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 <mjw@redhat.com>
diff --git a/libebl/ChangeLog b/libebl/ChangeLog
index e81fae9..1bc0868 100644
--- a/libebl/ChangeLog
+++ b/libebl/ChangeLog
@@ -1,3 +1,8 @@
+2013-10-06 Mark Wielaard <mjw@redhat.com>
+
+ * libebl.h (ebl_abi_cfi): Document restrictions using register
+ rules.
+
2013-09-26 Petr Machata <pmachata@redhat.com>
* eblcorenotetypename.c: Handle NT_ARM_TLS, NT_ARM_HW_BREAK,