6b+0x7ffff7ff+4)
+8:
+       addi    a0, a0, %pcrel_lo(7b)
+9:
+       auipc   a0, %pcrel_hi(8b-0x80000800+4)
+       addi    a0, a0, %pcrel_lo(9b)