diff options
| author | Mark Wielaard <[email protected]> | 2013-10-06 17:04:07 +0200 |
|---|---|---|
| committer | Mark Wielaard <[email protected]> | 2013-10-07 11:16:27 +0200 |
| commit | 3dec3e110bb2a2453156868e1221dc8192399e3e (patch) | |
| tree | 65eb424f42bfd80f2bcc2b6a8d1a6d96df5e475a /libdw/cfi.c | |
| parent | 5dbbc5e32cc1fb3a7cf33e52e0bfc6f47097f3fe (diff) | |
backends: ppc_abi_cfi reg1 use DW_CFA_val_offset not DW_CFA_val_expression.
Register rules using expressions are stored using an offset from the
start of the .eh_frame or .debug_frame ELF section data. Since abi_cfi
rules aren't stored in those ELF sections they should use neither
DW_CFA_expression nor DW_CFA_val_expression. The only backend that used
DW_CFA_val_expression was ppc_cfi.c. It was easier to express the same
rule using DW_CFA_val_offset than to change the code to handle register
rules using expressions. On most architectures this did work by accident.
See the definition of struct dwarf_frame_register value in libdw/cfi.h to
see why. But on ia64 the abi_cfi data and actual frame data were placed
too far apart and caused a crash in tests/run-addrcfi.sh for ppc32.
Signed-off-by: Mark Wielaard <[email protected]>
Diffstat (limited to 'libdw/cfi.c')
| -rw-r--r-- | libdw/cfi.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/libdw/cfi.c b/libdw/cfi.c index b1e8d485..a146f129 100644 --- a/libdw/cfi.c +++ b/libdw/cfi.c @@ -252,6 +252,8 @@ execute_cfi (Dwarf_CFI *cache, continue; case DW_CFA_expression: + /* Expression rule relies on section data, abi_cfi cannot use it. */ + assert (! abi_cfi); get_uleb128 (regno, program); offset = program - (const uint8_t *) cache->data->d.d_buf; /* DW_FORM_block is a ULEB128 length followed by that many bytes. */ @@ -262,6 +264,8 @@ execute_cfi (Dwarf_CFI *cache, continue; case DW_CFA_val_expression: + /* Expression rule relies on section data, abi_cfi cannot use it. */ + assert (! abi_cfi); get_uleb128 (regno, program); /* DW_FORM_block is a ULEB128 length followed by that many bytes. */ offset = program - (const uint8_t *) cache->data->d.d_buf; |