binutils: dwarf: fix display of large cfa_offset

eh_frame textual dump was not correct when the cfa_offset is a large
value.  The reason is that the dumping code generally assumes the
cfa_offset is an 'int'.

cfa_offset values can be updated by various DWARF opcodes, like:
  - DW_CFA_def_cfa, DW_CFA_def_cfa_offset which bring unsigned leb128
    cfa_offset
  - DW_CFA_def_cfa_sf, DW_CFA_def_cfa_offset_sf which bring signed
    leb128 cfa_offset

Internally, the routines in dwarf.c keep the value as 'uint64_t
cfa_offset'.  That size of the datatype is expected to work for most of
the real-world cases.  Care, however, needs to be taken when it comes
to the signedness of the value.  Fix the buggy behavior by adding an
additional field to track whether the value of cfa_offset is signed or
unsigned and display accordingly for "frames-interp" output.

The display of cfa_offset had issues in both "frames-interp" output
(objdump -WF or do_debug_frames_interp) and the "frames" output.

Add two new tests: cfi-common-10.s uses a large positive cfa_offset
(with "frames output), and cfi-x86_64-2.s uses a negative cfa_offset
(with "frames-interp" output).

ChangeLog:
	* binutils/dwarf.c (frame_display_row): Update format string
	based on signedness.
	(display_debug_frames): Track signedness.  Also fix display of
	cfa_offset using PRIu64 or PRId64 as applicable.
	* gas/testsuite/gas/cfi/cfi.exp: Add two new tests.
	* gas/testsuite/gas/cfi/cfi-common-10.d: New test.
	* gas/testsuite/gas/cfi/cfi-common-10.s: New test.
	* gas/testsuite/gas/cfi/cfi-x86_64-2.d: New test.
	* gas/testsuite/gas/cfi/cfi-x86_64-2.s: New test.
This commit is contained in:
Indu Bhagat
2025-08-19 01:08:06 -07:00
parent 7e432e93f8
commit 09292f4ae2
6 changed files with 58 additions and 4 deletions

View File

@@ -8574,6 +8574,7 @@ typedef struct Frame_Chunk
uint64_t pc_range;
unsigned int cfa_reg;
uint64_t cfa_offset;
bool cfa_ofs_signed_p;
unsigned int ra;
unsigned char fde_encoding;
unsigned char cfa_exp;
@@ -9071,7 +9072,8 @@ frame_display_row (Frame_Chunk *fc, int *need_col_headers, unsigned int *max_reg
if (fc->cfa_exp)
strcpy (tmp, "exp");
else
sprintf (tmp, "%s%+d", regname (fc->cfa_reg, 1), (int) fc->cfa_offset);
sprintf (tmp, (fc->cfa_ofs_signed_p ? "%s%+" PRId64 : "%s+%" PRIu64),
regname (fc->cfa_reg, 1), fc->cfa_offset);
printf ("%-8s ", tmp);
for (r = 0; r < fc->ncols; r++)
@@ -9794,6 +9796,7 @@ display_debug_frames (struct dwarf_section *section,
fc->data_factor = cie->data_factor;
fc->cfa_reg = cie->cfa_reg;
fc->cfa_offset = cie->cfa_offset;
fc->cfa_ofs_signed_p = cie->cfa_ofs_signed_p;
fc->ra = cie->ra;
if (frame_need_space (fc, max_regs > 0 ? max_regs - 1: 0) < 0)
{
@@ -10263,6 +10266,7 @@ display_debug_frames (struct dwarf_section *section,
printf (" DW_CFA_remember_state\n");
rs = (Frame_Chunk *) xmalloc (sizeof (Frame_Chunk));
rs->cfa_offset = fc->cfa_offset;
rs->cfa_ofs_signed_p = fc->cfa_ofs_signed_p;
rs->cfa_reg = fc->cfa_reg;
rs->ra = fc->ra;
rs->cfa_exp = fc->cfa_exp;
@@ -10285,6 +10289,7 @@ display_debug_frames (struct dwarf_section *section,
{
remembered_state = rs->next;
fc->cfa_offset = rs->cfa_offset;
fc->cfa_ofs_signed_p = rs->cfa_ofs_signed_p;
fc->cfa_reg = rs->cfa_reg;
fc->ra = rs->ra;
fc->cfa_exp = rs->cfa_exp;
@@ -10311,10 +10316,11 @@ display_debug_frames (struct dwarf_section *section,
case DW_CFA_def_cfa:
READ_ULEB (fc->cfa_reg, start, block_end);
READ_ULEB (fc->cfa_offset, start, block_end);
fc->cfa_ofs_signed_p = false;
fc->cfa_exp = 0;
if (! do_debug_frames_interp)
printf (" DW_CFA_def_cfa: %s ofs %d\n",
regname (fc->cfa_reg, 0), (int) fc->cfa_offset);
printf (" DW_CFA_def_cfa: %s ofs %" PRIu64 "\n",
regname (fc->cfa_reg, 0), fc->cfa_offset);
break;
case DW_CFA_def_cfa_register:
@@ -10327,8 +10333,9 @@ display_debug_frames (struct dwarf_section *section,
case DW_CFA_def_cfa_offset:
READ_ULEB (fc->cfa_offset, start, block_end);
fc->cfa_ofs_signed_p = false;
if (! do_debug_frames_interp)
printf (" DW_CFA_def_cfa_offset: %d\n", (int) fc->cfa_offset);
printf (" DW_CFA_def_cfa_offset: %" PRIu64 "\n", fc->cfa_offset);
break;
case DW_CFA_nop:
@@ -10448,6 +10455,7 @@ display_debug_frames (struct dwarf_section *section,
ofs = sofs;
ofs *= fc->data_factor;
fc->cfa_offset = ofs;
fc->cfa_ofs_signed_p = true;
fc->cfa_exp = 0;
if (! do_debug_frames_interp)
printf (" DW_CFA_def_cfa_sf: %s ofs %" PRId64 "\n",
@@ -10459,6 +10467,7 @@ display_debug_frames (struct dwarf_section *section,
ofs = sofs;
ofs *= fc->data_factor;
fc->cfa_offset = ofs;
fc->cfa_ofs_signed_p = true;
if (! do_debug_frames_interp)
printf (" DW_CFA_def_cfa_offset_sf: %" PRId64 "\n", ofs);
break;