/* Displaced stepping. */
+/* Return true if INSN is a non-branch RIL-b or RIL-c format
+ instruction. */
+
+static int
+is_non_branch_ril (gdb_byte *insn)
+{
+ gdb_byte op1 = insn[0];
+
+ if (op1 == 0xc4)
+ {
+ gdb_byte op2 = insn[1] & 0x0f;
+
+ switch (op2)
+ {
+ case 0x02: /* llhrl */
+ case 0x04: /* lghrl */
+ case 0x05: /* lhrl */
+ case 0x06: /* llghrl */
+ case 0x07: /* sthrl */
+ case 0x08: /* lgrl */
+ case 0x0b: /* stgrl */
+ case 0x0c: /* lgfrl */
+ case 0x0d: /* lrl */
+ case 0x0e: /* llgfrl */
+ case 0x0f: /* strl */
+ return 1;
+ }
+ }
+ else if (op1 == 0xc6)
+ {
+ gdb_byte op2 = insn[1] & 0x0f;
+
+ switch (op2)
+ {
+ case 0x00: /* exrl */
+ case 0x02: /* pfdrl */
+ case 0x04: /* cghrl */
+ case 0x05: /* chrl */
+ case 0x06: /* clghrl */
+ case 0x07: /* clhrl */
+ case 0x08: /* cgrl */
+ case 0x0a: /* clgrl */
+ case 0x0c: /* cgfrl */
+ case 0x0d: /* crl */
+ case 0x0e: /* clgfrl */
+ case 0x0f: /* clrl */
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/* Implementation of gdbarch_displaced_step_copy_insn. */
+
+static struct displaced_step_closure *
+s390_displaced_step_copy_insn (struct gdbarch *gdbarch,
+ CORE_ADDR from, CORE_ADDR to,
+ struct regcache *regs)
+{
+ size_t len = gdbarch_max_insn_length (gdbarch);
+ gdb_byte *buf = xmalloc (len);
+ struct cleanup *old_chain = make_cleanup (xfree, buf);
+
+ read_memory (from, buf, len);
+
+ /* Adjust the displacement field of PC-relative RIL instructions,
+ except branches. The latter are handled in the fixup hook. */
+ if (is_non_branch_ril (buf))
+ {
+ LONGEST offset;
+
+ offset = extract_signed_integer (buf + 2, 4, BFD_ENDIAN_BIG);
+ offset = (from - to + offset * 2) / 2;
+
+ /* If the instruction is too far from the jump pad, punt. This
+ will usually happen with instructions in shared libraries.
+ We could probably support these by rewriting them to be
+ absolute or fully emulating them. */
+ if (offset < INT32_MIN || offset > INT32_MAX)
+ {
+ /* Let the core fall back to stepping over the breakpoint
+ in-line. */
+ if (debug_displaced)
+ {
+ fprintf_unfiltered (gdb_stdlog,
+ "displaced: can't displaced step "
+ "RIL instruction: offset %s out of range\n",
+ plongest (offset));
+ }
+ do_cleanups (old_chain);
+ return NULL;
+ }
+
+ store_signed_integer (buf + 2, 4, BFD_ENDIAN_BIG, offset);
+ }
+
+ write_memory (to, buf, len);
+
+ if (debug_displaced)
+ {
+ fprintf_unfiltered (gdb_stdlog, "displaced: copy %s->%s: ",
+ paddress (gdbarch, from), paddress (gdbarch, to));
+ displaced_step_dump_bytes (gdb_stdlog, buf, len);
+ }
+
+ discard_cleanups (old_chain);
+ return (struct displaced_step_closure *) buf;
+}
+
/* Fix up the state of registers and memory after having single-stepped
a displaced instruction. */
static void
CORE_ADDR from, CORE_ADDR to,
struct regcache *regs)
{
- /* Since we use simple_displaced_step_copy_insn, our closure is a
- copy of the instruction. */
+ /* Our closure is a copy of the instruction. */
gdb_byte *insn = (gdb_byte *) closure;
static int s390_instrlen[] = { 2, 4, 4, 6 };
int insnlen = s390_instrlen[insn[0] >> 6];
}
else if (s390_function_arg_integer (type) && length <= word_size)
{
- ULONGEST val;
+ /* Initialize it just to avoid a GCC false warning. */
+ ULONGEST val = 0;
if (write_mode)
{
struct tdesc_arch_data *tdesc_data = NULL;
struct gdbarch *gdbarch;
struct gdbarch_tdep *tdep;
- int tdep_abi;
+ enum s390_abi_kind tdep_abi;
enum s390_vector_abi_kind vector_abi;
int have_upper = 0;
int have_linux_v1 = 0;
/* Displaced stepping. */
set_gdbarch_displaced_step_copy_insn (gdbarch,
- simple_displaced_step_copy_insn);
+ s390_displaced_step_copy_insn);
set_gdbarch_displaced_step_fixup (gdbarch, s390_displaced_step_fixup);
set_gdbarch_displaced_step_free_closure (gdbarch,
simple_displaced_step_free_closure);